* [PATCH v6 01/33] vfio: Use file-based reference counting for KVM
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
@ 2026-08-12 15:35 ` Steffen Eiden
2026-08-12 16:00 ` sashiko-bot
2026-08-12 15:35 ` [PATCH v6 02/33] KVM: Make device name configurable Steffen Eiden
` (32 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:35 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Replace manual module reference counting with file-based reference
counting for KVM integration. Previously, VFIO used symbol_get() to
obtain function pointers for kvm_get_kvm_safe() and kvm_put_kvm(),
then manually tracked module references through these symbols. This
approach required storing the put_kvm function pointer in each device
and carefully managing symbol references. Remove the put_kvm field in
struct vfio_device as is it no longer used.
Pass struct file pointers instead of struct kvm pointers throughout the
VFIO-KVM interface. This leverages the kernel's existing file reference
counting mechanism via get_file_active() and fput(), eliminating the
need for manual module reference tracking. The file->private_data field
provides access to the underlying struct kvm when needed.
This simplifies the code and removes all remaining externally exported
symbols for KVM, paving the path for a second concurrent KVM module.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/x86/include/asm/kvm_page_track.h | 8 ++---
arch/x86/kvm/Makefile | 3 --
arch/x86/kvm/mmu/page_track.c | 16 +++++----
drivers/s390/crypto/vfio_ap_ops.c | 30 ++++++++++++----
drivers/s390/crypto/vfio_ap_private.h | 1 +
drivers/vfio/device_cdev.c | 2 +-
drivers/vfio/group.c | 4 +--
drivers/vfio/pci/vfio_pci_zdev.c | 7 +++-
drivers/vfio/vfio.h | 10 +++---
drivers/vfio/vfio_main.c | 52 +++++++--------------------
include/linux/kvm_host.h | 7 ++++
include/linux/vfio.h | 5 ++-
virt/kvm/kvm_main.c | 22 ++++++++++--
virt/kvm/vfio.c | 8 ++---
14 files changed, 97 insertions(+), 78 deletions(-)
diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h
index 3d040741044b..046a25c8fe4f 100644
--- a/arch/x86/include/asm/kvm_page_track.h
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -44,13 +44,13 @@ struct kvm_page_track_notifier_node {
struct kvm_page_track_notifier_node *node);
};
-int kvm_page_track_register_notifier(struct kvm *kvm,
+int kvm_page_track_register_notifier(struct file *file,
struct kvm_page_track_notifier_node *n);
-void kvm_page_track_unregister_notifier(struct kvm *kvm,
+void kvm_page_track_unregister_notifier(struct file *file,
struct kvm_page_track_notifier_node *n);
-int kvm_write_track_add_gfn(struct kvm *kvm, gfn_t gfn);
-int kvm_write_track_remove_gfn(struct kvm *kvm, gfn_t gfn);
+int kvm_write_track_add_gfn(struct file *file, gfn_t gfn);
+int kvm_write_track_remove_gfn(struct file *file, gfn_t gfn);
#else
/*
* Allow defining a node in a structure even if page tracking is disabled, e.g.
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index 0474604ab8a1..70645c2cd8ed 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -61,9 +61,6 @@ exports_grep_trailer := --include='*.[ch]' -nrw $(srctree)/virt/kvm $(srctree)/a
-e kvm_page_track_unregister_notifier \
-e kvm_write_track_add_gfn \
-e kvm_write_track_remove_gfn \
- -e kvm_get_kvm \
- -e kvm_get_kvm_safe \
- -e kvm_put_kvm
# Force grep to emit a goofy group separator that can in turn be replaced with
# the above newline macro (newlines in Make are a nightmare). Note, grep only
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 7e8195a311bb..860049ed24ea 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -237,10 +237,11 @@ static int kvm_enable_external_write_tracking(struct kvm *kvm)
* register the notifier so that event interception for the tracked guest
* pages can be received.
*/
-int kvm_page_track_register_notifier(struct kvm *kvm,
+int kvm_page_track_register_notifier(struct file *file,
struct kvm_page_track_notifier_node *n)
{
struct kvm_page_track_notifier_head *head;
+ struct kvm *kvm = file_to_kvm(file);
int r;
if (!kvm || kvm->mm != current->mm)
@@ -252,7 +253,7 @@ int kvm_page_track_register_notifier(struct kvm *kvm,
return r;
}
- kvm_get_kvm(kvm);
+ get_file(file);
head = &kvm->arch.track_notifier_head;
@@ -267,10 +268,11 @@ EXPORT_SYMBOL_GPL(kvm_page_track_register_notifier);
* stop receiving the event interception. It is the opposed operation of
* kvm_page_track_register_notifier().
*/
-void kvm_page_track_unregister_notifier(struct kvm *kvm,
+void kvm_page_track_unregister_notifier(struct file *file,
struct kvm_page_track_notifier_node *n)
{
struct kvm_page_track_notifier_head *head;
+ struct kvm *kvm = file_to_kvm(file);
head = &kvm->arch.track_notifier_head;
@@ -279,7 +281,7 @@ void kvm_page_track_unregister_notifier(struct kvm *kvm,
write_unlock(&kvm->mmu_lock);
synchronize_srcu(&head->track_srcu);
- kvm_put_kvm(kvm);
+ fput(file);
}
EXPORT_SYMBOL_GPL(kvm_page_track_unregister_notifier);
@@ -339,8 +341,9 @@ void kvm_page_track_delete_slot(struct kvm *kvm, struct kvm_memory_slot *slot)
* @kvm: the guest instance we are interested in.
* @gfn: the guest page.
*/
-int kvm_write_track_add_gfn(struct kvm *kvm, gfn_t gfn)
+int kvm_write_track_add_gfn(struct file *file, gfn_t gfn)
{
+ struct kvm *kvm = file_to_kvm(file);
struct kvm_memory_slot *slot;
int idx;
@@ -369,8 +372,9 @@ EXPORT_SYMBOL_GPL(kvm_write_track_add_gfn);
* @kvm: the guest instance we are interested in.
* @gfn: the guest page.
*/
-int kvm_write_track_remove_gfn(struct kvm *kvm, gfn_t gfn)
+int kvm_write_track_remove_gfn(struct file *file, gfn_t gfn)
{
+ struct kvm *kvm = file_to_kvm(file);
struct kvm_memory_slot *slot;
int idx;
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 99a0efd999ef..875e67063d8e 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -8,6 +8,7 @@
* Halil Pasic <pasic@linux.ibm.com>
* Pierre Morel <pmorel@linux.ibm.com>
*/
+#include "linux/cleanup.h"
#include <linux/string.h>
#include <linux/vfio.h>
#include <linux/device.h>
@@ -1822,12 +1823,25 @@ static const struct attribute_group *vfio_ap_mdev_attr_groups[] = {
* @matrix_mdev: a mediated matrix device
* @kvm: reference to KVM instance
*
- * Return: 0 if no other mediated matrix device has a reference to @kvm;
- * otherwise, returns an -EPERM.
+ * Returns: 0 if the reference to kvm is successfully retrieved from @kvm_file
+ * and set into @matrix_mdev; otherwise, returns:
+ * -ENOENT if a reference to kvm could not be retrieved from @kvm_file
+ * -EPERM if another mediated matrix device already has a reference to the same kvm instance
*/
static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
- struct kvm *kvm)
+ struct file **kvm_file)
{
+ struct file *kvm_file_ref __free(fput) = NULL;
+ struct kvm *kvm;
+
+ kvm_file_ref = get_file_active(kvm_file);
+ if (!kvm_file_ref)
+ return -ENOENT;
+
+ kvm = kvm_file_ref->private_data;
+ if (!kvm)
+ return -ENOENT;
+
if (kvm->arch.crypto.crycbd) {
get_update_locks_for_kvm(kvm);
if (kvm->arch.crypto.pqap_hook) {
@@ -1836,10 +1850,11 @@ static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
}
kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
- kvm_get_kvm(kvm);
matrix_mdev->kvm = kvm;
vfio_ap_mdev_update_guest_apcb(matrix_mdev);
release_update_locks_for_kvm(kvm);
+
+ matrix_mdev->kvm_file = no_free_ptr(kvm_file_ref);
}
return 0;
@@ -1878,9 +1893,10 @@ static void vfio_ap_mdev_dma_unmap(struct vfio_device *vdev, u64 iova,
*/
static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev)
{
+ struct file *kvm_file = matrix_mdev->kvm_file;
struct kvm *kvm = matrix_mdev->kvm;
- if (kvm && kvm->arch.crypto.crycbd) {
+ if (kvm_file && kvm && kvm->arch.crypto.crycbd) {
get_update_locks_for_kvm(kvm);
kvm->arch.crypto.pqap_hook = NULL;
@@ -1889,7 +1905,7 @@ static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev)
matrix_mdev->kvm = NULL;
release_update_locks_for_kvm(kvm);
- kvm_put_kvm(kvm);
+ fput(kvm_file);
}
}
@@ -2053,7 +2069,7 @@ static int vfio_ap_mdev_open_device(struct vfio_device *vdev)
if (!vdev->kvm)
return -EINVAL;
- return vfio_ap_mdev_set_kvm(matrix_mdev, vdev->kvm);
+ return vfio_ap_mdev_set_kvm(matrix_mdev, &vdev->kvm);
}
static void vfio_ap_mdev_close_device(struct vfio_device *vdev)
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index 9bff666b0b35..4ec91c6827eb 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -117,6 +117,7 @@ struct ap_matrix_mdev {
struct ap_matrix matrix;
struct ap_matrix shadow_apcb;
struct kvm *kvm;
+ struct file *kvm_file;
crypto_hook pqap_hook;
struct mdev_device *mdev;
struct ap_queue_table qtable;
diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
index 1d9515c967b0..e32176a55c46 100644
--- a/drivers/vfio/device_cdev.c
+++ b/drivers/vfio/device_cdev.c
@@ -65,7 +65,7 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep)
static void vfio_df_get_kvm_safe(struct vfio_device_file *df)
{
spin_lock(&df->kvm_ref_lock);
- vfio_device_get_kvm_safe(df->device, df->kvm);
+ vfio_device_get_kvm_safe(df->device, &df->kvm);
spin_unlock(&df->kvm_ref_lock);
}
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index b2299e5bc6df..197298ca0003 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -163,7 +163,7 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group,
static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
{
spin_lock(&device->group->kvm_ref_lock);
- vfio_device_get_kvm_safe(device, device->group->kvm);
+ vfio_device_get_kvm_safe(device, &device->group->kvm);
spin_unlock(&device->group->kvm_ref_lock);
}
@@ -860,7 +860,7 @@ bool vfio_group_enforced_coherent(struct vfio_group *group)
return ret;
}
-void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
+void vfio_group_set_kvm(struct vfio_group *group, struct file *kvm)
{
spin_lock(&group->kvm_ref_lock);
group->kvm = kvm;
diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c
index 0990fdb146b7..d3a110101353 100644
--- a/drivers/vfio/pci/vfio_pci_zdev.c
+++ b/drivers/vfio/pci/vfio_pci_zdev.c
@@ -144,6 +144,7 @@ int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev)
{
struct zpci_dev *zdev = to_zpci(vdev->pdev);
+ struct kvm *kvm;
if (!zdev)
return -ENODEV;
@@ -151,8 +152,12 @@ int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev)
if (!vdev->vdev.kvm)
return 0;
+ kvm = vdev->vdev.kvm->private_data;
+ if (!kvm)
+ return -ENOENT;
+
if (zpci_kvm_hook.kvm_register)
- return zpci_kvm_hook.kvm_register(zdev, vdev->vdev.kvm);
+ return zpci_kvm_hook.kvm_register(zdev, kvm);
return -ENOENT;
}
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index 7728bc99b63d..7935c51ea1ac 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -23,7 +23,7 @@ struct vfio_device_file {
u8 access_granted;
u32 devid; /* only valid when iommufd is valid */
spinlock_t kvm_ref_lock; /* protect kvm field */
- struct kvm *kvm;
+ struct file *kvm;
struct iommufd_ctx *iommufd; /* protected by struct vfio_device_set::lock */
};
@@ -88,7 +88,7 @@ struct vfio_group {
#endif
enum vfio_group_type type;
struct mutex group_lock;
- struct kvm *kvm;
+ struct file *kvm;
struct file *opened_file;
struct iommufd_ctx *iommufd;
spinlock_t kvm_ref_lock;
@@ -107,7 +107,7 @@ void vfio_device_group_unuse_iommu(struct vfio_device *device);
void vfio_df_group_close(struct vfio_device_file *df);
struct vfio_group *vfio_group_from_file(struct file *file);
bool vfio_group_enforced_coherent(struct vfio_group *group);
-void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
+void vfio_group_set_kvm(struct vfio_group *group, struct file *kvm);
bool vfio_device_has_container(struct vfio_device *device);
int __init vfio_group_init(void);
void vfio_group_cleanup(void);
@@ -429,11 +429,11 @@ static inline void vfio_virqfd_exit(void)
#endif
#if IS_ENABLED(CONFIG_KVM)
-void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm);
+void vfio_device_get_kvm_safe(struct vfio_device *device, struct file **kvm);
void vfio_device_put_kvm(struct vfio_device *device);
#else
static inline void vfio_device_get_kvm_safe(struct vfio_device *device,
- struct kvm *kvm)
+ struct file **kvm)
{
}
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 423ead48aafe..b06d1a911605 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -472,36 +472,17 @@ void vfio_unregister_group_dev(struct vfio_device *device)
EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
#if IS_ENABLED(CONFIG_KVM)
-void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
+void vfio_device_get_kvm_safe(struct vfio_device *device, struct file **kvm)
{
- void (*pfn)(struct kvm *kvm);
- bool (*fn)(struct kvm *kvm);
- bool ret;
+ struct file *kvm_file_ref __free(fput) = NULL;
lockdep_assert_held(&device->dev_set->lock);
- if (!kvm)
+ kvm_file_ref = get_file_active(kvm);
+ if (!kvm_file_ref)
return;
- pfn = symbol_get(kvm_put_kvm);
- if (WARN_ON(!pfn))
- return;
-
- fn = symbol_get(kvm_get_kvm_safe);
- if (WARN_ON(!fn)) {
- symbol_put(kvm_put_kvm);
- return;
- }
-
- ret = fn(kvm);
- symbol_put(kvm_get_kvm_safe);
- if (!ret) {
- symbol_put(kvm_put_kvm);
- return;
- }
-
- device->put_kvm = pfn;
- device->kvm = kvm;
+ device->kvm = no_free_ptr(kvm_file_ref);
}
void vfio_device_put_kvm(struct vfio_device *device)
@@ -511,14 +492,7 @@ void vfio_device_put_kvm(struct vfio_device *device)
if (!device->kvm)
return;
- if (WARN_ON(!device->put_kvm))
- goto clear;
-
- device->put_kvm(device->kvm);
- device->put_kvm = NULL;
- symbol_put(kvm_put_kvm);
-
-clear:
+ fput(device->kvm);
device->kvm = NULL;
}
#endif
@@ -1544,7 +1518,7 @@ bool vfio_file_enforced_coherent(struct file *file)
}
EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
-static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
+static void vfio_device_file_set_kvm(struct file *file, struct file *kvm)
{
struct vfio_device_file *df = file->private_data;
@@ -1560,22 +1534,22 @@ static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
/**
* vfio_file_set_kvm - Link a kvm with VFIO drivers
- * @file: VFIO group file or VFIO device file
- * @kvm: KVM to link
+ * @vfio_file: VFIO group file or VFIO device file
+ * @kvm: KVM file to link
*
* When a VFIO device is first opened the KVM will be available in
* device->kvm if one was associated with the file.
*/
-void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+void vfio_file_set_kvm(struct file *vfio_file, struct file *kvm)
{
struct vfio_group *group;
- group = vfio_group_from_file(file);
+ group = vfio_group_from_file(vfio_file);
if (group)
vfio_group_set_kvm(group, kvm);
- if (vfio_device_from_file(file))
- vfio_device_file_set_kvm(file, kvm);
+ if (vfio_device_from_file(vfio_file))
+ vfio_device_file_set_kvm(vfio_file, kvm);
}
EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 03bfc92864b6..1c5bf2801bf1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -784,6 +784,12 @@ struct kvm {
* kvm_swap_active_memslots().
*/
struct mutex slots_arch_lock;
+ /*
+ * Back-reference to VM file descriptor without extra refcount held.
+ * Use get_file_active() to safely access the file without circular references.
+ * RCU-protected to ensure safe access even during file release.
+ */
+ struct file __rcu *file;
struct mm_struct *mm; /* userspace tied to this vm */
unsigned long nr_memslot_pages;
/* The two memslot sets - active and inactive (per address space) */
@@ -1082,6 +1088,7 @@ void kvm_get_kvm(struct kvm *kvm);
bool kvm_get_kvm_safe(struct kvm *kvm);
void kvm_put_kvm(struct kvm *kvm);
bool file_is_kvm(struct file *file);
+struct kvm *file_to_kvm(struct file *file);
void kvm_put_kvm_no_destroy(struct kvm *kvm);
static inline struct kvm_memslots *__kvm_memslots(struct kvm *kvm, int as_id)
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 45f08986359e..0cc91c6f96d2 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -54,7 +54,7 @@ struct vfio_device {
struct list_head dev_set_list;
unsigned int migration_flags;
u8 precopy_info_v2;
- struct kvm *kvm;
+ struct file *kvm;
/* Members below here are private, not for driver use */
unsigned int index;
@@ -66,7 +66,6 @@ struct vfio_device {
unsigned int open_count;
struct completion comp;
struct iommufd_access *iommufd_access;
- void (*put_kvm)(struct kvm *kvm);
struct inode *inode;
#if IS_ENABLED(CONFIG_IOMMUFD)
struct iommufd_device *iommufd_device;
@@ -378,7 +377,7 @@ static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *devi
#endif
bool vfio_file_is_valid(struct file *file);
bool vfio_file_enforced_coherent(struct file *file);
-void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
+void vfio_file_set_kvm(struct file *vfio_file, struct file *kvm);
#define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 65eb26a0520d..0d80730e8424 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1314,7 +1314,7 @@ void kvm_get_kvm(struct kvm *kvm)
{
refcount_inc(&kvm->users_count);
}
-EXPORT_SYMBOL_GPL(kvm_get_kvm);
+EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_get_kvm);
/*
* Make sure the vm is not during destruction, which is a safe version of
@@ -1324,14 +1324,14 @@ bool kvm_get_kvm_safe(struct kvm *kvm)
{
return refcount_inc_not_zero(&kvm->users_count);
}
-EXPORT_SYMBOL_GPL(kvm_get_kvm_safe);
+EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_get_kvm_safe);
void kvm_put_kvm(struct kvm *kvm)
{
if (refcount_dec_and_test(&kvm->users_count))
kvm_destroy_vm(kvm);
}
-EXPORT_SYMBOL_GPL(kvm_put_kvm);
+EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_put_kvm);
/*
* Used to put a reference that was taken on behalf of an object associated
@@ -1352,6 +1352,9 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
kvm_irqfd_release(kvm);
+ rcu_assign_pointer(kvm->file, NULL);
+ synchronize_rcu();
+
kvm_put_kvm(kvm);
return 0;
}
@@ -5496,6 +5499,15 @@ bool file_is_kvm(struct file *file)
}
EXPORT_SYMBOL_FOR_KVM_INTERNAL(file_is_kvm);
+struct kvm *file_to_kvm(struct file *file)
+{
+ if (!file_is_kvm(file))
+ return NULL;
+
+ return file->private_data;
+}
+EXPORT_SYMBOL_FOR_KVM_INTERNAL(file_to_kvm);
+
static int kvm_dev_ioctl_create_vm(unsigned long type)
{
char fdname[ITOA_MAX_LEN + 1];
@@ -5527,6 +5539,10 @@ static int kvm_dev_ioctl_create_vm(unsigned long type)
* cases it will be called by the final fput(file) and will take
* care of doing kvm_put_kvm(kvm).
*/
+
+ /* Store back-reference for VFIO and other subsystems */
+ rcu_assign_pointer(kvm->file, file);
+
kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm);
fd_install(fd, file);
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index 6cdc4e9a333a..0166cc4d39b3 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -35,15 +35,15 @@ struct kvm_vfio {
bool noncoherent;
};
-static void kvm_vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+static void kvm_vfio_file_set_kvm(struct file *vfio_file, struct file *kvm)
{
- void (*fn)(struct file *file, struct kvm *kvm);
+ void (*fn)(struct file *vfio_file, struct file *kvm);
fn = symbol_get(vfio_file_set_kvm);
if (!fn)
return;
- fn(file, kvm);
+ fn(vfio_file, kvm);
symbol_put(vfio_file_set_kvm);
}
@@ -168,7 +168,7 @@ static int kvm_vfio_file_add(struct kvm_device *dev, unsigned int fd)
kvf->file = get_file(filp);
list_add_tail(&kvf->node, &kv->file_list);
- kvm_vfio_file_set_kvm(kvf->file, dev->kvm);
+ kvm_vfio_file_set_kvm(kvf->file, dev->kvm->file);
kvm_vfio_update_coherency(dev);
return 0;
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 01/33] vfio: Use file-based reference counting for KVM
2026-08-12 15:35 ` [PATCH v6 01/33] vfio: Use file-based reference counting for KVM Steffen Eiden
@ 2026-08-12 16:00 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:00 UTC (permalink / raw)
To: Steffen Eiden
Cc: kvmarm, linux-s390, Marc Zyngier, Christian Borntraeger, kvm,
Heiko Carstens, Alexander Gordeev, Oliver Upton, Vasily Gorbik
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Critical] VFIO retains a dangling weak pointer to the KVM VM `struct file` when the VM fd is closed, leading to use-after-free and type confusion if the file memory is reallocated.
- [Medium] Direct, unsafe access to the RCU-protected pointer `kvm->file` without using RCU primitives.
--
--- Patch [1]: [PATCH v6 01/33] vfio: Use file-based reference counting for KVM ---
commit fbb73952530ea819e76b37873395b8b6ce2e0444
Author: Steffen Eiden <seiden@linux.ibm.com>
vfio: Use file-based reference counting for KVM
This commit replaces manual module reference counting with file-based
reference counting for KVM integration. It updates the VFIO-KVM interface
to pass struct file pointers instead of struct kvm pointers, relying on
get_file_active() and fput() for reference management.
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index 99a0efd999ef9..875e67063d8e5 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
[ ... ]
> @@ -1822,12 +1823,25 @@ static const struct attribute_group *vfio_ap_mdev_attr_groups[] = {
> * @matrix_mdev: a mediated matrix device
> * @kvm: reference to KVM instance
> *
> - * Return: 0 if no other mediated matrix device has a reference to @kvm;
> - * otherwise, returns an -EPERM.
> + * Returns: 0 if the reference to kvm is successfully retrieved from @kvm_file
> + * and set into @matrix_mdev; otherwise, returns:
> + * -ENOENT if a reference to kvm could not be retrieved from @kvm_file
> + * -EPERM if another mediated matrix device already has a reference to the same kvm instance
> */
> static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
> - struct kvm *kvm)
> + struct file **kvm_file)
> {
> + struct file *kvm_file_ref __free(fput) = NULL;
> + struct kvm *kvm;
> +
> + kvm_file_ref = get_file_active(kvm_file);
> + if (!kvm_file_ref)
> + return -ENOENT;
> +
> + kvm = kvm_file_ref->private_data;
> + if (!kvm)
> + return -ENOENT;
[Severity: Critical]
If kvm_file_ref points to a file that was freed and reallocated to a
completely different type of file (due to SLAB_TYPESAFE_BY_RCU), could
this cause type confusion?
Since struct file memory can be reused, extracting private_data without first
verifying the file's operations (f_op) could lead to arbitrary memory
corruption. Should this code use file_is_kvm() or file_to_kvm() before
dereferencing private_data?
> diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_zdev.c
> index 0990fdb146b78..d3a1101013531 100644
> --- a/drivers/vfio/pci/vfio_pci_zdev.c
> +++ b/drivers/vfio/pci/vfio_pci_zdev.c
[ ... ]
> @@ -144,6 +144,7 @@ int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
> int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev)
> {
> struct zpci_dev *zdev = to_zpci(vdev->pdev);
> + struct kvm *kvm;
>
> if (!zdev)
> return -ENODEV;
> @@ -151,8 +152,12 @@ int vfio_pci_zdev_open_device(struct vfio_pci_core_device *vdev)
> if (!vdev->vdev.kvm)
> return 0;
>
> + kvm = vdev->vdev.kvm->private_data;
> + if (!kvm)
> + return -ENOENT;
[Severity: Critical]
Does this code also need to validate that vdev->vdev.kvm is actually a KVM
file before interpreting its private_data as a struct kvm pointer?
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 423ead48aafe3..b06d1a9116051 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
[ ... ]
> @@ -472,36 +472,17 @@ void vfio_unregister_group_dev(struct vfio_device *device)
> EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
>
> #if IS_ENABLED(CONFIG_KVM)
> -void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
> +void vfio_device_get_kvm_safe(struct vfio_device *device, struct file **kvm)
> {
> - void (*pfn)(struct kvm *kvm);
> - bool (*fn)(struct kvm *kvm);
> - bool ret;
> + struct file *kvm_file_ref __free(fput) = NULL;
>
> lockdep_assert_held(&device->dev_set->lock);
>
> - if (!kvm)
> + kvm_file_ref = get_file_active(kvm);
> + if (!kvm_file_ref)
> return;
[Severity: Critical]
Can this result in getting a reference to a completely unrelated file object?
If userspace opens a KVM VM and creates a KVM VFIO device (taking a reference
to the kvm object), VFIO stores a weak pointer to the KVM struct file.
If userspace then closes the KVM VM fd while keeping the KVM VFIO device fd
open:
1. The VM fd closes, dropping the f_count to 0 and freeing the struct file
via RCU.
2. The kvm->users_count remains > 0 (due to the open KVM VFIO device fd), so
kvm_destroy_vm() is never called to clear the VFIO weak pointer.
3. Because struct file uses SLAB_TYPESAFE_BY_RCU, the freed memory can be
reallocated to a completely unrelated file.
When get_file_active() is later called here on the dangling pointer, wouldn't
it successfully take a reference on the reused struct file?
> diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
> index 6cdc4e9a333a3..0166cc4d39b31 100644
> --- a/virt/kvm/vfio.c
> +++ b/virt/kvm/vfio.c
[ ... ]
> @@ -168,7 +168,7 @@ static int kvm_vfio_file_add(struct kvm_device *dev, unsigned int fd)
> kvf->file = get_file(filp);
> list_add_tail(&kvf->node, &kv->file_list);
>
> - kvm_vfio_file_set_kvm(kvf->file, dev->kvm);
> + kvm_vfio_file_set_kvm(kvf->file, dev->kvm->file);
[Severity: Medium]
Is it safe to access dev->kvm->file directly here?
Since kvm->file is explicitly annotated as a __rcu pointer in struct kvm,
shouldn't this be accessed within an RCU read-side critical section using
rcu_dereference() to avoid data races with kvm_vm_release()?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=1
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 02/33] KVM: Make device name configurable
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
2026-08-12 15:35 ` [PATCH v6 01/33] vfio: Use file-based reference counting for KVM Steffen Eiden
@ 2026-08-12 15:35 ` Steffen Eiden
2026-08-12 16:08 ` sashiko-bot
2026-08-12 15:35 ` [PATCH v6 03/33] KVM: Allow KVM implementations to switch off MMIO independent of Kconfig Steffen Eiden
` (31 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:35 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Allow KVM implementations to choose alternative device names. This is
especially useful for architectures providing multiple KVM
implementations simultaneously.
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
include/linux/kvm_host.h | 4 +++-
virt/kvm/async_pf.c | 13 ++++++++++--
virt/kvm/async_pf.h | 4 ++--
virt/kvm/kvm_main.c | 43 ++++++++++++++++++++++++++++++----------
4 files changed, 49 insertions(+), 15 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 1c5bf2801bf1..6ea6322ba8b5 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1081,7 +1081,9 @@ static inline void kvm_irqfd_exit(void)
{
}
#endif
-int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module);
+int kvm_init(unsigned int vcpu_size, unsigned int vcpu_align, struct module *module);
+int kvm_init_with_dev(unsigned int vcpu_size, unsigned int vcpu_align,
+ struct module *module, const char *dev_name, int minor);
void kvm_exit(void);
void kvm_get_kvm(struct kvm *kvm);
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index b8aaa96b799b..015761249107 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -19,9 +19,18 @@
static struct kmem_cache *async_pf_cache;
-int kvm_async_pf_init(void)
+int kvm_async_pf_init(const char *cache_name)
{
- async_pf_cache = KMEM_CACHE(kvm_async_pf, 0);
+ char *full_cache_name;
+
+ full_cache_name = kasprintf(GFP_KERNEL, "%s_async_pf", cache_name);
+ if (!full_cache_name)
+ return -ENOMEM;
+
+ async_pf_cache = kmem_cache_create(full_cache_name,
+ sizeof(struct kvm_async_pf), 0,
+ SLAB_ACCOUNT, NULL);
+ kfree(full_cache_name);
if (!async_pf_cache)
return -ENOMEM;
diff --git a/virt/kvm/async_pf.h b/virt/kvm/async_pf.h
index 90d1a7d8c6de..829003899414 100644
--- a/virt/kvm/async_pf.h
+++ b/virt/kvm/async_pf.h
@@ -12,11 +12,11 @@
#define __KVM_ASYNC_PF_H__
#ifdef CONFIG_KVM_ASYNC_PF
-int kvm_async_pf_init(void);
+int kvm_async_pf_init(const char *cache_name);
void kvm_async_pf_deinit(void);
void kvm_async_pf_vcpu_init(struct kvm_vcpu *vcpu);
#else
-#define kvm_async_pf_init() (0)
+#define kvm_async_pf_init(name) (0)
#define kvm_async_pf_deinit() do {} while (0)
#define kvm_async_pf_vcpu_init(C) do {} while (0)
#endif
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 0d80730e8424..0b34477bf325 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -10,6 +10,7 @@
* Yaniv Kamay <yaniv@qumranet.com>
*/
+#include "linux/sprintf.h"
#include <kvm/iodev.h>
#include <linux/kvm_host.h>
@@ -5597,9 +5598,7 @@ static struct file_operations kvm_chardev_ops = {
};
static struct miscdevice kvm_dev = {
- KVM_MINOR,
- "kvm",
- &kvm_chardev_ops,
+ .fops = &kvm_chardev_ops,
};
#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
@@ -6371,13 +6370,13 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
kfree(env);
}
-static void kvm_init_debug(void)
+static void kvm_init_debug(const char *dev_name)
{
const struct file_operations *fops;
const struct kvm_stats_desc *pdesc;
int i;
- kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
+ kvm_debugfs_dir = debugfs_create_dir(dev_name, NULL);
for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
pdesc = &kvm_vm_stats_desc[i];
@@ -6513,23 +6512,42 @@ void kvm_unregister_perf_callbacks(void)
}
#endif
-int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
+int kvm_init(unsigned int vcpu_size, unsigned int vcpu_align, struct module *module)
{
+ return kvm_init_with_dev(vcpu_size, vcpu_align, module, "kvm", KVM_MINOR);
+}
+
+int kvm_init_with_dev(unsigned int vcpu_size, unsigned int vcpu_align,
+ struct module *module, const char *dev_name, int minor)
+{
+ char *cache_name;
int r;
int cpu;
+ kvm_dev.minor = minor;
+ kvm_dev.name = kstrdup_const(dev_name, GFP_KERNEL);
+ if (!kvm_dev.name)
+ return -ENOMEM;
+
/* A kmem cache lets us meet the alignment requirements of fx_save. */
if (!vcpu_align)
vcpu_align = __alignof__(struct kvm_vcpu);
+
+ r = -ENOMEM;
+ cache_name = kasprintf(GFP_KERNEL, "%s_vcpu", dev_name);
+ if (!cache_name)
+ goto err_dev_name;
kvm_vcpu_cache =
- kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align,
+ kmem_cache_create_usercopy(cache_name, vcpu_size, vcpu_align,
SLAB_ACCOUNT,
offsetof(struct kvm_vcpu, arch),
offsetofend(struct kvm_vcpu, stats_id)
- offsetof(struct kvm_vcpu, arch),
NULL);
+ kfree(cache_name);
+
if (!kvm_vcpu_cache)
- return -ENOMEM;
+ goto err_dev_name;
for_each_possible_cpu(cpu) {
if (!alloc_cpumask_var_node(&per_cpu(cpu_kick_mask, cpu),
@@ -6543,7 +6561,7 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
if (r)
goto err_irqfd;
- r = kvm_async_pf_init();
+ r = kvm_async_pf_init(dev_name);
if (r)
goto err_async_pf;
@@ -6555,7 +6573,7 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
kvm_preempt_ops.sched_in = kvm_sched_in;
kvm_preempt_ops.sched_out = kvm_sched_out;
- kvm_init_debug();
+ kvm_init_debug(kvm_dev.name);
r = kvm_vfio_ops_init();
if (WARN_ON_ONCE(r))
@@ -6597,6 +6615,8 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
for_each_possible_cpu(cpu)
free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
kmem_cache_destroy(kvm_vcpu_cache);
+err_dev_name:
+ kfree_const(kvm_dev.name);
return r;
}
EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_init);
@@ -6622,5 +6642,8 @@ void kvm_exit(void)
kvm_vfio_ops_exit();
kvm_async_pf_deinit();
kvm_irqfd_exit();
+
+ kfree_const(kvm_dev.name);
+ kvm_dev.name = NULL;
}
EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_exit);
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 02/33] KVM: Make device name configurable
2026-08-12 15:35 ` [PATCH v6 02/33] KVM: Make device name configurable Steffen Eiden
@ 2026-08-12 16:08 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:08 UTC (permalink / raw)
To: Steffen Eiden
Cc: Oliver Upton, Alexander Gordeev, linux-s390,
Christian Borntraeger, Marc Zyngier, kvmarm, Vasily Gorbik,
Heiko Carstens, kvm
Thank you for your contribution! Sashiko AI review found 4 potential issue(s) to consider:
- [High] Calling `kvm_init_with_dev()` multiple times within the same module to support multiple simultaneous KVM implementations corrupts KVM's static singleton state and guarantees list corruption.
- [High] `kvm_init_with_dev` is not exported, making it unusable by independent loadable KVM architecture modules.
- [Medium] The patch fails to parameterize the `kvm_gmem_inode_cache` name, causing a sysfs kmem_cache name collision when multiple KVM implementations are loaded simultaneously.
- [Medium] The patch silently adds the `SLAB_ACCOUNT` flag to the async page fault kmem_cache without justification in the commit message.
--
--- Patch [2]: [PATCH v6 02/33] KVM: Make device name configurable ---
commit fddf3fec3ead355cf194e06551ca60993f2aec03
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: Make device name configurable
Allow KVM implementations to choose alternative device names. This is
especially useful for architectures providing multiple KVM
implementations simultaneously.
> diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
> index b8aaa96b799bf..0157612491070 100644
> --- a/virt/kvm/async_pf.c
> +++ b/virt/kvm/async_pf.c
[ ... ]
> -int kvm_async_pf_init(void)
> +int kvm_async_pf_init(const char *cache_name)
> {
> - async_pf_cache = KMEM_CACHE(kvm_async_pf, 0);
> + char *full_cache_name;
> +
> + full_cache_name = kasprintf(GFP_KERNEL, "%s_async_pf", cache_name);
> + if (!full_cache_name)
> + return -ENOMEM;
> +
> + async_pf_cache = kmem_cache_create(full_cache_name,
> + sizeof(struct kvm_async_pf), 0,
> + SLAB_ACCOUNT, NULL);
[Severity: Medium]
Does this silently introduce a behavior change? The previous KMEM_CACHE call
passed 0 for flags, but this adds SLAB_ACCOUNT. While accounting these
to the vCPU's memory cgroup is likely correct, shouldn't this functional
change be documented in the commit message?
> + kfree(full_cache_name);
>
> if (!async_pf_cache)
> return -ENOMEM;
[ ... ]
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 0d80730e84240..0b34477bf325b 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
[ ... ]
> +int kvm_init_with_dev(unsigned int vcpu_size, unsigned int vcpu_align,
> + struct module *module, const char *dev_name, int minor)
> +{
> + char *cache_name;
> int r;
> int cpu;
>
> + kvm_dev.minor = minor;
> + kvm_dev.name = kstrdup_const(dev_name, GFP_KERNEL);
[Severity: High]
Can calling kvm_init_with_dev() multiple times corrupt the static miscdevice
and list state?
If multiple KVM implementations share the same kvm_main.o core and call this
initialization, they will unconditionally overwrite the shared static kvm_dev
struct. Calling misc_register(&kvm_dev) a second time with the exact same
static struct would overwrite its list_head pointers, which structurally
guarantees misc_list corruption and a fatal kernel panic on the next
traversal.
> + if (!kvm_dev.name)
> + return -ENOMEM;
> +
> /* A kmem cache lets us meet the alignment requirements of fx_save. */
> if (!vcpu_align)
> vcpu_align = __alignof__(struct kvm_vcpu);
> +
> + r = -ENOMEM;
> + cache_name = kasprintf(GFP_KERNEL, "%s_vcpu", dev_name);
> + if (!cache_name)
> + goto err_dev_name;
> kvm_vcpu_cache =
> - kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align,
> + kmem_cache_create_usercopy(cache_name, vcpu_size, vcpu_align,
[Severity: High]
Doesn't this also unconditionally overwrite the global kvm_vcpu_cache pointer
and leak the previous cache when multiple implementations initialize?
> SLAB_ACCOUNT,
> offsetof(struct kvm_vcpu, arch),
> offsetofend(struct kvm_vcpu, stats_id)
[ ... ]
> @@ -6597,6 +6615,8 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
> for_each_possible_cpu(cpu)
> free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
> kmem_cache_destroy(kvm_vcpu_cache);
> +err_dev_name:
> + kfree_const(kvm_dev.name);
> return r;
> }
> EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_init);
[Severity: High]
Should kvm_init_with_dev() be exported? The commit states it is meant for
architectures providing multiple KVM implementations simultaneously, but
without an export macro like EXPORT_SYMBOL_FOR_KVM_INTERNAL, external
loadable architecture modules will fail to link against it.
[Severity: Medium]
Also, if multiple implementations are statically linked to avoid the missing
export, wouldn't kvm_gmem_init() (called earlier in this function) cause a
sysfs naming collision?
It does not take a dev_name parameter and hardcodes the name
"kvm_gmem_inode_cache". Because SLAB_ACCOUNT caches are unmergeable, the
second creation attempt will fail sysfs registration and emit a SLUB error
in dmesg.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=2
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 03/33] KVM: Allow KVM implementations to switch off MMIO independent of Kconfig
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
2026-08-12 15:35 ` [PATCH v6 01/33] vfio: Use file-based reference counting for KVM Steffen Eiden
2026-08-12 15:35 ` [PATCH v6 02/33] KVM: Make device name configurable Steffen Eiden
@ 2026-08-12 15:35 ` Steffen Eiden
2026-08-12 15:49 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 04/33] arm64: Use proper include variant Steffen Eiden
` (30 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:35 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Only defining KVM_MMIO is not flexible enough for multi-KVM systems
where one KVM implements MMIO but others do not. Solve this by
additionally testing for the non-existence of KVM_NO_MMIO before
including MMIO code to KVM.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
virt/kvm/coalesced_mmio.c | 4 ++++
virt/kvm/coalesced_mmio.h | 2 +-
virt/kvm/kvm_main.c | 8 ++++----
3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 6b1d90161099..8ff9d9a6f47a 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -15,6 +15,8 @@
#include <linux/slab.h>
#include <linux/kvm.h>
+#ifndef KVM_NO_MMIO
+
#include "coalesced_mmio.h"
static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev)
@@ -188,3 +190,5 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
*/
return 0;
}
+
+#endif /* ifndef KVM_NO_MMIO */
diff --git a/virt/kvm/coalesced_mmio.h b/virt/kvm/coalesced_mmio.h
index 36f84264ed25..826af421a5be 100644
--- a/virt/kvm/coalesced_mmio.h
+++ b/virt/kvm/coalesced_mmio.h
@@ -11,7 +11,7 @@
*
*/
-#ifdef CONFIG_KVM_MMIO
+#if defined(CONFIG_KVM_MMIO) && !defined(KVM_NO_MMIO)
#include <linux/list.h>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 0b34477bf325..a5dcb38e80db 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4063,7 +4063,7 @@ static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf)
else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
page = virt_to_page(vcpu->arch.pio_data);
#endif
-#ifdef CONFIG_KVM_MMIO
+#if defined(CONFIG_KVM_MMIO) && !defined(KVM_NO_MMIO)
else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
#endif
@@ -4904,7 +4904,7 @@ static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
case KVM_CAP_ENABLE_CAP_VM:
case KVM_CAP_HALT_POLL:
return 1;
-#ifdef CONFIG_KVM_MMIO
+#if defined(CONFIG_KVM_MMIO) && !defined(KVM_NO_MMIO)
case KVM_CAP_COALESCED_MMIO:
return KVM_COALESCED_MMIO_PAGE_OFFSET;
case KVM_CAP_COALESCED_PIO:
@@ -5245,7 +5245,7 @@ static long kvm_vm_ioctl(struct file *filp,
break;
}
#endif
-#ifdef CONFIG_KVM_MMIO
+#if defined(CONFIG_KVM_MMIO) && !defined(KVM_NO_MMIO)
case KVM_REGISTER_COALESCED_MMIO: {
struct kvm_coalesced_mmio_zone zone;
@@ -5580,7 +5580,7 @@ static long kvm_dev_ioctl(struct file *filp,
#ifdef CONFIG_X86
r += PAGE_SIZE; /* pio data page */
#endif
-#ifdef CONFIG_KVM_MMIO
+#if defined(CONFIG_KVM_MMIO) && !defined(KVM_NO_MMIO)
r += PAGE_SIZE; /* coalesced mmio ring page */
#endif
break;
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 04/33] arm64: Use proper include variant
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (2 preceding siblings ...)
2026-08-12 15:35 ` [PATCH v6 03/33] KVM: Allow KVM implementations to switch off MMIO independent of Kconfig Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:52 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 05/33] arm64: ptrace: Use constants for compat register numbers Steffen Eiden
` (29 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Use <> for including the sysreg header as it is not discoverable from
the current directory.
Fixes: c07d8017bceb ("arm64/sysreg: Enable automatic generation of system register definitions")
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/arm64/include/asm/sysreg.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 7aa08d59d494..4bfdac9401bd 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -173,7 +173,7 @@
* come from here. The header relies on the definition of sys_reg()
* earlier in this file.
*/
-#include "asm/sysreg-defs.h"
+#include <asm/sysreg-defs.h>
/*
* System registers, organised loosely by encoding but grouped together
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 05/33] arm64: ptrace: Use constants for compat register numbers
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (3 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 04/33] arm64: Use proper include variant Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:46 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 06/33] arm64: sysreg: Convert SPSR_ELx to automatic register generation Steffen Eiden
` (28 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Define an enum to determine the register number for the mapping from
AArch32 and AArch64 registers. This allows for a more flexible use of
the register mappings.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/arm64/include/asm/ptrace.h | 60 ++++++++++++++++++++++-----------
1 file changed, 41 insertions(+), 19 deletions(-)
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index f7dc5fb9427d..49a83a0636b9 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -102,26 +102,48 @@
#define COMPAT_USER_SZ 296
/* Architecturally defined mapping between AArch32 and AArch64 registers */
+enum {
+ __compat_fp = 11,
+ __compat_sp = 13,
+ __compat_lr = 14,
+ __compat_sp_hyp = 15,
+ __compat_lr_irq = 16,
+ __compat_sp_irq = 17,
+ __compat_lr_svc = 18,
+ __compat_sp_svc = 19,
+ __compat_lr_abt = 20,
+ __compat_sp_abt = 21,
+ __compat_lr_und = 22,
+ __compat_sp_und = 23,
+ __compat_r8_fiq = 24,
+ __compat_r9_fiq = 25,
+ __compat_r10_fiq = 26,
+ __compat_r11_fiq = 27,
+ __compat_r12_fiq = 28,
+ __compat_sp_fiq = 29,
+ __compat_lr_fiq = 30,
+};
+
#define compat_usr(x) regs[(x)]
-#define compat_fp regs[11]
-#define compat_sp regs[13]
-#define compat_lr regs[14]
-#define compat_sp_hyp regs[15]
-#define compat_lr_irq regs[16]
-#define compat_sp_irq regs[17]
-#define compat_lr_svc regs[18]
-#define compat_sp_svc regs[19]
-#define compat_lr_abt regs[20]
-#define compat_sp_abt regs[21]
-#define compat_lr_und regs[22]
-#define compat_sp_und regs[23]
-#define compat_r8_fiq regs[24]
-#define compat_r9_fiq regs[25]
-#define compat_r10_fiq regs[26]
-#define compat_r11_fiq regs[27]
-#define compat_r12_fiq regs[28]
-#define compat_sp_fiq regs[29]
-#define compat_lr_fiq regs[30]
+#define compat_fp regs[__compat_fp]
+#define compat_sp regs[__compat_sp]
+#define compat_lr regs[__compat_lr]
+#define compat_sp_hyp regs[__compat_sp_hyp]
+#define compat_lr_irq regs[__compat_lr_irq]
+#define compat_sp_irq regs[__compat_sp_irq]
+#define compat_lr_svc regs[__compat_lr_svc]
+#define compat_sp_svc regs[__compat_sp_svc]
+#define compat_lr_abt regs[__compat_lr_abt]
+#define compat_sp_abt regs[__compat_sp_abt]
+#define compat_lr_und regs[__compat_lr_und]
+#define compat_sp_und regs[__compat_sp_und]
+#define compat_r8_fiq regs[__compat_r8_fiq]
+#define compat_r9_fiq regs[__compat_r9_fiq]
+#define compat_r10_fiq regs[__compat_r10_fiq]
+#define compat_r11_fiq regs[__compat_r11_fiq]
+#define compat_r12_fiq regs[__compat_r12_fiq]
+#define compat_sp_fiq regs[__compat_sp_fiq]
+#define compat_lr_fiq regs[__compat_lr_fiq]
static inline unsigned long compat_psr_to_pstate(const unsigned long psr)
{
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 06/33] arm64: sysreg: Convert SPSR_ELx to automatic register generation
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (4 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 05/33] arm64: ptrace: Use constants for compat register numbers Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:48 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 07/33] KVM: arm64: Access elements of vcpu_gp_regs individually Steffen Eiden
` (27 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Convert SPSR_EL{1, 2, 12} to automatic register generation as per
DDIO616 2026-06. No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/arm64/include/asm/sysreg.h | 3 ---
arch/arm64/tools/sysreg | 48 +++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 4bfdac9401bd..1aa601c95188 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -295,7 +295,6 @@
#define SYS_APGAKEYLO_EL1 sys_reg(3, 0, 2, 3, 0)
#define SYS_APGAKEYHI_EL1 sys_reg(3, 0, 2, 3, 1)
-#define SYS_SPSR_EL1 sys_reg(3, 0, 4, 0, 0)
#define SYS_ELR_EL1 sys_reg(3, 0, 4, 0, 1)
#define SYS_ICC_PMR_EL1 sys_reg(3, 0, 4, 6, 0)
@@ -518,7 +517,6 @@
#define SYS_VTTBR_EL2 sys_reg(3, 4, 2, 1, 0)
#define SYS_HAFGRTR_EL2 sys_reg(3, 4, 3, 1, 6)
-#define SYS_SPSR_EL2 sys_reg(3, 4, 4, 0, 0)
#define SYS_ELR_EL2 sys_reg(3, 4, 4, 0, 1)
#define SYS_SP_EL1 sys_reg(3, 4, 4, 1, 0)
#define SYS_SPSR_irq sys_reg(3, 4, 4, 3, 0)
@@ -604,7 +602,6 @@
#define SYS_BRBCR_EL12 sys_reg(2, 5, 9, 0, 0)
#define SYS_TTBR0_EL12 sys_reg(3, 5, 2, 0, 0)
#define SYS_TTBR1_EL12 sys_reg(3, 5, 2, 0, 1)
-#define SYS_SPSR_EL12 sys_reg(3, 5, 4, 0, 0)
#define SYS_ELR_EL12 sys_reg(3, 5, 4, 0, 1)
#define SYS_AFSR0_EL12 sys_reg(3, 5, 5, 1, 0)
#define SYS_AFSR1_EL12 sys_reg(3, 5, 5, 1, 1)
diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
index 94bf065c8ac7..6e625a05c477 100644
--- a/arch/arm64/tools/sysreg
+++ b/arch/arm64/tools/sysreg
@@ -401,6 +401,54 @@ Res0 3:1
Field 0 SO
EndSysreg
+SysregFields SPSR_ELx
+Res0 63:37
+Field 36 UNIJ
+Field 35 PACM
+Field 34 EXLOCK
+Res0 33
+Field 32 PM
+Field 31 N
+Field 30 Z
+Field 29 C
+Field 28 V
+Res0 27:26
+Field 25 TCO
+Field 24 DIT
+Field 23 UAO
+Field 22 PAN
+Field 21 SS
+Field 20 IL
+Res0 19:14
+Field 13 ALLINT
+Field 12 SSBS
+Field 11:10 BTYPE
+Field 9 D
+Field 8 A
+Field 7 I
+Field 6 F
+Res0 5
+Enum 4:0 M
+ 0b0000 EL0
+ 0b0100 EL1t
+ 0b0101 EL1h
+ 0b1000 EL2t
+ 0b1001 EL2h
+EndEnum
+EndSysregFields
+
+Sysreg SPSR_EL1 3 0 4 0 0
+Fields SPSR_ELx
+EndSysreg
+
+Sysreg SPSR_EL2 3 4 4 0 0
+Fields SPSR_ELx
+EndSysreg
+
+Sysreg SPSR_EL12 3 5 4 0 0
+Mapping SPSR_EL1
+EndSysreg
+
Sysreg ID_PFR0_EL1 3 0 0 1 0
Res0 63:32
UnsignedEnum 31:28 RAS
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 06/33] arm64: sysreg: Convert SPSR_ELx to automatic register generation
2026-08-12 15:36 ` [PATCH v6 06/33] arm64: sysreg: Convert SPSR_ELx to automatic register generation Steffen Eiden
@ 2026-08-12 15:48 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 15:48 UTC (permalink / raw)
To: Steffen Eiden
Cc: Christian Borntraeger, Alexander Gordeev, Heiko Carstens,
Oliver Upton, kvm, linux-s390, kvmarm, Vasily Gorbik,
Marc Zyngier
> Convert SPSR_EL{1, 2, 12} to automatic register generation as per
> DDIO616 2026-06. No functional change.
>
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=6
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 07/33] KVM: arm64: Access elements of vcpu_gp_regs individually
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (5 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 06/33] arm64: sysreg: Convert SPSR_ELx to automatic register generation Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:48 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 08/33] KVM: arm64: Use accessor functions for core regs Steffen Eiden
` (26 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
While for arm64 the members of vcpu_gp_regs are allocated continuous
this is not necessarily true for other architectures implementing ARM.
Let vcpu_gp_regs() no longer return the address of the user_pt_regs in
the vcpu context but the address of the gp-register array field in the
user_pt_reg struct. Note, this change semantically excludes pc from the
GPRs.
No functional change.
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/arm64/include/asm/kvm_emulate.h | 14 ++++++++------
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/arm64/kvm/hyp/exception.c | 4 ++--
arch/arm64/kvm/hyp/include/hyp/adjust_pc.h | 4 ++--
arch/arm64/kvm/hyp/include/hyp/switch.h | 4 ++--
5 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index a3c1928bdf74..8603766c1b4d 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -133,12 +133,12 @@ static inline void vcpu_set_vsesr(struct kvm_vcpu *vcpu, u64 vsesr)
static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
{
- return (unsigned long *)&vcpu_gp_regs(vcpu)->pc;
+ return (unsigned long *)&vcpu->arch.ctxt.regs.pc;
}
static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
{
- return (unsigned long *)&vcpu_gp_regs(vcpu)->pstate;
+ return (unsigned long *)&vcpu->arch.ctxt.regs.pstate;
}
static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
@@ -167,14 +167,14 @@ static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
static __always_inline unsigned long vcpu_get_reg(const struct kvm_vcpu *vcpu,
u8 reg_num)
{
- return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)->regs[reg_num];
+ return (reg_num == 31) ? 0 : vcpu_gp_regs(vcpu)[reg_num];
}
static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
unsigned long val)
{
if (reg_num != 31)
- vcpu_gp_regs(vcpu)->regs[reg_num] = val;
+ vcpu_gp_regs(vcpu)[reg_num] = val;
}
static inline bool vcpu_is_el2_ctxt(const struct kvm_cpu_context *ctxt)
@@ -750,13 +750,15 @@ static inline void kvm_reset_vcpu_core(struct kvm_vcpu *vcpu)
pstate = VCPU_RESET_PSTATE_EL1;
/* Reset core registers */
- memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu)));
+ memset(vcpu_gp_regs(vcpu), 0, sizeof(vcpu_gp_regs(vcpu)));
+ *vcpu_pc(vcpu) = 0;
+ vcpu->arch.ctxt.regs.sp = 0;
memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
vcpu->arch.ctxt.spsr_abt = 0;
vcpu->arch.ctxt.spsr_und = 0;
vcpu->arch.ctxt.spsr_irq = 0;
vcpu->arch.ctxt.spsr_fiq = 0;
- vcpu_gp_regs(vcpu)->pstate = pstate;
+ *vcpu_cpsr(vcpu) = pstate;
}
/* PSCI reset handling for a vcpu. */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 27fe0cd5b2d7..46c8d7928b3f 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1158,7 +1158,7 @@ struct kvm_vcpu_arch {
#define vcpu_clear_on_unsupported_cpu(vcpu) \
vcpu_clear_flag(vcpu, ON_UNSUPPORTED_CPU)
-#define vcpu_gp_regs(v) (&(v)->arch.ctxt.regs)
+#define vcpu_gp_regs(v) ((v)->arch.ctxt.regs.regs)
/*
* Only use __vcpu_sys_reg/ctxt_sys_reg if you know you want the
diff --git a/arch/arm64/kvm/hyp/exception.c b/arch/arm64/kvm/hyp/exception.c
index 754e2dc1df54..0640c9ccaa3c 100644
--- a/arch/arm64/kvm/hyp/exception.c
+++ b/arch/arm64/kvm/hyp/exception.c
@@ -276,12 +276,12 @@ static void enter_exception32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
switch(mode) {
case PSR_AA32_MODE_ABT:
__vcpu_write_spsr_abt(vcpu, host_spsr_to_spsr32(spsr));
- vcpu_gp_regs(vcpu)->compat_lr_abt = return_address;
+ vcpu_gp_regs(vcpu)[__compat_lr_abt] = return_address;
break;
case PSR_AA32_MODE_UND:
__vcpu_write_spsr_und(vcpu, host_spsr_to_spsr32(spsr));
- vcpu_gp_regs(vcpu)->compat_lr_und = return_address;
+ vcpu_gp_regs(vcpu)[__compat_lr_und] = return_address;
break;
}
diff --git a/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h b/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
index 4fdfeabefeb4..a049983bd5c3 100644
--- a/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
+++ b/arch/arm64/kvm/hyp/include/hyp/adjust_pc.h
@@ -33,11 +33,11 @@ static inline void kvm_skip_instr(struct kvm_vcpu *vcpu)
static inline void __kvm_skip_instr(struct kvm_vcpu *vcpu)
{
*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
- vcpu_gp_regs(vcpu)->pstate = read_sysreg_el2(SYS_SPSR);
+ *vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR);
kvm_skip_instr(vcpu);
- write_sysreg_el2(vcpu_gp_regs(vcpu)->pstate, SYS_SPSR);
+ write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR);
write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
}
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 1ce7130e2549..a2a054fec2e2 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -470,7 +470,7 @@ static inline bool kvm_hyp_handle_mops(struct kvm_vcpu *vcpu, u64 *exit_code)
u64 spsr;
*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
- arm64_mops_reset_regs(vcpu_gp_regs(vcpu), vcpu->arch.fault.esr_el2);
+ arm64_mops_reset_regs(&vcpu->arch.ctxt.regs, vcpu->arch.fault.esr_el2);
write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);
/*
@@ -902,7 +902,7 @@ static inline void synchronize_vcpu_pstate(struct kvm_vcpu *vcpu)
/*
* Check for the conditions of Cortex-A510's #2077057. When these occur
* SPSR_EL2 can't be trusted, but isn't needed either as it is
- * unchanged from the value in vcpu_gp_regs(vcpu)->pstate.
+ * unchanged from the value in vcpu_cpsr(vcpu).
* Are we single-stepping the guest, and took a PAC exception from the
* active-not-pending state?
*/
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 07/33] KVM: arm64: Access elements of vcpu_gp_regs individually
2026-08-12 15:36 ` [PATCH v6 07/33] KVM: arm64: Access elements of vcpu_gp_regs individually Steffen Eiden
@ 2026-08-12 15:48 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 15:48 UTC (permalink / raw)
To: Steffen Eiden
Cc: Heiko Carstens, Vasily Gorbik, Oliver Upton, kvm, Marc Zyngier,
Christian Borntraeger, kvmarm, linux-s390, Alexander Gordeev
> While for arm64 the members of vcpu_gp_regs are allocated continuous
> this is not necessarily true for other architectures implementing ARM.
>
> Let vcpu_gp_regs() no longer return the address of the user_pt_regs in
> the vcpu context but the address of the gp-register array field in the
> user_pt_reg struct. Note, this change semantically excludes pc from the
> GPRs.
>
> No functional change.
>
> Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
> Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=7
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 08/33] KVM: arm64: Use accessor functions for core regs
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (6 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 07/33] KVM: arm64: Access elements of vcpu_gp_regs individually Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:50 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 09/33] arm64: Prepare sharing arm64 headers with s390 Steffen Eiden
` (25 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Instead of accessing the value directly use assessor function that
abstract the actual location of the register values. Add a helper
function to reset fpsimd registers. Enable other KVM implementations to
reuse this code.
No functional changes.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/arm64/include/asm/kvm_emulate.h | 34 ++++++++++++++++++++++++++--
arch/arm64/kvm/guest.c | 16 ++++++-------
2 files changed, 40 insertions(+), 10 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 8603766c1b4d..b31d50bdf59e 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -141,6 +141,31 @@ static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
return (unsigned long *)&vcpu->arch.ctxt.regs.pstate;
}
+static __always_inline unsigned long *vcpu_sp_el0(struct kvm_vcpu *vcpu)
+{
+ return (unsigned long *)&vcpu->arch.ctxt.regs.sp;
+}
+
+static __always_inline u64 *vcpu_sp_el1(struct kvm_vcpu *vcpu)
+{
+ return __ctxt_sys_reg(&vcpu->arch.ctxt, SP_EL1);
+}
+
+static __always_inline __u128 *vcpu_vreg(struct kvm_vcpu *vcpu, int n)
+{
+ return &vcpu->arch.ctxt.fp_regs.vregs[n];
+}
+
+static __always_inline __u32 *vcpu_fpsr(struct kvm_vcpu *vcpu)
+{
+ return &vcpu->arch.ctxt.fp_regs.fpsr;
+}
+
+static __always_inline __u32 *vcpu_fpcr(struct kvm_vcpu *vcpu)
+{
+ return &vcpu->arch.ctxt.fp_regs.fpcr;
+}
+
static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
{
return !!(*vcpu_cpsr(vcpu) & PSR_MODE32_BIT);
@@ -737,6 +762,11 @@ static inline void vcpu_set_hcrx(struct kvm_vcpu *vcpu)
}
}
+static inline void kvm_reset_fpsimd(struct kvm_vcpu *vcpu)
+{
+ memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
+}
+
/* Reset a vcpu's core registers. */
static inline void kvm_reset_vcpu_core(struct kvm_vcpu *vcpu)
{
@@ -752,8 +782,8 @@ static inline void kvm_reset_vcpu_core(struct kvm_vcpu *vcpu)
/* Reset core registers */
memset(vcpu_gp_regs(vcpu), 0, sizeof(vcpu_gp_regs(vcpu)));
*vcpu_pc(vcpu) = 0;
- vcpu->arch.ctxt.regs.sp = 0;
- memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
+ *vcpu_sp_el0(vcpu) = 0;
+ kvm_reset_fpsimd(vcpu);
vcpu->arch.ctxt.spsr_abt = 0;
vcpu->arch.ctxt.spsr_und = 0;
vcpu->arch.ctxt.spsr_irq = 0;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index b01d6622b872..773f6c8e5026 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -134,19 +134,19 @@ static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
KVM_REG_ARM_CORE_REG(regs.regs[30]):
off -= KVM_REG_ARM_CORE_REG(regs.regs[0]);
off /= 2;
- return &vcpu->arch.ctxt.regs.regs[off];
+ return &vcpu_gp_regs(vcpu)[off];
case KVM_REG_ARM_CORE_REG(regs.sp):
- return &vcpu->arch.ctxt.regs.sp;
+ return vcpu_sp_el0(vcpu);
case KVM_REG_ARM_CORE_REG(regs.pc):
- return &vcpu->arch.ctxt.regs.pc;
+ return vcpu_pc(vcpu);
case KVM_REG_ARM_CORE_REG(regs.pstate):
- return &vcpu->arch.ctxt.regs.pstate;
+ return vcpu_cpsr(vcpu);
case KVM_REG_ARM_CORE_REG(sp_el1):
- return __ctxt_sys_reg(&vcpu->arch.ctxt, SP_EL1);
+ return vcpu_sp_el1(vcpu);
case KVM_REG_ARM_CORE_REG(elr_el1):
return __ctxt_sys_reg(&vcpu->arch.ctxt, ELR_EL1);
@@ -170,13 +170,13 @@ static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
off -= KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]);
off /= 4;
- return &vcpu->arch.ctxt.fp_regs.vregs[off];
+ return vcpu_vreg(vcpu, off);
case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
- return &vcpu->arch.ctxt.fp_regs.fpsr;
+ return vcpu_fpsr(vcpu);
case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
- return &vcpu->arch.ctxt.fp_regs.fpcr;
+ return vcpu_fpcr(vcpu);
default:
return NULL;
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 09/33] arm64: Prepare sharing arm64 headers with s390
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (7 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 08/33] KVM: arm64: Use accessor functions for core regs Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:52 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 10/33] arm64: Share " Steffen Eiden
` (24 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Prepare the sharing of arm64 headers with s390 by moving a few
definitions inside headers to reduce the number of shared markers.
Clean up some includes to further streamline the sharing of headers.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/arm64/include/asm/esr.h | 4 +-
arch/arm64/include/asm/kvm_arm.h | 5 ++-
arch/arm64/include/asm/kvm_emulate.h | 5 ++-
arch/arm64/include/asm/kvm_host.h | 59 ++++++++++++++--------------
arch/arm64/include/asm/sysreg.h | 2 +-
5 files changed, 39 insertions(+), 36 deletions(-)
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index f816f5d77f1a..da085c83b57e 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -7,7 +7,7 @@
#ifndef __ASM_ESR_H
#define __ASM_ESR_H
-#include <asm/memory.h>
+#include <asm/brk-imm.h>
#include <asm/sysreg.h>
#define ESR_ELx_EC_UNKNOWN UL(0x00)
@@ -435,7 +435,7 @@
#define ESR_ELx_IT_GCSPOPX 7
#ifndef __ASSEMBLER__
-#include <asm/types.h>
+#include <linux/types.h>
static inline unsigned long esr_brk_comment(unsigned long esr)
{
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 4bfbd827c5aa..57edd8437200 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -7,10 +7,11 @@
#ifndef __ARM64_KVM_ARM_H__
#define __ARM64_KVM_ARM_H__
+#include <linux/const.h>
+#include <linux/bits.h>
+#include <linux/types.h>
#include <asm/esr.h>
-#include <asm/memory.h>
#include <asm/sysreg.h>
-#include <asm/types.h>
/*
* Because I'm terribly lazy and that repainting the whole of the KVM
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index b31d50bdf59e..a34a9417ff4d 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -44,11 +44,12 @@ enum exception_type {
bool kvm_condition_valid32(const struct kvm_vcpu *vcpu);
void kvm_skip_instr32(struct kvm_vcpu *vcpu);
+int kvm_inject_dabt_excl_atomic(struct kvm_vcpu *vcpu, u64 addr);
+int kvm_inject_serror_esr(struct kvm_vcpu *vcpu, u64 esr);
+
void kvm_inject_undefined(struct kvm_vcpu *vcpu);
void kvm_inject_sync(struct kvm_vcpu *vcpu, u64 esr);
-int kvm_inject_serror_esr(struct kvm_vcpu *vcpu, u64 esr);
int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr);
-int kvm_inject_dabt_excl_atomic(struct kvm_vcpu *vcpu, u64 addr);
void kvm_inject_size_fault(struct kvm_vcpu *vcpu);
static inline int kvm_inject_sea_dabt(struct kvm_vcpu *vcpu, u64 addr)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 46c8d7928b3f..22770c1132cb 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -56,6 +56,36 @@
#define KVM_REQ_MAP_L1_VNCR_EL2 KVM_ARCH_REQ(10)
#define KVM_REQ_VGIC_PROCESS_UPDATE KVM_ARCH_REQ(11)
+/*
+ * If we encounter a data abort without valid instruction syndrome
+ * information, report this to user space. User space can (and
+ * should) opt in to this feature if KVM_CAP_ARM_NISV_TO_USER is
+ * supported.
+ */
+#define KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER 0
+/* Memory Tagging Extension enabled for the guest */
+#define KVM_ARCH_FLAG_MTE_ENABLED 1
+/* At least one vCPU has ran in the VM */
+#define KVM_ARCH_FLAG_HAS_RAN_ONCE 2
+/* The vCPU feature set for the VM is configured */
+#define KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED 3
+/* PSCI SYSTEM_SUSPEND enabled for the guest */
+#define KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED 4
+/* VM counter offset */
+#define KVM_ARCH_FLAG_VM_COUNTER_OFFSET 5
+/* Timer PPIs made immutable */
+#define KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE 6
+/* Initial ID reg values loaded */
+#define KVM_ARCH_FLAG_ID_REGS_INITIALIZED 7
+/* Fine-Grained UNDEF initialised */
+#define KVM_ARCH_FLAG_FGU_INITIALIZED 8
+/* SVE exposed to guest */
+#define KVM_ARCH_FLAG_GUEST_HAS_SVE 9
+/* MIDR_EL1, REVIDR_EL1, and AIDR_EL1 are writable from userspace */
+#define KVM_ARCH_FLAG_WRITABLE_IMP_ID_REGS 10
+/* Unhandled SEAs are taken to userspace */
+#define KVM_ARCH_FLAG_EXIT_SEA 11
+
#define KVM_DIRTY_LOG_MANUAL_CAPS (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \
KVM_DIRTY_LOG_INITIALLY_SET)
@@ -338,35 +368,6 @@ struct kvm_arch {
/* Protects VM-scoped configuration data */
struct mutex config_lock;
- /*
- * If we encounter a data abort without valid instruction syndrome
- * information, report this to user space. User space can (and
- * should) opt in to this feature if KVM_CAP_ARM_NISV_TO_USER is
- * supported.
- */
-#define KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER 0
- /* Memory Tagging Extension enabled for the guest */
-#define KVM_ARCH_FLAG_MTE_ENABLED 1
- /* At least one vCPU has ran in the VM */
-#define KVM_ARCH_FLAG_HAS_RAN_ONCE 2
- /* The vCPU feature set for the VM is configured */
-#define KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED 3
- /* PSCI SYSTEM_SUSPEND enabled for the guest */
-#define KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED 4
- /* VM counter offset */
-#define KVM_ARCH_FLAG_VM_COUNTER_OFFSET 5
- /* Timer PPIs made immutable */
-#define KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE 6
- /* Initial ID reg values loaded */
-#define KVM_ARCH_FLAG_ID_REGS_INITIALIZED 7
- /* Fine-Grained UNDEF initialised */
-#define KVM_ARCH_FLAG_FGU_INITIALIZED 8
- /* SVE exposed to guest */
-#define KVM_ARCH_FLAG_GUEST_HAS_SVE 9
- /* MIDR_EL1, REVIDR_EL1, and AIDR_EL1 are writable from userspace */
-#define KVM_ARCH_FLAG_WRITABLE_IMP_ID_REGS 10
- /* Unhandled SEAs are taken to userspace */
-#define KVM_ARCH_FLAG_EXIT_SEA 11
unsigned long flags;
/* VM-wide vCPU feature set */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 1aa601c95188..ab205f9db94a 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -1263,6 +1263,6 @@
FIELD_PREP(reg##_##field##_MASK, \
SYS_FIELD_VALUE(reg, field, val))
-#endif
+#endif /* __ASSEMBLER__ */
#endif /* __ASM_SYSREG_H */
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 10/33] arm64: Share arm64 headers with s390
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (8 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 09/33] arm64: Prepare sharing arm64 headers with s390 Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:20 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 11/33] KVM: arm64: Share arm64 code " Steffen Eiden
` (23 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Allow sharing of arm64 headers with s390 by marking the shared regions
or add a comment that the whole file is shared.
The shared regions are marked with:
#ifdef ARM64_S390_COMMON
/* insert shared definitions here */
#endif /* ARM64_S390_COMMON */
The preprocessor symbol ARM64_S390_COMMON is always defined for arm64.
s390 later will generate its own view of arm64 headers based on the
content inside the ifdef/endif block.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/arm64/Makefile | 2 ++
arch/arm64/include/asm/brk-imm.h | 1 +
arch/arm64/include/asm/esr.h | 1 +
arch/arm64/include/asm/kvm_arm.h | 1 +
arch/arm64/include/asm/kvm_emulate.h | 18 ++++++++++++++++++
arch/arm64/include/asm/kvm_host.h | 20 ++++++++++++++++++++
arch/arm64/include/asm/ptrace.h | 4 ++++
arch/arm64/include/asm/sysreg.h | 15 +++++++++++++++
8 files changed, 62 insertions(+)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 6b005c8fef70..1cd7cd94a855 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -43,7 +43,9 @@ CC_FLAGS_NO_FPU := -mgeneral-regs-only
KBUILD_CFLAGS += $(CC_FLAGS_NO_FPU) \
$(compat_vdso) $(cc_has_k_constraint)
KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
+KBUILD_CFLAGS += -DARM64_S390_COMMON
KBUILD_AFLAGS += $(compat_vdso)
+KBUILD_AFLAGS += -DARM64_S390_COMMON
ifeq ($(call rustc-min-version, 108500),y)
KBUILD_RUSTFLAGS += --target=aarch64-unknown-none-softfloat
diff --git a/arch/arm64/include/asm/brk-imm.h b/arch/arm64/include/asm/brk-imm.h
index beb42c62b6ac..dd2d153dc0d8 100644
--- a/arch/arm64/include/asm/brk-imm.h
+++ b/arch/arm64/include/asm/brk-imm.h
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2012 ARM Ltd.
*/
+/* Whole file is shared with s390 */
#ifndef __ASM_BRK_IMM_H
#define __ASM_BRK_IMM_H
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index da085c83b57e..2cb73bde7346 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -3,6 +3,7 @@
* Copyright (C) 2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
+/* Whole file is shared with s390 */
#ifndef __ASM_ESR_H
#define __ASM_ESR_H
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 57edd8437200..678f0daed445 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -3,6 +3,7 @@
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
+/* Whole file is shared with s390 */
#ifndef __ARM64_KVM_ARM_H__
#define __ARM64_KVM_ARM_H__
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index a34a9417ff4d..09f04a5686a1 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -47,6 +47,7 @@ void kvm_skip_instr32(struct kvm_vcpu *vcpu);
int kvm_inject_dabt_excl_atomic(struct kvm_vcpu *vcpu, u64 addr);
int kvm_inject_serror_esr(struct kvm_vcpu *vcpu, u64 esr);
+#ifdef ARM64_S390_COMMON
void kvm_inject_undefined(struct kvm_vcpu *vcpu);
void kvm_inject_sync(struct kvm_vcpu *vcpu, u64 esr);
int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr);
@@ -62,6 +63,8 @@ static inline int kvm_inject_sea_iabt(struct kvm_vcpu *vcpu, u64 addr)
return kvm_inject_sea(vcpu, true, addr);
}
+#endif /* ARM64_S390_COMMON */
+
static inline int kvm_inject_serror(struct kvm_vcpu *vcpu)
{
/*
@@ -185,6 +188,7 @@ static inline void vcpu_set_thumb(struct kvm_vcpu *vcpu)
*vcpu_cpsr(vcpu) |= PSR_AA32_T_BIT;
}
+#ifdef ARM64_S390_COMMON
/*
* vcpu_get_reg and vcpu_set_reg should always be passed a register number
* coming from a read of ESR_EL2. Otherwise, it may give the wrong result on
@@ -203,6 +207,8 @@ static __always_inline void vcpu_set_reg(struct kvm_vcpu *vcpu, u8 reg_num,
vcpu_gp_regs(vcpu)[reg_num] = val;
}
+#endif /* ARM64_S390_COMMON */
+
static inline bool vcpu_is_el2_ctxt(const struct kvm_cpu_context *ctxt)
{
switch (ctxt->regs.pstate & (PSR_MODE32_BIT | PSR_MODE_MASK)) {
@@ -405,6 +411,7 @@ static inline u64 kvm_vcpu_get_disr(const struct kvm_vcpu *vcpu)
return vcpu->arch.fault.disr_el1;
}
+#ifdef ARM64_S390_COMMON
static inline u32 kvm_vcpu_hvc_get_imm(const struct kvm_vcpu *vcpu)
{
return kvm_vcpu_get_esr(vcpu) & ESR_ELx_xVC_IMM_MASK;
@@ -482,6 +489,8 @@ static __always_inline u8 kvm_vcpu_trap_get_fault(const struct kvm_vcpu *vcpu)
return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC;
}
+#endif /* ARM64_S390_COMMON */
+
static inline
bool kvm_vcpu_trap_is_permission_fault(const struct kvm_vcpu *vcpu)
{
@@ -522,6 +531,7 @@ static __always_inline int kvm_vcpu_sys_get_rt(struct kvm_vcpu *vcpu)
return ESR_ELx_SYS64_ISS_RT(esr);
}
+#ifdef ARM64_S390_COMMON
static inline bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
{
if (kvm_vcpu_abt_iss1tw(vcpu)) {
@@ -546,6 +556,8 @@ static inline bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
return kvm_vcpu_dabt_iswrite(vcpu);
}
+#endif /* ARM64_S390_COMMON */
+
static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
{
return __vcpu_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
@@ -587,6 +599,7 @@ static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu)
return vcpu_read_sys_reg(vcpu, r) & bit;
}
+#ifdef ARM64_S390_COMMON
static inline unsigned long vcpu_data_guest_to_host(struct kvm_vcpu *vcpu,
unsigned long data,
unsigned int len)
@@ -662,6 +675,8 @@ static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
vcpu_set_flag((v), e); \
} while (0)
+#endif /* ARM64_S390_COMMON */
+
/*
* Returns a 'sanitised' view of CPTR_EL2, translating from nVHE to the VHE
* format if E2H isn't set.
@@ -768,6 +783,7 @@ static inline void kvm_reset_fpsimd(struct kvm_vcpu *vcpu)
memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
}
+#ifdef ARM64_S390_COMMON
/* Reset a vcpu's core registers. */
static inline void kvm_reset_vcpu_core(struct kvm_vcpu *vcpu)
{
@@ -792,6 +808,8 @@ static inline void kvm_reset_vcpu_core(struct kvm_vcpu *vcpu)
*vcpu_cpsr(vcpu) = pstate;
}
+#endif /* ARM64_S390_COMMON */
+
/* PSCI reset handling for a vcpu. */
static inline void kvm_reset_vcpu_psci(struct kvm_vcpu *vcpu,
struct vcpu_reset_state *reset_state)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 22770c1132cb..e6b3d42abb08 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -39,6 +39,7 @@
#define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS
+#ifdef ARM64_S390_COMMON
#define KVM_VCPU_MAX_FEATURES 10
#define KVM_VCPU_VALID_FEATURES (BIT(KVM_VCPU_MAX_FEATURES) - 1)
@@ -86,6 +87,8 @@
/* Unhandled SEAs are taken to userspace */
#define KVM_ARCH_FLAG_EXIT_SEA 11
+#endif /* ARM64_S390_COMMON */
+
#define KVM_DIRTY_LOG_MANUAL_CAPS (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \
KVM_DIRTY_LOG_INITIALLY_SET)
@@ -836,6 +839,8 @@ extern s64 kvm_nvhe_sym(hyp_physvirt_offset);
extern u64 kvm_nvhe_sym(hyp_cpu_logical_map)[NR_CPUS];
#define hyp_cpu_logical_map CHOOSE_NVHE_SYM(hyp_cpu_logical_map)
+#ifdef ARM64_S390_COMMON
+
struct vcpu_reset_state {
unsigned long pc;
unsigned long r0;
@@ -843,6 +848,8 @@ struct vcpu_reset_state {
bool reset;
};
+#endif /* ARM64_S390_COMMON */
+
struct vncr_tlb;
struct kvm_vcpu_arch {
@@ -952,6 +959,7 @@ struct kvm_vcpu_arch {
pid_t pid;
};
+#ifdef ARM64_S390_COMMON
/*
* Each 'flag' is composed of a comma-separated triplet:
*
@@ -1105,6 +1113,8 @@ struct kvm_vcpu_arch {
/* KVM is currently emulating an L2 to L1 exception */
#define IN_NESTED_EXCEPTION __vcpu_single_flag(sflags, BIT(9))
+#endif /* ARM64_S390_COMMON */
+
#define vcpu_sve_max_vq(vcpu) sve_vq_from_vl((vcpu)->arch.sve_max_vl)
#define vcpu_sve_zcr_elx(vcpu) \
@@ -1240,6 +1250,7 @@ struct kvm_vcpu_stat {
u64 exits;
};
+#ifdef ARM64_S390_COMMON
unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
@@ -1248,6 +1259,8 @@ int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu);
int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices);
+#endif /* ARM64_S390_COMMON */
+
int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
struct kvm_vcpu_events *events);
@@ -1326,6 +1339,7 @@ int __init populate_nv_trap_config(void);
void kvm_calculate_traps(struct kvm_vcpu *vcpu);
+#ifdef ARM64_S390_COMMON
/* MMIO helpers */
void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
@@ -1333,6 +1347,8 @@ unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
int kvm_handle_mmio_return(struct kvm_vcpu *vcpu);
int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa);
+#endif /* ARM64_S390_COMMON */
+
/*
* Returns true if a Performance Monitoring Interrupt (PMI), a.k.a. perf event,
* arrived in guest context. For arm64, any event that arrives while a vCPU is
@@ -1530,11 +1546,15 @@ static inline bool __vcpu_has_feature(const struct kvm_arch *ka, int feature)
return test_bit(feature, ka->vcpu_features);
}
+#ifdef ARM64_S390_COMMON
+
#define kvm_vcpu_has_feature(k, f) __vcpu_has_feature(&(k)->arch, (f))
#define vcpu_has_feature(v, f) __vcpu_has_feature(&(v)->kvm->arch, (f))
#define kvm_vcpu_initialized(v) vcpu_get_flag(v, VCPU_INITIALIZED)
+#endif /* ARM64_S390_COMMON */
+
int kvm_trng_call(struct kvm_vcpu *vcpu);
#ifdef CONFIG_KVM
extern phys_addr_t hyp_mem_base;
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index 49a83a0636b9..05c1307fa62f 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -26,6 +26,8 @@
#define GIC_PRIO_PSR_I_SET GICV3_PRIO_PSR_I_SET
+#ifdef ARM64_S390_COMMON
+
/* Additional SPSR bits not exposed in the UABI */
#define PSR_MODE_THREAD_BIT (1 << 0)
#define PSR_IL_BIT (1 << 20)
@@ -66,6 +68,8 @@
#define PSR_AA32_IT_MASK 0x0600fc00 /* If-Then execution state mask */
#define PSR_AA32_GE_MASK 0x000f0000
+#endif /* ARM64_S390_COMMON */
+
#ifdef CONFIG_CPU_BIG_ENDIAN
#define PSR_AA32_ENDSTATE PSR_AA32_E_BIT
#else
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index ab205f9db94a..1c5c4df260be 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -16,6 +16,8 @@
#include <asm/gpr-num.h>
+#ifdef ARM64_S390_COMMON
+
/*
* ARMv8 ARM reserves the following encoding for system registers:
* (Ref: ARMv8 ARM, Section: "System instruction class encoding overview",
@@ -50,6 +52,8 @@
#define sys_reg_CRm(id) (((id) >> CRm_shift) & CRm_mask)
#define sys_reg_Op2(id) (((id) >> Op2_shift) & Op2_mask)
+#endif /* ARM64_S390_COMMON */
+
#ifndef CONFIG_BROKEN_GAS_INST
#ifdef __ASSEMBLER__
@@ -123,6 +127,8 @@
#define GSB_SYS_BARRIER_INSN __SYS_BARRIER_INSN(1, 0, 12, 0, 0, 31)
#define GSB_ACK_BARRIER_INSN __SYS_BARRIER_INSN(1, 0, 12, 0, 1, 31)
+#ifdef ARM64_S390_COMMON
+
/* Data cache zero operations */
#define SYS_DC_ISW sys_insn(1, 0, 7, 6, 2)
#define SYS_DC_IGSW sys_insn(1, 0, 7, 6, 4)
@@ -832,6 +838,8 @@
#define SCTLR_ELx_A (BIT(1))
#define SCTLR_ELx_M (BIT(0))
+#endif /* ARM64_S390_COMMON */
+
#ifdef CONFIG_CPU_BIG_ENDIAN
#define ENDIAN_SET_EL2 SCTLR_ELx_EE
#else
@@ -866,6 +874,7 @@
SCTLR_EL1_LSMAOE | SCTLR_EL1_nTLSMD | SCTLR_EL1_EIS | \
SCTLR_EL1_TSCXT | SCTLR_EL1_EOS)
+#ifdef ARM64_S390_COMMON
/* MAIR_ELx memory attributes (used by Linux) */
#define MAIR_ATTR_DEVICE_nGnRnE UL(0x00)
#define MAIR_ATTR_DEVICE_nGnRE UL(0x04)
@@ -1102,6 +1111,8 @@
#define GICV5_GICR_CDNMIA_TYPE_MASK GENMASK_ULL(31, 29)
#define GICV5_GICR_CDNMIA_ID_MASK GENMASK_ULL(23, 0)
+#endif /* ARM64_S390_COMMON */
+
#define gicr_insn(insn) read_sysreg_s(GICV5_OP_GICR_##insn)
#define gic_insn(v, insn) write_sysreg_s(v, GICV5_OP_GIC_##insn)
@@ -1251,6 +1262,8 @@
par; \
})
+#ifdef ARM64_S390_COMMON
+
#define SYS_FIELD_VALUE(reg, field, val) reg##_##field##_##val
#define SYS_FIELD_GET(reg, field, val) \
@@ -1263,6 +1276,8 @@
FIELD_PREP(reg##_##field##_MASK, \
SYS_FIELD_VALUE(reg, field, val))
+#endif /* ARM64_S390_COMMON */
+
#endif /* __ASSEMBLER__ */
#endif /* __ASM_SYSREG_H */
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 10/33] arm64: Share arm64 headers with s390
2026-08-12 15:36 ` [PATCH v6 10/33] arm64: Share " Steffen Eiden
@ 2026-08-12 16:20 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:20 UTC (permalink / raw)
To: Steffen Eiden
Cc: linux-s390, kvm, kvmarm, Heiko Carstens, Oliver Upton,
Alexander Gordeev, Marc Zyngier, Christian Borntraeger,
Vasily Gorbik
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] Gating core arm64 macros behind `#ifdef ARM64_S390_COMMON` breaks userspace tooling (perf, KVM selftests, BPF) and creates inconsistent header views for linker scripts.
- [Medium] Using active C preprocessor `#ifdef` blocks as text-extraction markers for another architecture creates fragile coupling and pollutes the arm64 build system.
--
--- Patch [10]: [PATCH v6 10/33] arm64: Share arm64 headers with s390 ---
commit 20e1eb14886be076f6d4d8836cb6c7175057685e
Author: Steffen Eiden <seiden@linux.ibm.com>
arm64: Share arm64 headers with s390
Allow sharing of arm64 headers with s390 by marking the shared regions
or add a comment that the whole file is shared. The preprocessor symbol
ARM64_S390_COMMON is always defined for arm64.
> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
> index 6b005c8fef706..1cd7cd94a8554 100644
> --- a/arch/arm64/Makefile
> +++ b/arch/arm64/Makefile
> @@ -43,7 +43,9 @@ CC_FLAGS_NO_FPU := -mgeneral-regs-only
> KBUILD_CFLAGS += $(CC_FLAGS_NO_FPU) \
> $(compat_vdso) $(cc_has_k_constraint)
> KBUILD_CFLAGS += $(call cc-disable-warning, psabi)
> +KBUILD_CFLAGS += -DARM64_S390_COMMON
> KBUILD_AFLAGS += $(compat_vdso)
> +KBUILD_AFLAGS += -DARM64_S390_COMMON
[Severity: Medium]
Since this macro is injected into C and assembly compilation flags, does this
omit it from KBUILD_CPPFLAGS used for linker scripts?
Could this create an inconsistency where the C and assembly code sees the shared
blocks, but the linker script preprocessing silently strips them?
[ ... ]
> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
> index a34a9417ff4da..09f04a5686a18 100644
> --- a/arch/arm64/include/asm/kvm_emulate.h
> +++ b/arch/arm64/include/asm/kvm_emulate.h
> @@ -47,6 +47,7 @@ void kvm_skip_instr32(struct kvm_vcpu *vcpu);
> int kvm_inject_dabt_excl_atomic(struct kvm_vcpu *vcpu, u64 addr);
> int kvm_inject_serror_esr(struct kvm_vcpu *vcpu, u64 esr);
>
> +#ifdef ARM64_S390_COMMON
> void kvm_inject_undefined(struct kvm_vcpu *vcpu);
> void kvm_inject_sync(struct kvm_vcpu *vcpu, u64 esr);
[Severity: Medium]
Is using an active C preprocessor macro as a text-extraction marker for
another architecture a robust design?
By using an active ifdef to delineate text for an s390 extraction script, it
forces arm64 to modify its global Makefiles just to parse its own native
headers. Would it be safer to use specially formatted code comments for script
scraping to avoid altering C preprocessor semantics?
[ ... ]
> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
> index ab205f9db94ad..1c5c4df260bea 100644
> --- a/arch/arm64/include/asm/sysreg.h
> +++ b/arch/arm64/include/asm/sysreg.h
> @@ -16,6 +16,8 @@
>
> #include <asm/gpr-num.h>
>
> +#ifdef ARM64_S390_COMMON
> +
> /*
> * ARMv8 ARM reserves the following encoding for system registers:
> * (Ref: ARMv8 ARM, Section: "System instruction class encoding overview",
> @@ -50,6 +52,8 @@
> #define sys_reg_CRm(id) (((id) >> CRm_shift) & CRm_mask)
> #define sys_reg_Op2(id) (((id) >> Op2_shift) & Op2_mask)
>
> +#endif /* ARM64_S390_COMMON */
[Severity: Medium]
Will gating fundamental arm64 macros like sys_reg() behind this macro break
userspace tooling (such as perf, KVM selftests, and BPF)?
When these headers are synced to tools/, their independent Makefiles will not
inherit the kernel's KBUILD_CFLAGS. This means the macro is undefined and
core arm64 macros are completely hidden from those builds.
[ ... ]
> @@ -1251,6 +1262,8 @@
> par; \
> })
>
> +#ifdef ARM64_S390_COMMON
> +
> #define SYS_FIELD_VALUE(reg, field, val) reg##_##field##_##val
>
> #define SYS_FIELD_GET(reg, field, val) \
[Severity: Medium]
Similar to the sys_reg() macro above, does hiding widely used field-extraction
macros behind this conditional break builds for external tools that lack the
new compiler flag when headers are synced?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=10
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 11/33] KVM: arm64: Share arm64 code with s390
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (9 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 10/33] arm64: Share " Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:59 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 12/33] KVM: s390: Extract gmap tracing to a separate header Steffen Eiden
` (22 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Mark functions that s390 can use to implement arm on s390 as shared
functions.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/arm64/kvm/arm.c | 3 +++
arch/arm64/kvm/guest.c | 6 ++++++
arch/arm64/kvm/handle_exit.c | 6 ++++++
arch/arm64/kvm/mmio.c | 2 ++
4 files changed, 17 insertions(+)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 8b080804bc90..6b92a3c1d490 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1603,6 +1603,7 @@ static unsigned long system_supported_vcpu_features(void)
return features;
}
+#ifdef ARM64_S390_COMMON
static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu,
const struct kvm_vcpu_init *init)
{
@@ -1656,6 +1657,8 @@ static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu,
KVM_VCPU_MAX_FEATURES);
}
+#endif /* ARM64_S390_COMMON */
+
static int kvm_setup_vcpu(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 773f6c8e5026..6ca5a9f357cd 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -62,6 +62,7 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
sizeof(kvm_vcpu_stats_desc),
};
+#ifdef ARM64_S390_COMMON
static bool core_reg_offset_is_vreg(u64 off)
{
return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) &&
@@ -306,6 +307,8 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
return err;
}
+#endif /* ARM64_S390_COMMON */
+
#define vq_word(vq) (((vq) - SVE_VQ_MIN) / 64)
#define vq_mask(vq) ((u64)1 << ((vq) - SVE_VQ_MIN) % 64)
#define vq_present(vqs, vq) (!!((vqs)[vq_word(vq)] & vq_mask(vq)))
@@ -543,6 +546,7 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
return -EINVAL;
}
+#ifdef ARM64_S390_COMMON
static int copy_core_reg_indices(const struct kvm_vcpu *vcpu,
u64 __user *uindices)
{
@@ -591,6 +595,8 @@ static unsigned long num_core_regs(const struct kvm_vcpu *vcpu)
return copy_core_reg_indices(vcpu, NULL);
}
+#endif /* ARM64_S390_COMMON */
+
static unsigned long num_sve_regs(const struct kvm_vcpu *vcpu)
{
const unsigned int slices = vcpu_sve_slices(vcpu);
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 29108e5c0206..6a6ef2c074f4 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -213,6 +213,7 @@ static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu)
return 0;
}
+#ifdef ARM64_S390_COMMON
static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu)
{
u64 esr = kvm_vcpu_get_esr(vcpu);
@@ -224,6 +225,8 @@ static int kvm_handle_unknown_ec(struct kvm_vcpu *vcpu)
return 1;
}
+#endif /* ARM64_S390_COMMON */
+
/*
* Guest access to SVE registers should be routed to this handler only
* when the system doesn't support SVE.
@@ -404,6 +407,7 @@ static exit_handle_fn arm_exit_handlers[] = {
[ESR_ELx_EC_GCS] = kvm_handle_gcs,
};
+#ifdef ARM64_S390_COMMON
static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
{
u64 esr = kvm_vcpu_get_esr(vcpu);
@@ -439,6 +443,8 @@ static int handle_trap_exceptions(struct kvm_vcpu *vcpu)
return handled;
}
+#endif /* ARM64_S390_COMMON */
+
/*
* Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
* proper exit to userspace.
diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c
index d1c3a352d5a2..5161102da507 100644
--- a/arch/arm64/kvm/mmio.c
+++ b/arch/arm64/kvm/mmio.c
@@ -10,6 +10,7 @@
#include "trace.h"
+#ifdef ARM64_S390_COMMON
void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data)
{
void *datap = NULL;
@@ -258,3 +259,4 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
run->exit_reason = KVM_EXIT_MMIO;
return 0;
}
+#endif /* ARM64_S390_COMMON */
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 12/33] KVM: s390: Extract gmap tracing to a separate header
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (10 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 11/33] KVM: arm64: Share arm64 code " Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:57 ` sashiko-bot
2026-08-12 17:13 ` Christian Borntraeger
2026-08-12 15:36 ` [PATCH v6 13/33] KVM: s390: Prepare include guards for a new location Steffen Eiden
` (21 subsequent siblings)
33 siblings, 2 replies; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Move the kvm_s390_major_guest_pfault trace event from trace.h to a new
trace_gmap.h header. This separates gmap-specific tracing from general
KVM/s390 tracing, preparing for code sharing between multiple KVM
implementations.
The trace event definition is updated to use local defines for
parameters so that they can be replaced later with ease for when another
KVM implementation uses these traces.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/faultin.c | 3 ++-
arch/s390/kvm/trace.h | 14 ------------
arch/s390/kvm/trace_gmap.h | 47 ++++++++++++++++++++++++++++++++++++++
3 files changed, 49 insertions(+), 15 deletions(-)
create mode 100644 arch/s390/kvm/trace_gmap.h
diff --git a/arch/s390/kvm/faultin.c b/arch/s390/kvm/faultin.c
index 3cc45f7f5b2d..1dc79807012c 100644
--- a/arch/s390/kvm/faultin.c
+++ b/arch/s390/kvm/faultin.c
@@ -9,10 +9,11 @@
#include <linux/kvm_host.h>
#include "gmap.h"
-#include "trace.h"
#include "faultin.h"
bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu);
+#define CREATE_TRACE_POINTS
+#include "trace_gmap.h"
/*
* kvm_s390_faultin_gfn() - handle a dat fault.
diff --git a/arch/s390/kvm/trace.h b/arch/s390/kvm/trace.h
index dd2685c7df5b..3d2fffb1555a 100644
--- a/arch/s390/kvm/trace.h
+++ b/arch/s390/kvm/trace.h
@@ -45,20 +45,6 @@ TRACE_EVENT(kvm_s390_skey_related_inst,
VCPU_TP_PRINTK("%s", "storage key related instruction")
);
-TRACE_EVENT(kvm_s390_major_guest_pfault,
- TP_PROTO(VCPU_PROTO_COMMON),
- TP_ARGS(VCPU_ARGS_COMMON),
-
- TP_STRUCT__entry(
- VCPU_FIELD_COMMON
- ),
-
- TP_fast_assign(
- VCPU_ASSIGN_COMMON
- ),
- VCPU_TP_PRINTK("%s", "major fault, maybe applicable for pfault")
- );
-
TRACE_EVENT(kvm_s390_pfault_init,
TP_PROTO(VCPU_PROTO_COMMON, long pfault_token),
TP_ARGS(VCPU_ARGS_COMMON, pfault_token),
diff --git a/arch/s390/kvm/trace_gmap.h b/arch/s390/kvm/trace_gmap.h
new file mode 100644
index 000000000000..a3cad705021b
--- /dev/null
+++ b/arch/s390/kvm/trace_gmap.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if !defined(GMAP_TRACE_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define GMAP_TRACE_KVM_H
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM kvm
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace_gmap
+
+#define __KVM_FIELDS \
+ __field(unsigned long, pswmask) \
+ __field(unsigned long, pswaddr)
+#define __KVM_ASSIGN ({\
+ __entry->pswmask = vcpu->arch.sie_block->gpsw.mask; \
+ __entry->pswaddr = vcpu->arch.sie_block->gpsw.addr; \
+ })
+#define __KVM_PRINT \
+ __entry->pswmask,\
+ __entry->pswaddr
+
+TRACE_EVENT(kvm_s390_major_guest_pfault,
+ TP_PROTO(struct kvm_vcpu *vcpu),
+ TP_ARGS(vcpu),
+
+ TP_STRUCT__entry(
+ __field(int, id)
+ __KVM_FIELDS
+ ),
+
+ TP_fast_assign(
+ __entry->id = vcpu->vcpu_id;
+ __KVM_ASSIGN
+ ),
+ TP_printk("%02d[%016lx-%016lx]: major fault, maybe applicable for pfault",
+ __entry->id,
+ __KVM_PRINT
+ )
+ );
+
+#endif /* GMAP_TRACE_KVM_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 12/33] KVM: s390: Extract gmap tracing to a separate header
2026-08-12 15:36 ` [PATCH v6 12/33] KVM: s390: Extract gmap tracing to a separate header Steffen Eiden
@ 2026-08-12 15:57 ` sashiko-bot
2026-08-12 17:13 ` Christian Borntraeger
1 sibling, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 15:57 UTC (permalink / raw)
To: Steffen Eiden
Cc: Heiko Carstens, kvmarm, linux-s390, Vasily Gorbik,
Christian Borntraeger, kvm, Marc Zyngier, Oliver Upton,
Alexander Gordeev
> Move the kvm_s390_major_guest_pfault trace event from trace.h to a new
> trace_gmap.h header. This separates gmap-specific tracing from general
> KVM/s390 tracing, preparing for code sharing between multiple KVM
> implementations.
>
> The trace event definition is updated to use local defines for
> parameters so that they can be replaced later with ease for when another
> KVM implementation uses these traces.
>
> No functional change.
>
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=12
^ permalink raw reply [flat|nested] 70+ messages in thread
* Re: [PATCH v6 12/33] KVM: s390: Extract gmap tracing to a separate header
2026-08-12 15:36 ` [PATCH v6 12/33] KVM: s390: Extract gmap tracing to a separate header Steffen Eiden
2026-08-12 15:57 ` sashiko-bot
@ 2026-08-12 17:13 ` Christian Borntraeger
1 sibling, 0 replies; 70+ messages in thread
From: Christian Borntraeger @ 2026-08-12 17:13 UTC (permalink / raw)
To: Steffen Eiden, kvm, kvmarm, linux-arm-kernel, linux-kernel,
linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Claudio Imbrenda, David Hildenbrand,
Friedrich Welter, Fuad Tabba, Gautam Gala, Hariharan Mari,
Heiko Carstens, Hendrik Brueckner, Ilya Leoshkevich,
Janosch Frank, Joey Gouly, Marc Zyngier, Nico Boehr,
Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Am 12.08.26 um 17:36 schrieb Steffen Eiden:
> Move the kvm_s390_major_guest_pfault trace event from trace.h to a new
> trace_gmap.h header. This separates gmap-specific tracing from general
> KVM/s390 tracing, preparing for code sharing between multiple KVM
> implementations.
>
> The trace event definition is updated to use local defines for
> parameters so that they can be replaced later with ease for when another
> KVM implementation uses these traces.
>
> No functional change.
>
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
> ---
> arch/s390/kvm/faultin.c | 3 ++-
> arch/s390/kvm/trace.h | 14 ------------
> arch/s390/kvm/trace_gmap.h | 47 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 49 insertions(+), 15 deletions(-)
> create mode 100644 arch/s390/kvm/trace_gmap.h
>
> diff --git a/arch/s390/kvm/faultin.c b/arch/s390/kvm/faultin.c
> index 3cc45f7f5b2d..1dc79807012c 100644
> --- a/arch/s390/kvm/faultin.c
> +++ b/arch/s390/kvm/faultin.c
> @@ -9,10 +9,11 @@
> #include <linux/kvm_host.h>
>
> #include "gmap.h"
> -#include "trace.h"
> #include "faultin.h"
>
> bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu);
> +#define CREATE_TRACE_POINTS
> +#include "trace_gmap.h"
>
> /*
> * kvm_s390_faultin_gfn() - handle a dat fault.
> diff --git a/arch/s390/kvm/trace.h b/arch/s390/kvm/trace.h
> index dd2685c7df5b..3d2fffb1555a 100644
> --- a/arch/s390/kvm/trace.h
> +++ b/arch/s390/kvm/trace.h
> @@ -45,20 +45,6 @@ TRACE_EVENT(kvm_s390_skey_related_inst,
> VCPU_TP_PRINTK("%s", "storage key related instruction")
> );
>
> -TRACE_EVENT(kvm_s390_major_guest_pfault,
> - TP_PROTO(VCPU_PROTO_COMMON),
> - TP_ARGS(VCPU_ARGS_COMMON),
> -
> - TP_STRUCT__entry(
> - VCPU_FIELD_COMMON
> - ),
> -
> - TP_fast_assign(
> - VCPU_ASSIGN_COMMON
> - ),
> - VCPU_TP_PRINTK("%s", "major fault, maybe applicable for pfault")
> - );
> -
> TRACE_EVENT(kvm_s390_pfault_init,
> TP_PROTO(VCPU_PROTO_COMMON, long pfault_token),
> TP_ARGS(VCPU_ARGS_COMMON, pfault_token),
> diff --git a/arch/s390/kvm/trace_gmap.h b/arch/s390/kvm/trace_gmap.h
> new file mode 100644
> index 000000000000..a3cad705021b
> --- /dev/null
> +++ b/arch/s390/kvm/trace_gmap.h
> @@ -0,0 +1,47 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#if !defined(GMAP_TRACE_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define GMAP_TRACE_KVM_H
> +
> +#include <linux/tracepoint.h>
> +
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM kvm
> +#undef TRACE_INCLUDE_PATH
> +#define TRACE_INCLUDE_PATH .
> +#undef TRACE_INCLUDE_FILE
> +#define TRACE_INCLUDE_FILE trace_gmap
> +
> +#define __KVM_FIELDS \
> + __field(unsigned long, pswmask) \
> + __field(unsigned long, pswaddr)
> +#define __KVM_ASSIGN ({\
> + __entry->pswmask = vcpu->arch.sie_block->gpsw.mask; \
> + __entry->pswaddr = vcpu->arch.sie_block->gpsw.addr; \
> + })
> +#define __KVM_PRINT \
> + __entry->pswmask,\
> + __entry->pswaddr
> +
> +TRACE_EVENT(kvm_s390_major_guest_pfault,
> + TP_PROTO(struct kvm_vcpu *vcpu),
> + TP_ARGS(vcpu),
> +
> + TP_STRUCT__entry(
> + __field(int, id)
> + __KVM_FIELDS
> + ),
> +
> + TP_fast_assign(
> + __entry->id = vcpu->vcpu_id;
> + __KVM_ASSIGN
> + ),
> + TP_printk("%02d[%016lx-%016lx]: major fault, maybe applicable for pfault",
> + __entry->id,
> + __KVM_PRINT
> + )
> + );
> +
> +#endif /* GMAP_TRACE_KVM_H */
> +
> +/* This part must be outside protection */
> +#include <trace/define_trace.h>
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 13/33] KVM: s390: Prepare include guards for a new location
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (11 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 12/33] KVM: s390: Extract gmap tracing to a separate header Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:53 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 14/33] KVM: s390: Rename kvm-s390.{c,h} to s390.{c,h} Steffen Eiden
` (20 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Update include guard names in dat.h, faultin.h, and gmap.h to
ARCH_KVM_GMAP_* to reflect their upcoming relocation to a shared gmap
directory.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/dat.h | 6 +++---
arch/s390/kvm/faultin.h | 6 +++---
arch/s390/kvm/gmap.h | 6 +++---
3 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/s390/kvm/dat.h b/arch/s390/kvm/dat.h
index 141ee7b9f019..87108f51228e 100644
--- a/arch/s390/kvm/dat.h
+++ b/arch/s390/kvm/dat.h
@@ -6,8 +6,8 @@
* Author(s): Claudio Imbrenda <imbrenda@linux.ibm.com>
*/
-#ifndef __KVM_S390_DAT_H
-#define __KVM_S390_DAT_H
+#ifndef ARCH_KVM_GMAP_DAT_H
+#define ARCH_KVM_GMAP_DAT_H
#include <linux/radix-tree.h>
#include <linux/refcount.h>
@@ -975,4 +975,4 @@ static inline bool crste_is_ucas(union crste crste)
return is_pmd(crste) && crste.h.i && crste.h.fc0.tl == 1 && crste.h.fc == 0;
}
-#endif /* __KVM_S390_DAT_H */
+#endif /* ARCH_KVM_GMAP_DAT_H */
diff --git a/arch/s390/kvm/faultin.h b/arch/s390/kvm/faultin.h
index f86176d2769c..f343b6fb6f16 100644
--- a/arch/s390/kvm/faultin.h
+++ b/arch/s390/kvm/faultin.h
@@ -6,8 +6,8 @@
* Author(s): Claudio Imbrenda <imbrenda@linux.ibm.com>
*/
-#ifndef __KVM_S390_FAULTIN_H
-#define __KVM_S390_FAULTIN_H
+#ifndef ARCH_KVM_GMAP_FAULTIN_H
+#define ARCH_KVM_GMAP_FAULTIN_H
#include <linux/kvm_host.h>
@@ -89,4 +89,4 @@ static inline int kvm_s390_get_guest_pages(struct kvm *kvm, struct guest_fault *
#define kvm_s390_array_needs_retry_safe(kvm, seq, array) \
kvm_s390_multiple_faults_need_retry(kvm, seq, array, ARRAY_SIZE(array), false)
-#endif /* __KVM_S390_FAULTIN_H */
+#endif /* ARCH_KVM_GMAP_FAULTIN_H */
diff --git a/arch/s390/kvm/gmap.h b/arch/s390/kvm/gmap.h
index 39938d363ec9..c54c35e47d6d 100644
--- a/arch/s390/kvm/gmap.h
+++ b/arch/s390/kvm/gmap.h
@@ -7,8 +7,8 @@
* Claudio Imbrenda <imbrenda@linux.ibm.com>
*/
-#ifndef ARCH_KVM_S390_GMAP_H
-#define ARCH_KVM_S390_GMAP_H
+#ifndef ARCH_KVM_GMAP_GMAP_H
+#define ARCH_KVM_GMAP_GMAP_H
#include "dat.h"
@@ -330,4 +330,4 @@ static inline bool gmap_is_shadow_valid(struct gmap *sg, union asce asce, int ed
return sg->guest_asce.val == asce.val && sg->edat_level == edat_level;
}
-#endif /* ARCH_KVM_S390_GMAP_H */
+#endif /* ARCH_KVM_GMAP_GMAP_H */
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 13/33] KVM: s390: Prepare include guards for a new location
2026-08-12 15:36 ` [PATCH v6 13/33] KVM: s390: Prepare include guards for a new location Steffen Eiden
@ 2026-08-12 15:53 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 15:53 UTC (permalink / raw)
To: Steffen Eiden
Cc: kvm, Christian Borntraeger, Marc Zyngier, linux-s390,
Heiko Carstens, Vasily Gorbik, Oliver Upton, kvmarm,
Alexander Gordeev
> Update include guard names in dat.h, faultin.h, and gmap.h to
> ARCH_KVM_GMAP_* to reflect their upcoming relocation to a shared gmap
> directory.
>
> No functional change.
>
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=13
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 14/33] KVM: s390: Rename kvm-s390.{c,h} to s390.{c,h}
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (12 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 13/33] KVM: s390: Prepare include guards for a new location Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:58 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 15/33] KVM: s390: Move kvm_host definitions to kvm_host_s390 Steffen Eiden
` (19 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Rename kvm-s390.c to s390.c and kvm-s390.h to s390.h for consistency
with the new directory structure. Update all include statements and
simplify Makefile ccflags from explicit paths to -I$(src).
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/Makefile | 4 ++--
arch/s390/kvm/diag.c | 2 +-
arch/s390/kvm/gaccess.c | 2 +-
arch/s390/kvm/gaccess.h | 2 +-
arch/s390/kvm/gmap.c | 2 +-
arch/s390/kvm/guestdbg.c | 2 +-
arch/s390/kvm/intercept.c | 2 +-
arch/s390/kvm/interrupt.c | 2 +-
arch/s390/kvm/pci.c | 2 +-
arch/s390/kvm/priv.c | 2 +-
arch/s390/kvm/pv.c | 2 +-
arch/s390/kvm/{kvm-s390.c => s390.c} | 2 +-
arch/s390/kvm/{kvm-s390.h => s390.h} | 2 +-
arch/s390/kvm/sigp.c | 2 +-
arch/s390/kvm/vsie.c | 2 +-
15 files changed, 16 insertions(+), 16 deletions(-)
rename arch/s390/kvm/{kvm-s390.c => s390.c} (99%)
rename arch/s390/kvm/{kvm-s390.h => s390.h} (99%)
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index dac9d53b23d8..961de97b8e80 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -5,9 +5,9 @@
include $(srctree)/virt/kvm/Makefile.kvm
-ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
+ccflags-y := -I$(src)
-kvm-y += kvm-s390.o intercept.o interrupt.o priv.o sigp.o
+kvm-y += s390.o intercept.o interrupt.o priv.o sigp.o
kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o
kvm-y += dat.o gmap.o faultin.o
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c
index 031ab6e5d6c4..09033c8ff1bb 100644
--- a/arch/s390/kvm/diag.c
+++ b/arch/s390/kvm/diag.c
@@ -12,7 +12,7 @@
#include <linux/kvm_host.h>
#include <asm/gmap_helpers.h>
#include <asm/virtio-ccw.h>
-#include "kvm-s390.h"
+#include "s390.h"
#include "trace.h"
#include "trace-s390.h"
#include "gaccess.h"
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index 0d389a302a70..e5c064f263df 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -17,7 +17,7 @@
#include <asm/access-regs.h>
#include <asm/fault.h>
#include <asm/dat-bits.h>
-#include "kvm-s390.h"
+#include "s390.h"
#include "dat.h"
#include "gmap.h"
#include "gaccess.h"
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/gaccess.h
index b5385cec60f4..ef922b3b4990 100644
--- a/arch/s390/kvm/gaccess.h
+++ b/arch/s390/kvm/gaccess.h
@@ -14,7 +14,7 @@
#include <linux/kvm_host.h>
#include <linux/uaccess.h>
#include <linux/ptrace.h>
-#include "kvm-s390.h"
+#include "s390.h"
/**
* kvm_s390_real_to_abs - convert guest real address to guest absolute address
diff --git a/arch/s390/kvm/gmap.c b/arch/s390/kvm/gmap.c
index 3758e4009709..b5b920392378 100644
--- a/arch/s390/kvm/gmap.c
+++ b/arch/s390/kvm/gmap.c
@@ -21,7 +21,7 @@
#include "dat.h"
#include "gmap.h"
-#include "kvm-s390.h"
+#include "s390.h"
#include "faultin.h"
static inline bool kvm_s390_is_in_sie(struct kvm_vcpu *vcpu)
diff --git a/arch/s390/kvm/guestdbg.c b/arch/s390/kvm/guestdbg.c
index 9a6149e310bb..1bf7e91b7e61 100644
--- a/arch/s390/kvm/guestdbg.c
+++ b/arch/s390/kvm/guestdbg.c
@@ -8,7 +8,7 @@
*/
#include <linux/kvm_host.h>
#include <linux/errno.h>
-#include "kvm-s390.h"
+#include "s390.h"
#include "gaccess.h"
/*
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 1980df61ef30..ca1205dfac8b 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -17,7 +17,7 @@
#include <asm/sysinfo.h>
#include <asm/uv.h>
-#include "kvm-s390.h"
+#include "s390.h"
#include "gaccess.h"
#include "trace.h"
#include "trace-s390.h"
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 0d9fbe75dc66..9aa786952718 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -29,7 +29,7 @@
#include <asm/nmi.h>
#include <asm/airq.h>
#include <asm/tpi.h>
-#include "kvm-s390.h"
+#include "s390.h"
#include "gaccess.h"
#include "trace-s390.h"
#include "pci.h"
diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
index 50f5ec79600e..82892e1e03d9 100644
--- a/arch/s390/kvm/pci.c
+++ b/arch/s390/kvm/pci.c
@@ -14,7 +14,7 @@
#include <asm/pci_io.h>
#include <asm/sclp.h>
#include "pci.h"
-#include "kvm-s390.h"
+#include "s390.h"
struct zpci_aift *aift;
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index b1ba24c346ef..b3cb2c2c3aa7 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -26,7 +26,7 @@
#include <asm/ap.h>
#include <asm/gmap_helpers.h>
#include "gaccess.h"
-#include "kvm-s390.h"
+#include "s390.h"
#include "trace.h"
#include "gmap.h"
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index f549b161b972..7adfdc9b62be 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -18,7 +18,7 @@
#include <linux/sched/mm.h>
#include <linux/mmu_notifier.h>
#include <asm/gmap_helpers.h>
-#include "kvm-s390.h"
+#include "s390.h"
#include "dat.h"
#include "gaccess.h"
#include "gmap.h"
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/s390.c
similarity index 99%
rename from arch/s390/kvm/kvm-s390.c
rename to arch/s390/kvm/s390.c
index 4faff6625da3..ff09ffc10f0d 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/s390.c
@@ -50,7 +50,7 @@
#include <asm/fpu.h>
#include <asm/ap.h>
#include <asm/uv.h>
-#include "kvm-s390.h"
+#include "s390.h"
#include "gaccess.h"
#include "gmap.h"
#include "faultin.h"
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/s390.h
similarity index 99%
rename from arch/s390/kvm/kvm-s390.h
rename to arch/s390/kvm/s390.h
index 6d2842fb71a3..e144ca2e6d5e 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/s390.h
@@ -452,7 +452,7 @@ void kvm_s390_vsie_destroy(struct kvm *kvm);
int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu);
int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu);
-/* implemented in kvm-s390.c */
+/* implemented in s390.c */
int kvm_s390_try_set_tod_clock(struct kvm *kvm, const struct kvm_s390_vm_tod_clock *gtod);
int kvm_s390_store_status_unloaded(struct kvm_vcpu *vcpu, unsigned long addr);
int kvm_s390_vcpu_store_status(struct kvm_vcpu *vcpu, unsigned long addr);
diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c
index 55c34cb35428..131b3371ef4f 100644
--- a/arch/s390/kvm/sigp.c
+++ b/arch/s390/kvm/sigp.c
@@ -14,7 +14,7 @@
#include <linux/slab.h>
#include <asm/sigp.h>
#include "gaccess.h"
-#include "kvm-s390.h"
+#include "s390.h"
#include "trace.h"
static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index f546239d8ff8..cc94ede0621f 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -23,7 +23,7 @@
#include <asm/nmi.h>
#include <asm/dis.h>
#include <asm/facility.h>
-#include "kvm-s390.h"
+#include "s390.h"
#include "gaccess.h"
#include "gmap.h"
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 14/33] KVM: s390: Rename kvm-s390.{c,h} to s390.{c,h}
2026-08-12 15:36 ` [PATCH v6 14/33] KVM: s390: Rename kvm-s390.{c,h} to s390.{c,h} Steffen Eiden
@ 2026-08-12 15:58 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 15:58 UTC (permalink / raw)
To: Steffen Eiden
Cc: Vasily Gorbik, linux-s390, kvmarm, Oliver Upton, kvm,
Marc Zyngier, Christian Borntraeger, Alexander Gordeev,
Heiko Carstens
> Rename kvm-s390.c to s390.c and kvm-s390.h to s390.h for consistency
> with the new directory structure. Update all include statements and
> simplify Makefile ccflags from explicit paths to -I$(src).
>
> No functional change.
>
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=14
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 15/33] KVM: s390: Move kvm_host definitions to kvm_host_s390
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (13 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 14/33] KVM: s390: Rename kvm-s390.{c,h} to s390.{c,h} Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 15:54 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 16/33] KVM: s390: Move s390 kvm code into a subdirectory Steffen Eiden
` (18 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Rename kvm_host.h to kvm_host_s390.h and kvm_host_types.h to
kvm_host_s390_types.h to distinguish s390-specific KVM definitions
from the generic kvm_host.h that will be used for shared definitions.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/include/asm/kvm_host.h | 780 +-----------------
.../asm/{kvm_host.h => kvm_host_s390.h} | 6 +-
...kvm_host_types.h => kvm_host_s390_types.h} | 6 +-
arch/s390/include/asm/kvm_host_types.h | 349 +-------
4 files changed, 12 insertions(+), 1129 deletions(-)
copy arch/s390/include/asm/{kvm_host.h => kvm_host_s390.h} (99%)
copy arch/s390/include/asm/{kvm_host_types.h => kvm_host_s390_types.h} (98%)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index b4182ca4435f..e76ceee11ef5 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -1,784 +1,8 @@
/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * definition for kernel virtual machines on s390
- *
- * Copyright IBM Corp. 2008, 2018
- *
- * Author(s): Carsten Otte <cotte@de.ibm.com>
- */
-
#ifndef ASM_KVM_HOST_H
#define ASM_KVM_HOST_H
-#include <linux/types.h>
-#include <linux/hrtimer.h>
-#include <linux/interrupt.h>
-#include <linux/kvm_types.h>
-#include <linux/kvm.h>
-#include <linux/seqlock.h>
-#include <linux/module.h>
-#include <linux/pci.h>
-#include <linux/mmu_notifier.h>
-#include <asm/kvm_host_types.h>
-#include <asm/debug.h>
-#include <asm/cpu.h>
-#include <asm/fpu.h>
-#include <asm/isc.h>
-#include <asm/guarded_storage.h>
-
-#define KVM_HAVE_MMU_RWLOCK
-#define KVM_MAX_VCPUS 255
-
-#define KVM_INTERNAL_MEM_SLOTS 1
-
-/*
- * These seem to be used for allocating ->chip in the routing table, which we
- * don't use. 1 is as small as we can get to reduce the needed memory. If we
- * need to look at ->chip later on, we'll need to revisit this.
- */
-#define KVM_NR_IRQCHIPS 1
-#define KVM_IRQCHIP_NUM_PINS 1
-#define KVM_HALT_POLL_NS_DEFAULT 50000
-
-/* s390-specific vcpu->requests bit members */
-#define KVM_REQ_ENABLE_IBS KVM_ARCH_REQ(0)
-#define KVM_REQ_DISABLE_IBS KVM_ARCH_REQ(1)
-#define KVM_REQ_ICPT_OPEREXC KVM_ARCH_REQ(2)
-#define KVM_REQ_START_MIGRATION KVM_ARCH_REQ(3)
-#define KVM_REQ_STOP_MIGRATION KVM_ARCH_REQ(4)
-#define KVM_REQ_VSIE_RESTART KVM_ARCH_REQ(5)
-#define KVM_REQ_REFRESH_GUEST_PREFIX \
- KVM_ARCH_REQ_FLAGS(6, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
-
-struct kvm_vcpu_stat {
- struct kvm_vcpu_stat_generic generic;
- u64 exit_userspace;
- u64 exit_null;
- u64 exit_external_request;
- u64 exit_io_request;
- u64 exit_external_interrupt;
- u64 exit_stop_request;
- u64 exit_validity;
- u64 exit_instruction;
- u64 exit_pei;
- u64 halt_no_poll_steal;
- u64 instruction_lctl;
- u64 instruction_lctlg;
- u64 instruction_stctl;
- u64 instruction_stctg;
- u64 exit_program_interruption;
- u64 exit_instr_and_program;
- u64 exit_operation_exception;
- u64 deliver_ckc;
- u64 deliver_cputm;
- u64 deliver_external_call;
- u64 deliver_emergency_signal;
- u64 deliver_service_signal;
- u64 deliver_virtio;
- u64 deliver_stop_signal;
- u64 deliver_prefix_signal;
- u64 deliver_restart_signal;
- u64 deliver_program;
- u64 deliver_io;
- u64 deliver_machine_check;
- u64 exit_wait_state;
- u64 inject_ckc;
- u64 inject_cputm;
- u64 inject_external_call;
- u64 inject_emergency_signal;
- u64 inject_mchk;
- u64 inject_pfault_init;
- u64 inject_program;
- u64 inject_restart;
- u64 inject_set_prefix;
- u64 inject_stop_signal;
- u64 instruction_epsw;
- u64 instruction_gs;
- u64 instruction_io_other;
- u64 instruction_lpsw;
- u64 instruction_lpswe;
- u64 instruction_lpswey;
- u64 instruction_pfmf;
- u64 instruction_ptff;
- u64 instruction_sck;
- u64 instruction_sckpf;
- u64 instruction_stidp;
- u64 instruction_spx;
- u64 instruction_stpx;
- u64 instruction_stap;
- u64 instruction_iske;
- u64 instruction_ri;
- u64 instruction_rrbe;
- u64 instruction_sske;
- u64 instruction_ipte_interlock;
- u64 instruction_stsi;
- u64 instruction_stfl;
- u64 instruction_tb;
- u64 instruction_tpi;
- u64 instruction_tprot;
- u64 instruction_tsch;
- u64 instruction_sie;
- u64 instruction_essa;
- u64 instruction_sthyi;
- u64 instruction_sigp_sense;
- u64 instruction_sigp_sense_running;
- u64 instruction_sigp_external_call;
- u64 instruction_sigp_emergency;
- u64 instruction_sigp_cond_emergency;
- u64 instruction_sigp_start;
- u64 instruction_sigp_stop;
- u64 instruction_sigp_stop_store_status;
- u64 instruction_sigp_store_status;
- u64 instruction_sigp_store_adtl_status;
- u64 instruction_sigp_arch;
- u64 instruction_sigp_prefix;
- u64 instruction_sigp_restart;
- u64 instruction_sigp_init_cpu_reset;
- u64 instruction_sigp_cpu_reset;
- u64 instruction_sigp_unknown;
- u64 instruction_diagnose_10;
- u64 instruction_diagnose_44;
- u64 instruction_diagnose_9c;
- u64 diag_9c_ignored;
- u64 diag_9c_forward;
- u64 instruction_diagnose_258;
- u64 instruction_diagnose_308;
- u64 instruction_diagnose_500;
- u64 instruction_diagnose_other;
- u64 pfault_sync;
- u64 signal_exits;
-};
-
-#define PGM_OPERATION 0x01
-#define PGM_PRIVILEGED_OP 0x02
-#define PGM_EXECUTE 0x03
-#define PGM_PROTECTION 0x04
-#define PGM_ADDRESSING 0x05
-#define PGM_SPECIFICATION 0x06
-#define PGM_DATA 0x07
-#define PGM_FIXED_POINT_OVERFLOW 0x08
-#define PGM_FIXED_POINT_DIVIDE 0x09
-#define PGM_DECIMAL_OVERFLOW 0x0a
-#define PGM_DECIMAL_DIVIDE 0x0b
-#define PGM_HFP_EXPONENT_OVERFLOW 0x0c
-#define PGM_HFP_EXPONENT_UNDERFLOW 0x0d
-#define PGM_HFP_SIGNIFICANCE 0x0e
-#define PGM_HFP_DIVIDE 0x0f
-#define PGM_SEGMENT_TRANSLATION 0x10
-#define PGM_PAGE_TRANSLATION 0x11
-#define PGM_TRANSLATION_SPEC 0x12
-#define PGM_SPECIAL_OPERATION 0x13
-#define PGM_OPERAND 0x15
-#define PGM_TRACE_TABEL 0x16
-#define PGM_VECTOR_PROCESSING 0x1b
-#define PGM_SPACE_SWITCH 0x1c
-#define PGM_HFP_SQUARE_ROOT 0x1d
-#define PGM_PC_TRANSLATION_SPEC 0x1f
-#define PGM_AFX_TRANSLATION 0x20
-#define PGM_ASX_TRANSLATION 0x21
-#define PGM_LX_TRANSLATION 0x22
-#define PGM_EX_TRANSLATION 0x23
-#define PGM_PRIMARY_AUTHORITY 0x24
-#define PGM_SECONDARY_AUTHORITY 0x25
-#define PGM_LFX_TRANSLATION 0x26
-#define PGM_LSX_TRANSLATION 0x27
-#define PGM_ALET_SPECIFICATION 0x28
-#define PGM_ALEN_TRANSLATION 0x29
-#define PGM_ALE_SEQUENCE 0x2a
-#define PGM_ASTE_VALIDITY 0x2b
-#define PGM_ASTE_SEQUENCE 0x2c
-#define PGM_EXTENDED_AUTHORITY 0x2d
-#define PGM_LSTE_SEQUENCE 0x2e
-#define PGM_ASTE_INSTANCE 0x2f
-#define PGM_STACK_FULL 0x30
-#define PGM_STACK_EMPTY 0x31
-#define PGM_STACK_SPECIFICATION 0x32
-#define PGM_STACK_TYPE 0x33
-#define PGM_STACK_OPERATION 0x34
-#define PGM_ASCE_TYPE 0x38
-#define PGM_REGION_FIRST_TRANS 0x39
-#define PGM_REGION_SECOND_TRANS 0x3a
-#define PGM_REGION_THIRD_TRANS 0x3b
-#define PGM_SECURE_STORAGE_ACCESS 0x3d
-#define PGM_NON_SECURE_STORAGE_ACCESS 0x3e
-#define PGM_SECURE_STORAGE_VIOLATION 0x3f
-#define PGM_MONITOR 0x40
-#define PGM_PER 0x80
-#define PGM_CRYPTO_OPERATION 0x119
-
-/* irq types in ascend order of priorities */
-enum irq_types {
- IRQ_PEND_SET_PREFIX = 0,
- IRQ_PEND_RESTART,
- IRQ_PEND_SIGP_STOP,
- IRQ_PEND_IO_ISC_7,
- IRQ_PEND_IO_ISC_6,
- IRQ_PEND_IO_ISC_5,
- IRQ_PEND_IO_ISC_4,
- IRQ_PEND_IO_ISC_3,
- IRQ_PEND_IO_ISC_2,
- IRQ_PEND_IO_ISC_1,
- IRQ_PEND_IO_ISC_0,
- IRQ_PEND_VIRTIO,
- IRQ_PEND_PFAULT_DONE,
- IRQ_PEND_PFAULT_INIT,
- IRQ_PEND_EXT_HOST,
- IRQ_PEND_EXT_SERVICE,
- IRQ_PEND_EXT_SERVICE_EV,
- IRQ_PEND_EXT_TIMING,
- IRQ_PEND_EXT_CPU_TIMER,
- IRQ_PEND_EXT_CLOCK_COMP,
- IRQ_PEND_EXT_EXTERNAL,
- IRQ_PEND_EXT_EMERGENCY,
- IRQ_PEND_EXT_MALFUNC,
- IRQ_PEND_EXT_IRQ_KEY,
- IRQ_PEND_MCHK_REP,
- IRQ_PEND_PROG,
- IRQ_PEND_SVC,
- IRQ_PEND_MCHK_EX,
- IRQ_PEND_COUNT
-};
-
-/* We have 2M for virtio device descriptor pages. Smallest amount of
- * memory per page is 24 bytes (1 queue), so (2048*1024) / 24 = 87381
- */
-#define KVM_S390_MAX_VIRTIO_IRQS 87381
-
-/*
- * Repressible (non-floating) machine check interrupts
- * subclass bits in MCIC
- */
-#define MCHK_EXTD_BIT 58
-#define MCHK_DEGR_BIT 56
-#define MCHK_WARN_BIT 55
-#define MCHK_REP_MASK ((1UL << MCHK_DEGR_BIT) | \
- (1UL << MCHK_EXTD_BIT) | \
- (1UL << MCHK_WARN_BIT))
-
-/* Exigent machine check interrupts subclass bits in MCIC */
-#define MCHK_SD_BIT 63
-#define MCHK_PD_BIT 62
-#define MCHK_EX_MASK ((1UL << MCHK_SD_BIT) | (1UL << MCHK_PD_BIT))
-
-#define IRQ_PEND_EXT_MASK ((1UL << IRQ_PEND_EXT_IRQ_KEY) | \
- (1UL << IRQ_PEND_EXT_CLOCK_COMP) | \
- (1UL << IRQ_PEND_EXT_CPU_TIMER) | \
- (1UL << IRQ_PEND_EXT_MALFUNC) | \
- (1UL << IRQ_PEND_EXT_EMERGENCY) | \
- (1UL << IRQ_PEND_EXT_EXTERNAL) | \
- (1UL << IRQ_PEND_EXT_TIMING) | \
- (1UL << IRQ_PEND_EXT_HOST) | \
- (1UL << IRQ_PEND_EXT_SERVICE) | \
- (1UL << IRQ_PEND_EXT_SERVICE_EV) | \
- (1UL << IRQ_PEND_VIRTIO) | \
- (1UL << IRQ_PEND_PFAULT_INIT) | \
- (1UL << IRQ_PEND_PFAULT_DONE))
-
-#define IRQ_PEND_IO_MASK ((1UL << IRQ_PEND_IO_ISC_0) | \
- (1UL << IRQ_PEND_IO_ISC_1) | \
- (1UL << IRQ_PEND_IO_ISC_2) | \
- (1UL << IRQ_PEND_IO_ISC_3) | \
- (1UL << IRQ_PEND_IO_ISC_4) | \
- (1UL << IRQ_PEND_IO_ISC_5) | \
- (1UL << IRQ_PEND_IO_ISC_6) | \
- (1UL << IRQ_PEND_IO_ISC_7))
-
-#define IRQ_PEND_MCHK_MASK ((1UL << IRQ_PEND_MCHK_REP) | \
- (1UL << IRQ_PEND_MCHK_EX))
-
-#define IRQ_PEND_EXT_II_MASK ((1UL << IRQ_PEND_EXT_CPU_TIMER) | \
- (1UL << IRQ_PEND_EXT_CLOCK_COMP) | \
- (1UL << IRQ_PEND_EXT_EMERGENCY) | \
- (1UL << IRQ_PEND_EXT_EXTERNAL) | \
- (1UL << IRQ_PEND_EXT_SERVICE) | \
- (1UL << IRQ_PEND_EXT_SERVICE_EV))
-
-struct kvm_s390_interrupt_info {
- struct list_head list;
- u64 type;
- union {
- struct kvm_s390_io_info io;
- struct kvm_s390_ext_info ext;
- struct kvm_s390_pgm_info pgm;
- struct kvm_s390_emerg_info emerg;
- struct kvm_s390_extcall_info extcall;
- struct kvm_s390_prefix_info prefix;
- struct kvm_s390_stop_info stop;
- struct kvm_s390_mchk_info mchk;
- };
-};
-
-struct kvm_s390_irq_payload {
- struct kvm_s390_io_info io;
- struct kvm_s390_ext_info ext;
- struct kvm_s390_pgm_info pgm;
- struct kvm_s390_emerg_info emerg;
- struct kvm_s390_extcall_info extcall;
- struct kvm_s390_prefix_info prefix;
- struct kvm_s390_stop_info stop;
- struct kvm_s390_mchk_info mchk;
-};
-
-struct kvm_s390_local_interrupt {
- spinlock_t lock;
- DECLARE_BITMAP(sigp_emerg_pending, KVM_MAX_VCPUS);
- struct kvm_s390_irq_payload irq;
- unsigned long pending_irqs;
-};
-
-#define FIRQ_LIST_IO_ISC_0 0
-#define FIRQ_LIST_IO_ISC_1 1
-#define FIRQ_LIST_IO_ISC_2 2
-#define FIRQ_LIST_IO_ISC_3 3
-#define FIRQ_LIST_IO_ISC_4 4
-#define FIRQ_LIST_IO_ISC_5 5
-#define FIRQ_LIST_IO_ISC_6 6
-#define FIRQ_LIST_IO_ISC_7 7
-#define FIRQ_LIST_PFAULT 8
-#define FIRQ_LIST_VIRTIO 9
-#define FIRQ_LIST_COUNT 10
-#define FIRQ_CNTR_IO 0
-#define FIRQ_CNTR_SERVICE 1
-#define FIRQ_CNTR_VIRTIO 2
-#define FIRQ_CNTR_PFAULT 3
-#define FIRQ_MAX_COUNT 4
-
-/* mask the AIS mode for a given ISC */
-#define AIS_MODE_MASK(isc) (0x80 >> isc)
-
-#define KVM_S390_AIS_MODE_ALL 0
-#define KVM_S390_AIS_MODE_SINGLE 1
-
-struct kvm_s390_float_interrupt {
- unsigned long pending_irqs;
- unsigned long masked_irqs;
- spinlock_t lock;
- struct list_head lists[FIRQ_LIST_COUNT];
- int counters[FIRQ_MAX_COUNT];
- struct kvm_s390_mchk_info mchk;
- struct kvm_s390_ext_info srv_signal;
- int last_sleep_cpu;
- spinlock_t ais_lock;
- u8 simm;
- u8 nimm;
-};
-
-struct kvm_hw_wp_info_arch {
- unsigned long addr;
- unsigned long phys_addr;
- int len;
- char *old_data;
-};
-
-struct kvm_hw_bp_info_arch {
- unsigned long addr;
- int len;
-};
-
-/*
- * Only the upper 16 bits of kvm_guest_debug->control are arch specific.
- * Further KVM_GUESTDBG flags which an be used from userspace can be found in
- * arch/s390/include/uapi/asm/kvm.h
- */
-#define KVM_GUESTDBG_EXIT_PENDING 0x10000000
-
-#define guestdbg_enabled(vcpu) \
- (vcpu->guest_debug & KVM_GUESTDBG_ENABLE)
-#define guestdbg_sstep_enabled(vcpu) \
- (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
-#define guestdbg_hw_bp_enabled(vcpu) \
- (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
-#define guestdbg_exit_pending(vcpu) (guestdbg_enabled(vcpu) && \
- (vcpu->guest_debug & KVM_GUESTDBG_EXIT_PENDING))
-
-#define KVM_GUESTDBG_VALID_MASK \
- (KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_SINGLESTEP |\
- KVM_GUESTDBG_USE_HW_BP | KVM_GUESTDBG_EXIT_PENDING)
-
-struct kvm_guestdbg_info_arch {
- unsigned long cr0;
- unsigned long cr9;
- unsigned long cr10;
- unsigned long cr11;
- struct kvm_hw_bp_info_arch *hw_bp_info;
- struct kvm_hw_wp_info_arch *hw_wp_info;
- int nr_hw_bp;
- int nr_hw_wp;
- unsigned long last_bp;
-};
-
-struct kvm_s390_pv_vcpu {
- u64 handle;
- unsigned long stor_base;
-};
-
-struct kvm_vcpu_arch {
- struct kvm_s390_sie_block *sie_block;
- /* if vsie is active, currently executed shadow sie control block */
- struct kvm_s390_sie_block *vsie_block;
- unsigned int host_acrs[NUM_ACRS];
- struct gs_cb *host_gscb;
- struct kvm_s390_local_interrupt local_int;
- struct hrtimer ckc_timer;
- struct kvm_s390_pgm_info pgm;
- struct gmap *gmap;
- struct kvm_guestdbg_info_arch guestdbg;
- unsigned long pfault_token;
- unsigned long pfault_select;
- unsigned long pfault_compare;
- bool cputm_enabled;
- /*
- * The seqcount protects updates to cputm_start and sie_block.cputm,
- * this way we can have non-blocking reads with consistent values.
- * Only the owning VCPU thread (vcpu->cpu) is allowed to change these
- * values and to start/stop/enable/disable cpu timer accounting.
- */
- seqcount_t cputm_seqcount;
- __u64 cputm_start;
- bool gs_enabled;
- bool skey_enabled;
- /* Indicator if the access registers have been loaded from guest */
- bool acrs_loaded;
- bool initialized;
- struct kvm_s390_pv_vcpu pv;
- union diag318_info diag318_info;
- struct kvm_s390_mmu_cache *mc;
-};
-
-struct kvm_vm_stat {
- struct kvm_vm_stat_generic generic;
- u64 inject_io;
- u64 io_390_adapter_map;
- u64 io_390_adapter_unmap;
- u64 io_390_inatomic;
- u64 io_flic_inject_airq;
- u64 io_set_adapter_int;
- u64 io_390_inatomic_no_inject;
- u64 inject_float_mchk;
- u64 inject_pfault_done;
- u64 inject_service_signal;
- u64 inject_virtio;
- u64 aen_forward;
- u64 gmap_shadow_create;
- u64 gmap_shadow_reuse;
- u64 gmap_shadow_r1_entry;
- u64 gmap_shadow_r2_entry;
- u64 gmap_shadow_r3_entry;
- u64 gmap_shadow_sg_entry;
- u64 gmap_shadow_pg_entry;
-};
-
-struct kvm_arch_memory_slot {
-};
-
-struct s390_map_info {
- struct list_head list;
- __u64 guest_addr;
- __u64 addr;
- struct page *page;
- /*
- * True if the page is long-term pinned. False if long-term pinning
- * failed and this entry exists only to preserve MAP/UNMAP symmetry.
- */
- bool pinned;
-};
-
-struct s390_io_adapter {
- unsigned int id;
- int isc;
- bool maskable;
- bool masked;
- bool swap;
- bool suppressible;
- spinlock_t maps_lock;
- struct list_head maps;
- unsigned int nr_maps;
-};
-
-#define MAX_S390_IO_ADAPTERS ((MAX_ISC + 1) * 8)
-#define MAX_S390_ADAPTER_MAPS 256
-
-/* maximum size of facilities and facility mask is 2k bytes */
-#define S390_ARCH_FAC_LIST_SIZE_BYTE (1<<11)
-#define S390_ARCH_FAC_LIST_SIZE_U64 \
- (S390_ARCH_FAC_LIST_SIZE_BYTE / sizeof(u64))
-#define S390_ARCH_FAC_MASK_SIZE_BYTE S390_ARCH_FAC_LIST_SIZE_BYTE
-#define S390_ARCH_FAC_MASK_SIZE_U64 \
- (S390_ARCH_FAC_MASK_SIZE_BYTE / sizeof(u64))
-
-struct kvm_s390_cpu_model {
- /* facility mask supported by kvm & hosting machine */
- __u64 fac_mask[S390_ARCH_FAC_MASK_SIZE_U64];
- struct kvm_s390_vm_cpu_subfunc subfuncs;
- /* facility list requested by guest (in dma page) */
- __u64 *fac_list;
- u64 cpuid;
- unsigned short ibc;
- /* subset of available UV-features for pv-guests enabled by user space */
- struct kvm_s390_vm_cpu_uv_feat uv_feat_guest;
-};
-
-#define S390_ARCH_FAC_FORMAT_2 2
-struct kvm_s390_flcb2 {
- union {
- struct {
- u8 reserved0[7];
- u8 length;
- };
- u64 header_val;
- };
- u64 facilities[S390_ARCH_FAC_LIST_SIZE_U64];
-};
-
-typedef int (*crypto_hook)(struct kvm_vcpu *vcpu);
-
-struct kvm_s390_crypto {
- struct kvm_s390_crypto_cb *crycb;
- struct rw_semaphore pqap_hook_rwsem;
- crypto_hook *pqap_hook;
- __u32 crycbd;
- __u8 aes_kw;
- __u8 dea_kw;
- __u8 apie;
-};
-
-#define APCB0_MASK_SIZE 1
-struct kvm_s390_apcb0 {
- __u64 apm[APCB0_MASK_SIZE]; /* 0x0000 */
- __u64 aqm[APCB0_MASK_SIZE]; /* 0x0008 */
- __u64 adm[APCB0_MASK_SIZE]; /* 0x0010 */
- __u64 reserved18; /* 0x0018 */
-};
-
-#define APCB1_MASK_SIZE 4
-struct kvm_s390_apcb1 {
- __u64 apm[APCB1_MASK_SIZE]; /* 0x0000 */
- __u64 aqm[APCB1_MASK_SIZE]; /* 0x0020 */
- __u64 adm[APCB1_MASK_SIZE]; /* 0x0040 */
- __u64 reserved60[4]; /* 0x0060 */
-};
-
-struct kvm_s390_crypto_cb {
- struct kvm_s390_apcb0 apcb0; /* 0x0000 */
- __u8 reserved20[0x0048 - 0x0020]; /* 0x0020 */
- __u8 dea_wrapping_key_mask[24]; /* 0x0048 */
- __u8 aes_wrapping_key_mask[32]; /* 0x0060 */
- struct kvm_s390_apcb1 apcb1; /* 0x0080 */
-};
-
-struct kvm_s390_gisa {
- union {
- struct { /* common to all formats */
- u32 next_alert;
- u8 ipm;
- u8 reserved01[2];
- u8 iam;
- };
- struct { /* format 0 */
- u32 next_alert;
- u8 ipm;
- u8 reserved01;
- u8 : 6;
- u8 g : 1;
- u8 c : 1;
- u8 iam;
- u8 reserved02[4];
- u32 airq_count;
- } g0;
- struct { /* format 1 */
- u32 next_alert;
- u8 ipm;
- u8 simm;
- u8 nimm;
- u8 iam;
- u8 aism[8];
- u8 : 6;
- u8 g : 1;
- u8 c : 1;
- u8 reserved03[11];
- u32 airq_count;
- } g1;
- struct {
- u64 word[4];
- } u64;
- };
-};
-
-struct kvm_s390_gib {
- u32 alert_list_origin;
- u32 reserved01;
- u8:5;
- u8 nisc:3;
- u8 reserved03[3];
- u32 reserved04[5];
-};
-
-/*
- * sie_page2 has to be allocated as DMA because fac_list, crycb and
- * gisa need 31bit addresses in the sie control block.
- */
-struct sie_page2 {
- __u64 fac_list[S390_ARCH_FAC_LIST_SIZE_U64]; /* 0x0000 */
- struct kvm_s390_crypto_cb crycb; /* 0x0800 */
- struct kvm_s390_gisa gisa; /* 0x0900 */
- struct kvm *kvm; /* 0x0920 */
- u8 reserved928[0x1000 - 0x928]; /* 0x0928 */
-};
-
-struct vsie_page;
-
-struct kvm_s390_vsie {
- struct mutex mutex;
- struct radix_tree_root addr_to_page;
- int page_count;
- int next;
- struct vsie_page *pages[KVM_MAX_VCPUS];
-};
-
-struct kvm_s390_gisa_iam {
- u8 mask;
- spinlock_t ref_lock;
- u32 ref_count[MAX_ISC + 1];
-};
-
-struct kvm_s390_gisa_interrupt {
- struct kvm_s390_gisa *origin;
- struct kvm_s390_gisa_iam alert;
- struct hrtimer timer;
- u64 expires;
- DECLARE_BITMAP(kicked_mask, KVM_MAX_VCPUS);
-};
-
-struct kvm_s390_pv {
- u64 handle;
- u64 guest_len;
- unsigned long stor_base;
- void *stor_var;
- bool dumping;
- void *set_aside;
- struct list_head need_cleanup;
- struct mmu_notifier mmu_notifier;
- /* Protects against concurrent import-like operations */
- struct mutex import_lock;
-};
-
-struct kvm_s390_mmu_cache;
-
-struct kvm_arch {
- struct esca_block *sca;
- debug_info_t *dbf;
- struct kvm_s390_float_interrupt float_int;
- struct kvm_device *flic;
- struct gmap *gmap;
- unsigned long mem_limit;
- int css_support;
- int use_irqchip;
- int use_cmma;
- int use_pfmfi;
- int use_skf;
- int use_zpci_interp;
- int user_cpu_state_ctrl;
- int user_sigp;
- int user_stsi;
- int user_instr0;
- int user_operexec;
- int allow_vsie_esamode;
- struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS];
- wait_queue_head_t ipte_wq;
- int ipte_lock_count;
- struct mutex ipte_mutex;
- spinlock_t start_stop_lock;
- struct sie_page2 *sie_page2;
- struct kvm_s390_cpu_model model;
- struct kvm_s390_crypto crypto;
- struct kvm_s390_vsie vsie;
- u8 epdx;
- u64 epoch;
- int migration_mode;
- atomic64_t cmma_dirty_pages;
- /* subset of available cpu features enabled by user space */
- DECLARE_BITMAP(cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS);
- /* indexed by vcpu_idx */
- DECLARE_BITMAP(idle_mask, KVM_MAX_VCPUS);
- struct kvm_s390_gisa_interrupt gisa_int;
- struct kvm_s390_pv pv;
- struct list_head kzdev_list;
- spinlock_t kzdev_list_lock;
- struct kvm_s390_mmu_cache *mc;
-};
-
-#define KVM_HVA_ERR_BAD (-1UL)
-#define KVM_HVA_ERR_RO_BAD (-2UL)
-
-static inline bool kvm_is_error_hva(unsigned long addr)
-{
- return IS_ERR_VALUE(addr);
-}
-
-#define ASYNC_PF_PER_VCPU 64
-struct kvm_arch_async_pf {
- unsigned long pfault_token;
-};
-
-bool kvm_arch_can_dequeue_async_page_present(struct kvm_vcpu *vcpu);
-
-void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu,
- struct kvm_async_pf *work);
-
-bool kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
- struct kvm_async_pf *work);
-
-void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
- struct kvm_async_pf *work);
-
-static inline void kvm_arch_async_page_present_queued(struct kvm_vcpu *vcpu) {}
-
-void kvm_arch_crypto_clear_masks(struct kvm *kvm);
-void kvm_arch_crypto_set_masks(struct kvm *kvm, unsigned long *apm,
- unsigned long *aqm, unsigned long *adm);
-
-#define SIE64_RETURN_NORMAL 0
-#define SIE64_RETURN_MCCK 1
-
-int __sie64a(phys_addr_t sie_block_phys, struct kvm_s390_sie_block *sie_block, u64 *rsa,
- unsigned long gasce);
-
-static inline int sie64a(struct kvm_s390_sie_block *sie_block, u64 *rsa, unsigned long gasce)
-{
- return __sie64a(virt_to_phys(sie_block), sie_block, rsa, gasce);
-}
-
-extern char sie_exit;
-
-bool kvm_s390_pv_is_protected(struct kvm *kvm);
-bool kvm_s390_pv_cpu_is_protected(struct kvm_vcpu *vcpu);
-
-extern int kvm_s390_enter_exit_sie(struct kvm_s390_sie_block *scb,
- u64 *gprs, unsigned long gasce);
-
-extern int kvm_s390_gisc_register(struct kvm *kvm, u32 gisc);
-extern int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc);
-
-bool kvm_s390_is_gpa_in_memslot(struct kvm *kvm, gpa_t gpa);
-
-static inline void kvm_arch_free_memslot(struct kvm *kvm,
- struct kvm_memory_slot *slot) {}
-static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
-static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
-static inline void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
- struct kvm_memory_slot *slot) {}
-static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
-static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
-
-#define __KVM_HAVE_ARCH_VM_FREE
-void kvm_arch_free_vm(struct kvm *kvm);
-
-struct zpci_kvm_hook {
- int (*kvm_register)(void *opaque, struct kvm *kvm);
- void (*kvm_unregister)(void *opaque);
-};
-
-extern struct zpci_kvm_hook zpci_kvm_hook;
+#include <asm/kvm_host_s390.h>
-#endif
+#endif /* ASM_KVM_HOST_H */
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host_s390.h
similarity index 99%
copy from arch/s390/include/asm/kvm_host.h
copy to arch/s390/include/asm/kvm_host_s390.h
index b4182ca4435f..0c4e061d7437 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host_s390.h
@@ -8,8 +8,8 @@
*/
-#ifndef ASM_KVM_HOST_H
-#define ASM_KVM_HOST_H
+#ifndef ASM_KVM_HOST_S390_H
+#define ASM_KVM_HOST_S390_H
#include <linux/types.h>
#include <linux/hrtimer.h>
@@ -781,4 +781,4 @@ struct zpci_kvm_hook {
extern struct zpci_kvm_hook zpci_kvm_hook;
-#endif
+#endif /* ASM_KVM_HOST_S390_H */
diff --git a/arch/s390/include/asm/kvm_host_types.h b/arch/s390/include/asm/kvm_host_s390_types.h
similarity index 98%
copy from arch/s390/include/asm/kvm_host_types.h
copy to arch/s390/include/asm/kvm_host_s390_types.h
index ac82dd09fce5..9e348a530421 100644
--- a/arch/s390/include/asm/kvm_host_types.h
+++ b/arch/s390/include/asm/kvm_host_s390_types.h
@@ -1,7 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_KVM_HOST_TYPES_H
-#define _ASM_KVM_HOST_TYPES_H
+#ifndef _ASM_KVM_HOST_S390_TYPES_H
+#define _ASM_KVM_HOST_S390_TYPES_H
#include <linux/atomic.h>
#include <linux/types.h>
@@ -346,4 +346,4 @@ struct sie_page {
__u8 reserved700[2304]; /* 0x0700 */
};
-#endif /* _ASM_KVM_HOST_TYPES_H */
+#endif /* _ASM_KVM_HOST_S390_TYPES_H */
diff --git a/arch/s390/include/asm/kvm_host_types.h b/arch/s390/include/asm/kvm_host_types.h
index ac82dd09fce5..e5bdba07cab0 100644
--- a/arch/s390/include/asm/kvm_host_types.h
+++ b/arch/s390/include/asm/kvm_host_types.h
@@ -1,349 +1,8 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_KVM_HOST_TYPES_H
-#define _ASM_KVM_HOST_TYPES_H
+#ifndef ASM_KVM_HOST_TYPES_H
+#define ASM_KVM_HOST_TYPES_H
-#include <linux/atomic.h>
-#include <linux/types.h>
+#include <asm/kvm_host_s390_types.h>
-#define KVM_S390_BSCA_CPU_SLOTS 64
-#define KVM_S390_ESCA_CPU_SLOTS 248
-
-#define SCB_ALIGNMENT_SHIFT 9
-
-#define SIGP_CTRL_C 0x80
-#define SIGP_CTRL_SCN_MASK 0x3f
-
-union bsca_sigp_ctrl {
- __u8 value;
- struct {
- __u8 c : 1;
- __u8 r : 1;
- __u8 scn : 6;
- };
-};
-
-union esca_sigp_ctrl {
- __u16 value;
- struct {
- __u8 c : 1;
- __u8 reserved: 7;
- __u8 scn;
- };
-};
-
-struct esca_entry {
- union esca_sigp_ctrl sigp_ctrl;
- __u16 reserved1[3];
- __u64 sda;
- __u64 reserved2[6];
-};
-
-struct bsca_entry {
- __u8 reserved0;
- union bsca_sigp_ctrl sigp_ctrl;
- __u16 reserved[3];
- __u64 sda;
- __u64 reserved2[2];
-};
-
-union ipte_control {
- unsigned long val;
- struct {
- unsigned long k : 1;
- unsigned long kh : 31;
- unsigned long kg : 32;
- };
-};
-
-/*
- * Utility is defined as two bytes but having it four bytes wide
- * generates more efficient code. Since the following bytes are
- * reserved this makes no functional difference.
- */
-union sca_utility {
- __u32 val;
- struct {
- __u32 mtcr : 1;
- __u32 : 31;
- };
-};
-
-struct bsca_block {
- union ipte_control ipte_control;
- __u64 reserved[5];
- __u64 mcn;
- union sca_utility utility;
- __u8 reserved2[4];
- struct bsca_entry cpu[KVM_S390_BSCA_CPU_SLOTS];
-};
-
-struct esca_block {
- union ipte_control ipte_control;
- __u64 reserved1[6];
- union sca_utility utility;
- __u8 reserved2[4];
- __u64 mcn[4];
- __u64 reserved3[20];
- struct esca_entry cpu[KVM_S390_ESCA_CPU_SLOTS];
-};
-
-/*
- * This struct is used to store some machine check info from lowcore
- * for machine checks that happen while the guest is running.
- * This info in host's lowcore might be overwritten by a second machine
- * check from host when host is in the machine check's high-level handling.
- * The size is 24 bytes.
- */
-struct mcck_volatile_info {
- __u64 mcic;
- __u64 failing_storage_address;
- __u32 ext_damage_code;
- __u32 reserved;
-};
-
-#define CR0_INITIAL_MASK (CR0_UNUSED_56 | CR0_INTERRUPT_KEY_SUBMASK | \
- CR0_MEASUREMENT_ALERT_SUBMASK)
-#define CR14_INITIAL_MASK (CR14_UNUSED_32 | CR14_UNUSED_33 | \
- CR14_EXTERNAL_DAMAGE_SUBMASK)
-
-#define SIDAD_SIZE_MASK 0xff
-#define sida_addr(sie_block) phys_to_virt((sie_block)->sidad & PAGE_MASK)
-#define sida_size(sie_block) \
- ((((sie_block)->sidad & SIDAD_SIZE_MASK) + 1) * PAGE_SIZE)
-
-#define CPUSTAT_STOPPED 0x80000000
-#define CPUSTAT_WAIT 0x10000000
-#define CPUSTAT_ECALL_PEND 0x08000000
-#define CPUSTAT_STOP_INT 0x04000000
-#define CPUSTAT_IO_INT 0x02000000
-#define CPUSTAT_EXT_INT 0x01000000
-#define CPUSTAT_RUNNING 0x00800000
-#define CPUSTAT_RETAINED 0x00400000
-#define CPUSTAT_TIMING_SUB 0x00020000
-#define CPUSTAT_SIE_SUB 0x00010000
-#define CPUSTAT_RRF 0x00008000
-#define CPUSTAT_SLSV 0x00004000
-#define CPUSTAT_SLSR 0x00002000
-#define CPUSTAT_ZARCH 0x00000800
-#define CPUSTAT_MCDS 0x00000100
-#define CPUSTAT_KSS 0x00000200
-#define CPUSTAT_SM 0x00000080
-#define CPUSTAT_IBS 0x00000040
-#define CPUSTAT_GED2 0x00000010
-#define CPUSTAT_G 0x00000008
-#define CPUSTAT_GED 0x00000004
-#define CPUSTAT_J 0x00000002
-#define CPUSTAT_P 0x00000001
-
-struct kvm_s390_sie_block {
- atomic_t cpuflags; /* 0x0000 */
- __u32 : 1; /* 0x0004 */
- __u32 prefix : 19;
- __u32 ibc : 12;
- __u8 reserved08[4]; /* 0x0008 */
-#define PROG_IN_SIE (1<<0)
- __u32 prog0c; /* 0x000c */
- union {
- __u8 reserved10[16]; /* 0x0010 */
- struct {
- __u64 pv_handle_cpu;
- __u64 pv_handle_config;
- };
- };
-#define PROG_BLOCK_SIE (1<<0)
-#define PROG_REQUEST (1<<1)
- atomic_t prog20; /* 0x0020 */
- __u8 reserved24[4]; /* 0x0024 */
- __u64 cputm; /* 0x0028 */
- __u64 ckc; /* 0x0030 */
- __u64 epoch; /* 0x0038 */
- __u32 svcc; /* 0x0040 */
-#define LCTL_CR0 0x8000
-#define LCTL_CR6 0x0200
-#define LCTL_CR9 0x0040
-#define LCTL_CR10 0x0020
-#define LCTL_CR11 0x0010
-#define LCTL_CR14 0x0002
- __u16 lctl; /* 0x0044 */
- __s16 icpua; /* 0x0046 */
-#define ICTL_OPEREXC 0x80000000
-#define ICTL_PINT 0x20000000
-#define ICTL_LPSW 0x00400000
-#define ICTL_STCTL 0x00040000
-#define ICTL_ISKE 0x00004000
-#define ICTL_SSKE 0x00002000
-#define ICTL_RRBE 0x00001000
-#define ICTL_TPROT 0x00000200
- __u32 ictl; /* 0x0048 */
-#define ECA_CEI 0x80000000
-#define ECA_IB 0x40000000
-#define ECA_SIGPI 0x10000000
-#define ECA_MVPGI 0x01000000
-#define ECA_AIV 0x00200000
-#define ECA_VX 0x00020000
-#define ECA_PROTEXCI 0x00002000
-#define ECA_APIE 0x00000008
-#define ECA_SII 0x00000001
- __u32 eca; /* 0x004c */
-#define ICPT_INST 0x04
-#define ICPT_PROGI 0x08
-#define ICPT_INSTPROGI 0x0C
-#define ICPT_EXTREQ 0x10
-#define ICPT_EXTINT 0x14
-#define ICPT_IOREQ 0x18
-#define ICPT_WAIT 0x1c
-#define ICPT_VALIDITY 0x20
-#define ICPT_STOP 0x28
-#define ICPT_OPEREXC 0x2C
-#define ICPT_PARTEXEC 0x38
-#define ICPT_IOINST 0x40
-#define ICPT_KSS 0x5c
-#define ICPT_MCHKREQ 0x60
-#define ICPT_INT_ENABLE 0x64
-#define ICPT_PV_INSTR 0x68
-#define ICPT_PV_NOTIFY 0x6c
-#define ICPT_PV_PREF 0x70
- __u8 icptcode; /* 0x0050 */
- __u8 icptstatus; /* 0x0051 */
- __u16 ihcpu; /* 0x0052 */
- __u8 reserved54; /* 0x0054 */
-#define IICTL_CODE_NONE 0x00
-#define IICTL_CODE_MCHK 0x01
-#define IICTL_CODE_EXT 0x02
-#define IICTL_CODE_IO 0x03
-#define IICTL_CODE_RESTART 0x04
-#define IICTL_CODE_SPECIFICATION 0x10
-#define IICTL_CODE_OPERAND 0x11
- __u8 iictl; /* 0x0055 */
- __u16 ipa; /* 0x0056 */
- __u32 ipb; /* 0x0058 */
- __u32 scaoh; /* 0x005c */
-#define FPF_BPBC 0x20
- __u8 fpf; /* 0x0060 */
-#define ECB_GS 0x40
-#define ECB_TE 0x10
-#define ECB_SPECI 0x08
-#define ECB_SRSI 0x04
-#define ECB_HOSTPROTINT 0x02
-#define ECB_PTF 0x01
- __u8 ecb; /* 0x0061 */
-#define ECB2_CMMA 0x80
-#define ECB2_IEP 0x20
-#define ECB2_PFMFI 0x08
-#define ECB2_ESCA 0x04
-#define ECB2_ZPCI_LSI 0x02
- __u8 ecb2; /* 0x0062 */
-#define ECB3_AISI 0x20
-#define ECB3_AISII 0x10
-#define ECB3_DEA 0x08
-#define ECB3_AES 0x04
-#define ECB3_RI 0x01
- __u8 ecb3; /* 0x0063 */
-#define ESCA_SCAOL_MASK ~0x3fU
- __u32 scaol; /* 0x0064 */
- __u8 sdf; /* 0x0068 */
- __u8 epdx; /* 0x0069 */
- __u8 cpnc; /* 0x006a */
- __u8 reserved6b; /* 0x006b */
- __u32 todpr; /* 0x006c */
-#define GISA_FORMAT1 0x00000001
- __u32 gd; /* 0x0070 */
- __u8 reserved74[12]; /* 0x0074 */
- __u64 mso; /* 0x0080 */
- __u64 msl; /* 0x0088 */
- psw_t gpsw; /* 0x0090 */
- __u64 gg14; /* 0x00a0 */
- __u64 gg15; /* 0x00a8 */
- __u8 reservedb0[8]; /* 0x00b0 */
-#define HPID_KVM 0x4
-#define HPID_VSIE 0x5
- __u8 hpid; /* 0x00b8 */
- __u8 reservedb9[7]; /* 0x00b9 */
- union {
- struct {
- __u32 eiparams; /* 0x00c0 */
- __u16 extcpuaddr; /* 0x00c4 */
- __u16 eic; /* 0x00c6 */
- };
- __u64 mcic; /* 0x00c0 */
- } __packed;
- __u32 reservedc8; /* 0x00c8 */
- union {
- struct {
- __u16 pgmilc; /* 0x00cc */
- __u16 iprcc; /* 0x00ce */
- };
- __u32 edc; /* 0x00cc */
- } __packed;
- union {
- struct {
- __u32 dxc; /* 0x00d0 */
- __u16 mcn; /* 0x00d4 */
- __u8 perc; /* 0x00d6 */
- __u8 peratmid; /* 0x00d7 */
- };
- __u64 faddr; /* 0x00d0 */
- } __packed;
- __u64 peraddr; /* 0x00d8 */
- __u8 eai; /* 0x00e0 */
- __u8 peraid; /* 0x00e1 */
- __u8 oai; /* 0x00e2 */
- __u8 armid; /* 0x00e3 */
- __u8 reservede4[4]; /* 0x00e4 */
- union {
- __u64 tecmc; /* 0x00e8 */
- struct {
- __u16 subchannel_id; /* 0x00e8 */
- __u16 subchannel_nr; /* 0x00ea */
- __u32 io_int_parm; /* 0x00ec */
- __u32 io_int_word; /* 0x00f0 */
- };
- } __packed;
- __u8 reservedf4[8]; /* 0x00f4 */
-#define CRYCB_FORMAT_MASK 0x00000003
-#define CRYCB_FORMAT0 0x00000000
-#define CRYCB_FORMAT1 0x00000001
-#define CRYCB_FORMAT2 0x00000003
- __u32 crycbd; /* 0x00fc */
- __u64 gcr[16]; /* 0x0100 */
- union {
- __u64 gbea; /* 0x0180 */
- __u64 sidad;
- };
- __u8 reserved188[8]; /* 0x0188 */
- __u64 sdnxo; /* 0x0190 */
- __u8 reserved198[8]; /* 0x0198 */
- __u32 fac; /* 0x01a0 */
- __u8 reserved1a4[20]; /* 0x01a4 */
- __u64 cbrlo; /* 0x01b8 */
- __u8 reserved1c0[8]; /* 0x01c0 */
-#define ECD_HOSTREGMGMT 0x20000000
-#define ECD_MEF 0x08000000
-#define ECD_ETOKENF 0x02000000
-#define ECD_ECC 0x00200000
-#define ECD_HMAC 0x00004000
- __u32 ecd; /* 0x01c8 */
- __u8 reserved1cc[18]; /* 0x01cc */
- __u64 pp; /* 0x01de */
- __u8 reserved1e6[2]; /* 0x01e6 */
- __u64 itdba; /* 0x01e8 */
- __u64 riccbd; /* 0x01f0 */
- __u64 gvrd; /* 0x01f8 */
-} __packed __aligned(512);
-
-struct kvm_s390_itdb {
- __u8 data[256];
-};
-
-struct sie_page {
- struct kvm_s390_sie_block sie_block;
- struct mcck_volatile_info mcck_info; /* 0x0200 */
- __u8 reserved218[360]; /* 0x0218 */
- __u64 pv_grregs[16]; /* 0x0380 */
- __u8 reserved400[512]; /* 0x0400 */
- struct kvm_s390_itdb itdb; /* 0x0600 */
- __u8 reserved700[2304]; /* 0x0700 */
-};
-
-#endif /* _ASM_KVM_HOST_TYPES_H */
+#endif /* ASM_KVM_HOST_TYPES_H */
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 16/33] KVM: s390: Move s390 kvm code into a subdirectory
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (14 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 15/33] KVM: s390: Move kvm_host definitions to kvm_host_s390 Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:02 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 17/33] KVM: s390: Move PGM code definitions to asm/kvm_host.h Steffen Eiden
` (17 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Move all the code required to run s390 KVM guests on s390 to a s390
subdirectory. Move gmap related code into a gmap directory to later
share gmap code between KVM implementations.
Update S390 VFIO-PCI MAINTAINERS filepath.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
MAINTAINERS | 2 +-
arch/s390/kvm/Makefile | 11 +----------
arch/s390/kvm/gmap/Makefile | 5 +++++
arch/s390/kvm/{ => gmap}/dat.c | 0
arch/s390/kvm/{ => gmap}/dat.h | 0
arch/s390/kvm/{ => gmap}/faultin.c | 0
arch/s390/kvm/{ => gmap}/faultin.h | 0
arch/s390/kvm/{ => gmap}/gmap.c | 0
arch/s390/kvm/{ => gmap}/gmap.h | 0
arch/s390/kvm/{ => gmap}/trace_gmap.h | 2 +-
arch/s390/kvm/{ => s390}/Makefile | 9 ++++-----
arch/s390/kvm/{ => s390}/diag.c | 0
arch/s390/kvm/{ => s390}/gaccess.c | 0
arch/s390/kvm/{ => s390}/gaccess.h | 0
arch/s390/kvm/{ => s390}/guestdbg.c | 0
arch/s390/kvm/{ => s390}/intercept.c | 0
arch/s390/kvm/{ => s390}/interrupt.c | 0
arch/s390/kvm/{ => s390}/pci.c | 0
arch/s390/kvm/{ => s390}/pci.h | 0
arch/s390/kvm/{ => s390}/priv.c | 0
arch/s390/kvm/{ => s390}/pv.c | 0
arch/s390/kvm/{ => s390}/s390.c | 0
arch/s390/kvm/{ => s390}/s390.h | 0
arch/s390/kvm/{ => s390}/sigp.c | 0
arch/s390/kvm/{ => s390}/trace-s390.h | 0
arch/s390/kvm/{ => s390}/trace.h | 0
arch/s390/kvm/{ => s390}/vsie.c | 0
27 files changed, 12 insertions(+), 17 deletions(-)
create mode 100644 arch/s390/kvm/gmap/Makefile
rename arch/s390/kvm/{ => gmap}/dat.c (100%)
rename arch/s390/kvm/{ => gmap}/dat.h (100%)
rename arch/s390/kvm/{ => gmap}/faultin.c (100%)
rename arch/s390/kvm/{ => gmap}/faultin.h (100%)
rename arch/s390/kvm/{ => gmap}/gmap.c (100%)
rename arch/s390/kvm/{ => gmap}/gmap.h (100%)
rename arch/s390/kvm/{ => gmap}/trace_gmap.h (96%)
copy arch/s390/kvm/{ => s390}/Makefile (62%)
rename arch/s390/kvm/{ => s390}/diag.c (100%)
rename arch/s390/kvm/{ => s390}/gaccess.c (100%)
rename arch/s390/kvm/{ => s390}/gaccess.h (100%)
rename arch/s390/kvm/{ => s390}/guestdbg.c (100%)
rename arch/s390/kvm/{ => s390}/intercept.c (100%)
rename arch/s390/kvm/{ => s390}/interrupt.c (100%)
rename arch/s390/kvm/{ => s390}/pci.c (100%)
rename arch/s390/kvm/{ => s390}/pci.h (100%)
rename arch/s390/kvm/{ => s390}/priv.c (100%)
rename arch/s390/kvm/{ => s390}/pv.c (100%)
rename arch/s390/kvm/{ => s390}/s390.c (100%)
rename arch/s390/kvm/{ => s390}/s390.h (100%)
rename arch/s390/kvm/{ => s390}/sigp.c (100%)
rename arch/s390/kvm/{ => s390}/trace-s390.h (100%)
rename arch/s390/kvm/{ => s390}/trace.h (100%)
rename arch/s390/kvm/{ => s390}/vsie.c (100%)
diff --git a/MAINTAINERS b/MAINTAINERS
index 15c7dc516f7c..29802f061063 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -24150,7 +24150,7 @@ L: linux-s390@vger.kernel.org
L: kvm@vger.kernel.org
S: Supported
T: git git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git
-F: arch/s390/kvm/pci*
+F: arch/s390/kvm/s390/pci*
F: drivers/vfio/pci/vfio_pci_zdev.c
F: include/uapi/linux/vfio_zdev.h
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index 961de97b8e80..a4e3875b5bdd 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -3,13 +3,4 @@
#
# Copyright IBM Corp. 2008
-include $(srctree)/virt/kvm/Makefile.kvm
-
-ccflags-y := -I$(src)
-
-kvm-y += s390.o intercept.o interrupt.o priv.o sigp.o
-kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o
-kvm-y += dat.o gmap.o faultin.o
-
-kvm-$(CONFIG_VFIO_PCI_ZDEV_KVM) += pci.o
-obj-$(CONFIG_KVM) += kvm.o
+obj-$(CONFIG_KVM) += s390/
diff --git a/arch/s390/kvm/gmap/Makefile b/arch/s390/kvm/gmap/Makefile
new file mode 100644
index 000000000000..3a4f8df11622
--- /dev/null
+++ b/arch/s390/kvm/gmap/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+
+GMAP ?= ../gmap
+
+gmap-y += $(GMAP)/dat.o $(GMAP)/gmap.o $(GMAP)/faultin.o
diff --git a/arch/s390/kvm/dat.c b/arch/s390/kvm/gmap/dat.c
similarity index 100%
rename from arch/s390/kvm/dat.c
rename to arch/s390/kvm/gmap/dat.c
diff --git a/arch/s390/kvm/dat.h b/arch/s390/kvm/gmap/dat.h
similarity index 100%
rename from arch/s390/kvm/dat.h
rename to arch/s390/kvm/gmap/dat.h
diff --git a/arch/s390/kvm/faultin.c b/arch/s390/kvm/gmap/faultin.c
similarity index 100%
rename from arch/s390/kvm/faultin.c
rename to arch/s390/kvm/gmap/faultin.c
diff --git a/arch/s390/kvm/faultin.h b/arch/s390/kvm/gmap/faultin.h
similarity index 100%
rename from arch/s390/kvm/faultin.h
rename to arch/s390/kvm/gmap/faultin.h
diff --git a/arch/s390/kvm/gmap.c b/arch/s390/kvm/gmap/gmap.c
similarity index 100%
rename from arch/s390/kvm/gmap.c
rename to arch/s390/kvm/gmap/gmap.c
diff --git a/arch/s390/kvm/gmap.h b/arch/s390/kvm/gmap/gmap.h
similarity index 100%
rename from arch/s390/kvm/gmap.h
rename to arch/s390/kvm/gmap/gmap.h
diff --git a/arch/s390/kvm/trace_gmap.h b/arch/s390/kvm/gmap/trace_gmap.h
similarity index 96%
rename from arch/s390/kvm/trace_gmap.h
rename to arch/s390/kvm/gmap/trace_gmap.h
index a3cad705021b..15ec88bdce55 100644
--- a/arch/s390/kvm/trace_gmap.h
+++ b/arch/s390/kvm/gmap/trace_gmap.h
@@ -7,7 +7,7 @@
#undef TRACE_SYSTEM
#define TRACE_SYSTEM kvm
#undef TRACE_INCLUDE_PATH
-#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_PATH ../gmap
#undef TRACE_INCLUDE_FILE
#define TRACE_INCLUDE_FILE trace_gmap
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/s390/Makefile
similarity index 62%
copy from arch/s390/kvm/Makefile
copy to arch/s390/kvm/s390/Makefile
index 961de97b8e80..762a63826423 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/s390/Makefile
@@ -1,15 +1,14 @@
# SPDX-License-Identifier: GPL-2.0
-# Makefile for kernel virtual machines on s390
-#
-# Copyright IBM Corp. 2008
+KVM := ../../../../virt/kvm
include $(srctree)/virt/kvm/Makefile.kvm
+include $(srctree)/arch/s390/kvm/gmap/Makefile
-ccflags-y := -I$(src)
+ccflags-y := -I$(src) -I$(srctree)/arch/s390/kvm/gmap
kvm-y += s390.o intercept.o interrupt.o priv.o sigp.o
kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o
-kvm-y += dat.o gmap.o faultin.o
+kvm-y += $(gmap-y)
kvm-$(CONFIG_VFIO_PCI_ZDEV_KVM) += pci.o
obj-$(CONFIG_KVM) += kvm.o
diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/s390/diag.c
similarity index 100%
rename from arch/s390/kvm/diag.c
rename to arch/s390/kvm/s390/diag.c
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/s390/gaccess.c
similarity index 100%
rename from arch/s390/kvm/gaccess.c
rename to arch/s390/kvm/s390/gaccess.c
diff --git a/arch/s390/kvm/gaccess.h b/arch/s390/kvm/s390/gaccess.h
similarity index 100%
rename from arch/s390/kvm/gaccess.h
rename to arch/s390/kvm/s390/gaccess.h
diff --git a/arch/s390/kvm/guestdbg.c b/arch/s390/kvm/s390/guestdbg.c
similarity index 100%
rename from arch/s390/kvm/guestdbg.c
rename to arch/s390/kvm/s390/guestdbg.c
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/s390/intercept.c
similarity index 100%
rename from arch/s390/kvm/intercept.c
rename to arch/s390/kvm/s390/intercept.c
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/s390/interrupt.c
similarity index 100%
rename from arch/s390/kvm/interrupt.c
rename to arch/s390/kvm/s390/interrupt.c
diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/s390/pci.c
similarity index 100%
rename from arch/s390/kvm/pci.c
rename to arch/s390/kvm/s390/pci.c
diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/s390/pci.h
similarity index 100%
rename from arch/s390/kvm/pci.h
rename to arch/s390/kvm/s390/pci.h
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/s390/priv.c
similarity index 100%
rename from arch/s390/kvm/priv.c
rename to arch/s390/kvm/s390/priv.c
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/s390/pv.c
similarity index 100%
rename from arch/s390/kvm/pv.c
rename to arch/s390/kvm/s390/pv.c
diff --git a/arch/s390/kvm/s390.c b/arch/s390/kvm/s390/s390.c
similarity index 100%
rename from arch/s390/kvm/s390.c
rename to arch/s390/kvm/s390/s390.c
diff --git a/arch/s390/kvm/s390.h b/arch/s390/kvm/s390/s390.h
similarity index 100%
rename from arch/s390/kvm/s390.h
rename to arch/s390/kvm/s390/s390.h
diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/s390/sigp.c
similarity index 100%
rename from arch/s390/kvm/sigp.c
rename to arch/s390/kvm/s390/sigp.c
diff --git a/arch/s390/kvm/trace-s390.h b/arch/s390/kvm/s390/trace-s390.h
similarity index 100%
rename from arch/s390/kvm/trace-s390.h
rename to arch/s390/kvm/s390/trace-s390.h
diff --git a/arch/s390/kvm/trace.h b/arch/s390/kvm/s390/trace.h
similarity index 100%
rename from arch/s390/kvm/trace.h
rename to arch/s390/kvm/s390/trace.h
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/s390/vsie.c
similarity index 100%
rename from arch/s390/kvm/vsie.c
rename to arch/s390/kvm/s390/vsie.c
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 17/33] KVM: s390: Move PGM code definitions to asm/kvm_host.h
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (15 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 16/33] KVM: s390: Move s390 kvm code into a subdirectory Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:04 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 18/33] KVM: s390: Prepare gmap for a second KVM implementation Steffen Eiden
` (16 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Move PGM code definitions from kvm_host_s390.h (back) to the generic
kvm_host.h. These definitions are needed by multiple KVM implementations
and should be in a shared location.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/include/asm/kvm_host.h | 57 +++++++++++++++++++++++++++
arch/s390/include/asm/kvm_host_s390.h | 57 ---------------------------
2 files changed, 57 insertions(+), 57 deletions(-)
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index e76ceee11ef5..147325978225 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -5,4 +5,61 @@
#include <asm/kvm_host_s390.h>
+#define PGM_OPERATION 0x01
+#define PGM_PRIVILEGED_OP 0x02
+#define PGM_EXECUTE 0x03
+#define PGM_PROTECTION 0x04
+#define PGM_ADDRESSING 0x05
+#define PGM_SPECIFICATION 0x06
+#define PGM_DATA 0x07
+#define PGM_FIXED_POINT_OVERFLOW 0x08
+#define PGM_FIXED_POINT_DIVIDE 0x09
+#define PGM_DECIMAL_OVERFLOW 0x0a
+#define PGM_DECIMAL_DIVIDE 0x0b
+#define PGM_HFP_EXPONENT_OVERFLOW 0x0c
+#define PGM_HFP_EXPONENT_UNDERFLOW 0x0d
+#define PGM_HFP_SIGNIFICANCE 0x0e
+#define PGM_HFP_DIVIDE 0x0f
+#define PGM_SEGMENT_TRANSLATION 0x10
+#define PGM_PAGE_TRANSLATION 0x11
+#define PGM_TRANSLATION_SPEC 0x12
+#define PGM_SPECIAL_OPERATION 0x13
+#define PGM_OPERAND 0x15
+#define PGM_TRACE_TABEL 0x16
+#define PGM_VECTOR_PROCESSING 0x1b
+#define PGM_SPACE_SWITCH 0x1c
+#define PGM_HFP_SQUARE_ROOT 0x1d
+#define PGM_PC_TRANSLATION_SPEC 0x1f
+#define PGM_AFX_TRANSLATION 0x20
+#define PGM_ASX_TRANSLATION 0x21
+#define PGM_LX_TRANSLATION 0x22
+#define PGM_EX_TRANSLATION 0x23
+#define PGM_PRIMARY_AUTHORITY 0x24
+#define PGM_SECONDARY_AUTHORITY 0x25
+#define PGM_LFX_TRANSLATION 0x26
+#define PGM_LSX_TRANSLATION 0x27
+#define PGM_ALET_SPECIFICATION 0x28
+#define PGM_ALEN_TRANSLATION 0x29
+#define PGM_ALE_SEQUENCE 0x2a
+#define PGM_ASTE_VALIDITY 0x2b
+#define PGM_ASTE_SEQUENCE 0x2c
+#define PGM_EXTENDED_AUTHORITY 0x2d
+#define PGM_LSTE_SEQUENCE 0x2e
+#define PGM_ASTE_INSTANCE 0x2f
+#define PGM_STACK_FULL 0x30
+#define PGM_STACK_EMPTY 0x31
+#define PGM_STACK_SPECIFICATION 0x32
+#define PGM_STACK_TYPE 0x33
+#define PGM_STACK_OPERATION 0x34
+#define PGM_ASCE_TYPE 0x38
+#define PGM_REGION_FIRST_TRANS 0x39
+#define PGM_REGION_SECOND_TRANS 0x3a
+#define PGM_REGION_THIRD_TRANS 0x3b
+#define PGM_SECURE_STORAGE_ACCESS 0x3d
+#define PGM_NON_SECURE_STORAGE_ACCESS 0x3e
+#define PGM_SECURE_STORAGE_VIOLATION 0x3f
+#define PGM_MONITOR 0x40
+#define PGM_PER 0x80
+#define PGM_CRYPTO_OPERATION 0x119
+
#endif /* ASM_KVM_HOST_H */
diff --git a/arch/s390/include/asm/kvm_host_s390.h b/arch/s390/include/asm/kvm_host_s390.h
index 0c4e061d7437..22e8d7c4a755 100644
--- a/arch/s390/include/asm/kvm_host_s390.h
+++ b/arch/s390/include/asm/kvm_host_s390.h
@@ -150,63 +150,6 @@ struct kvm_vcpu_stat {
u64 signal_exits;
};
-#define PGM_OPERATION 0x01
-#define PGM_PRIVILEGED_OP 0x02
-#define PGM_EXECUTE 0x03
-#define PGM_PROTECTION 0x04
-#define PGM_ADDRESSING 0x05
-#define PGM_SPECIFICATION 0x06
-#define PGM_DATA 0x07
-#define PGM_FIXED_POINT_OVERFLOW 0x08
-#define PGM_FIXED_POINT_DIVIDE 0x09
-#define PGM_DECIMAL_OVERFLOW 0x0a
-#define PGM_DECIMAL_DIVIDE 0x0b
-#define PGM_HFP_EXPONENT_OVERFLOW 0x0c
-#define PGM_HFP_EXPONENT_UNDERFLOW 0x0d
-#define PGM_HFP_SIGNIFICANCE 0x0e
-#define PGM_HFP_DIVIDE 0x0f
-#define PGM_SEGMENT_TRANSLATION 0x10
-#define PGM_PAGE_TRANSLATION 0x11
-#define PGM_TRANSLATION_SPEC 0x12
-#define PGM_SPECIAL_OPERATION 0x13
-#define PGM_OPERAND 0x15
-#define PGM_TRACE_TABEL 0x16
-#define PGM_VECTOR_PROCESSING 0x1b
-#define PGM_SPACE_SWITCH 0x1c
-#define PGM_HFP_SQUARE_ROOT 0x1d
-#define PGM_PC_TRANSLATION_SPEC 0x1f
-#define PGM_AFX_TRANSLATION 0x20
-#define PGM_ASX_TRANSLATION 0x21
-#define PGM_LX_TRANSLATION 0x22
-#define PGM_EX_TRANSLATION 0x23
-#define PGM_PRIMARY_AUTHORITY 0x24
-#define PGM_SECONDARY_AUTHORITY 0x25
-#define PGM_LFX_TRANSLATION 0x26
-#define PGM_LSX_TRANSLATION 0x27
-#define PGM_ALET_SPECIFICATION 0x28
-#define PGM_ALEN_TRANSLATION 0x29
-#define PGM_ALE_SEQUENCE 0x2a
-#define PGM_ASTE_VALIDITY 0x2b
-#define PGM_ASTE_SEQUENCE 0x2c
-#define PGM_EXTENDED_AUTHORITY 0x2d
-#define PGM_LSTE_SEQUENCE 0x2e
-#define PGM_ASTE_INSTANCE 0x2f
-#define PGM_STACK_FULL 0x30
-#define PGM_STACK_EMPTY 0x31
-#define PGM_STACK_SPECIFICATION 0x32
-#define PGM_STACK_TYPE 0x33
-#define PGM_STACK_OPERATION 0x34
-#define PGM_ASCE_TYPE 0x38
-#define PGM_REGION_FIRST_TRANS 0x39
-#define PGM_REGION_SECOND_TRANS 0x3a
-#define PGM_REGION_THIRD_TRANS 0x3b
-#define PGM_SECURE_STORAGE_ACCESS 0x3d
-#define PGM_NON_SECURE_STORAGE_ACCESS 0x3e
-#define PGM_SECURE_STORAGE_VIOLATION 0x3f
-#define PGM_MONITOR 0x40
-#define PGM_PER 0x80
-#define PGM_CRYPTO_OPERATION 0x119
-
/* irq types in ascend order of priorities */
enum irq_types {
IRQ_PEND_SET_PREFIX = 0,
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 18/33] KVM: s390: Prepare gmap for a second KVM implementation
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (16 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 17/33] KVM: s390: Move PGM code definitions to asm/kvm_host.h Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:10 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 19/33] KVM: s390: gmap: Make storage keys optional Steffen Eiden
` (15 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Refactor gmap code such that a second s390 (host) KVM implementation can
use the gmap code as well. Move mmu code from s390 to gmap so the other
KVM implementation can use it as well.
No functional change.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/gmap/Makefile | 2 +-
arch/s390/kvm/gmap/kvm_mmu.c | 133 +++++++++++++++++++++++++++++++++++
arch/s390/kvm/gmap/kvm_mmu.h | 18 +++++
arch/s390/kvm/s390/s390.c | 126 ++++-----------------------------
arch/s390/kvm/s390/s390.h | 8 +++
5 files changed, 175 insertions(+), 112 deletions(-)
create mode 100644 arch/s390/kvm/gmap/kvm_mmu.c
create mode 100644 arch/s390/kvm/gmap/kvm_mmu.h
diff --git a/arch/s390/kvm/gmap/Makefile b/arch/s390/kvm/gmap/Makefile
index 3a4f8df11622..dd4ef062c536 100644
--- a/arch/s390/kvm/gmap/Makefile
+++ b/arch/s390/kvm/gmap/Makefile
@@ -2,4 +2,4 @@
GMAP ?= ../gmap
-gmap-y += $(GMAP)/dat.o $(GMAP)/gmap.o $(GMAP)/faultin.o
+gmap-y += $(GMAP)/dat.o $(GMAP)/gmap.o $(GMAP)/faultin.o $(GMAP)/kvm_mmu.o
diff --git a/arch/s390/kvm/gmap/kvm_mmu.c b/arch/s390/kvm/gmap/kvm_mmu.c
new file mode 100644
index 000000000000..b08b8229bb6f
--- /dev/null
+++ b/arch/s390/kvm/gmap/kvm_mmu.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kvm_types.h>
+#include <linux/kvm_host.h>
+
+#include "s390.h"
+#include "gmap.h"
+#include "dat.h"
+#include "kvm_mmu.h"
+
+/*
+ * Get (and clear) the dirty memory log for a memory slot.
+ */
+int s390_kvm_mmu_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+ int r;
+ unsigned long n;
+ struct kvm_memory_slot *memslot;
+ int is_dirty;
+
+ if (kvm_is_ucontrol(kvm))
+ return -EINVAL;
+
+ mutex_lock(&kvm->slots_lock);
+
+ r = -EINVAL;
+ if (log->slot >= KVM_USER_MEM_SLOTS)
+ goto out;
+
+ r = kvm_get_dirty_log(kvm, log, &is_dirty, &memslot);
+ if (r)
+ goto out;
+
+ /* Clear the dirty log */
+ if (is_dirty) {
+ n = kvm_dirty_bitmap_bytes(memslot);
+ memset(memslot->dirty_bitmap, 0, n);
+ }
+ r = 0;
+out:
+ mutex_unlock(&kvm->slots_lock);
+ return r;
+}
+
+int s390_kvm_mmu_prepare_memory_region(struct kvm *kvm,
+ const struct kvm_memory_slot *old,
+ struct kvm_memory_slot *new,
+ enum kvm_mr_change change)
+{
+ if (kvm_is_ucontrol(kvm) && new && new->id < KVM_USER_MEM_SLOTS)
+ return -EINVAL;
+
+ /* When we are protected, we should not change the memory slots */
+ if (kvm_s390_pv_get_handle(kvm))
+ return -EINVAL;
+
+ if (change != KVM_MR_DELETE && change != KVM_MR_FLAGS_ONLY) {
+ /*
+ * A few sanity checks. The memory in userland is ok to be
+ * fragmented into various different vmas. It is okay to mmap()
+ * and munmap() stuff in this slot after doing this call at any
+ * time.
+ */
+ if (new->userspace_addr & ~PAGE_MASK)
+ return -EINVAL;
+ if ((new->base_gfn + new->npages) * PAGE_SIZE > kvm->arch.mem_limit)
+ return -EINVAL;
+ if (!asce_contains_gfn(kvm->arch.gmap->asce, new->base_gfn + new->npages - 1))
+ return -EINVAL;
+ }
+
+ if (!kvm_s390_is_migration_mode(kvm))
+ return 0;
+
+ /*
+ * Turn off migration mode when:
+ * - userspace creates a new memslot with dirty logging off,
+ * - userspace modifies an existing memslot (MOVE or FLAGS_ONLY) and
+ * dirty logging is turned off.
+ * Migration mode expects dirty page logging being enabled to store
+ * its dirty bitmap.
+ */
+ if (change != KVM_MR_DELETE &&
+ !(new->flags & KVM_MEM_LOG_DIRTY_PAGES))
+ WARN(kvm_s390_vm_stop_migration(kvm),
+ "Failed to stop migration mode");
+
+ return 0;
+}
+
+void s390_kvm_mmu_commit_memory_region(struct kvm *kvm,
+ struct kvm_memory_slot *old,
+ const struct kvm_memory_slot *new,
+ enum kvm_mr_change change)
+{
+ struct kvm_s390_mmu_cache *mc __free(kvm_s390_mmu_cache) = NULL;
+ int rc = 0;
+
+ guard(mutex)(&kvm->slots_arch_lock);
+
+ if (change == KVM_MR_FLAGS_ONLY)
+ return;
+
+ mc = kvm_s390_new_mmu_cache();
+ if (!mc) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ scoped_guard(write_lock, &kvm->mmu_lock) {
+ kvm_s390_update_cmma_dirty(kvm, old);
+ switch (change) {
+ case KVM_MR_DELETE:
+ rc = dat_delete_slot(mc, kvm->arch.gmap->asce, old->base_gfn, old->npages);
+ break;
+ case KVM_MR_MOVE:
+ rc = dat_delete_slot(mc, kvm->arch.gmap->asce, old->base_gfn, old->npages);
+ if (rc)
+ break;
+ fallthrough;
+ case KVM_MR_CREATE:
+ rc = dat_create_slot(mc, kvm->arch.gmap->asce, new->base_gfn, new->npages);
+ break;
+ case KVM_MR_FLAGS_ONLY:
+ break;
+ default:
+ WARN(1, "Unknown KVM MR CHANGE: %d\n", change);
+ }
+ }
+out:
+ if (rc)
+ pr_warn("failed to commit memory region\n");
+}
diff --git a/arch/s390/kvm/gmap/kvm_mmu.h b/arch/s390/kvm/gmap/kvm_mmu.h
new file mode 100644
index 000000000000..cdbd390bd33c
--- /dev/null
+++ b/arch/s390/kvm/gmap/kvm_mmu.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef ARCH_KVM_GMAP_KVM_MMU_H
+#define ARCH_KVM_GMAP_KVM_MMU_H
+
+#include <linux/kvm_host.h>
+
+int s390_kvm_mmu_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log);
+int s390_kvm_mmu_prepare_memory_region(struct kvm *kvm,
+ const struct kvm_memory_slot *old,
+ struct kvm_memory_slot *new,
+ enum kvm_mr_change change);
+void s390_kvm_mmu_commit_memory_region(struct kvm *kvm,
+ struct kvm_memory_slot *old,
+ const struct kvm_memory_slot *new,
+ enum kvm_mr_change change);
+
+#endif /* ARCH_KVM_GMAP_KVM_MMU_H */
diff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c
index ff09ffc10f0d..1d0d94f000f7 100644
--- a/arch/s390/kvm/s390/s390.c
+++ b/arch/s390/kvm/s390/s390.c
@@ -55,6 +55,7 @@
#include "gmap.h"
#include "faultin.h"
#include "pci.h"
+#include "kvm_mmu.h"
#define CREATE_TRACE_POINTS
#include "trace.h"
@@ -745,33 +746,7 @@ static void sca_del_vcpu(struct kvm_vcpu *vcpu);
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
struct kvm_dirty_log *log)
{
- int r;
- unsigned long n;
- struct kvm_memory_slot *memslot;
- int is_dirty;
-
- if (kvm_is_ucontrol(kvm))
- return -EINVAL;
-
- mutex_lock(&kvm->slots_lock);
-
- r = -EINVAL;
- if (log->slot >= KVM_USER_MEM_SLOTS)
- goto out;
-
- r = kvm_get_dirty_log(kvm, log, &is_dirty, &memslot);
- if (r)
- goto out;
-
- /* Clear the dirty log */
- if (is_dirty) {
- n = kvm_dirty_bitmap_bytes(memslot);
- memset(memslot->dirty_bitmap, 0, n);
- }
- r = 0;
-out:
- mutex_unlock(&kvm->slots_lock);
- return r;
+ return s390_kvm_mmu_get_dirty_log(kvm, log);
}
static void icpt_operexc_on_all_vcpus(struct kvm *kvm)
@@ -1266,7 +1241,7 @@ static int kvm_s390_vm_start_migration(struct kvm *kvm)
* Must be called with kvm->slots_arch_lock to avoid races with ourselves,
* kvm_s390_vm_start_migration() and kvm_s390_get_cmma_bits().
*/
-static int kvm_s390_vm_stop_migration(struct kvm *kvm)
+int kvm_s390_vm_stop_migration(struct kvm *kvm)
{
/* migration mode already disabled */
if (!kvm->arch.migration_mode)
@@ -5770,45 +5745,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *new,
enum kvm_mr_change change)
{
- if (kvm_is_ucontrol(kvm) && new && new->id < KVM_USER_MEM_SLOTS)
- return -EINVAL;
-
- /* When we are protected, we should not change the memory slots */
- if (kvm_s390_pv_get_handle(kvm))
- return -EINVAL;
-
- if (change != KVM_MR_DELETE && change != KVM_MR_FLAGS_ONLY) {
- /*
- * A few sanity checks. The memory in userland is ok to be
- * fragmented into various different vmas. It is okay to mmap()
- * and munmap() stuff in this slot after doing this call at any
- * time.
- */
- if (new->userspace_addr & ~PAGE_MASK)
- return -EINVAL;
- if ((new->base_gfn + new->npages) * PAGE_SIZE > kvm->arch.mem_limit)
- return -EINVAL;
- if (!asce_contains_gfn(kvm->arch.gmap->asce, new->base_gfn + new->npages - 1))
- return -EINVAL;
- }
-
- if (!kvm->arch.migration_mode)
- return 0;
-
- /*
- * Turn off migration mode when:
- * - userspace creates a new memslot with dirty logging off,
- * - userspace modifies an existing memslot (MOVE or FLAGS_ONLY) and
- * dirty logging is turned off.
- * Migration mode expects dirty page logging being enabled to store
- * its dirty bitmap.
- */
- if (change != KVM_MR_DELETE &&
- !(new->flags & KVM_MEM_LOG_DIRTY_PAGES))
- WARN(kvm_s390_vm_stop_migration(kvm),
- "Failed to stop migration mode");
-
- return 0;
+ return s390_kvm_mmu_prepare_memory_region(kvm, old, new, change);
}
static long cmma_d_count_pte(union pte *ptep, gfn_t gfn, gfn_t next, struct dat_walk *walk)
@@ -5824,55 +5761,22 @@ static long cmma_d_count_pte(union pte *ptep, gfn_t gfn, gfn_t next, struct dat_
return 0;
}
-void kvm_arch_commit_memory_region(struct kvm *kvm,
- struct kvm_memory_slot *old,
- const struct kvm_memory_slot *new,
- enum kvm_mr_change change)
+void kvm_s390_update_cmma_dirty(struct kvm *kvm, struct kvm_memory_slot *old)
{
const struct dat_walk_ops ops = { .pte_entry = cmma_d_count_pte, };
- struct kvm_s390_mmu_cache *mc __free(kvm_s390_mmu_cache) = NULL;
- int rc = 0;
- guard(mutex)(&kvm->slots_arch_lock);
-
- if (change == KVM_MR_FLAGS_ONLY)
- return;
-
- mc = kvm_s390_new_mmu_cache();
- if (!mc) {
- rc = -ENOMEM;
- goto out;
+ if (kvm->arch.migration_mode && kvm->arch.use_cmma && old) {
+ _dat_walk_gfn_range(old->base_gfn, old->base_gfn + old->npages,
+ kvm->arch.gmap->asce, &ops, DAT_WALK_IGN_HOLES,
+ &kvm->arch.cmma_dirty_pages);
}
+}
- scoped_guard(write_lock, &kvm->mmu_lock) {
- if (kvm->arch.migration_mode && kvm->arch.use_cmma && old) {
- _dat_walk_gfn_range(old->base_gfn, old->base_gfn + old->npages,
- kvm->arch.gmap->asce, &ops, DAT_WALK_IGN_HOLES,
- &kvm->arch.cmma_dirty_pages);
- }
-
- switch (change) {
- case KVM_MR_DELETE:
- rc = dat_delete_slot(mc, kvm->arch.gmap->asce, old->base_gfn, old->npages);
- break;
- case KVM_MR_MOVE:
- rc = dat_delete_slot(mc, kvm->arch.gmap->asce, old->base_gfn, old->npages);
- if (rc)
- break;
- fallthrough;
- case KVM_MR_CREATE:
- rc = dat_create_slot(mc, kvm->arch.gmap->asce, new->base_gfn, new->npages);
- break;
- case KVM_MR_FLAGS_ONLY:
- break;
- default:
- WARN(1, "Unknown KVM MR CHANGE: %d\n", change);
- }
- }
-out:
- if (rc)
- pr_warn("failed to commit memory region\n");
- return;
+void kvm_arch_commit_memory_region(struct kvm *kvm, struct kvm_memory_slot *old,
+ const struct kvm_memory_slot *new,
+ enum kvm_mr_change change)
+{
+ s390_kvm_mmu_commit_memory_region(kvm, old, new, change);
}
/**
diff --git a/arch/s390/kvm/s390/s390.h b/arch/s390/kvm/s390/s390.h
index e144ca2e6d5e..d284a263ba70 100644
--- a/arch/s390/kvm/s390/s390.h
+++ b/arch/s390/kvm/s390/s390.h
@@ -472,6 +472,9 @@ int __kvm_s390_mprotect_many(struct gmap *gmap, gpa_t gpa, u8 npages, unsigned i
unsigned long bits);
bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu);
+void kvm_s390_update_cmma_dirty(struct kvm *kvm, struct kvm_memory_slot *old);
+int kvm_s390_vm_stop_migration(struct kvm *kvm);
+
/* implemented in diag.c */
int kvm_s390_handle_diag(struct kvm_vcpu *vcpu);
@@ -594,6 +597,11 @@ static inline bool kvm_s390_cur_gmap_fault_is_write(void)
return test_facility(75) && (current->thread.gmap_teid.fsi == TEID_FSI_STORE);
}
+static __always_inline int kvm_s390_is_migration_mode(struct kvm *kvm)
+{
+ return kvm->arch.migration_mode;
+}
+
/**
* kvm_s390_vcpu_crypto_reset_all
*
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 18/33] KVM: s390: Prepare gmap for a second KVM implementation
2026-08-12 15:36 ` [PATCH v6 18/33] KVM: s390: Prepare gmap for a second KVM implementation Steffen Eiden
@ 2026-08-12 16:10 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:10 UTC (permalink / raw)
To: Steffen Eiden
Cc: linux-s390, Marc Zyngier, kvmarm, Alexander Gordeev, Oliver Upton,
Heiko Carstens, Vasily Gorbik, Christian Borntraeger, kvm
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
Pre-existing issues:
- [Critical] This problem wasn't introduced by this patch, but an unrecoverable failure in s390_kvm_mmu_commit_memory_region() leaves hardware page tables out of sync with KVM memslots.
- [High] This problem wasn't introduced by this patch, but non-atomic clear of dirty_bitmap in s390_kvm_mmu_get_dirty_log() causes dirty page tracking loss.
--
--- Patch [18]: [PATCH v6 18/33] KVM: s390: Prepare gmap for a second KVM implementation ---
commit e0cdf68355be56510fa59547630f7974c617a6a1
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: Prepare gmap for a second KVM implementation
Refactor gmap code such that a second s390 (host) KVM implementation can
use the gmap code as well. Move mmu code from s390 to gmap so the other
KVM implementation can use it as well.
No functional change.
> diff --git a/arch/s390/kvm/gmap/kvm_mmu.c b/arch/s390/kvm/gmap/kvm_mmu.c
> new file mode 100644
> index 0000000000000..b08b8229bb6ff
> --- /dev/null
> +++ b/arch/s390/kvm/gmap/kvm_mmu.c
> @@ -0,0 +1,133 @@
[ ... ]
> +/*
> + * Get (and clear) the dirty memory log for a memory slot.
> + */
> +int s390_kvm_mmu_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
> +{
[ ... ]
> + /* Clear the dirty log */
> + if (is_dirty) {
> + n = kvm_dirty_bitmap_bytes(memslot);
> + memset(memslot->dirty_bitmap, 0, n);
[Severity: High]
This isn't a bug introduced by this patch, but in s390_kvm_mmu_get_dirty_log()
is it safe to use a non-atomic memset() here? If mark_page_dirty() sets bits
concurrently (e.g. via DMA or adapter interrupts) using atomic set_bit_le(),
this non-atomic memset() might overwrite those newly dirtied bits. Could this
lead to lost dirty page tracking and data corruption post-migration?
> + }
> + r = 0;
> +out:
> + mutex_unlock(&kvm->slots_lock);
> + return r;
> +}
[ ... ]
> +void s390_kvm_mmu_commit_memory_region(struct kvm *kvm,
> + struct kvm_memory_slot *old,
> + const struct kvm_memory_slot *new,
> + enum kvm_mr_change change)
> +{
> + struct kvm_s390_mmu_cache *mc __free(kvm_s390_mmu_cache) = NULL;
> + int rc = 0;
> +
> + guard(mutex)(&kvm->slots_arch_lock);
> +
> + if (change == KVM_MR_FLAGS_ONLY)
> + return;
> +
> + mc = kvm_s390_new_mmu_cache();
> + if (!mc) {
> + rc = -ENOMEM;
> + goto out;
[Severity: Critical]
This is a pre-existing issue, but in s390_kvm_mmu_commit_memory_region(),
could this early return on allocation failure leave hardware page tables out of
sync with KVM memslots? If an unprivileged userspace process deletes a
memslot and triggers KVM_MR_DELETE, jumping to the out label skips
dat_delete_slot(). The generic KVM code removes the memslot, but the guest
hardware could retain the physical memory mapping, potentially allowing the
guest to access stale or reallocated host memory.
> + }
> +
> + scoped_guard(write_lock, &kvm->mmu_lock) {
> + kvm_s390_update_cmma_dirty(kvm, old);
> + switch (change) {
> + case KVM_MR_DELETE:
> + rc = dat_delete_slot(mc, kvm->arch.gmap->asce, old->base_gfn, old->npages);
> + break;
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=18
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 19/33] KVM: s390: gmap: Make storage keys optional
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (17 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 18/33] KVM: s390: Prepare gmap for a second KVM implementation Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:06 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 20/33] KVM: s390: gmap: Make CMMA optional Steffen Eiden
` (14 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Guard guest storage key handling behind `KVM_S390_MANAGES_S390_GUEST`.
This enables other KVM implementations to use gmap without implementing
storage key infrastructure. Define KVM_S390_MANAGES_S390_GUEST to 1 for
KVM hosts managing s390 guests (in kvm_host_s390.h). A KVM
implementation not implementing those features must define
KVM_S390_MANAGES_S390_GUEST to 0 in its kvm_host_<guest_arch>.h.
No functional changes besides the new guard.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/include/asm/kvm_host_s390.h | 2 ++
arch/s390/kvm/gmap/dat.c | 2 ++
arch/s390/kvm/gmap/dat.h | 4 ++++
arch/s390/kvm/gmap/gmap.c | 3 +++
arch/s390/kvm/gmap/gmap.h | 6 ++++++
5 files changed, 17 insertions(+)
diff --git a/arch/s390/include/asm/kvm_host_s390.h b/arch/s390/include/asm/kvm_host_s390.h
index 22e8d7c4a755..cd692f8fb764 100644
--- a/arch/s390/include/asm/kvm_host_s390.h
+++ b/arch/s390/include/asm/kvm_host_s390.h
@@ -32,6 +32,8 @@
#define KVM_INTERNAL_MEM_SLOTS 1
+#define KVM_S390_MANAGES_S390_GUEST 1
+
/*
* These seem to be used for allocating ->chip in the routing table, which we
* don't use. 1 is as small as we can get to reduce the needed memory. If we
diff --git a/arch/s390/kvm/gmap/dat.c b/arch/s390/kvm/gmap/dat.c
index 3f2d6e8902d7..f4e142995367 100644
--- a/arch/s390/kvm/gmap/dat.c
+++ b/arch/s390/kvm/gmap/dat.c
@@ -613,6 +613,7 @@ long _dat_walk_gfn_range(gfn_t start, gfn_t end, union asce asce,
return dat_crste_walk_range(start, min(end, asce_end(asce)), table, &walk);
}
+#if KVM_S390_MANAGES_S390_GUEST
int dat_get_storage_key(union asce asce, gfn_t gfn, union skey *skey)
{
union crste *crstep;
@@ -839,6 +840,7 @@ long dat_reset_skeys(union asce asce, gfn_t start)
return _dat_walk_gfn_range(start, asce_end(asce), asce, &ops, DAT_WALK_IGN_HOLES, NULL);
}
+#endif /* KVM_S390_MANAGES_S390_GUEST */
struct slot_priv {
unsigned long token;
diff --git a/arch/s390/kvm/gmap/dat.h b/arch/s390/kvm/gmap/dat.h
index 87108f51228e..2cc072168810 100644
--- a/arch/s390/kvm/gmap/dat.h
+++ b/arch/s390/kvm/gmap/dat.h
@@ -9,6 +9,7 @@
#ifndef ARCH_KVM_GMAP_DAT_H
#define ARCH_KVM_GMAP_DAT_H
+#include <linux/kvm_host.h>
#include <linux/radix-tree.h>
#include <linux/refcount.h>
#include <linux/io.h>
@@ -532,6 +533,8 @@ int dat_entry_walk(struct kvm_s390_mmu_cache *mc, gfn_t gfn, union asce asce, in
void dat_free_level(struct crst_table *table, bool owns_ptes);
struct crst_table *dat_alloc_crst_sleepable(unsigned long init);
int dat_set_asce_limit(struct kvm_s390_mmu_cache *mc, union asce *asce, int newtype);
+
+#if KVM_S390_MANAGES_S390_GUEST
int dat_get_storage_key(union asce asce, gfn_t gfn, union skey *skey);
int dat_set_storage_key(struct kvm_s390_mmu_cache *mc, union asce asce, gfn_t gfn,
union skey skey, bool nq);
@@ -539,6 +542,7 @@ int dat_cond_set_storage_key(struct kvm_s390_mmu_cache *mmc, union asce asce, gf
union skey skey, union skey *oldkey, bool nq, bool mr, bool mc);
int dat_reset_reference_bit(union asce asce, gfn_t gfn, union skey *skey);
long dat_reset_skeys(union asce asce, gfn_t start);
+#endif /* KVM_S390_MANAGES_S390_GUEST */
unsigned long dat_get_ptval(struct page_table *table, struct ptval_param param);
void dat_set_ptval(struct page_table *table, struct ptval_param param, unsigned long val);
diff --git a/arch/s390/kvm/gmap/gmap.c b/arch/s390/kvm/gmap/gmap.c
index b5b920392378..c1b0e2572818 100644
--- a/arch/s390/kvm/gmap/gmap.c
+++ b/arch/s390/kvm/gmap/gmap.c
@@ -944,6 +944,8 @@ void gmap_split_huge_pages(struct gmap *gmap)
} while (start);
}
+#if KVM_S390_MANAGES_S390_GUEST
+
static int _gmap_enable_skeys(struct gmap *gmap)
{
gfn_t start = 0;
@@ -975,6 +977,7 @@ int gmap_enable_skeys(struct gmap *gmap)
mmap_write_unlock(gmap->kvm->mm);
return rc;
}
+#endif /* KVM_S390_MANAGES_S390_GUEST */
static long _destroy_pages_pte(union pte *ptep, gfn_t gfn, gfn_t next, struct dat_walk *walk)
{
diff --git a/arch/s390/kvm/gmap/gmap.h b/arch/s390/kvm/gmap/gmap.h
index c54c35e47d6d..328a81c72c7a 100644
--- a/arch/s390/kvm/gmap/gmap.h
+++ b/arch/s390/kvm/gmap/gmap.h
@@ -10,6 +10,8 @@
#ifndef ARCH_KVM_GMAP_GMAP_H
#define ARCH_KVM_GMAP_GMAP_H
+#include <linux/kvm_host.h>
+
#include "dat.h"
/**
@@ -98,7 +100,11 @@ int gmap_set_limit(struct gmap *gmap, gfn_t limit);
int gmap_ucas_translate(struct kvm_s390_mmu_cache *mc, struct gmap *gmap, gpa_t *gaddr);
int gmap_ucas_map(struct gmap *gmap, gfn_t p_gfn, gfn_t c_gfn, unsigned long count);
void gmap_ucas_unmap(struct gmap *gmap, gfn_t c_gfn, unsigned long count);
+
+#if KVM_S390_MANAGES_S390_GUEST
int gmap_enable_skeys(struct gmap *gmap);
+#endif /* KVM_S390_MANAGES_S390_GUEST */
+
int gmap_pv_destroy_range(struct gmap *gmap, gfn_t start, gfn_t end, bool interruptible);
int gmap_insert_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gfn,
gfn_t r_gfn, int level);
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 20/33] KVM: s390: gmap: Make CMMA optional
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (18 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 19/33] KVM: s390: gmap: Make storage keys optional Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:09 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 21/33] KVM: s390: gmap: Make prefix handling optional Steffen Eiden
` (13 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Guard guest CMMA behind `KVM_S390_MANAGES_S390_GUEST`. This enables
other KVM implementations to use gmap without implementing CMMA.
No functional changes.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/gmap/dat.c | 2 ++
arch/s390/kvm/gmap/dat.h | 2 ++
arch/s390/kvm/gmap/gmap.c | 2 ++
arch/s390/kvm/gmap/gmap.h | 4 +++-
4 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/s390/kvm/gmap/dat.c b/arch/s390/kvm/gmap/dat.c
index f4e142995367..43ebafb56ce5 100644
--- a/arch/s390/kvm/gmap/dat.c
+++ b/arch/s390/kvm/gmap/dat.c
@@ -1059,6 +1059,7 @@ int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn)
return 0;
}
+#if KVM_S390_MANAGES_S390_GUEST
/**
* dat_perform_essa() - Perform ESSA actions on the PGSTE.
* @asce: The asce to operate on.
@@ -1336,3 +1337,4 @@ int dat_set_cmma_bits(struct kvm_s390_mmu_cache *mc, union asce asce, gfn_t gfn,
}
return _dat_walk_gfn_range(gfn, gfn + count, asce, &ops, DAT_WALK_IGN_HOLES, &state);
}
+#endif /* KVM_S390_MANAGES_S390_GUEST */
diff --git a/arch/s390/kvm/gmap/dat.h b/arch/s390/kvm/gmap/dat.h
index 2cc072168810..4f11f9bbd83a 100644
--- a/arch/s390/kvm/gmap/dat.h
+++ b/arch/s390/kvm/gmap/dat.h
@@ -552,12 +552,14 @@ int dat_set_slot(struct kvm_s390_mmu_cache *mc, union asce asce, gfn_t start, gf
int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn);
bool dat_test_age_gfn(union asce asce, gfn_t start, gfn_t end);
+#if KVM_S390_MANAGES_S390_GUEST
int dat_perform_essa(union asce asce, gfn_t gfn, int orc, union essa_state *state, bool *dirty);
long dat_reset_cmma(union asce asce, gfn_t start_gfn);
int dat_peek_cmma(gfn_t start, union asce asce, unsigned int *count, u8 *values);
int dat_get_cmma(union asce asce, gfn_t *start, unsigned int *count, u8 *values, atomic64_t *rem);
int dat_set_cmma_bits(struct kvm_s390_mmu_cache *mc, union asce asce, gfn_t gfn,
unsigned long count, unsigned long mask, const uint8_t *bits);
+#endif /* KVM_S390_MANAGES_S390_GUEST */
int kvm_s390_mmu_cache_topup(struct kvm_s390_mmu_cache *mc);
diff --git a/arch/s390/kvm/gmap/gmap.c b/arch/s390/kvm/gmap/gmap.c
index c1b0e2572818..86513f653850 100644
--- a/arch/s390/kvm/gmap/gmap.c
+++ b/arch/s390/kvm/gmap/gmap.c
@@ -1098,6 +1098,7 @@ int gmap_protect_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gf
return 0;
}
+#if KVM_S390_MANAGES_S390_GUEST
static long __set_cmma_clean_pte(union pte *ptep, gfn_t gfn, gfn_t next, struct dat_walk *walk)
{
union pgste pgste;
@@ -1140,6 +1141,7 @@ void _gmap_set_cmma_all(struct gmap *gmap, bool dirty)
&gmap->kvm->arch.cmma_dirty_pages);
} while (gfn);
}
+#endif /* KVM_S390_MANAGES_S390_GUEST */
static void gmap_unshadow_level(struct gmap *sg, gfn_t r_gfn, int level)
{
diff --git a/arch/s390/kvm/gmap/gmap.h b/arch/s390/kvm/gmap/gmap.h
index 328a81c72c7a..6f3bf11d2166 100644
--- a/arch/s390/kvm/gmap/gmap.h
+++ b/arch/s390/kvm/gmap/gmap.h
@@ -110,7 +110,6 @@ int gmap_insert_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gfn
gfn_t r_gfn, int level);
int gmap_protect_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gfn, gfn_t r_gfn,
kvm_pfn_t pfn, int level, bool wr);
-void _gmap_set_cmma_all(struct gmap *gmap, bool dirty);
void _gmap_handle_vsie_unshadow_event(struct gmap *parent, gfn_t gfn);
struct gmap *gmap_create_shadow(struct kvm_s390_mmu_cache *mc, struct gmap *gmap,
union asce asce, int edat_level);
@@ -204,6 +203,8 @@ static inline bool pte_needs_unshadow(union pte oldpte, union pte newpte, union
return !newpte.h.p || !newpte.s.pr;
}
+#if KVM_S390_MANAGES_S390_GUEST
+void _gmap_set_cmma_all(struct gmap *gmap, bool dirty);
static inline void gmap_set_cmma_all_dirty(struct gmap *gmap)
{
_gmap_set_cmma_all(gmap, true);
@@ -213,6 +214,7 @@ static inline void gmap_set_cmma_all_clean(struct gmap *gmap)
{
_gmap_set_cmma_all(gmap, false);
}
+#endif /* KVM_S390_MANAGES_S390_GUEST */
static inline union pgste _gmap_ptep_xchg(struct gmap *gmap, union pte *ptep, union pte newpte,
union pgste pgste, gfn_t gfn, bool needs_lock)
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 21/33] KVM: s390: gmap: Make prefix handling optional
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (19 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 20/33] KVM: s390: gmap: Make CMMA optional Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:08 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 22/33] KVM: s390: Prepare KVM/s390 for a second KVM module Steffen Eiden
` (12 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Guard guest prefix handling behind `KVM_S390_MANAGES_S390_GUEST`. This
enables other KVM implementations to use gmap without implementing
prefix handling. The prefix handling is integrated deeply in the gmap
implementation. Therefore, provide safe default implementations for the
guarded functions.
No functional changes.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/gmap/dat.c | 2 +-
arch/s390/kvm/gmap/dat.h | 9 +++++++++
arch/s390/kvm/gmap/gmap.c | 12 +++++++-----
arch/s390/kvm/gmap/gmap.h | 9 ++++++++-
4 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/arch/s390/kvm/gmap/dat.c b/arch/s390/kvm/gmap/dat.c
index 43ebafb56ce5..3038eae1cfcc 100644
--- a/arch/s390/kvm/gmap/dat.c
+++ b/arch/s390/kvm/gmap/dat.c
@@ -1011,6 +1011,7 @@ bool dat_test_age_gfn(union asce asce, gfn_t start, gfn_t end)
return _dat_walk_gfn_range(start, end, asce, &test_age_ops, 0, NULL) > 0;
}
+#if KVM_S390_MANAGES_S390_GUEST
static long dat_set_pn_crste(union crste *crstep, gfn_t gfn, gfn_t next, struct dat_walk *walk)
{
union crste newcrste, oldcrste;
@@ -1059,7 +1060,6 @@ int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn)
return 0;
}
-#if KVM_S390_MANAGES_S390_GUEST
/**
* dat_perform_essa() - Perform ESSA actions on the PGSTE.
* @asce: The asce to operate on.
diff --git a/arch/s390/kvm/gmap/dat.h b/arch/s390/kvm/gmap/dat.h
index 4f11f9bbd83a..e452c141b841 100644
--- a/arch/s390/kvm/gmap/dat.h
+++ b/arch/s390/kvm/gmap/dat.h
@@ -549,7 +549,16 @@ void dat_set_ptval(struct page_table *table, struct ptval_param param, unsigned
int dat_set_slot(struct kvm_s390_mmu_cache *mc, union asce asce, gfn_t start, gfn_t end,
u16 type, u16 param);
+
+#if KVM_S390_MANAGES_S390_GUEST
int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn);
+#else
+static inline int dat_set_prefix_notif_bit(union asce asce, gfn_t gfn)
+{
+ return 0;
+}
+#endif /* KVM_S390_MANAGES_S390_GUEST */
+
bool dat_test_age_gfn(union asce asce, gfn_t start, gfn_t end);
#if KVM_S390_MANAGES_S390_GUEST
diff --git a/arch/s390/kvm/gmap/gmap.c b/arch/s390/kvm/gmap/gmap.c
index 86513f653850..4968330e9553 100644
--- a/arch/s390/kvm/gmap/gmap.c
+++ b/arch/s390/kvm/gmap/gmap.c
@@ -24,11 +24,6 @@
#include "s390.h"
#include "faultin.h"
-static inline bool kvm_s390_is_in_sie(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.sie_block->prog0c & PROG_IN_SIE;
-}
-
static int gmap_limit_to_type(gfn_t limit)
{
if (!limit)
@@ -256,6 +251,12 @@ int s390_replace_asce(struct gmap *gmap)
return 0;
}
+#if KVM_S390_MANAGES_S390_GUEST
+static inline bool kvm_s390_is_in_sie(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.sie_block->prog0c & PROG_IN_SIE;
+}
+
bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint)
{
struct kvm *kvm = gmap->kvm;
@@ -278,6 +279,7 @@ bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint)
}
return true;
}
+#endif /* KVM_S390_MANAGES_S390_GUEST */
struct clear_young_pte_priv {
struct gmap *gmap;
diff --git a/arch/s390/kvm/gmap/gmap.h b/arch/s390/kvm/gmap/gmap.h
index 6f3bf11d2166..8f47f29c89fd 100644
--- a/arch/s390/kvm/gmap/gmap.h
+++ b/arch/s390/kvm/gmap/gmap.h
@@ -85,7 +85,6 @@ struct gmap_cache {
for (pos = (head); n = pos ? pos->next : NULL, pos; pos = n)
int s390_replace_asce(struct gmap *gmap);
-bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint);
bool gmap_age_gfn(struct gmap *gmap, gfn_t start, gfn_t end);
bool gmap_unmap_gfn_range(struct gmap *gmap, struct kvm_memory_slot *slot, gfn_t start, gfn_t end);
int gmap_try_fixup_minor(struct gmap *gmap, struct guest_fault *fault);
@@ -163,6 +162,14 @@ static inline void gmap_handle_vsie_unshadow_event(struct gmap *parent, gfn_t gf
_gmap_handle_vsie_unshadow_event(parent, gfn);
}
+#if KVM_S390_MANAGES_S390_GUEST
+bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint);
+#else
+static inline bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint)
+{
+ return true;
+}
+#endif /* KVM_S390_MANAGES_S390_GUEST */
static inline bool gmap_mkold_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end)
{
return _gmap_unmap_prefix(gmap, gfn, end, true);
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 21/33] KVM: s390: gmap: Make prefix handling optional
2026-08-12 15:36 ` [PATCH v6 21/33] KVM: s390: gmap: Make prefix handling optional Steffen Eiden
@ 2026-08-12 16:08 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:08 UTC (permalink / raw)
To: Steffen Eiden
Cc: Christian Borntraeger, Alexander Gordeev, linux-s390,
Oliver Upton, Marc Zyngier, kvm, Vasily Gorbik, Heiko Carstens,
kvmarm
> Guard guest prefix handling behind `KVM_S390_MANAGES_S390_GUEST`. This
> enables other KVM implementations to use gmap without implementing
> prefix handling. The prefix handling is integrated deeply in the gmap
> implementation. Therefore, provide safe default implementations for the
> guarded functions.
>
> No functional changes.
>
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=21
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 22/33] KVM: s390: Prepare KVM/s390 for a second KVM module
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (20 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 21/33] KVM: s390: gmap: Make prefix handling optional Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:21 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 23/33] s390: Use arm64 headers Steffen Eiden
` (11 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
The second KVM module will have a different Kconfig set. When both
modules are compiled the Kconfig sets get merged and the native s390 KVM
needs to implement functionality required by the respective config
options. Ensure that s390-KVM will still compile by implementing a stub
for kvm_arch_vcpu_run_pid_change if CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
is enabled and defining KVM_NO_MMIO to disable KVM_MMIO.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/include/asm/kvm_host_s390.h | 1 +
arch/s390/kvm/s390/s390.c | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/s390/include/asm/kvm_host_s390.h b/arch/s390/include/asm/kvm_host_s390.h
index cd692f8fb764..207f44cb86d9 100644
--- a/arch/s390/include/asm/kvm_host_s390.h
+++ b/arch/s390/include/asm/kvm_host_s390.h
@@ -29,6 +29,7 @@
#define KVM_HAVE_MMU_RWLOCK
#define KVM_MAX_VCPUS 255
+#define KVM_NO_MMIO
#define KVM_INTERNAL_MEM_SLOTS 1
diff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c
index 1d0d94f000f7..d1e736e1f06f 100644
--- a/arch/s390/kvm/s390/s390.c
+++ b/arch/s390/kvm/s390/s390.c
@@ -5868,6 +5868,14 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
return gmap_unmap_gfn_range(kvm->arch.gmap, range->slot, range->start, range->end);
}
+#ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
+/* Make s390 compile if arm64-on-s390 is selected */
+int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
+{
+ return 0;
+}
+#endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */
+
static inline unsigned long nonhyp_mask(int i)
{
unsigned int nonhyp_fai = (sclp.hmfai << i * 2) >> 30;
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 22/33] KVM: s390: Prepare KVM/s390 for a second KVM module
2026-08-12 15:36 ` [PATCH v6 22/33] KVM: s390: Prepare KVM/s390 for a second KVM module Steffen Eiden
@ 2026-08-12 16:21 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:21 UTC (permalink / raw)
To: Steffen Eiden
Cc: Marc Zyngier, Alexander Gordeev, linux-s390, kvmarm, Oliver Upton,
Heiko Carstens, kvm, Vasily Gorbik, Christian Borntraeger
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The patch fails to provide all necessary stubs to make s390 KVM compile when merged with an arm64 KVM Kconfig, leading to undefined references to functions like `kvm_get_dirty_log` and `kvm_arch_allow_write_without_running_vcpu`.
--
--- Patch [22]: [PATCH v6 22/33] KVM: s390: Prepare KVM/s390 for a second KVM module ---
commit fb387e8f82c2198f5fffbab975b0cb04cd2ac49c
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: Prepare KVM/s390 for a second KVM module
The second KVM module will have a different Kconfig set. When both
modules are compiled the Kconfig sets get merged and the native s390 KVM
needs to implement functionality required by the respective config
options. Ensure that s390-KVM will still compile by implementing a stub
for kvm_arch_vcpu_run_pid_change if CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
is enabled and defining KVM_NO_MMIO to disable KVM_MMIO.
> diff --git a/arch/s390/kvm/s390/s390.c b/arch/s390/kvm/s390/s390.c
> index 1d0d94f000f72..d1e736e1f06f2 100644
> --- a/arch/s390/kvm/s390/s390.c
> +++ b/arch/s390/kvm/s390/s390.c
> @@ -5868,6 +5868,14 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
> return gmap_unmap_gfn_range(kvm->arch.gmap, range->slot, range->start, range->end);
> }
>
> +#ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
> +/* Make s390 compile if arm64-on-s390 is selected */
> +int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
> +{
> + return 0;
> +}
> +#endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */
[Severity: Low]
Are there other missing stubs required to make s390 KVM compile when merged
with the arm64 KVM Kconfig?
If CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT and
CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP are enabled by the merged configs,
could there be undefined references to functions like kvm_get_dirty_log() and
kvm_arch_allow_write_without_running_vcpu()?
For instance, s390_kvm_mmu_get_dirty_log() in arch/s390/kvm/gmap/kvm_mmu.c
calls kvm_get_dirty_log(), which is omitted from virt/kvm/kvm_main.c when
CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT is selected.
Would adding stubs for these functions be needed to fully resolve the linker
errors this patch aims to fix?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=22
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 23/33] s390: Use arm64 headers
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (21 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 22/33] KVM: s390: Prepare KVM/s390 for a second KVM module Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:23 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 24/33] KVM: s390: Use arm64 code Steffen Eiden
` (10 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Introduce a flexible system for sharing ARM64 headers with s390 KVM.
Selected arm64 headers or snippet of headers will be reachable by s390
code through asm/header.h.
Add copy-arm64h.awk that detects ARM64_S390_COMMON markers and extracts
marked section into a generated header consumable by s390. Falls back to
full file copy when no markers are found.
Transform copied includes by replacing '#include <asm/...>' with
'#include <arm64/...>' and similar for uapi headers to ensure
correct path resolution on s390 and allow for a clear separation of s390
asm headers and arm64 asm headers.
Integrate this extraction into the s390/kapi target, conditional on (the
not yet existing) CONFIG_KVM_ARM64.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/tools/Makefile | 9 +++-
arch/s390/tools/Makefile.arm64h | 57 ++++++++++++++++++++++
arch/s390/tools/copy-arm64h-full.awk | 47 ++++++++++++++++++
arch/s390/tools/copy-arm64h.awk | 72 ++++++++++++++++++++++++++++
4 files changed, 184 insertions(+), 1 deletion(-)
create mode 100644 arch/s390/tools/Makefile.arm64h
create mode 100644 arch/s390/tools/copy-arm64h-full.awk
create mode 100644 arch/s390/tools/copy-arm64h.awk
diff --git a/arch/s390/tools/Makefile b/arch/s390/tools/Makefile
index f2862364fb42..a624b2639b43 100644
--- a/arch/s390/tools/Makefile
+++ b/arch/s390/tools/Makefile
@@ -3,12 +3,19 @@
# Makefile for s390 specific build tools
#
+include $(srctree)/arch/s390/tools/Makefile.arm64h
+
kapi := arch/$(ARCH)/include/generated/asm
kapi-hdrs-y := $(kapi)/facility-defs.h $(kapi)/dis-defs.h
+targets += $(addprefix ../../../,$(kapi-hdrs-y))
+targets += $(patsubst $(objtree)/%,../../../%,$(ARM64_TARGETS))
+
+kapi-hdrs-$(CONFIG_KVM_ARM64) += $(ARM64_TARGETS)
+
PHONY += kapi
-kapi: $(kapi-hdrs-y)
+kapi: $(kapi-hdrs-y) $(kapi-hdrs-m)
hostprogs += gen_facilities
hostprogs += gen_opcode_table
diff --git a/arch/s390/tools/Makefile.arm64h b/arch/s390/tools/Makefile.arm64h
new file mode 100644
index 000000000000..3e033630470a
--- /dev/null
+++ b/arch/s390/tools/Makefile.arm64h
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Share ARM64 headers with s390 KVM
+#
+
+arm64api := $(objtree)/arch/$(ARCH)/include/generated/arm64
+arm64uapi := $(objtree)/arch/$(ARCH)/include/generated/uapi/arm64
+
+# List of ARM64 headers to share with s390 KVM
+# Format: [uapi:]header.h or header-gen.h
+#
+# * header.h - from arch/arm64/include/asm/ to arm64/
+# * uapi:header.h - from arch/arm64/include/uapi/asm/ to uapi/arm64/
+# * header-gen.h - generated as header-gen.h from ARM64 header header.h
+# If a header contains partial markers (#ifdef ARM64_S390_COMMON) only this part will be copied.
+# If the file does not contain any markers the whole file will be copied.
+ARM64_SHARED_HEADERS := \
+ brk-imm.h \
+ esr.h \
+ kvm_arm.h \
+ kvm_emulate-gen.h \
+ kvm_host.h \
+ ptrace-gen.h \
+ sysreg-gen.h \
+ uapi:hwcap.h \
+ uapi:kvm.h \
+ uapi:ptrace.h \
+ uapi:sve_context.h \
+
+quiet_cmd_gen_arm_hdr = GEN $@
+ cmd_gen_arm_hdr = mkdir -p $(dir $@); \
+ $(AWK) -f $(src)/copy-arm64h.awk $< > $@ || \
+ $(AWK) -f $(src)/copy-arm64h-full.awk -v srcfile="$(subst $(srctree)/,,$(subst $(srctree)/../,,$<))" $< > $@ || \
+ { echo "Error: Unbalanced ARM64_S390_COMMON markers in $<" >&2; rm -f $@; exit 1; }
+
+arm64-type = $(firstword $(subst :, ,$(1)))
+arm64-base = $(or $(word 2,$(subst :, ,$(1))),$(1))
+arm64-src-base = $(patsubst %-gen.h,%.h,$(call arm64-base,$(1)))
+
+arm64-src = $(srctree)/arch/arm64/include/$(if $(filter uapi,$(call arm64-type,$(1))),uapi/)asm/$(call arm64-src-base,$(1))
+arm64-dst = $(if $(filter uapi,$(call arm64-type,$(1))),$(arm64uapi),$(arm64api))/$(call arm64-base,$(1))
+
+$(foreach hdr,$(ARM64_SHARED_HEADERS),\
+ $(eval $(call arm64-dst,$(hdr)): $(call arm64-src,$(hdr)) $(src)/copy-arm64h.awk $(src)/copy-arm64h-full.awk))
+
+ARM64_TARGETS := $(sort $(foreach hdr,$(ARM64_SHARED_HEADERS),$(call arm64-dst,$(hdr))))
+
+$(ARM64_TARGETS):
+ $(call cmd,gen_arm_hdr)
+
+quiet_cmd_gen_sysreg_arm64 = GEN $@
+ cmd_gen_sysreg_arm64 = mkdir -p $(dir $@); $(AWK) -f $(srctree)/arch/arm64/tools/gen-sysreg.awk $(srctree)/arch/arm64/tools/sysreg > $@
+
+$(arm64api)/sysreg-defs.h: $(srctree)/arch/arm64/tools/gen-sysreg.awk $(srctree)/arch/arm64/tools/sysreg FORCE
+ $(call if_changed,gen_sysreg_arm64)
+
+ARM64_TARGETS += $(arm64api)/sysreg-defs.h
diff --git a/arch/s390/tools/copy-arm64h-full.awk b/arch/s390/tools/copy-arm64h-full.awk
new file mode 100644
index 000000000000..a6aaf9cc3332
--- /dev/null
+++ b/arch/s390/tools/copy-arm64h-full.awk
@@ -0,0 +1,47 @@
+#!/usr/bin/awk -f
+# SPDX-License-Identifier: GPL-2.0
+#
+# Process entire ARM64 headers for sharing with s390 KVM
+#
+# Usage: copy-arm64h-full.awk -v srcfile=<source_path> <input_file>
+#
+# This processes the entire file (unlike copy-arm64h.awk which only extracts marked sections)
+
+BEGIN {
+ max_guard_line = 25
+ guard_found = 0
+ header_added = 0
+}
+
+# Find and process the include guard in the first few lines
+NR <= max_guard_line && !guard_found && /^#ifndef [A-Z_0-9]+$/ {
+ guard_name = $2
+ guard_found = 1
+ print "/* This header was copied from " srcfile " */"
+ print ""
+ print
+ header_added = 1
+ next
+}
+
+# Transform include directives
+/^#include <uapi\/asm\// {
+ sub(/<uapi\/asm\//, "<uapi/arm64/")
+ print
+ next
+}
+
+/^#include <asm\// {
+ sub(/<asm\//, "<arm64/")
+ print
+ next
+}
+
+/ARM64_S390_COMMON/ {
+ exit 1
+}
+
+# Pass through all other lines
+{
+ print
+}
diff --git a/arch/s390/tools/copy-arm64h.awk b/arch/s390/tools/copy-arm64h.awk
new file mode 100644
index 000000000000..d74df368c1b5
--- /dev/null
+++ b/arch/s390/tools/copy-arm64h.awk
@@ -0,0 +1,72 @@
+#!/usr/bin/awk -f
+# SPDX-License-Identifier: GPL-2.0
+#
+# Extract marked sections from ARM64 headers for sharing with s390 KVM
+#
+# Usage: share-arm64-header.awk <input_file>
+#
+# Extracts all sections between start/end markers. If no markers found, signals for fallback.
+#TODO verification script or c file for arm to verify the ifdef things keep working
+BEGIN {
+ # Constants
+ start_pattern = "^#ifdef ARM64_S390_COMMON$"
+ end_pattern = "^#endif \\/\\* ARM64_S390_COMMON \\*\\/$"
+ max_guard_line = 25
+
+ # State variables
+ copying = found_marker = 0
+ guard_name = ""
+ file_header_done = 0
+}
+
+NR <= max_guard_line && !guard_name && /^#ifndef [A-Za-z0-9_]+$/ {
+ guard_name = $2
+ filename = FILENAME
+ sub(/^.*arch\/arm64\//, "arch/arm64/", filename)
+ print "/*"
+ print " * This header was automatically generated from " filename
+ print " * Do not modify this file directly."
+ print " */"
+ print "#ifndef " guard_name
+ print "#define " guard_name
+ print ""
+ next
+}
+
+NR > max_guard_line && !guard_name && !file_header_done {
+ print "error: no include guard found in first " max_guard_line " lines" > "/dev/stderr"
+ file_header_done = 1
+ exit 1
+}
+
+!guard_name {
+ print
+ next
+}
+
+$0 ~ start_pattern {
+ if (copying) { exit 1 }
+ copying = found_marker = 1
+ next
+}
+
+guard_name && !found_marker {
+ next
+}
+
+$0 ~ end_pattern { copying = 0; next }
+
+copying {
+ gsub(/#include <asm\//, "#include <arm64/")
+ gsub(/#include <uapi\/asm\//, "#include <uapi/arm64/")
+ print
+ next
+}
+
+END {
+ if (found_marker) {
+ print ""
+ print "#endif /* " guard_name " */"
+ }
+ exit !found_marker || copying
+}
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 23/33] s390: Use arm64 headers
2026-08-12 15:36 ` [PATCH v6 23/33] s390: Use arm64 headers Steffen Eiden
@ 2026-08-12 16:23 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:23 UTC (permalink / raw)
To: Steffen Eiden
Cc: Oliver Upton, kvm, kvmarm, Vasily Gorbik, Marc Zyngier,
Alexander Gordeev, linux-s390, Christian Borntraeger,
Heiko Carstens
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Low] The header sharing mechanism generates sysreg-gen.h instead of sysreg.h, causing unresolved includes. esr.h is fully copied since it has no ARM64_S390_COMMON markers, meaning its `#include <asm/sysreg.h>` is retained and transformed to `#include <arm64/sysreg.h>`. However, because sysreg.h is mapped to sysreg-gen.h in ARM64_SHARED_HEADERS, the target file is generated as arm64/sysreg-gen.h. As a result, the include in esr.h will fail to find arm64/sysreg.h.
- [Low] The Make rule for generating $(ARM64_TARGETS) uses `$(call cmd,gen_arm_hdr)` without `if_changed` or `FORCE`. In Kbuild, files added to `targets` must be generated using `if_changed` so that `.cmd` files are created to track command-line modifications. The omission of `if_changed` defeats this dependency tracking.
--
--- Patch [23]: [PATCH v6 23/33] s390: Use arm64 headers ---
commit 505a7f9c35b46d1872a2e9da2ab63e0bc5a7471f
Author: Steffen Eiden <seiden@linux.ibm.com>
s390: Use arm64 headers
This commit introduces a flexible system for sharing ARM64 headers with
s390 KVM. It adds awk scripts to extract marked sections or copy full files,
and transforms includes to ensure correct path resolution on s390.
> diff --git a/arch/s390/tools/Makefile.arm64h b/arch/s390/tools/Makefile.arm64h
> new file mode 100644
> index 0000000000000..3e033630470a1
> --- /dev/null
> +++ b/arch/s390/tools/Makefile.arm64h
> @@ -0,0 +1,57 @@
[ ... ]
> +ARM64_SHARED_HEADERS := \
> + brk-imm.h \
> + esr.h \
> + kvm_arm.h \
> + kvm_emulate-gen.h \
> + kvm_host.h \
> + ptrace-gen.h \
> + sysreg-gen.h \
[Severity: Low]
Will this result in an unresolved include when esr.h is compiled?
esr.h has no ARM64_S390_COMMON markers, so it is fully copied using
copy-arm64h-full.awk. That script transforms #include <asm/sysreg.h> into
#include <arm64/sysreg.h>. However, since ARM64_SHARED_HEADERS maps
sysreg.h to sysreg-gen.h, the generated file will be arm64/sysreg-gen.h,
and the include in esr.h will fail to find arm64/sysreg.h.
[ ... ]
> +ARM64_TARGETS := $(sort $(foreach hdr,$(ARM64_SHARED_HEADERS),$(call arm64-dst,$(hdr))))
> +
> +$(ARM64_TARGETS):
> + $(call cmd,gen_arm_hdr)
[Severity: Low]
Should this use if_changed and FORCE instead of directly calling cmd?
In Kbuild, files added to targets must be generated using if_changed so that
.cmd files are created to track command-line modifications. Omitting
if_changed here prevents automatic rebuilds if the command-line arguments
or rules change.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=23
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 24/33] KVM: s390: Use arm64 code
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (22 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 23/33] s390: Use arm64 headers Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:18 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 25/33] s390: Introduce Start Arm Execution instruction Steffen Eiden
` (9 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Add the infrastructure to extract KVM/arm64 code into s390 at built
time similar to the arm64 header sharing. Add copy-arm64c.awk hat
detects ARM64_S390_COMMON markers and extracts marked section into an
.inc file that can be consumed by arm on s390 host code. If no marker is
found make will fail.
To ensure that no code is consumed twice by accident a guard is added
during file generation. A s390 C file wanting to consume such an inc
file must first define __INCL_GEN_ARM_FILE otherwise the inc file will
emit a compile error.
Example:
#define __INCL_GEN_ARM_FILE
#include <generated/arm.inc>
#undef __INCL_GEN_ARM_FILE
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/arm64/.gitignore | 2 +
arch/s390/kvm/arm64/Makefile.gen | 29 ++++++++++++
arch/s390/kvm/arm64/copy-arm64c.awk | 72 +++++++++++++++++++++++++++++
3 files changed, 103 insertions(+)
create mode 100644 arch/s390/kvm/arm64/.gitignore
create mode 100644 arch/s390/kvm/arm64/Makefile.gen
create mode 100644 arch/s390/kvm/arm64/copy-arm64c.awk
diff --git a/arch/s390/kvm/arm64/.gitignore b/arch/s390/kvm/arm64/.gitignore
new file mode 100644
index 000000000000..bd9d90694676
--- /dev/null
+++ b/arch/s390/kvm/arm64/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+generated/*
diff --git a/arch/s390/kvm/arm64/Makefile.gen b/arch/s390/kvm/arm64/Makefile.gen
new file mode 100644
index 000000000000..cb9482eb947b
--- /dev/null
+++ b/arch/s390/kvm/arm64/Makefile.gen
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Extracts ARM64 marked sections to .inc files that are included by main source
+# files
+
+# List of ARM64 C files to extract
+ARM64_CFILES := \
+ arm.c \
+ guest.c \
+ handle_exit.c \
+ mmio.c \
+
+quiet_cmd_extract_inc = GEN $@
+ cmd_extract_inc = mkdir -p $(dir $@); \
+ $(AWK) -f $(src)/copy-arm64c.awk $< > $@ || \
+ { echo "Error: No or unbalanced ARM64_S390_COMMON markers in $<" >&2; rm -f $@; exit 1; }
+
+$(obj)/generated/%.inc: $(srctree)/arch/arm64/kvm/%.c $(src)/copy-arm64c.awk FORCE
+ $(call if_changed,extract_inc)
+
+ARM64_INC_FILES := $(foreach cfile,$(ARM64_CFILES),generated/$(basename $(cfile)).inc)
+
+targets += $(ARM64_INC_FILES)
+clean-files += generated/*.inc
+
+$(addprefix $(obj)/,$(kvm-arm64-obj)): $(addprefix $(obj)/,$(ARM64_INC_FILES))
+
+$(foreach cfile,$(basename $(ARM64_CFILES)),\
+ $(eval $(obj)/$(cfile).o: $(obj)/generated/$(cfile).inc))
diff --git a/arch/s390/kvm/arm64/copy-arm64c.awk b/arch/s390/kvm/arm64/copy-arm64c.awk
new file mode 100644
index 000000000000..20bd73c52ec4
--- /dev/null
+++ b/arch/s390/kvm/arm64/copy-arm64c.awk
@@ -0,0 +1,72 @@
+#!/usr/bin/awk -f
+# SPDX-License-Identifier: GPL-2.0
+#
+# Extract marked sections from ARM64 C files for sharing with s390 KVM
+#
+# Usage: share-arm64-cfile.awk <input_file>
+#
+# Extracts all sections between start/end markers. If no markers found, signals failure.
+
+BEGIN {
+ # Constants
+ start_pattern = "^#ifdef ARM64_S390_COMMON$"
+ end_pattern = "^#endif /\\* ARM64_S390_COMMON \\*/$"
+
+ # State variables
+ copying = found_marker = 0
+ file_header_done = 0
+}
+
+!file_header_done {
+ if (/^\/\*/ || /^\/\/ SPDX-License-Identifier:/) {
+ print
+ next
+ }
+ if (/[[:space:]]\*([[:space:]]|$)/) {
+ print
+ next
+ }
+ if (/\*\//) {
+ print " *"
+ } else {
+ print "/*"
+ }
+
+ filename = FILENAME
+ sub(/^.*arch\/arm64\//, "arch/arm64/", filename)
+ print " * This file was automatically generated from " filename
+ print " * Do not modify this file directly."
+ print " */"
+ print ""
+ print "#ifndef __INCL_GEN_ARM_FILE"
+ print "#error included .inc file w/o proper guard definition"
+ print "#else"
+ print "#undef __INCL_GEN_ARM_FILE"
+ print "#endif /* __INCL_GEN_ARM_FILE */"
+ print ""
+
+ file_header_done = 1
+}
+
+$0 ~ start_pattern {
+ if (copying) { exit 1 }
+ copying = found_marker = 1
+ next
+}
+
+$0 ~ end_pattern {
+ if (!copying) { exit 1 }
+ copying = 0
+ next
+}
+
+copying {
+ gsub(/#include <asm\//, "#include <arm64/")
+ gsub(/#include <uapi\/asm\//, "#include <uapi/arm64/")
+ print
+ next
+}
+
+END {
+ exit !found_marker || copying
+}
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 24/33] KVM: s390: Use arm64 code
2026-08-12 15:36 ` [PATCH v6 24/33] KVM: s390: Use arm64 code Steffen Eiden
@ 2026-08-12 16:18 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:18 UTC (permalink / raw)
To: Steffen Eiden
Cc: kvm, Marc Zyngier, Oliver Upton, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Heiko Carstens, kvmarm, linux-s390
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Potential Makefile syntax error due to an incorrectly named variable `kvm-arm64-obj`.
--
--- Patch [24]: [PATCH v6 24/33] KVM: s390: Use arm64 code ---
commit e4207bffe34b1de1b2b51c1d13254c153e76c1b6
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: Use arm64 code
This commit adds the infrastructure to extract KVM/arm64 code into s390 at build
time. It introduces an awk script to extract marked sections into .inc files
and a Makefile.gen to generate these dependencies. A guard macro is also
included in the generated files to prevent accidental double consumption.
> diff --git a/arch/s390/kvm/arm64/Makefile.gen b/arch/s390/kvm/arm64/Makefile.gen
> new file mode 100644
> index 0000000000000..cb9482eb947b9
> --- /dev/null
> +++ b/arch/s390/kvm/arm64/Makefile.gen
> @@ -0,0 +1,29 @@
[ ... ]
> +ARM64_INC_FILES := $(foreach cfile,$(ARM64_CFILES),generated/$(basename $(cfile)).inc)
> +
> +targets += $(ARM64_INC_FILES)
> +clean-files += generated/*.inc
> +
> +$(addprefix $(obj)/,$(kvm-arm64-obj)): $(addprefix $(obj)/,$(ARM64_INC_FILES))
^^^^^^^^^^^^^
[Severity: Low]
Will this result in a fatal make syntax error if the Makefile is included?
The variable kvm-arm64-obj is used here to declare dependencies, but it does
not appear to be defined anywhere in the tree. If this evaluates to an empty
string, the addprefix function will return empty on the left side of the
colon, breaking make with a missing rule before recipe error.
Should this variable be defined before use, or was a different variable name
intended?
> +
> +$(foreach cfile,$(basename $(ARM64_CFILES)),\
> + $(eval $(obj)/$(cfile).o: $(obj)/generated/$(cfile).inc))
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=24
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 25/33] s390: Introduce Start Arm Execution instruction
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (23 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 24/33] KVM: s390: Use arm64 code Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:24 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 26/33] KVM: s390: arm64: Introduce host definitions Steffen Eiden
` (8 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
The Start Arm Execution (SAE) instruction is the centerpiece for
executing arm64 (KVM) guests on s390. Its purpose is, similar to SIE, to
enable accelerated execution of arm64 virtual machines. SAE expects the
physical address of a control block as the only argument.
The host is responsible to save & restore
- GPRs 0-13
- access register 0-15
- breaking event register (BEAR)
- vector/floating point registers
between SAE executions to guarantee host consistency.
GPRs and BEAR are save and restores in the asm functions. The other
register are handled in within C code. Access registers are handled in a
later patch and SVEs will be handled when they are introduced in a
future series. Most arm64 registers are handled by a satellite block
called save_area. Some registers, frequently used by hypervisors, are
placed into the SAE control block itself.
Enlighten asm/kvm_host_types.h for the new header variant. The new
header is chosen instead of asm/kvm_host_s390_types.h if KVM_S390_ARM64
is defined.
Co-developed-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Andreas Grapentin <gra@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/include/asm/asm-prototypes.h | 1 +
arch/s390/include/asm/kvm_host_arm64_types.h | 118 +++++++++++++++++++
arch/s390/include/asm/kvm_host_types.h | 4 +
arch/s390/include/asm/sae.h | 57 +++++++++
arch/s390/include/asm/stacktrace.h | 5 +
arch/s390/kernel/asm-offsets.c | 1 +
arch/s390/kernel/entry.S | 22 ++++
arch/s390/tools/opcodes.txt | 3 +
8 files changed, 211 insertions(+)
create mode 100644 arch/s390/include/asm/kvm_host_arm64_types.h
create mode 100644 arch/s390/include/asm/sae.h
diff --git a/arch/s390/include/asm/asm-prototypes.h b/arch/s390/include/asm/asm-prototypes.h
index d4da4436d02b..faa2afb259a1 100644
--- a/arch/s390/include/asm/asm-prototypes.h
+++ b/arch/s390/include/asm/asm-prototypes.h
@@ -6,6 +6,7 @@
#include <asm/bug.h>
#include <asm/fpu.h>
#include <asm/nospec-branch.h>
+#include <asm/sae.h>
#include <asm-generic/asm-prototypes.h>
#endif /* _ASM_S390_PROTOTYPES_H */
diff --git a/arch/s390/include/asm/kvm_host_arm64_types.h b/arch/s390/include/asm/kvm_host_arm64_types.h
new file mode 100644
index 000000000000..d112ca8c6bc1
--- /dev/null
+++ b/arch/s390/include/asm/kvm_host_arm64_types.h
@@ -0,0 +1,118 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ASM_KVM_HOST_ARM64_TYPES_H
+#define ASM_KVM_HOST_ARM64_TYPES_H
+
+#include <linux/types.h>
+#include <linux/kvm_types.h>
+#include <linux/compiler_attributes.h>
+#include <asm/page.h>
+#include <asm/fault.h>
+
+struct kvm_sae_block {
+ u64 _0000[16]; /* 0x0000 */
+#define SAE_ICPTR_SPURIOUS 0x00
+#define SAE_ICPTR_VALIDITY 0x01
+#define SAE_ICPTR_HOST_ACCESS_EXCEPTION 0x02
+#define SAE_ICPTR_SYNCHRONOUS_EXCEPTION 0x03
+#define SAE_ICPTR_TIMER 0x04
+#define SAE_ICPTR_PE_INTERCOMM 0x05
+#define SAE_ICPTR_GUEST_ADDRESS_SIZE 0x06
+#define SAE_ICPTR_STOP 0x07
+#define SAE_ICPTR_SYSTEM_REGISTER 0x08
+#define SAE_ICPTR_PMU 0x09
+#define SAE_ICPTR_MAINTENANCE 0x0a
+ u8 icptr; /* 0x0080 */
+ u8 _0081[7]; /* 0x0081 */
+ u64 scad; /* 0x0088 */
+ u64 _0090[16]; /* 0x00b0 */
+ u32 cntp_ctl; /* 0x0110 */
+ u32 cntv_ctl; /* 0x0114 */
+ u8 irq_ctl; /* 0x0118 */
+ u8 _0119[7]; /* 0x0119 */
+ struct {
+ u64 ich_hcr_el2; /* 0x0120 */
+ u64 ich_vmcr_el2; /* 0x0128 */
+ u64 ich_ap0r0_el2; /* 0x0130 */
+ u64 ich_ap1r0_el2; /* 0x0138 */
+ u64 _0140[2]; /* 0x0140 */
+ u64 ich_lrn_el2[4]; /* 0x0150 */
+ u64 _0170[4]; /* 0x0170 */
+ } ic_regs;
+ u64 _0190[12]; /* 0x0190 */
+ u64 contextidr_el1; /* 0x01f0 */
+ u32 wip; /* 0x01f8 */
+ u32 _01fc; /* 0x01fc */
+#define SAE_SD_FORMAT_0 0x00
+ u8 sdf; /* 0x0200 */
+ u8 _0201[7]; /* 0x0201 */
+ u64 mso; /* 0x0208 */
+ u64 msl; /* 0x0210 */
+ u64 hbasce; /* 0x0218 */
+ u64 _0220; /* 0x0220 */
+ u64 gpto; /* 0x0228 */
+ u64 ic; /* 0x0230 */
+ u64 ec; /* 0x0238 */
+ u64 save_area; /* 0x0240 */
+ u64 _0248[7]; /* 0x0248 */
+ u8 _0280[6]; /* 0x0280 */
+ u16 lrcpua; /* 0x0286 */
+ u64 pstate; /* 0x0288 */
+ u64 pc; /* 0x0290 */
+ u64 sp_el0; /* 0x0298 */
+ u64 sp_el1; /* 0x02a0 */
+ u64 _02a8; /* 0x02a8 */
+ u64 fpcr; /* 0x02b0 */
+ u64 fpsr; /* 0x02b8 */
+ u16 sve_pregs[16]; /* 0x02c0 */
+ u16 sve_ffr; /* 0x02e0 */
+ u8 _02e2[6]; /* 0x02e2 */
+ u64 _02e8[3]; /* 0x02e8 */
+
+ u64 gpr[31]; /* 0x0300 */
+ u64 _03f8; /* 0x03f8 */
+
+ union {
+ u64 icptd[8]; /* 0x0400 */
+ /* validity-interception reason; icptr 0x01 */
+ u16 vir; /* 0x0400 */
+ /* host access interception details; icptr 0x02 */
+ struct {
+ u64 esr_elz; /* 0x0400 */
+ u8 _0408[6]; /* 0x0408 */
+ u16 pic; /* 0x040e */
+ union teid teid; /* 0x0410 */
+ gva_t far_elz; /* 0x0418 */
+ gva_t vaddr; /* 0x0420 */
+ u64 suppl; /* 0x0428 */
+ u8 gltl; /* 0x0430 */
+ u8 _0431[7]; /* 0x0431 */
+ u64 _0438; /* 0x0438 */
+ } hai;
+ /* exception-interception details; icptr 0x03 */
+ struct {
+ u64 esr_elz; /* 0x0400 */
+ u64 _0408[2]; /* 0x0408 */
+ gva_t far_elz; /* 0x0418 */
+ } trap;
+ /* timer-interception reason; icptr 0x04 */
+#define SAE_IR_TIMER_ID_VIRT BIT(6)
+#define SAE_IR_TIMER_ID_PHYS BIT(7)
+ u8 tir; /* 0x0400 */
+ };
+ u64 _0440[376]; /* 0x0440 */
+} __packed __aligned(PAGE_SIZE);
+static_assert(sizeof(struct kvm_sae_block) == PAGE_SIZE);
+
+struct kvm_sae_save_area {
+#define SAE_SAVE_AREA_FORMAT_0 0x00
+ u8 saf; /* 0x0000 */
+ u8 _0001[5]; /* 0x0001 */
+#define SAE_SAS_VALID BIT(0)
+ u16 sas; /* 0x0006 */
+ u64 sdo; /* 0x0008 */
+ u64 _0010[2]; /* 0x0010 */
+ u64 regs[508]; /* 0x0020 */
+} __packed __aligned(PAGE_SIZE);
+static_assert(sizeof(struct kvm_sae_save_area) == PAGE_SIZE);
+
+#endif /* ASM_KVM_HOST_ARM64_TYPES_H */
diff --git a/arch/s390/include/asm/kvm_host_types.h b/arch/s390/include/asm/kvm_host_types.h
index e5bdba07cab0..d308739ebcf5 100644
--- a/arch/s390/include/asm/kvm_host_types.h
+++ b/arch/s390/include/asm/kvm_host_types.h
@@ -3,6 +3,10 @@
#ifndef ASM_KVM_HOST_TYPES_H
#define ASM_KVM_HOST_TYPES_H
+#ifdef KVM_S390_ARM64
+#include <asm/kvm_host_arm64_types.h>
+#else
#include <asm/kvm_host_s390_types.h>
+#endif /* KVM_S390_ARM64 */
#endif /* ASM_KVM_HOST_TYPES_H */
diff --git a/arch/s390/include/asm/sae.h b/arch/s390/include/asm/sae.h
new file mode 100644
index 000000000000..389c5ac2a36c
--- /dev/null
+++ b/arch/s390/include/asm/sae.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_S390_SAE_H
+#define __ASM_S390_SAE_H
+
+#include <linux/linkage.h>
+#include <linux/types.h>
+
+#ifndef __ASSEMBLER__
+
+/* defined in arch/s390/kernel/entry.S */
+asmlinkage void __sae64a(phys_addr_t sae_block_phys);
+
+#include <linux/io.h>
+#include <asm/kvm_host_arm64_types.h>
+
+/**
+ * __sae64a() - Start Arm Execution
+ */
+static inline void sae64a(struct kvm_sae_block *sae_block)
+{
+ __sae64a(virt_to_phys(sae_block));
+}
+
+/**
+ * stiasrm() - STore and Invalidate Arm System Register Multiple
+ * @save_area: Pointer to SAE save area
+ *
+ * Store the guest system register to the save area.
+ * The values in the guest are not valid anymore..
+ */
+static __always_inline void stiasrm(struct kvm_sae_save_area *save_area)
+{
+ asm volatile(
+ " .insn rre,0xb9a70000,%[r1],0\n"
+ : "+m"(*save_area)
+ : [r1] "a"(save_area)
+ );
+}
+
+/**
+ * lasrm() - Load Arm System Register Multiple
+ *
+ * @save_area: Pointer to SAE save area
+ *
+ * Load the system registers from save_area into the guest.
+ */
+static __always_inline void lasrm(struct kvm_sae_save_area *save_area)
+{
+ asm volatile(
+ " .insn rre,0xb9a60000,%[r1],0\n"
+ :
+ : "m"(*save_area), [r1] "a"(save_area)
+ );
+}
+
+#endif /* !__ASSEMBLER__ */
+#endif /* __ASM_S390_SAE_H */
diff --git a/arch/s390/include/asm/stacktrace.h b/arch/s390/include/asm/stacktrace.h
index ac3606c3babe..2d332d7c8145 100644
--- a/arch/s390/include/asm/stacktrace.h
+++ b/arch/s390/include/asm/stacktrace.h
@@ -59,6 +59,7 @@ static inline bool on_stack(struct stack_info *info,
struct stack_frame {
union {
unsigned long empty[9];
+ /* SIE stack frame */
struct {
unsigned long sie_control_block;
unsigned long sie_savearea;
@@ -68,6 +69,10 @@ struct stack_frame {
unsigned long sie_guest_asce;
unsigned long sie_irq;
};
+ /* SAE stack frame */
+ struct {
+ unsigned long sae_bear;
+ };
};
unsigned long gprs[10];
unsigned long back_chain;
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index f6dd2b67dcee..f9f9c2246074 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -70,6 +70,7 @@ int main(void)
OFFSET(__SF_SIE_CONTROL_PHYS, stack_frame, sie_control_block_phys);
OFFSET(__SF_SIE_GUEST_ASCE, stack_frame, sie_guest_asce);
OFFSET(__SF_SIE_IRQ, stack_frame, sie_irq);
+ OFFSET(__SF_SAE_BEAR, stack_frame, sae_bear);
DEFINE(STACK_FRAME_OVERHEAD, sizeof(struct stack_frame));
BLANK();
OFFSET(__SFUSER_BACKCHAIN, stack_frame_user, back_chain);
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 10dd9bbdf985..5d9817acab0b 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -245,6 +245,28 @@ EXPORT_SYMBOL(__sie64a)
EXPORT_SYMBOL(sie_exit)
#endif
+#if IS_ENABLED(CONFIG_KVM_ARM64)
+/*
+ * __sae64a calling convention:
+ * %r2 pointer to sae control block physical address
+ */
+SYM_FUNC_START(__sae64a)
+ stmg %r6,%r14,__SF_GPRS(%r15) # store kernel registers
+ STBEAR __SF_SAE_BEAR(%r15) # save breaking event address register
+ .insn rre,0xb9a50000,%r2,0 # Start Arm Execution
+ LBEAR __SF_SAE_BEAR(%r15) # restore breaking event address register
+ lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
+ xgr %r0,%r0 # clear guest registers to
+ xgr %r1,%r1 # prevent speculative use
+ xgr %r2,%r2
+ xgr %r3,%r3
+ xgr %r4,%r4
+ xgr %r5,%r5
+ BR_EX %r14
+SYM_FUNC_END(__sae64a)
+EXPORT_SYMBOL(__sae64a)
+#endif
+
/*
* SVC interrupt handler routine. System calls are synchronous events and
* are entered with interrupts disabled.
diff --git a/arch/s390/tools/opcodes.txt b/arch/s390/tools/opcodes.txt
index def2659f6602..0e4773c94af0 100644
--- a/arch/s390/tools/opcodes.txt
+++ b/arch/s390/tools/opcodes.txt
@@ -594,6 +594,9 @@ b9a0 clp RRF_U0RR
b9a1 tpei RRE_RR
b9a2 ptf RRE_R0
b9a4 uvc RRF_URR
+b9a5 sae RRE_R0
+b9a6 lasrm RRE_R0
+b9a7 stiasrm RRE_R0
b9aa lptea RRF_RURR2
b9ab essa RRF_U0RR
b9ac irbm RRE_RR
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 25/33] s390: Introduce Start Arm Execution instruction
2026-08-12 15:36 ` [PATCH v6 25/33] s390: Introduce Start Arm Execution instruction Steffen Eiden
@ 2026-08-12 16:24 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:24 UTC (permalink / raw)
To: Steffen Eiden
Cc: Vasily Gorbik, Oliver Upton, kvm, Heiko Carstens,
Christian Borntraeger, Marc Zyngier, Alexander Gordeev,
linux-s390, kvmarm
Thank you for your contribution! Sashiko AI review found 4 potential issue(s) to consider:
- [High] __sae64a lacks integration with the host's machine check handler, causing guest-induced machine checks to panic the host kernel.
- [High] Missing branch prediction isolation (Spectre v2 mitigation) around the SAE instruction.
- [High] Missing host interrupt intercept/exit protocol for SAE, which can lead to a CPU lockup.
- [Medium] Potential machine check misattribution due to a missing NOP padding instruction immediately after the SAE instruction.
--
--- Patch [25]: [PATCH v6 25/33] s390: Introduce Start Arm Execution instruction ---
commit 06d16be51e15035979052bdd29d727897f102ac2
Author: Steffen Eiden <seiden@linux.ibm.com>
s390: Introduce Start Arm Execution instruction
This commit introduces the Start Arm Execution (SAE) instruction to enable
accelerated execution of arm64 virtual machines on s390. It adds the __sae64a
assembly function to handle the execution context switch.
[ ... ]
> diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
> index 10dd9bbdf9856..5d9817acab0b6 100644
> --- a/arch/s390/kernel/entry.S
> +++ b/arch/s390/kernel/entry.S
> @@ -245,6 +245,28 @@ EXPORT_SYMBOL(__sie64a)
> EXPORT_SYMBOL(sie_exit)
> #endif
>
> +#if IS_ENABLED(CONFIG_KVM_ARM64)
> +/*
> + * __sae64a calling convention:
> + * %r2 pointer to sae control block physical address
> + */
> +SYM_FUNC_START(__sae64a)
> + stmg %r6,%r14,__SF_GPRS(%r15) # store kernel registers
> + STBEAR __SF_SAE_BEAR(%r15) # save breaking event address register
[Severity: High]
Are we missing branch predictor isolation (BPEXIT/BPOFF/BPENTER) around
the sae instruction?
Without these macros, the host branch predictor might be left exposed to
the guest. Could a malicious guest intentionally mistrain the branch predictor
to mount a Spectre v2 branch target injection attack against the host kernel?
[Severity: High]
Should this function set a thread flag before execution, similar to __TI_sie,
to allow host interrupts to break the execution loop?
Without a flag like __TI_sae, host interrupt handlers (like ext_int_handler
and io_int_handler) will return directly to the sae instruction instead of
rewriting the return address. Could this cause the host VCPU thread to enter
an infinite execution loop, preventing signal delivery and causing a CPU lockup?
> + .insn rre,0xb9a50000,%r2,0 # Start Arm Execution
[Severity: High]
Does this instruction need .Lsae_entry and .Lsae_leave bounds, similar
to __sie64a, so the machine check handler can detect guest context?
In mcck_int_handler(), it checks for .Lsie_entry bounds:
mcck_int_handler:
larl %r14,.Lsie_entry
clgrjl %r9,%r14, 4f
larl %r14,.Lsie_leave
clgrjhe %r9,%r14, 4f
lg %r10,__LC_PCPU(%r13)
oi __PCPU_FLAGS+7(%r10), _CIF_MCCK_GUEST
Without equivalent bounds for sae, a guest-induced machine check might be
incorrectly handled as a host kernel machine check, leaving _CIF_MCCK_GUEST
unset and panicking the host.
> + LBEAR __SF_SAE_BEAR(%r15) # restore breaking event address register
[Severity: Medium]
Is a padding instruction needed immediately following the sae instruction?
In __sie64a, a nopr 7 instruction immediately follows the sie instruction
to safely absorb deferred boundary machine checks without attributing them to
the host context. Without padding, could a deferred machine check be incorrectly
attributed to the host?
> + lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
> + xgr %r0,%r0 # clear guest registers to
> + xgr %r1,%r1 # prevent speculative use
> + xgr %r2,%r2
> + xgr %r3,%r3
> + xgr %r4,%r4
> + xgr %r5,%r5
> + BR_EX %r14
> +SYM_FUNC_END(__sae64a)
> +EXPORT_SYMBOL(__sae64a)
> +#endif
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=25
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 26/33] KVM: s390: arm64: Introduce host definitions
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (24 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 25/33] s390: Introduce Start Arm Execution instruction Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:27 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 27/33] s390/hwcaps: Report SAE support as hwcap Steffen Eiden
` (7 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Add all basic definitions the arm on s390 KVM host requires. Including,
but not limited to, struct kvm*arch definitions, various functions (to
be implemented in the following patches), and various defines required
to run arm64 guests.
Enlighten asm/kvm_host.h for the new header variant. The new
header is chosen instead of asm/kvm_host_s390.h if KVM_S390_ARM64
is defined.
Co-developed-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Andreas Grapentin <gra@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/include/asm/kvm.h | 6 +
arch/s390/include/asm/kvm_host.h | 9 +
arch/s390/include/asm/kvm_host_arm64.h | 220 +++++++++++++++++++++++++
3 files changed, 235 insertions(+)
create mode 100644 arch/s390/include/asm/kvm.h
create mode 100644 arch/s390/include/asm/kvm_host_arm64.h
diff --git a/arch/s390/include/asm/kvm.h b/arch/s390/include/asm/kvm.h
new file mode 100644
index 000000000000..aeb11dc631d5
--- /dev/null
+++ b/arch/s390/include/asm/kvm.h
@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef KVM_S390_ARM64
+#include <uapi/arm64/kvm.h>
+#else
+#include <uapi/asm/kvm.h>
+#endif
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 147325978225..cd6d572883ab 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -3,7 +3,16 @@
#ifndef ASM_KVM_HOST_H
#define ASM_KVM_HOST_H
+#ifdef KVM_S390_ARM64
+#include <asm/kvm_host_arm64.h>
+#else
#include <asm/kvm_host_s390.h>
+#endif
+
+static inline bool kvm_arch_pmi_in_guest(struct kvm_vcpu *vcpu)
+{
+ return false;
+}
#define PGM_OPERATION 0x01
#define PGM_PRIVILEGED_OP 0x02
diff --git a/arch/s390/include/asm/kvm_host_arm64.h b/arch/s390/include/asm/kvm_host_arm64.h
new file mode 100644
index 000000000000..8088409bb041
--- /dev/null
+++ b/arch/s390/include/asm/kvm_host_arm64.h
@@ -0,0 +1,220 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ASM_KVM_HOST_ARM64_H
+#define ASM_KVM_HOST_ARM64_H
+
+#include <linux/bug.h>
+
+#include <asm/kvm_host_types.h>
+#include <asm/debug.h>
+
+#define vcpu_gp_regs(v) ((v)->arch.sae_block.gpr)
+
+#include <arm64/kvm_host.h>
+#include <arm64/ptrace.h>
+
+#include <asm/sae.h>
+
+#define KVM_HAVE_MMU_RWLOCK
+#define KVM_MAX_VCPUS 1
+#define KVM_S390_ARM64_IMPL_FEATURES \
+ (BIT(KVM_ARM_VCPU_PTRAUTH_ADDRESS) | BIT(KVM_ARM_VCPU_PTRAUTH_GENERIC))
+
+#define KVM_HALT_POLL_NS_DEFAULT 50000
+
+#define KVM_S390_MANAGES_S390_GUEST 0
+
+/* Minimal (=no) vgic definitions */
+#define KVM_IRQCHIP_NUM_PINS 1
+#define irqchip_in_kernel(_k) false
+
+#define __ctxt_sys_reg(ctx, reg) NULL
+struct kvm_cpu_context {
+ /*
+ * These are just for 32 bit, which we don't have, making them RES0.
+ * They are exposed to user space.
+ */
+ u64 spsr_abt;
+ u64 spsr_und;
+ u64 spsr_irq;
+ u64 spsr_fiq;
+
+ __vector128 __aligned(16) vregs[32];
+};
+
+struct kvm_vcpu_arch {
+ struct kvm_sae_block sae_block;
+ struct kvm_sae_save_area save_area;
+ struct kvm_cpu_context ctxt;
+
+ u32 host_acrs[NUM_ACRS];
+
+ /* Hypervisor Configuration Register */
+ u64 hcr_elz;
+
+ /* Configuration flags, set once and for all before the vcpu can run */
+ u8 cflags;
+
+ /* Input flags to the hypervisor code, potentially cleared after use */
+ u8 iflags;
+
+ /* State flags for kernel bookkeeping, unused by the hypervisor code */
+ u8 sflags;
+
+ /*
+ * Don't run the guest (internal implementation need).
+ *
+ * Contrary to the flags above, this is set/cleared outside of
+ * a vcpu context, and thus cannot be mixed with the flags
+ * themselves (or the flag accesses need to be made atomic).
+ */
+ bool pause;
+
+ /* vcpu power state */
+ struct kvm_mp_state mp_state;
+ /* lock for mp_state & reset_state.reset */
+ spinlock_t mp_state_lock;
+
+ /* vcpu reset state */
+ struct vcpu_reset_state reset_state;
+
+ /* GMAP */
+ struct gmap *gmap;
+ struct kvm_s390_mmu_cache *mc;
+
+ void *debugfs_state_data;
+};
+
+struct kvm_vcpu_stat {
+ struct kvm_vcpu_stat_generic generic;
+ /* ARM64 stats */
+ u64 hvc_exit_stat;
+ u64 wfe_exit_stat;
+ u64 wfi_exit_stat;
+ u64 mmio_exit_user;
+ u64 mmio_exit_kernel;
+ u64 signal_exits;
+ u64 exits;
+ /* GMAP stats */
+ u64 pfault_sync;
+};
+
+#define _vcpu_get_flag(v, flagset, ...) \
+ __vcpu_get_flag(&(v)->arch.flagset, __VA_ARGS__)
+#define _vcpu_set_flag(v, flagset, ...) \
+ __vcpu_set_flag(&(v)->arch.flagset, __VA_ARGS__)
+#define _vcpu_clear_flag(v, flagset, ...) \
+ __vcpu_clear_flag(&(v)->arch.flagset, __VA_ARGS__)
+#define _vcpu_test_and_clear_flag(v, flagset, ...) \
+ __vcpu_test_and_clear_flag(&(v)->arch.flagset, __VA_ARGS__)
+
+#define kvm_has_mte(_kvm) false
+#define vcpu_has_sve(_vcpu) false
+#define vcpu_has_ptrauth(_vcpu) false
+
+struct kvm_arch_memory_slot {
+};
+
+struct kvm_arch {
+ struct gmap *gmap;
+ u64 guest_phys_size;
+
+ /* VM-wide vCPU feature set */
+ unsigned long flags;
+
+ /* Protects VM-scoped configuration data */
+ struct mutex config_lock;
+
+ debug_info_t *dbf;
+
+ DECLARE_BITMAP(vcpu_features, KVM_VCPU_MAX_FEATURES);
+
+ unsigned long mem_limit;
+};
+
+static inline bool __vcpu_has_feature(const struct kvm_arch *ka, int feature)
+{
+ return test_bit(feature, ka->vcpu_features);
+}
+
+struct kvm_vm_stat {
+ struct kvm_vm_stat_generic generic;
+};
+
+static inline bool system_has_full_ptr_auth(void)
+{
+ return true;
+}
+
+#define kvm_vm_is_protected(_kvm) false
+#define vcpu_is_protected(_vcpu) false
+
+#define vcpu_is_loaded(_vcpu) ((_vcpu)->cpu != -1)
+
+#define KVM_HVA_ERR_BAD -1UL
+#define KVM_HVA_ERR_RO_BAD -2UL
+
+#define kvm_phys_size(__kvm) ((__kvm)->arch.guest_phys_size)
+static inline bool kvm_is_error_hva(unsigned long addr)
+{
+ return IS_ERR_VALUE(addr);
+}
+
+u32 get_kvm_ipa_limit(void);
+
+/* unused, but required functions */
+static inline void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) {}
+static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
+static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
+static inline void kvm_arch_flush_shadow_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) {}
+static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_sync_events(struct kvm *kvm) {}
+static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
+ struct kvm_memory_slot *slot,
+ gfn_t gfn_offset,
+ unsigned long mask) {}
+
+int kvm_handle_guest_abort(struct kvm_vcpu *vcpu);
+
+/* arm64 guests do not use async-pf. Defined because Kbuild requires it as s390 kvm turns it on. */
+#define ASYNC_PF_PER_VCPU 0
+struct kvm_arch_async_pf {
+ unsigned long pfault_token;
+};
+
+#define __unsupp_async_call(fn) WARN_ONCE(true, "async not supported on kvm-arm64 %s", fn)
+
+static inline bool kvm_arch_can_dequeue_async_page_present(struct kvm_vcpu *vcpu)
+{
+ __unsupp_async_call(__func__);
+ return false;
+};
+
+static inline void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu,
+ struct kvm_async_pf *work)
+{
+ __unsupp_async_call(__func__);
+};
+
+static inline bool kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
+ struct kvm_async_pf *work)
+{
+ __unsupp_async_call(__func__);
+ return false;
+};
+
+static inline void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
+ struct kvm_async_pf *work)
+{
+ __unsupp_async_call(__func__);
+};
+
+static inline void kvm_arch_async_page_present_queued(struct kvm_vcpu *vcpu)
+{
+ __unsupp_async_call(__func__);
+};
+
+#define kvm_supports_32bit_el0() false
+
+#endif /* ASM_KVM_HOST_ARM64_H */
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 26/33] KVM: s390: arm64: Introduce host definitions
2026-08-12 15:36 ` [PATCH v6 26/33] KVM: s390: arm64: Introduce host definitions Steffen Eiden
@ 2026-08-12 16:27 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:27 UTC (permalink / raw)
To: Steffen Eiden
Cc: kvm, Heiko Carstens, kvmarm, Oliver Upton, Christian Borntraeger,
Alexander Gordeev, linux-s390, Marc Zyngier, Vasily Gorbik
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The vcpu flag wrapper macros (`_vcpu_get_flag`, `_vcpu_set_flag`, etc.) are syntactically broken and will cause build failures if instantiated.
--
--- Patch [26]: [PATCH v6 26/33] KVM: s390: arm64: Introduce host definitions ---
commit 9d09eb59e082ce9c0d035d93867a0ac53fc503a3
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: arm64: Introduce host definitions
This commit adds basic definitions required by the ARM on s390 KVM host.
It introduces struct kvm*arch definitions and various defines needed to
run arm64 guests, selecting the new header variant if KVM_S390_ARM64 is
defined.
> diff --git a/arch/s390/include/asm/kvm_host_arm64.h b/arch/s390/include/asm/kvm_host_arm64.h
> new file mode 100644
> index 0000000000000..8088409bb0411
> --- /dev/null
> +++ b/arch/s390/include/asm/kvm_host_arm64.h
[ ... ]
> +#define _vcpu_get_flag(v, flagset, ...) \
> + __vcpu_get_flag(&(v)->arch.flagset, __VA_ARGS__)
> +#define _vcpu_set_flag(v, flagset, ...) \
> + __vcpu_set_flag(&(v)->arch.flagset, __VA_ARGS__)
> +#define _vcpu_clear_flag(v, flagset, ...) \
> + __vcpu_clear_flag(&(v)->arch.flagset, __VA_ARGS__)
> +#define _vcpu_test_and_clear_flag(v, flagset, ...) \
> + __vcpu_test_and_clear_flag(&(v)->arch.flagset, __VA_ARGS__)
[Severity: Low]
Will these wrapper macros cause a build failure when instantiated?
Looking at __vcpu_get_flag() and the related macros from the shared arm64
headers, they expect exactly four arguments: v, flagset, f, and m.
In these wrappers, we pass &(v)->arch.flagset as the first argument and
__VA_ARGS__ as the remaining arguments. Since standard flag constants usually
expand to two arguments (for example, BIT(0), BIT(0) for f and m), this
invocation only provides three arguments in total instead of the required four.
Does this need an additional argument or a different macro structure to
resolve the arity mismatch?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=26
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 27/33] s390/hwcaps: Report SAE support as hwcap
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (25 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 26/33] KVM: s390: arm64: Introduce host definitions Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:15 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 28/33] KVM: s390: Add basic arm64 kvm module Steffen Eiden
` (6 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
From: Hendrik Brueckner <brueckner@linux.ibm.com>
Report SAE support as hwcap (and /proc/cpuinfo)
Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
---
arch/s390/include/asm/elf.h | 2 ++
arch/s390/include/asm/sclp.h | 5 ++++-
arch/s390/kernel/processor.c | 3 +++
drivers/s390/char/sclp_early.c | 1 +
4 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h
index bb63fa4d20bb..ad3108ecfb07 100644
--- a/arch/s390/include/asm/elf.h
+++ b/arch/s390/include/asm/elf.h
@@ -123,6 +123,7 @@ enum {
HWCAP_NR_NNPA = 20,
HWCAP_NR_PCI_MIO = 21,
HWCAP_NR_SIE = 22,
+ HWCAP_NR_SAE = 23,
HWCAP_NR_MAX
};
@@ -150,6 +151,7 @@ enum {
#define HWCAP_NNPA BIT(HWCAP_NR_NNPA)
#define HWCAP_PCI_MIO BIT(HWCAP_NR_PCI_MIO)
#define HWCAP_SIE BIT(HWCAP_NR_SIE)
+#define HWCAP_SAE BIT(HWCAP_NR_SAE)
/*
* These are used to set parameters in the core dumps.
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h
index 44066550b9b1..68f61b71a2d5 100644
--- a/arch/s390/include/asm/sclp.h
+++ b/arch/s390/include/asm/sclp.h
@@ -56,7 +56,9 @@ struct sclp_core_entry {
u8 siif : 1;
u8 sigpif : 1;
u8 : 3;
- u8 reserved2[3];
+ u8 aef: 1;
+ u8 : 7;
+ u8 reserved2[2];
u8 : 2;
u8 ib : 1;
u8 cei : 1;
@@ -109,6 +111,7 @@ struct sclp_info {
unsigned char has_aeni : 1;
unsigned char has_aisi : 1;
unsigned char has_astfleie2 : 1;
+ unsigned char has_aef : 1;
unsigned int ibc;
unsigned int mtid;
unsigned int mtid_cp;
diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c
index e33a3eccda56..6da55a158027 100644
--- a/arch/s390/kernel/processor.c
+++ b/arch/s390/kernel/processor.c
@@ -150,6 +150,7 @@ static void show_cpu_summary(struct seq_file *m, void *v)
[HWCAP_NR_NNPA] = "nnpa",
[HWCAP_NR_PCI_MIO] = "pcimio",
[HWCAP_NR_SIE] = "sie",
+ [HWCAP_NR_SAE] = "sae",
};
int i, cpu;
@@ -254,6 +255,8 @@ static int __init setup_hwcaps(void)
/* virtualization support */
if (sclp.has_sief2)
elf_hwcap |= HWCAP_SIE;
+ if (sclp.has_aef)
+ elf_hwcap |= HWCAP_SAE;
return 0;
}
diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c
index 22dd797e6229..e58d24b95bd1 100644
--- a/drivers/s390/char/sclp_early.c
+++ b/drivers/s390/char/sclp_early.c
@@ -96,6 +96,7 @@ static void __init sclp_early_facilities_detect(void)
sclp.has_ib = cpue->ib;
sclp.has_cei = cpue->cei;
sclp.has_skey = cpue->skey;
+ sclp.has_aef = cpue->aef;
break;
}
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* [PATCH v6 28/33] KVM: s390: Add basic arm64 kvm module
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (26 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 27/33] s390/hwcaps: Report SAE support as hwcap Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:23 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 29/33] KVM: s390: arm64: Implement required functions Steffen Eiden
` (5 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Add basic code for the new arm64 on s390 KVM implementation.
Add kernel module boilerplate code and trivial functions.
Add tracing scaffolding.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/arm64/arm.c | 157 ++++++++++++++++++++++++++++++++++++
arch/s390/kvm/arm64/arm.h | 7 ++
arch/s390/kvm/arm64/guest.c | 92 +++++++++++++++++++++
arch/s390/kvm/arm64/trace.h | 18 +++++
4 files changed, 274 insertions(+)
create mode 100644 arch/s390/kvm/arm64/arm.c
create mode 100644 arch/s390/kvm/arm64/arm.h
create mode 100644 arch/s390/kvm/arm64/guest.c
create mode 100644 arch/s390/kvm/arm64/trace.h
diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
new file mode 100644
index 000000000000..8e17b7eef813
--- /dev/null
+++ b/arch/s390/kvm/arm64/arm.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define KMSG_COMPONENT "kvm-s390-arm64"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/miscdevice.h>
+#include <linux/kvm.h>
+#include <linux/kvm_types.h>
+#include <linux/kvm_host.h>
+
+#include "arm.h"
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
+static unsigned long system_supported_vcpu_features(void);
+
+#define __INCL_GEN_ARM_FILE
+#include "generated/arm.inc"
+#undef __INCL_GEN_ARM_FILE
+
+int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
+{
+ int ret;
+
+ switch (ext) {
+ case KVM_CAP_NR_VCPUS:
+ case KVM_CAP_MAX_VCPUS:
+ case KVM_CAP_MAX_VCPU_ID:
+ ret = KVM_MAX_VCPUS;
+ break;
+ case KVM_CAP_ARM_VM_IPA_SIZE:
+ ret = get_kvm_ipa_limit();
+ break;
+ case KVM_CAP_IOEVENTFD:
+ ret = 1;
+ break;
+ default:
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static u64 kvm_max_guest_address(void)
+{
+ u64 max_addr;
+
+ if (sclp.hamax == U64_MAX)
+ max_addr = TASK_SIZE_MAX;
+ else
+ max_addr = min_t(u64, TASK_SIZE_MAX, sclp.hamax);
+ return ALIGN_DOWN(max_addr + 1, 1 << 30) - 1;
+}
+
+vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
+{
+ return VM_FAULT_SIGBUS;
+}
+
+long kvm_arch_dev_ioctl(struct file *filp,
+ unsigned int ioctl, unsigned long arg)
+{
+ return -EINVAL;
+}
+
+u32 get_kvm_ipa_limit(void)
+{
+ return fls64(kvm_max_guest_address() + 1) - 1;
+}
+
+int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
+{
+ return 0;
+}
+
+void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
+{
+}
+
+int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
+ struct kvm_mp_state *mp_state)
+{
+ *mp_state = READ_ONCE(vcpu->arch.mp_state);
+ return 0;
+}
+
+int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
+ struct kvm_mp_state *mp_state)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
+{
+ return 0;
+}
+
+static unsigned long system_supported_vcpu_features(void)
+{
+ unsigned long features = KVM_S390_ARM64_IMPL_FEATURES;
+
+ return features;
+}
+
+bool kvm_arch_irqchip_in_kernel(struct kvm *kvm)
+{
+ return false;
+}
+
+int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, struct kvm *kvm,
+ int irq_source_id, int level, bool line_status)
+{
+ return -EINVAL;
+}
+
+int kvm_set_routing_entry(struct kvm *kvm,
+ struct kvm_kernel_irq_routing_entry *e,
+ const struct kvm_irq_routing_entry *ue)
+{
+ return -EINVAL;
+}
+
+int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
+{
+ return 0;
+}
+
+#ifdef CONFIG_HAVE_KVM_NO_POLL
+__weak bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+#endif
+
+long kvm_arch_vcpu_unlocked_ioctl(struct file *filp, unsigned int ioctl,
+ unsigned long arg)
+{
+ return -ENOIOCTLCMD;
+}
+
+static int __init kvm_s390_arm64_init(void)
+{
+ if (!sclp.has_aef)
+ return -ENXIO;
+
+ return kvm_init_with_dev(sizeof(struct kvm_vcpu), 0, THIS_MODULE,
+ KVM_DEV_NAME, MISC_DYNAMIC_MINOR);
+}
+
+static __exit void kvm_s390_arm64_exit(void)
+{
+ kvm_exit();
+}
+
+module_init(kvm_s390_arm64_init);
+module_exit(kvm_s390_arm64_exit);
diff --git a/arch/s390/kvm/arm64/arm.h b/arch/s390/kvm/arm64/arm.h
new file mode 100644
index 000000000000..a3db254462c0
--- /dev/null
+++ b/arch/s390/kvm/arm64/arm.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_S390_KVM_ARM64_H
+#define ARCH_S390_KVM_ARM64_H
+
+#define KVM_DEV_NAME "kvm-arm64"
+
+#endif /* ARCH_S390_KVM_ARM64_H */
diff --git a/arch/s390/kvm/arm64/guest.c b/arch/s390/kvm/arm64/guest.c
new file mode 100644
index 000000000000..fd6442d9e4f4
--- /dev/null
+++ b/arch/s390/kvm/arm64/guest.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+
+#include <arm64/kvm_emulate.h>
+#include <arm64/kvm_nested.h>
+
+#include "guest.h"
+
+#define __INCL_GEN_ARM_FILE
+#include "generated/guest.inc"
+#undef __INCL_GEN_ARM_FILE
+
+const struct kvm_stats_desc kvm_vm_stats_desc[] = {
+ KVM_GENERIC_VM_STATS()
+};
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+ .name_size = KVM_STATS_NAME_SIZE,
+ .num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+ .id_offset = sizeof(struct kvm_stats_header),
+ .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+ .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+ sizeof(kvm_vm_stats_desc),
+};
+
+const struct kvm_stats_desc kvm_vcpu_stats_desc[] = {
+ KVM_GENERIC_VCPU_STATS(),
+ /* ARM64 stats */
+ STATS_DESC_COUNTER(VCPU, hvc_exit_stat),
+ STATS_DESC_COUNTER(VCPU, wfe_exit_stat),
+ STATS_DESC_COUNTER(VCPU, wfi_exit_stat),
+ STATS_DESC_COUNTER(VCPU, mmio_exit_user),
+ STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
+ STATS_DESC_COUNTER(VCPU, signal_exits),
+ STATS_DESC_COUNTER(VCPU, exits),
+ /* GMAP stats */
+ STATS_DESC_COUNTER(VCPU, pfault_sync),
+};
+
+const struct kvm_stats_header kvm_vcpu_stats_header = {
+ .name_size = KVM_STATS_NAME_SIZE,
+ .num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
+ .id_offset = sizeof(struct kvm_stats_header),
+ .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+ .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+ sizeof(kvm_vcpu_stats_desc),
+};
+
+int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
+ struct kvm_sregs *sregs)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
+ struct kvm_sregs *sregs)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
+ struct kvm_translation *tr)
+{
+ return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
+ struct kvm_guest_debug *dbg)
+{
+ return -EINVAL;
+}
diff --git a/arch/s390/kvm/arm64/trace.h b/arch/s390/kvm/arm64/trace.h
new file mode 100644
index 000000000000..3a5dcd039c13
--- /dev/null
+++ b/arch/s390/kvm/arm64/trace.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#if !defined(KVM_ARM64_TRACE_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define KVM_ARM64_TRACE_KVM_H
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM kvm
+
+#endif /* KVM_ARM64_TRACE_KVM_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 28/33] KVM: s390: Add basic arm64 kvm module
2026-08-12 15:36 ` [PATCH v6 28/33] KVM: s390: Add basic arm64 kvm module Steffen Eiden
@ 2026-08-12 16:23 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:23 UTC (permalink / raw)
To: Steffen Eiden
Cc: linux-s390, Vasily Gorbik, Oliver Upton, Alexander Gordeev, kvm,
Heiko Carstens, Marc Zyngier, Christian Borntraeger, kvmarm
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Integer underflow in `kvm_max_guest_address()` bypasses KVM IPA limit validation for systems with less than 1GB of max address.
--
--- Patch [28]: [PATCH v6 28/33] KVM: s390: Add basic arm64 kvm module ---
commit 57ce89696f07b8212cf2fc85a369b60b1ec4f89b
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: Add basic arm64 kvm module
This commit adds the initial architecture-specific KVM infrastructure for
supporting arm64 guests on s390 hosts. It includes basic module
initialization, tracepoint scaffolding, and API skeleton functions.
> diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
> new file mode 100644
> index 0000000000000..8e17b7eef8131
> --- /dev/null
> +++ b/arch/s390/kvm/arm64/arm.c
[ ... ]
> +static u64 kvm_max_guest_address(void)
> +{
> + u64 max_addr;
> +
> + if (sclp.hamax == U64_MAX)
> + max_addr = TASK_SIZE_MAX;
> + else
> + max_addr = min_t(u64, TASK_SIZE_MAX, sclp.hamax);
> + return ALIGN_DOWN(max_addr + 1, 1 << 30) - 1;
[Severity: High]
Can this underflow if max_addr + 1 is less than 1GB (1 << 30)?
On a system with a small maximum address limit, ALIGN_DOWN() will evaluate
to 0. Subtracting 1 from 0 will result in a U64_MAX return value, bypassing
the intended limit.
> +}
[ ... ]
> +u32 get_kvm_ipa_limit(void)
> +{
> + return fls64(kvm_max_guest_address() + 1) - 1;
[Severity: High]
If kvm_max_guest_address() underflows to U64_MAX as mentioned above, does
this cause get_kvm_ipa_limit() to return U32_MAX?
Adding 1 to U64_MAX wraps to 0. Calling fls64(0) - 1 would then evaluate
to U32_MAX. This effectively disables the IPA size limit validation in
kvm_vm_type_ipa_size_shift(), allowing userspace to request unsupported
IPA sizes during VM creation.
> +}
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=28
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 29/33] KVM: s390: arm64: Implement required functions
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (27 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 28/33] KVM: s390: Add basic arm64 kvm module Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:36 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 30/33] KVM: s390: arm64: Implement vm/vcpu create destroy Steffen Eiden
` (4 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Implement the mostly trivial functions that the shared arm64 (kvm)
code & headers oblige s390 to implement.
Implement a very basic smccc handler that (non-compliantly) is just able
to stop a vcpu.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/include/arm64/kvm_emulate.h | 130 ++++++++++++++++++++++++++
arch/s390/include/arm64/kvm_nested.h | 11 +++
arch/s390/include/arm64/ptrace.h | 11 +++
arch/s390/include/arm64/sysreg.h | 13 +++
arch/s390/kvm/arm64/handle_exit.c | 98 +++++++++++++++++++
arch/s390/kvm/arm64/inject_fault.c | 21 +++++
6 files changed, 284 insertions(+)
create mode 100644 arch/s390/include/arm64/kvm_emulate.h
create mode 100644 arch/s390/include/arm64/kvm_nested.h
create mode 100644 arch/s390/include/arm64/ptrace.h
create mode 100644 arch/s390/include/arm64/sysreg.h
create mode 100644 arch/s390/kvm/arm64/handle_exit.c
create mode 100644 arch/s390/kvm/arm64/inject_fault.c
diff --git a/arch/s390/include/arm64/kvm_emulate.h b/arch/s390/include/arm64/kvm_emulate.h
new file mode 100644
index 000000000000..c1551e3da8f4
--- /dev/null
+++ b/arch/s390/include/arm64/kvm_emulate.h
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __S390_ARM64_KVM_EMULATE_H__
+#define __S390_ARM64_KVM_EMULATE_H__
+
+#include <asm/fault.h>
+#include <linux/kvm_host.h>
+
+#include <arm64/kvm_nested.h>
+#include <arm64/ptrace.h>
+#include <arm64/kvm_arm.h>
+#include <arm64/sysreg.h>
+
+static __always_inline unsigned long *vcpu_pc(const struct kvm_vcpu *vcpu)
+{
+ return (unsigned long *)&vcpu->arch.sae_block.pc;
+}
+
+static __always_inline unsigned long *vcpu_cpsr(const struct kvm_vcpu *vcpu)
+{
+ return (unsigned long *)&vcpu->arch.sae_block.pstate;
+}
+
+static __always_inline unsigned long *vcpu_sp_el0(const struct kvm_vcpu *vcpu)
+{
+ return (unsigned long *)&vcpu->arch.sae_block.sp_el0;
+}
+
+static __always_inline u64 *vcpu_sp_el1(struct kvm_vcpu *vcpu)
+{
+ return &vcpu->arch.sae_block.sp_el1;
+}
+
+static __always_inline __vector128 *vcpu_vreg(struct kvm_vcpu *vcpu, int off)
+{
+ return &vcpu->arch.ctxt.vregs[off];
+}
+
+static __always_inline u64 *vcpu_fpsr(struct kvm_vcpu *vcpu)
+{
+ return &vcpu->arch.sae_block.fpsr;
+}
+
+static __always_inline u64 *vcpu_fpcr(struct kvm_vcpu *vcpu)
+{
+ return &vcpu->arch.sae_block.fpcr;
+}
+
+static __always_inline bool vcpu_mode_is_32bit(const struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+
+static __always_inline u64 kvm_vcpu_get_esr(const struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.sae_block.hai.esr_elz;
+}
+
+static inline unsigned long *vcpu_hcr(struct kvm_vcpu *vcpu)
+{
+ return (unsigned long *)&vcpu->arch.hcr_elz;
+}
+
+static __always_inline unsigned long kvm_vcpu_get_hfar(const struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.sae_block.hai.far_elz;
+}
+
+static __always_inline phys_addr_t kvm_vcpu_get_fault_ipa(const struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.sae_block.hai.teid.addr * PAGE_SIZE;
+}
+
+static inline u16 kvm_vcpu_fault_pic(const struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.sae_block.hai.pic & PGM_INT_CODE_MASK;
+}
+
+static __always_inline
+bool kvm_vcpu_trap_is_permission_fault(const struct kvm_vcpu *vcpu)
+{
+ return kvm_vcpu_fault_pic(vcpu) == PGM_PROTECTION;
+}
+
+static __always_inline bool kvm_condition_valid(const struct kvm_vcpu *vcpu)
+{
+ return true;
+}
+
+static __always_inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+
+static inline bool kvm_vcpu_is_be(struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+
+static inline int kvm_vcpu_abt_gltl(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.sae_block.hai.gltl;
+}
+
+static inline bool vcpu_mode_priv(const struct kvm_vcpu *vcpu)
+{
+ u32 mode = *vcpu_cpsr(vcpu) & PSR_MODE_MASK;
+
+ return mode != PSR_MODE_EL0t;
+}
+
+static inline void kvm_skip_instr(struct kvm_vcpu *vcpu)
+{
+ *vcpu_pc(vcpu) += 4;
+ *vcpu_cpsr(vcpu) &= ~PSR_BTYPE_MASK;
+
+ /* advance the singlestep state machine */
+ *vcpu_cpsr(vcpu) &= ~SPSR_ELx_SS;
+}
+
+static inline void kvm_reset_fpsimd(struct kvm_vcpu *vcpu)
+{
+ memset(vcpu->arch.ctxt.vregs, 0, sizeof(vcpu->arch.ctxt.vregs));
+ vcpu->arch.sae_block.fpsr = 0;
+ vcpu->arch.sae_block.fpcr = 0;
+}
+
+#include <arm64/kvm_emulate-gen.h>
+
+#endif /* __S390_ARM64_KVM_EMULATE_H__ */
diff --git a/arch/s390/include/arm64/kvm_nested.h b/arch/s390/include/arm64/kvm_nested.h
new file mode 100644
index 000000000000..e950b1a10c41
--- /dev/null
+++ b/arch/s390/include/arm64/kvm_nested.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef ASM_KVM_NESTED_H
+#define ASM_KVM_NESTED_H
+
+static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+
+#endif /* ASM_KVM_NESTED_H */
diff --git a/arch/s390/include/arm64/ptrace.h b/arch/s390/include/arm64/ptrace.h
new file mode 100644
index 000000000000..449b85582c97
--- /dev/null
+++ b/arch/s390/include/arm64/ptrace.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __S390_ARM64_PTRACE_H__
+#define __S390_ARM64_PTRACE_H__
+
+#include <arm64/sysreg.h>
+#include <uapi/arm64/ptrace.h>
+
+#include <arm64/ptrace-gen.h>
+
+#endif /* __S390_ARM64_PTRACE_H__ */
diff --git a/arch/s390/include/arm64/sysreg.h b/arch/s390/include/arm64/sysreg.h
new file mode 100644
index 000000000000..ac6b638fef56
--- /dev/null
+++ b/arch/s390/include/arm64/sysreg.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __S390_ARM64_SYSREG_H__
+#define __S390_ARM64_SYSREG_H__
+
+#include <linux/bits.h>
+#include <linux/stringify.h>
+#include <linux/kasan-tags.h>
+#include <linux/kconfig.h>
+
+#include <arm64/sysreg-gen.h>
+
+#endif /* __S390_ARM64_SYSREG_H__ */
diff --git a/arch/s390/kvm/arm64/handle_exit.c b/arch/s390/kvm/arm64/handle_exit.c
new file mode 100644
index 000000000000..ed872cd804dc
--- /dev/null
+++ b/arch/s390/kvm/arm64/handle_exit.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kvm_host.h>
+
+#include <arm64/esr.h>
+#include <arm64/kvm_emulate.h>
+
+typedef int (*exit_handle_fn)(struct kvm_vcpu *);
+static exit_handle_fn arm_exit_handlers[ESR_ELx_EC_MAX + 1];
+
+#define __INCL_GEN_ARM_FILE
+#include "generated/handle_exit.inc"
+#undef __INCL_GEN_ARM_FILE
+
+#define PSCI_0_2_FN_SYSTEM_OFF 0x84000008
+#define PSCI_RET_NOT_SUPPORTED -1
+#define PSCI_RET_INTERNAL_FAILURE -6
+/*
+ * Temporary smc/hvc handler. Non-compliant implementation (features missing).
+ * Implements only system off so that test programs are able to end their execution
+ */
+static int kvm_smccc_call_handler(struct kvm_vcpu *vcpu)
+{
+ u32 func_id = vcpu_get_reg(vcpu, 0);
+ u64 val = PSCI_RET_NOT_SUPPORTED;
+ int ret = 1;
+
+ if (func_id == PSCI_0_2_FN_SYSTEM_OFF) {
+ scoped_guard(spinlock, &vcpu->arch.mp_state_lock) {
+ WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED);
+ }
+ kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
+ memset(&vcpu->run->system_event, 0,
+ sizeof(vcpu->run->system_event));
+ vcpu->run->system_event.type = KVM_SYSTEM_EVENT_SHUTDOWN;
+ vcpu->run->system_event.ndata = 1;
+ vcpu->run->system_event.data[0] = 0;
+ vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
+ val = PSCI_RET_INTERNAL_FAILURE;
+ ret = 0;
+ }
+ vcpu_set_reg(vcpu, 0, val);
+
+ return ret;
+}
+
+static int handle_hvc(struct kvm_vcpu *vcpu)
+{
+ vcpu->stat.hvc_exit_stat++;
+ return kvm_smccc_call_handler(vcpu);
+}
+
+static exit_handle_fn arm_exit_handlers[] = {
+ [0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec,
+ [ESR_ELx_EC_HVC64] = handle_hvc,
+};
+
+/* manually copied from arch/arm64/kernel/traps.c */
+static const char * const esr_class_str[] = {
+ [0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC",
+ [ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized",
+ [ESR_ELx_EC_WFx] = "WFI/WFE",
+ [ESR_ELx_EC_FP_ASIMD] = "ASIMD",
+ [ESR_ELx_EC_PAC] = "PAC",
+ [ESR_ELx_EC_BTI] = "BTI",
+ [ESR_ELx_EC_ILL] = "PSTATE.IL",
+ [ESR_ELx_EC_SVC64] = "SVC (AArch64)",
+ [ESR_ELx_EC_HVC64] = "HVC (AArch64)",
+ [ESR_ELx_EC_SMC64] = "SMC (AArch64)",
+ [ESR_ELx_EC_SYS64] = "MSR/MRS (AArch64)",
+ [ESR_ELx_EC_SVE] = "SVE",
+ [ESR_ELx_EC_ERET] = "ERET/ERETAA/ERETAB",
+ [ESR_ELx_EC_FPAC] = "FPAC",
+ [ESR_ELx_EC_SME] = "SME",
+ [ESR_ELx_EC_IMP_DEF] = "EL3 IMP DEF",
+ [ESR_ELx_EC_IABT_LOW] = "IABT (lower EL)",
+ [ESR_ELx_EC_IABT_CUR] = "IABT (current EL)",
+ [ESR_ELx_EC_PC_ALIGN] = "PC Alignment",
+ [ESR_ELx_EC_DABT_LOW] = "DABT (lower EL)",
+ [ESR_ELx_EC_DABT_CUR] = "DABT (current EL)",
+ [ESR_ELx_EC_SP_ALIGN] = "SP Alignment",
+ [ESR_ELx_EC_MOPS] = "MOPS",
+ [ESR_ELx_EC_FP_EXC64] = "FP (AArch64)",
+ [ESR_ELx_EC_GCS] = "Guarded Control Stack",
+ [ESR_ELx_EC_SERROR] = "SError",
+ [ESR_ELx_EC_BREAKPT_LOW] = "Breakpoint (lower EL)",
+ [ESR_ELx_EC_BREAKPT_CUR] = "Breakpoint (current EL)",
+ [ESR_ELx_EC_SOFTSTP_LOW] = "Software Step (lower EL)",
+ [ESR_ELx_EC_SOFTSTP_CUR] = "Software Step (current EL)",
+ [ESR_ELx_EC_WATCHPT_LOW] = "Watchpoint (lower EL)",
+ [ESR_ELx_EC_WATCHPT_CUR] = "Watchpoint (current EL)",
+ [ESR_ELx_EC_BRK64] = "BRK (AArch64)",
+};
+
+const char *esr_get_class_string(unsigned long esr)
+{
+ return esr_class_str[ESR_ELx_EC(esr)];
+}
diff --git a/arch/s390/kvm/arm64/inject_fault.c b/arch/s390/kvm/arm64/inject_fault.c
new file mode 100644
index 000000000000..425dbeaa421c
--- /dev/null
+++ b/arch/s390/kvm/arm64/inject_fault.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <arm64/kvm_emulate.h>
+
+/**
+ * kvm_inject_undefined - inject an undefined instruction into the guest
+ * @vcpu: The vCPU in which to inject the exception
+ *
+ * It is assumed that this code is called from the VCPU thread and that the
+ * VCPU therefore is not currently executing guest code.
+ */
+void kvm_inject_undefined(struct kvm_vcpu *vcpu)
+{
+ /* Stub until s390 supports arm64 sysregs TODO sysregs*/
+}
+
+int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr)
+{
+ /* Stub until s390 supports arm64 sysregs TODO sysregs*/
+ return 1;
+}
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 29/33] KVM: s390: arm64: Implement required functions
2026-08-12 15:36 ` [PATCH v6 29/33] KVM: s390: arm64: Implement required functions Steffen Eiden
@ 2026-08-12 16:36 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:36 UTC (permalink / raw)
To: Steffen Eiden
Cc: Vasily Gorbik, Christian Borntraeger, linux-s390,
Alexander Gordeev, Heiko Carstens, Oliver Upton, Marc Zyngier,
kvmarm, kvm
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] Uninitialized lock acquisition causes lockdep splat or kernel crash.
- [High] Empty exception injection stubs cause infinite VCPU exit loops.
--
--- Patch [29]: [PATCH v6 29/33] KVM: s390: arm64: Implement required functions ---
commit 7893f22f5b221e3beeba9913544dc8c7efcfbfc0
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: arm64: Implement required functions
Implement the mostly trivial functions that the shared arm64 (kvm)
code & headers oblige s390 to implement.
Implement a very basic smccc handler that (non-compliantly) is just able
to stop a vcpu.
> diff --git a/arch/s390/kvm/arm64/handle_exit.c b/arch/s390/kvm/arm64/handle_exit.c
> new file mode 100644
> --- /dev/null
> +++ b/arch/s390/kvm/arm64/handle_exit.c
[ ... ]
> +static int kvm_smccc_call_handler(struct kvm_vcpu *vcpu)
> +{
> + u32 func_id = vcpu_get_reg(vcpu, 0);
> + u64 val = PSCI_RET_NOT_SUPPORTED;
> + int ret = 1;
> +
> + if (func_id == PSCI_0_2_FN_SYSTEM_OFF) {
> + scoped_guard(spinlock, &vcpu->arch.mp_state_lock) {
[Severity: High]
Can this cause a lockdep splat or kernel crash?
This lock is an arm64-specific state that does not appear to be initialized
via spin_lock_init() in the s390 VCPU creation path.
If a guest triggers an SMC/HVC trap with func_id == PSCI_0_2_FN_SYSTEM_OFF,
the host handles this in kvm_smccc_call_handler() and attempts to acquire
vcpu->arch.mp_state_lock. Attempting to acquire the uninitialized lock here
will cause a crash or lockdep warning.
> + WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED);
> + }
[ ... ]
> diff --git a/arch/s390/kvm/arm64/inject_fault.c b/arch/s390/kvm/arm64/inject_fault.c
> new file mode 100644
> --- /dev/null
> +++ b/arch/s390/kvm/arm64/inject_fault.c
[ ... ]
> +void kvm_inject_undefined(struct kvm_vcpu *vcpu)
> +{
> + /* Stub until s390 supports arm64 sysregs TODO sysregs*/
> +}
> +
> +int kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr)
> +{
> + /* Stub until s390 supports arm64 sysregs TODO sysregs*/
> + return 1;
> +}
[Severity: High]
Do these empty stubs cause an infinite exit loop?
If a guest executes an undefined instruction or accesses an unmapped memory
address, the host KVM code attempts to inject an exception via
kvm_inject_undefined() or kvm_inject_sea().
Because these functions are empty stubs, they do not advance the guest PC or
alter its exception state. When the exit handler returns 1 to resume
execution, the guest will immediately re-execute the exact same faulting
instruction and trap again indefinitely. Any unprivileged guest process can
trigger this to cause a denial of service against the host and the VM.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=29
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 30/33] KVM: s390: arm64: Implement vm/vcpu create destroy.
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (28 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 29/33] KVM: s390: arm64: Implement required functions Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:38 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 31/33] KVM: s390: arm64: Implement vCPU IOCTLs Steffen Eiden
` (3 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Implement init and destroy IOCTLS for vcpu and vm.
Implement arch vm IOCTL. Use s390 gmap and gmap plumbing.
Implement function (stubs) required by gamp.
Co-developed-by: Janosch Frank <frankja@linux.ibm.com>
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Co-developed-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Andreas Grapentin <gra@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/arm64/arm.c | 197 ++++++++++++++++++++++++++++++++
arch/s390/kvm/arm64/arm.h | 56 +++++++++
arch/s390/kvm/gmap/faultin.c | 5 +
arch/s390/kvm/gmap/gmap.c | 4 +
arch/s390/kvm/gmap/kvm_mmu.c | 4 +
arch/s390/kvm/gmap/trace_gmap.h | 17 +++
6 files changed, 283 insertions(+)
diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
index 8e17b7eef813..69d43066f9e1 100644
--- a/arch/s390/kvm/arm64/arm.c
+++ b/arch/s390/kvm/arm64/arm.c
@@ -8,6 +8,9 @@
#include <linux/kvm_types.h>
#include <linux/kvm_host.h>
+#include <gmap.h>
+#include <kvm_mmu.h>
+
#include "arm.h"
#define CREATE_TRACE_POINTS
@@ -19,6 +22,8 @@ static unsigned long system_supported_vcpu_features(void);
#include "generated/arm.inc"
#undef __INCL_GEN_ARM_FILE
+#define KVM_PHYS_SHIFT (40)
+
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
int ret;
@@ -53,6 +58,83 @@ static u64 kvm_max_guest_address(void)
return ALIGN_DOWN(max_addr + 1, 1 << 30) - 1;
}
+static int kvm_gmap_init(struct kvm *kvm)
+{
+ struct crst_table *table;
+
+ kvm->arch.gmap = gmap_new(kvm, gpa_to_gfn(kvm->arch.guest_phys_size));
+
+ if (!kvm->arch.gmap)
+ return -ENOMEM;
+
+ /* arm64 (on s390) do not have pfault */
+ clear_bit(GMAP_FLAG_PFAULT_ENABLED, &kvm->arch.gmap->flags);
+ set_bit(GMAP_FLAG_ALLOW_HPAGE_1M, &kvm->arch.gmap->flags);
+
+ table = dereference_asce(kvm->arch.gmap->asce);
+ crst_table_init((void *)table, _CRSTE_HOLE(table->crstes[0].h.tt).val);
+
+ return 0;
+}
+
+static int kvm_vm_type_ipa_size_shift(unsigned long type)
+{
+ int phys_shift;
+
+ phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
+ if (phys_shift) {
+ if (phys_shift > get_kvm_ipa_limit() ||
+ phys_shift < ARM64_MIN_PARANGE_BITS)
+ return -EINVAL;
+ } else {
+ phys_shift = KVM_PHYS_SHIFT;
+ if (phys_shift > get_kvm_ipa_limit()) {
+ pr_warn_once("%s using unsupported default IPA limit\n",
+ current->comm);
+ return -EINVAL;
+ }
+ }
+
+ return phys_shift;
+}
+
+int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
+{
+ char debug_name[32];
+ int ret;
+
+ if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
+ return -EINVAL;
+
+ ret = kvm_vm_type_ipa_size_shift(type);
+ if (ret < 0)
+ return ret;
+ kvm->arch.guest_phys_size = 1UL << ret;
+
+ mutex_init(&kvm->arch.config_lock);
+ bitmap_zero(kvm->arch.vcpu_features, KVM_VCPU_MAX_FEATURES);
+
+ snprintf(debug_name, sizeof(debug_name), "kvm-arm64-%u-%u",
+ current->pid, get_random_u32());
+ kvm->arch.dbf = debug_register(debug_name, 32, 1, 7 * sizeof(long));
+ if (!kvm->arch.dbf)
+ return -ENOMEM;
+ debug_register_view(kvm->arch.dbf, &debug_sprintf_view);
+
+ ret = kvm_gmap_init(kvm);
+ if (ret)
+ goto out_err;
+ kvm->arch.mem_limit = kvm_max_guest_address();
+
+ VM_EVENT(kvm, 3, "vm created with type %lu", type);
+ return 0;
+
+out_err:
+ debug_unregister(kvm->arch.dbf);
+
+ return ret;
+}
+
vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
{
return VM_FAULT_SIGBUS;
@@ -64,6 +146,13 @@ long kvm_arch_dev_ioctl(struct file *filp,
return -EINVAL;
}
+void kvm_arch_destroy_vm(struct kvm *kvm)
+{
+ kvm_destroy_vcpus(kvm);
+ debug_unregister(kvm->arch.dbf);
+ kvm->arch.gmap = gmap_put(kvm->arch.gmap);
+}
+
u32 get_kvm_ipa_limit(void)
{
return fls64(kvm_max_guest_address() + 1) - 1;
@@ -74,10 +163,43 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
return 0;
}
+int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
+{
+ struct kvm_sae_block *sae_block = &vcpu->arch.sae_block;
+ struct kvm_sae_save_area *save_area = &vcpu->arch.save_area;
+
+ spin_lock_init(&vcpu->arch.mp_state_lock);
+
+ /* Force users to call KVM_ARM_VCPU_INIT */
+ vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
+
+ vcpu->arch.mc = kvm_s390_new_mmu_cache();
+ if (!vcpu->arch.mc)
+ return -ENOMEM;
+
+ sae_block->hbasce = vcpu->kvm->arch.gmap->asce.val;
+ sae_block->mso = 0L;
+ sae_block->msl = kvm_max_guest_address();
+ sae_block->save_area = virt_to_phys(save_area);
+
+ VM_EVENT(vcpu->kvm, 3,
+ "create cpu %d at 0x%p, sae block at 0x%p, satellite at 0x%p",
+ vcpu->vcpu_id, vcpu, &vcpu->arch.sae_block,
+ &vcpu->arch.save_area);
+ return 0;
+}
+
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
}
+void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
+{
+ kvm_s390_free_mmu_cache(vcpu->arch.mc);
+
+ VCPU_EVENT(vcpu, 3, "%s", "free cpu");
+}
+
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
@@ -103,6 +225,81 @@ static unsigned long system_supported_vcpu_features(void)
return features;
}
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
+ struct kvm_dirty_log *log)
+{
+ return s390_kvm_mmu_get_dirty_log(kvm, log);
+}
+
+bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ scoped_guard(read_lock, &kvm->mmu_lock)
+ return gmap_age_gfn(kvm->arch.gmap, range->start, range->end);
+}
+
+void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
+{
+ gfn_t last_gfn = memslot->base_gfn + memslot->npages;
+
+ scoped_guard(read_lock, &kvm->mmu_lock)
+ gmap_sync_dirty_log(kvm->arch.gmap, memslot->base_gfn, last_gfn);
+}
+
+int kvm_arch_prepare_memory_region(struct kvm *kvm,
+ const struct kvm_memory_slot *old,
+ struct kvm_memory_slot *new,
+ enum kvm_mr_change change)
+{
+ return s390_kvm_mmu_prepare_memory_region(kvm, old, new, change);
+}
+
+void kvm_arch_commit_memory_region(struct kvm *kvm, struct kvm_memory_slot *old,
+ const struct kvm_memory_slot *new,
+ enum kvm_mr_change change)
+{
+ s390_kvm_mmu_commit_memory_region(kvm, old, new, change);
+}
+
+bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ return gmap_unmap_gfn_range(kvm->arch.gmap, range->slot, range->start, range->end);
+}
+
+bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ scoped_guard(read_lock, &kvm->mmu_lock)
+ return dat_test_age_gfn(kvm->arch.gmap->asce, range->start, range->end);
+}
+
+#ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY
+long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu,
+ struct kvm_pre_fault_memory *range)
+{
+ return -EOPNOTSUPP;
+}
+#endif /* CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY*/
+
+int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+
+ switch (ioctl) {
+ case KVM_ARM_PREFERRED_TARGET: {
+ struct kvm_vcpu_init init = {
+ .target = KVM_ARM_TARGET_GENERIC_V8,
+ };
+
+ if (copy_to_user(argp, &init, sizeof(init)))
+ return -EFAULT;
+
+ return 0;
+ }
+
+ default:
+ return -EINVAL;
+ }
+}
+
bool kvm_arch_irqchip_in_kernel(struct kvm *kvm)
{
return false;
diff --git a/arch/s390/kvm/arm64/arm.h b/arch/s390/kvm/arm64/arm.h
index a3db254462c0..289e148a6b02 100644
--- a/arch/s390/kvm/arm64/arm.h
+++ b/arch/s390/kvm/arm64/arm.h
@@ -2,6 +2,62 @@
#ifndef ARCH_S390_KVM_ARM64_H
#define ARCH_S390_KVM_ARM64_H
+#include <linux/compiler_attributes.h>
+#include <linux/kvm_host.h>
+
#define KVM_DEV_NAME "kvm-arm64"
+#define VM_EVENT(d_kvm, d_loglevel, d_string, d_args...)\
+do { \
+ debug_sprintf_event((d_kvm)->arch.dbf, d_loglevel, KVM_DEV_NAME ": " d_string "\n", d_args); \
+} while (0)
+
+#define VCPU_EVENT(d_vcpu, d_loglevel, d_string, d_args...) \
+ do { \
+ debug_sprintf_event( \
+ (d_vcpu)->kvm->arch.dbf, d_loglevel, \
+ KVM_DEV_NAME " %02d[%016llx-%016llx]: " d_string "\n", \
+ (d_vcpu)->vcpu_id, (d_vcpu)->arch.sae_block.pstate, \
+ (d_vcpu)->arch.sae_block.pc, d_args); \
+ } while (0)
+
+static __always_inline int kvm_is_ucontrol(struct kvm *kvm)
+{
+ return 0;
+}
+
+static __always_inline int __kvm_s390_pv_destroy_page(struct page *page)
+{
+ return 0;
+}
+
+static __always_inline void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, gpa_t start, gpa_t end)
+{
+}
+
+static __always_inline int kvm_s390_pv_get_handle(struct kvm *kvm)
+{
+ return 0;
+}
+
+static __always_inline int kvm_s390_is_migration_mode(struct kvm *kvm)
+{
+ return false;
+}
+
+static __always_inline bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+
+static __always_inline void kvm_s390_update_cmma_dirty(struct kvm *kvm, struct kvm_memory_slot *old)
+{
+}
+
+/* should never be called */
+static __always_inline int kvm_s390_vm_stop_migration(struct kvm *kvm)
+{
+ return -EINVAL;
+}
+
#endif /* ARCH_S390_KVM_ARM64_H */
diff --git a/arch/s390/kvm/gmap/faultin.c b/arch/s390/kvm/gmap/faultin.c
index 1dc79807012c..2e93bd563d5c 100644
--- a/arch/s390/kvm/gmap/faultin.c
+++ b/arch/s390/kvm/gmap/faultin.c
@@ -10,6 +10,11 @@
#include "gmap.h"
#include "faultin.h"
+#ifdef KVM_S390_ARM64
+#include "arm.h"
+#else
+#include "s390.h"
+#endif
bool kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu);
#define CREATE_TRACE_POINTS
diff --git a/arch/s390/kvm/gmap/gmap.c b/arch/s390/kvm/gmap/gmap.c
index 4968330e9553..b7071f50f7ad 100644
--- a/arch/s390/kvm/gmap/gmap.c
+++ b/arch/s390/kvm/gmap/gmap.c
@@ -21,7 +21,11 @@
#include "dat.h"
#include "gmap.h"
+#ifdef KVM_S390_ARM64
+#include "arm.h"
+#else
#include "s390.h"
+#endif
#include "faultin.h"
static int gmap_limit_to_type(gfn_t limit)
diff --git a/arch/s390/kvm/gmap/kvm_mmu.c b/arch/s390/kvm/gmap/kvm_mmu.c
index b08b8229bb6f..a26a16193467 100644
--- a/arch/s390/kvm/gmap/kvm_mmu.c
+++ b/arch/s390/kvm/gmap/kvm_mmu.c
@@ -3,7 +3,11 @@
#include <linux/kvm_types.h>
#include <linux/kvm_host.h>
+#ifdef KVM_S390_ARM64
+#include "arm.h"
+#else
#include "s390.h"
+#endif
#include "gmap.h"
#include "dat.h"
#include "kvm_mmu.h"
diff --git a/arch/s390/kvm/gmap/trace_gmap.h b/arch/s390/kvm/gmap/trace_gmap.h
index 15ec88bdce55..431c9442b10c 100644
--- a/arch/s390/kvm/gmap/trace_gmap.h
+++ b/arch/s390/kvm/gmap/trace_gmap.h
@@ -5,12 +5,28 @@
#include <linux/tracepoint.h>
#undef TRACE_SYSTEM
+#ifdef KVM_S390_ARM64
+#define TRACE_SYSTEM kvm_arm64
+#else
#define TRACE_SYSTEM kvm
+#endif
#undef TRACE_INCLUDE_PATH
#define TRACE_INCLUDE_PATH ../gmap
#undef TRACE_INCLUDE_FILE
#define TRACE_INCLUDE_FILE trace_gmap
+#ifdef KVM_S390_ARM64
+#define __KVM_FIELDS \
+ __field(unsigned long, pstate) \
+ __field(unsigned long, pc)
+#define __KVM_ASSIGN ({\
+ __entry->pstate = vcpu->arch.sae_block.pstate; \
+ __entry->pc = vcpu->arch.sae_block.pc; \
+ })
+#define __KVM_PRINT \
+ __entry->pstate, \
+ __entry->pc
+#else
#define __KVM_FIELDS \
__field(unsigned long, pswmask) \
__field(unsigned long, pswaddr)
@@ -21,6 +37,7 @@
#define __KVM_PRINT \
__entry->pswmask,\
__entry->pswaddr
+#endif
TRACE_EVENT(kvm_s390_major_guest_pfault,
TP_PROTO(struct kvm_vcpu *vcpu),
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 30/33] KVM: s390: arm64: Implement vm/vcpu create destroy.
2026-08-12 15:36 ` [PATCH v6 30/33] KVM: s390: arm64: Implement vm/vcpu create destroy Steffen Eiden
@ 2026-08-12 16:38 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:38 UTC (permalink / raw)
To: Steffen Eiden
Cc: Oliver Upton, linux-s390, kvmarm, Marc Zyngier,
Christian Borntraeger, Alexander Gordeev, Vasily Gorbik, kvm,
Heiko Carstens
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] Integer underflow in `kvm_max_guest_address()` bypassing KVM's IPA limits and causing Undefined Behavior.
- [High] VM IPA size configuration is ignored for memory boundaries, and mem_limit suffers from an off-by-one error.
--
--- Patch [30]: [PATCH v6 30/33] KVM: s390: arm64: Implement vm/vcpu create destroy. ---
commit ac331802b4f3974b686910d63a6161cfc71cfae4
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: arm64: Implement vm/vcpu create destroy.
Implement init and destroy IOCTLS for vcpu and vm.
Implement arch vm IOCTL. Use s390 gmap and gmap plumbing.
Implement function (stubs) required by gamp.
> diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
> index 8e17b7eef8131..69d43066f9e1a 100644
> --- a/arch/s390/kvm/arm64/arm.c
> +++ b/arch/s390/kvm/arm64/arm.c
> @@ -53,6 +58,83 @@ static u64 kvm_max_guest_address(void)
> return ALIGN_DOWN(max_addr + 1, 1 << 30) - 1;
> }
[Severity: High]
Does this underflow if the host is booted with less than 1GB of memory?
If sclp.hamax is less than 1GB, max_addr + 1 is less than 1 << 30.
ALIGN_DOWN would result in 0, and 0 - 1 would underflow to U64_MAX.
[ ... ]
> +static int kvm_vm_type_ipa_size_shift(unsigned long type)
> +{
> + int phys_shift;
> +
> + phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
> + if (phys_shift) {
> + if (phys_shift > get_kvm_ipa_limit() ||
> + phys_shift < ARM64_MIN_PARANGE_BITS)
> + return -EINVAL;
[Severity: High]
This seems to cascade from the potential underflow in kvm_max_guest_address().
If get_kvm_ipa_limit() computes fls64(0) - 1, it would return -1 as 0xFFFFFFFF
via u32. Could a malicious userspace then bypass this IPA size check since
phys_shift > get_kvm_ipa_limit() would evaluate to false?
[ ... ]
> +int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
> +{
> + char debug_name[32];
> + int ret;
> +
> + if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
> + return -EINVAL;
> +
> + ret = kvm_vm_type_ipa_size_shift(type);
> + if (ret < 0)
> + return ret;
> + kvm->arch.guest_phys_size = 1UL << ret;
[Severity: High]
If the check in kvm_vm_type_ipa_size_shift() is bypassed, the phys_shift value
(up to 255) would be used in this shift. Would this invoke undefined behavior
since the shift amount could exceed the width of the type?
[ ... ]
> + ret = kvm_gmap_init(kvm);
> + if (ret)
> + goto out_err;
> + kvm->arch.mem_limit = kvm_max_guest_address();
[Severity: High]
Is it intended that kvm->arch.mem_limit is hardcoded to the global host
maximum instead of the VM's configured IPA size limit
(kvm->arch.guest_phys_size)?
If it uses the host's maximum, could userspace successfully map memory higher
than the configured VM IPA size limit?
Also, kvm_max_guest_address() appears to return an inclusive limit, but when
s390_kvm_mmu_prepare_memory_region() checks this limit:
if ((new->base_gfn + new->npages) * PAGE_SIZE > kvm->arch.mem_limit)
it treats mem_limit as an exclusive boundary. Does this off-by-one prevent
userspace from mapping the final page of the allowed memory region?
[ ... ]
> +int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
> +{
> + struct kvm_sae_block *sae_block = &vcpu->arch.sae_block;
> + struct kvm_sae_save_area *save_area = &vcpu->arch.save_area;
> +
> + spin_lock_init(&vcpu->arch.mp_state_lock);
> +
> + /* Force users to call KVM_ARM_VCPU_INIT */
> + vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
> +
> + vcpu->arch.mc = kvm_s390_new_mmu_cache();
> + if (!vcpu->arch.mc)
> + return -ENOMEM;
> +
> + sae_block->hbasce = vcpu->kvm->arch.gmap->asce.val;
> + sae_block->mso = 0L;
> + sae_block->msl = kvm_max_guest_address();
[Severity: High]
Does sae_block->msl also need to be scoped to the VM's requested size rather
than the host maximum?
Setting this to the host maximum might remove hardware emulation boundaries if
the guest physical size was configured to be smaller.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=30
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 31/33] KVM: s390: arm64: Implement vCPU IOCTLs
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (29 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 30/33] KVM: s390: arm64: Implement vm/vcpu create destroy Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:41 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 32/33] KVM: s390: arm64: Implement basic page fault handler Steffen Eiden
` (2 subsequent siblings)
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Implement all required vCPU IOCTLs.
Co-developed-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Andreas Grapentin <gra@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/arm64/arm.c | 392 ++++++++++++++++++++++++++++++
arch/s390/kvm/arm64/guest.c | 47 +++-
arch/s390/kvm/arm64/handle_exit.c | 31 +++
arch/s390/kvm/arm64/handle_exit.h | 9 +
arch/s390/kvm/arm64/reset.c | 73 ++++++
arch/s390/kvm/arm64/reset.h | 11 +
arch/s390/kvm/arm64/trace.h | 2 +-
7 files changed, 562 insertions(+), 3 deletions(-)
create mode 100644 arch/s390/kvm/arm64/handle_exit.h
create mode 100644 arch/s390/kvm/arm64/reset.c
create mode 100644 arch/s390/kvm/arm64/reset.h
diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
index 69d43066f9e1..ef941f408744 100644
--- a/arch/s390/kvm/arm64/arm.c
+++ b/arch/s390/kvm/arm64/arm.c
@@ -7,11 +7,20 @@
#include <linux/kvm.h>
#include <linux/kvm_types.h>
#include <linux/kvm_host.h>
+#include <linux/cleanup.h>
+#include <linux/fpu.h>
+
+#include <asm/access-regs.h>
+
+#include <arm64/kvm_emulate.h>
+#include <arm64/sysreg.h>
#include <gmap.h>
#include <kvm_mmu.h>
#include "arm.h"
+#include "handle_exit.h"
+#include "reset.h"
#define CREATE_TRACE_POINTS
#include "trace.h"
@@ -200,6 +209,22 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
VCPU_EVENT(vcpu, 3, "%s", "free cpu");
}
+void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+ save_access_regs(&vcpu->arch.host_acrs[0]);
+ vcpu->cpu = cpu;
+
+ lasrm(&vcpu->arch.save_area);
+}
+
+void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
+{
+ stiasrm(&vcpu->arch.save_area);
+
+ vcpu->cpu = -1;
+ restore_access_regs(&vcpu->arch.host_acrs[0]);
+}
+
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
@@ -225,6 +250,373 @@ static unsigned long system_supported_vcpu_features(void)
return features;
}
+bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
+{
+ return vcpu_mode_priv(vcpu);
+}
+
+int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+
+ if (!kvm_vcpu_initialized(vcpu))
+ return -ENOEXEC;
+
+ if (!kvm_arm_vcpu_is_finalized(vcpu))
+ return -EPERM;
+
+ if (likely(READ_ONCE(vcpu->pid)))
+ return 0;
+
+ scoped_guard(mutex, &kvm->arch.config_lock)
+ set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags);
+
+ return 0;
+}
+
+/**
+ * check_vcpu_requests - check and handle pending vCPU requests
+ * @vcpu: the VCPU pointer
+ *
+ * Return: 1 if we should enter the guest
+ * 0 if we should exit to userspace
+ * < 0 if we should exit to userspace, where the return value indicates
+ * an error
+ */
+static int check_vcpu_requests(struct kvm_vcpu *vcpu)
+{
+ if (kvm_request_pending(vcpu)) {
+ if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
+ kvm_reset_vcpu(vcpu);
+ /*
+ * Clear IRQ_PENDING requests that were made to guarantee
+ * that a VCPU sees new virtual interrupts.
+ */
+ kvm_check_request(KVM_REQ_IRQ_PENDING, vcpu);
+ }
+
+ return 1;
+}
+
+static int kvm_vcpu_initialize(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
+ unsigned long features = init->features[0];
+ struct kvm *kvm = vcpu->kvm;
+
+ scoped_guard(mutex, &kvm->arch.config_lock) {
+ if (test_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED,
+ &kvm->arch.flags) &&
+ kvm_vcpu_init_changed(vcpu, init))
+ return -EINVAL;
+
+ bitmap_copy(kvm->arch.vcpu_features, &features,
+ KVM_VCPU_MAX_FEATURES);
+
+ kvm_reset_vcpu(vcpu);
+
+ set_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED,
+ &kvm->arch.flags);
+ vcpu_set_flag(vcpu, VCPU_INITIALIZED);
+ }
+
+ return 0;
+}
+
+static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+ const struct kvm_vcpu_init *init)
+{
+ int ret;
+
+ if (init->target != KVM_ARM_TARGET_GENERIC_V8)
+ return -EINVAL;
+
+ ret = kvm_vcpu_init_check_features(vcpu, init);
+ if (ret)
+ return ret;
+
+ if (!kvm_vcpu_initialized(vcpu))
+ return kvm_vcpu_initialize(vcpu, init);
+
+ if (kvm_vcpu_init_changed(vcpu, init))
+ return -EINVAL;
+
+ kvm_reset_vcpu(vcpu);
+
+ return 0;
+}
+
+static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
+ struct kvm_vcpu_init *init)
+{
+ struct kvm_sae_save_area *save_area = &vcpu->arch.save_area;
+ struct kvm_sae_block *sae_block = &vcpu->arch.sae_block;
+ int ret;
+
+ sae_block->save_area = virt_to_phys(save_area);
+ save_area->sdo = virt_to_phys(sae_block);
+
+ ret = kvm_vcpu_set_target(vcpu, init);
+ if (ret)
+ return ret;
+
+ scoped_guard(spinlock, &vcpu->arch.mp_state_lock) {
+ WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE);
+ }
+
+ return 0;
+}
+
+int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
+ bool line_status)
+{
+ /* stub for now*/
+ return -EINVAL;
+}
+
+static void adjust_pc(struct kvm_vcpu *vcpu)
+{
+ if (vcpu_get_flag(vcpu, INCREMENT_PC)) {
+ kvm_skip_instr(vcpu);
+ vcpu_clear_flag(vcpu, INCREMENT_PC);
+ }
+}
+
+static void arm_vcpu_run(struct kvm_vcpu *vcpu)
+{
+ struct kvm_sae_block *sae_block = &vcpu->arch.sae_block;
+
+ adjust_pc(vcpu);
+
+ local_irq_disable();
+ guest_enter_irqoff();
+ local_irq_enable();
+
+ sae_block->icptr = 0;
+
+ sae64a(sae_block);
+
+ local_irq_disable();
+ guest_exit_irqoff();
+ local_irq_enable();
+}
+
+/** kvm_arch_vcpu_ioctl_run() - run arm64 vCPU
+ *
+ * Execute arm64 guest instructions using SAE.
+ *
+ * Returns:
+ * 1 enter the guest (should not be observed by userspace)
+ * 0 exit to userspace
+ * < 0 exit to userspace, where the return value indicates n error
+ *
+ *
+ */
+int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
+{
+ DECLARE_KERNEL_FPU_ONSTACK32(fpu_save);
+ struct kvm_run *kvm_run = vcpu->run;
+ int ret;
+
+ if (kvm_run->exit_reason == KVM_EXIT_MMIO) {
+ ret = kvm_handle_mmio_return(vcpu);
+ if (ret <= 0)
+ return ret;
+ }
+
+ vcpu_load(vcpu);
+
+ kernel_fpu_begin(&fpu_save, KERNEL_FPC | KERNEL_VXR);
+ load_vx_regs((vcpu->arch.ctxt.vregs));
+
+ if (!vcpu->wants_to_run) {
+ ret = -EINTR;
+ goto out;
+ }
+
+ kvm_sigset_activate(vcpu);
+
+ might_fault();
+
+ ret = 1;
+ do {
+ if (signal_pending(current)) {
+ kvm_run->exit_reason = KVM_EXIT_INTR;
+ ret = -EINTR;
+ continue;
+ }
+
+ if (need_resched())
+ schedule();
+
+ if (ret > 0)
+ ret = check_vcpu_requests(vcpu);
+
+ vcpu->arch.sae_block.icptr = 0;
+
+ arm_vcpu_run(vcpu);
+
+ ret = handle_exit(vcpu);
+
+ } while (ret > 0);
+
+ kvm_sigset_deactivate(vcpu);
+out:
+ if (unlikely(vcpu_get_flag(vcpu, INCREMENT_PC)))
+ adjust_pc(vcpu);
+
+ save_vx_regs(vcpu->arch.ctxt.vregs);
+ kernel_fpu_end(&fpu_save, KERNEL_FPC | KERNEL_VXR);
+ vcpu_put(vcpu);
+
+ return ret;
+}
+
+static int kvm_arm_vcpu_set_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ int ret;
+
+ switch (attr->group) {
+ default:
+ ret = -ENXIO;
+ break;
+ }
+
+ return ret;
+}
+
+static int kvm_arm_vcpu_get_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ int ret;
+
+ switch (attr->group) {
+ default:
+ ret = -ENXIO;
+ break;
+ }
+
+ return ret;
+}
+
+static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
+ struct kvm_device_attr *attr)
+{
+ int ret;
+
+ switch (attr->group) {
+ default:
+ ret = -ENXIO;
+ break;
+ }
+
+ return ret;
+}
+
+long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
+{
+ struct kvm_vcpu *vcpu = filp->private_data;
+ void __user *argp = (void __user *)arg;
+ struct kvm_device_attr attr;
+ int ret;
+
+ switch (ioctl) {
+ case KVM_ARM_VCPU_INIT: {
+ struct kvm_vcpu_init init;
+
+ ret = -EFAULT;
+ if (copy_from_user(&init, argp, sizeof(init)))
+ break;
+
+ ret = kvm_arch_vcpu_ioctl_vcpu_init(vcpu, &init);
+ break;
+ }
+ case KVM_SET_ONE_REG:
+ case KVM_GET_ONE_REG: {
+ struct kvm_one_reg reg;
+
+ ret = -ENOEXEC;
+ if (unlikely(!kvm_vcpu_initialized(vcpu)))
+ break;
+
+ ret = -EFAULT;
+ if (copy_from_user(®, argp, sizeof(reg)))
+ break;
+
+ if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
+ kvm_reset_vcpu(vcpu);
+
+ if (ioctl == KVM_SET_ONE_REG)
+ ret = kvm_arm_set_reg(vcpu, ®);
+ else
+ ret = kvm_arm_get_reg(vcpu, ®);
+ break;
+ }
+ case KVM_GET_REG_LIST: {
+ struct kvm_reg_list __user *user_list = argp;
+ struct kvm_reg_list reg_list;
+ unsigned int n;
+
+ ret = -ENOEXEC;
+ if (unlikely(!kvm_vcpu_initialized(vcpu)))
+ break;
+ ret = -EPERM;
+ if (!kvm_arm_vcpu_is_finalized(vcpu))
+ break;
+ ret = -EFAULT;
+ if (copy_from_user(®_list, user_list, sizeof(reg_list)))
+ break;
+ n = reg_list.n;
+ reg_list.n = kvm_arm_num_regs(vcpu);
+ if (copy_to_user(user_list, ®_list, sizeof(reg_list)))
+ break;
+ ret = -E2BIG;
+ if (n < reg_list.n)
+ break;
+ ret = kvm_arm_copy_reg_indices(vcpu, user_list->reg);
+ break;
+ }
+ case KVM_ARM_VCPU_FINALIZE: {
+ int what;
+
+ if (!kvm_vcpu_initialized(vcpu))
+ return -ENOEXEC;
+
+ if (get_user(what, (const int __user *)argp))
+ return -EFAULT;
+
+ ret = kvm_arm_vcpu_finalize(vcpu, what);
+ break;
+ }
+ case KVM_SET_DEVICE_ATTR: {
+ ret = -EFAULT;
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ break;
+ ret = kvm_arm_vcpu_set_attr(vcpu, &attr);
+ break;
+ }
+ case KVM_GET_DEVICE_ATTR: {
+ ret = -EFAULT;
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ break;
+ ret = kvm_arm_vcpu_get_attr(vcpu, &attr);
+ break;
+ }
+ case KVM_HAS_DEVICE_ATTR: {
+ ret = -EFAULT;
+ if (copy_from_user(&attr, argp, sizeof(attr)))
+ break;
+ ret = kvm_arm_vcpu_has_attr(vcpu, &attr);
+ break;
+ }
+ default:
+ ret = -EINVAL;
+ }
+
+ return ret;
+}
+
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
struct kvm_dirty_log *log)
{
diff --git a/arch/s390/kvm/arm64/guest.c b/arch/s390/kvm/arm64/guest.c
index fd6442d9e4f4..4ea6fe2c270d 100644
--- a/arch/s390/kvm/arm64/guest.c
+++ b/arch/s390/kvm/arm64/guest.c
@@ -5,8 +5,6 @@
#include <arm64/kvm_emulate.h>
#include <arm64/kvm_nested.h>
-#include "guest.h"
-
#define __INCL_GEN_ARM_FILE
#include "generated/guest.inc"
#undef __INCL_GEN_ARM_FILE
@@ -47,6 +45,51 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
sizeof(kvm_vcpu_stats_desc),
};
+int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
+{
+ int ret;
+
+ ret = copy_core_reg_indices(vcpu, uindices);
+ if (ret < 0)
+ return ret;
+ uindices += ret;
+
+ return 0;
+}
+
+unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
+{
+ return num_core_regs(vcpu);
+}
+
+int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+ /* We currently use nothing arch-specific in upper 32 bits */
+ if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
+ return -EINVAL;
+
+ switch (reg->id & KVM_REG_ARM_COPROC_MASK) {
+ case KVM_REG_ARM_CORE:
+ return get_core_reg(vcpu, reg);
+ default:
+ return -EINVAL;
+ }
+}
+
+int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
+{
+ /* We currently use nothing arch-specific in upper 32 bits */
+ if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
+ return -EINVAL;
+
+ switch (reg->id & KVM_REG_ARM_COPROC_MASK) {
+ case KVM_REG_ARM_CORE:
+ return set_core_reg(vcpu, reg);
+ default:
+ return -EINVAL;
+ }
+}
+
int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
return -EINVAL;
diff --git a/arch/s390/kvm/arm64/handle_exit.c b/arch/s390/kvm/arm64/handle_exit.c
index ed872cd804dc..1286a64783e0 100644
--- a/arch/s390/kvm/arm64/handle_exit.c
+++ b/arch/s390/kvm/arm64/handle_exit.c
@@ -5,6 +5,8 @@
#include <arm64/esr.h>
#include <arm64/kvm_emulate.h>
+#include "handle_exit.h"
+
typedef int (*exit_handle_fn)(struct kvm_vcpu *);
static exit_handle_fn arm_exit_handlers[ESR_ELx_EC_MAX + 1];
@@ -55,6 +57,35 @@ static exit_handle_fn arm_exit_handlers[] = {
[ESR_ELx_EC_HVC64] = handle_hvc,
};
+/*
+ * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
+ * proper exit to userspace.
+ */
+int handle_exit(struct kvm_vcpu *vcpu)
+{
+ u8 icptr = vcpu->arch.sae_block.icptr;
+ int ret = 1;
+
+ switch (icptr) {
+ case SAE_ICPTR_SPURIOUS:
+ break;
+ case SAE_ICPTR_VALIDITY:
+ WARN_ONCE(true, "SAE: validity intercept. vir: 0x%04x",
+ vcpu->arch.sae_block.vir);
+ ret = -EINVAL;
+ break;
+ case SAE_ICPTR_HOST_ACCESS_EXCEPTION:
+ case SAE_ICPTR_SYNCHRONOUS_EXCEPTION:
+ ret = handle_trap_exceptions(vcpu);
+ break;
+ default:
+ WARN_ONCE(true, "SAE: unknown interception reason 0x%02x",
+ icptr);
+ ret = -EINVAL;
+ }
+ return ret;
+}
+
/* manually copied from arch/arm64/kernel/traps.c */
static const char * const esr_class_str[] = {
[0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC",
diff --git a/arch/s390/kvm/arm64/handle_exit.h b/arch/s390/kvm/arm64/handle_exit.h
new file mode 100644
index 000000000000..65ae58721537
--- /dev/null
+++ b/arch/s390/kvm/arm64/handle_exit.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef KVM_ARM64_HANDLE_EXIT_H
+#define KVM_ARM64_HANDLE_EXIT_H
+
+#include <linux/kvm_host.h>
+
+int handle_exit(struct kvm_vcpu *vcpu);
+
+#endif /* KVM_ARM64_HANDLE_EXIT_H */
diff --git a/arch/s390/kvm/arm64/reset.c b/arch/s390/kvm/arm64/reset.c
new file mode 100644
index 000000000000..d107d2ae47f4
--- /dev/null
+++ b/arch/s390/kvm/arm64/reset.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kvm_host.h>
+#include <linux/fpu.h>
+
+#include <arm64/kvm_emulate.h>
+#include <arm64/kvm_nested.h>
+
+#include "reset.h"
+
+bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu)
+{
+ return true;
+}
+
+static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.hcr_elz = HCR_EL2_E2H | HCR_EL2_RW | HCR_EL2_AMO |
+ HCR_EL2_IMO | HCR_EL2_FMO | HCR_EL2_PTW;
+ /* traps */
+ vcpu->arch.hcr_elz |= HCR_EL2_TSC | HCR_EL2_TID1 | HCR_EL2_TID2 |
+ HCR_EL2_TID3 | HCR_EL2_TID4 | HCR_EL2_TID5 |
+ HCR_EL2_TIDCP;
+}
+
+void kvm_reset_vcpu(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_reset_state reset_state;
+ bool loaded;
+
+ scoped_guard(spinlock, &vcpu->arch.mp_state_lock) {
+ reset_state = vcpu->arch.reset_state;
+ vcpu->arch.reset_state.reset = false;
+ }
+
+ /*
+ * Disable preemption around the vcpu reset as we might otherwise race with
+ * preempt notifiers which call stiasrm/lasrm from put/load
+ */
+ preempt_disable();
+
+ /* The reset must run with an unloaded save area */
+ loaded = vcpu_is_loaded(vcpu);
+ if (loaded)
+ vcpu_put(vcpu);
+
+ kvm_reset_vcpu_core(vcpu);
+
+ /* Reset special registers */
+ vcpu_reset_hcr(vcpu);
+
+ if (reset_state.reset) {
+ *vcpu_pc(vcpu) = reset_state.pc;
+ vcpu_clear_flag(vcpu, PENDING_EXCEPTION);
+ vcpu_clear_flag(vcpu, EXCEPT_MASK);
+ vcpu_clear_flag(vcpu, INCREMENT_PC);
+ vcpu_set_reg(vcpu, 0, reset_state.r0);
+ }
+
+ /* Load new vx-regs into HW if they are currently loaded */
+ if (current->thread.kfpu_flags)
+ load_vx_regs(vcpu->arch.ctxt.vregs);
+
+ if (loaded)
+ vcpu_load(vcpu);
+
+ preempt_enable();
+}
+
+int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature)
+{
+ return 0;
+}
diff --git a/arch/s390/kvm/arm64/reset.h b/arch/s390/kvm/arm64/reset.h
new file mode 100644
index 000000000000..a5c5304e47bc
--- /dev/null
+++ b/arch/s390/kvm/arm64/reset.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef KVM_ARM_RESET_H
+#define KVM_ARM_RESET_H
+
+#include <linux/kvm_host.h>
+
+bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
+void kvm_reset_vcpu(struct kvm_vcpu *vcpu);
+int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);
+
+#endif /* KVM_ARM_RESET_H */
diff --git a/arch/s390/kvm/arm64/trace.h b/arch/s390/kvm/arm64/trace.h
index 3a5dcd039c13..1e3cb6108196 100644
--- a/arch/s390/kvm/arm64/trace.h
+++ b/arch/s390/kvm/arm64/trace.h
@@ -5,7 +5,7 @@
#include <linux/tracepoint.h>
#undef TRACE_SYSTEM
-#define TRACE_SYSTEM kvm
+#define TRACE_SYSTEM kvm_arm64
#endif /* KVM_ARM64_TRACE_KVM_H */
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 31/33] KVM: s390: arm64: Implement vCPU IOCTLs
2026-08-12 15:36 ` [PATCH v6 31/33] KVM: s390: arm64: Implement vCPU IOCTLs Steffen Eiden
@ 2026-08-12 16:41 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:41 UTC (permalink / raw)
To: Steffen Eiden
Cc: Vasily Gorbik, Heiko Carstens, linux-s390, Alexander Gordeev,
kvmarm, Marc Zyngier, Oliver Upton, kvm, Christian Borntraeger
Thank you for your contribution! Sashiko AI review found 6 potential issue(s) to consider:
- [Critical] kvm_arch_vcpu_ioctl_run() fails to acquire the kvm->srcu read lock, leading to a Use-After-Free when accessing memslots during guest aborts.
- [High] Guest-reachable WARN_ONCE on SAE validity intercept enables a host DoS.
- [High] Calling local_irq_enable() immediately after guest_enter_irqoff() violates strict RCU extended quiescent state (EQS) rules.
- [High] check_vcpu_requests() fails to handle critical KVM requests like KVM_REQ_TLB_FLUSH and KVM_REQ_VM_DEAD.
- [High] Missing IN_GUEST_MODE coordination in the vCPU run loop creates a race condition that can delay or drop signals and KVM requests.
- [High] Missing vcpu_load() and vcpu_put() around KVM IOCTLs that modify architectural state in kvm_arch_vcpu_ioctl.
--
--- Patch [31]: [PATCH v6 31/33] KVM: s390: arm64: Implement vCPU IOCTLs ---
commit e43ea7af3ba7491497b01c2a0860a8b946aad58d
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: arm64: Implement vCPU IOCTLs
This commit implements the required vCPU IOCTLs for the s390 arm64 KVM
port. It provides the core structures for register access, lifecycle
management, and the main vCPU execution loop.
> diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
> --- a/arch/s390/kvm/arm64/arm.c
> +++ b/arch/s390/kvm/arm64/arm.c
[ ... ]
> @@ -284,15 +309,15 @@
> +static int check_vcpu_requests(struct kvm_vcpu *vcpu)
> +{
> + if (kvm_request_pending(vcpu)) {
> + if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
> + kvm_reset_vcpu(vcpu);
> + /*
> + * Clear IRQ_PENDING requests that were made to guarantee
> + * that a VCPU sees new virtual interrupts.
> + */
> + kvm_check_request(KVM_REQ_IRQ_PENDING, vcpu);
> + }
[Severity: High]
Does this function properly handle all critical KVM requests?
It appears to drop requests like KVM_REQ_TLB_FLUSH and KVM_REQ_VM_DEAD by
not explicitly handling or clearing them. Can this bypass necessary TLB
invalidations and dead VM checks?
> +
> + return 1;
> +}
[ ... ]
> @@ -390,13 +415,13 @@
> +static void arm_vcpu_run(struct kvm_vcpu *vcpu)
> +{
> + struct kvm_sae_block *sae_block = &vcpu->arch.sae_block;
> +
> + adjust_pc(vcpu);
> +
> + local_irq_disable();
> + guest_enter_irqoff();
> + local_irq_enable();
[Severity: High]
Does this sequence violate RCU extended quiescent state rules?
Calling local_irq_enable() immediately after guest_enter_irqoff() allows
host interrupts to fire while RCU believes the CPU is idle.
> +
> + sae_block->icptr = 0;
> +
> + sae64a(sae_block);
[ ... ]
> @@ -436,15 +461,15 @@
> + ret = 1;
> + do {
> + if (signal_pending(current)) {
> + kvm_run->exit_reason = KVM_EXIT_INTR;
> + ret = -EINTR;
> + continue;
> + }
> +
> + if (need_resched())
> + schedule();
> +
> + if (ret > 0)
> + ret = check_vcpu_requests(vcpu);
> +
> + vcpu->arch.sae_block.icptr = 0;
> +
> + arm_vcpu_run(vcpu);
[Severity: High]
Could this loop race with concurrent IPI kicks?
It executes arm_vcpu_run() without coordinating via vcpu->mode = IN_GUEST_MODE.
A concurrent request kick via kvm_vcpu_kick() might see OUTSIDE_GUEST_MODE
and skip sending the IPI.
> +
> + ret = handle_exit(vcpu);
[Severity: Critical]
Does handle_exit() require SRCU protection here?
The loop calls handle_exit() which routes synchronous exceptions to the guest
abort handler. If the abort handler translates guest addresses and accesses
active memslots without holding kvm->srcu, could a concurrent userspace
operation like KVM_SET_USER_MEMORY_REGION trigger a use-after-free?
> +
> + } while (ret > 0);
[ ... ]
> @@ -515,15 +540,15 @@
> +long kvm_arch_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
> +{
> + struct kvm_vcpu *vcpu = filp->private_data;
> + void __user *argp = (void __user *)arg;
> + struct kvm_device_attr attr;
> + int ret;
> +
> + switch (ioctl) {
> + case KVM_ARM_VCPU_INIT: {
> + struct kvm_vcpu_init init;
[Severity: High]
Are vcpu_load() and vcpu_put() required around these ioctls?
Operations like KVM_SET_ONE_REG modify architectural state but do not acquire
the vcpu_load locks, potentially bypassing preempt notifiers and physical-CPU
hardware state tracking hooks.
> +
> + ret = -EFAULT;
> + if (copy_from_user(&init, argp, sizeof(init)))
> + break;
[ ... ]
> diff --git a/arch/s390/kvm/arm64/handle_exit.c b/arch/s390/kvm/arm64/handle_exit.c
> --- a/arch/s390/kvm/arm64/handle_exit.c
> +++ b/arch/s390/kvm/arm64/handle_exit.c
[ ... ]
> @@ -66,13 +78,13 @@
> +int handle_exit(struct kvm_vcpu *vcpu)
> +{
> + u8 icptr = vcpu->arch.sae_block.icptr;
> + int ret = 1;
> +
> + switch (icptr) {
> + case SAE_ICPTR_SPURIOUS:
> + break;
> + case SAE_ICPTR_VALIDITY:
> + WARN_ONCE(true, "SAE: validity intercept. vir: 0x%04x",
> + vcpu->arch.sae_block.vir);
[Severity: High]
Is it safe to use a guest-reachable WARN_ONCE here?
An unprivileged userspace process configuring KVM could set malformed guest
state via KVM_SET_ONE_REG, and the hardware would reject this during
execution, returning a validity intercept. Should this return an error to
userspace instead of triggering a host warning?
> + ret = -EINVAL;
> + break;
[ ... ]
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=31
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 32/33] KVM: s390: arm64: Implement basic page fault handler
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (30 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 31/33] KVM: s390: arm64: Implement vCPU IOCTLs Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:34 ` sashiko-bot
2026-08-12 15:36 ` [PATCH v6 33/33] KVM: s390: arm64: Enable KVM_ARM64 config and Kbuild Steffen Eiden
2026-08-12 16:28 ` [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Christian Borntraeger
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Add host functionality to page in guest memory. If the guest does
something unexpected or illegal exit to userspace abort guest execution.
This behaviour will be changed to guest error injects once all sysregs
are accessible for the host.
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/kvm/arm64/handle_exit.c | 2 +
arch/s390/kvm/arm64/mmio.c | 15 +++
arch/s390/kvm/arm64/mmu.c | 177 ++++++++++++++++++++++++++++++
arch/s390/kvm/arm64/trace.h | 24 ++++
4 files changed, 218 insertions(+)
create mode 100644 arch/s390/kvm/arm64/mmio.c
create mode 100644 arch/s390/kvm/arm64/mmu.c
diff --git a/arch/s390/kvm/arm64/handle_exit.c b/arch/s390/kvm/arm64/handle_exit.c
index 1286a64783e0..8b03e8ee5acf 100644
--- a/arch/s390/kvm/arm64/handle_exit.c
+++ b/arch/s390/kvm/arm64/handle_exit.c
@@ -55,6 +55,8 @@ static int handle_hvc(struct kvm_vcpu *vcpu)
static exit_handle_fn arm_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = kvm_handle_unknown_ec,
[ESR_ELx_EC_HVC64] = handle_hvc,
+ [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort,
+ [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort,
};
/*
diff --git a/arch/s390/kvm/arm64/mmio.c b/arch/s390/kvm/arm64/mmio.c
new file mode 100644
index 000000000000..908a6b43ddf7
--- /dev/null
+++ b/arch/s390/kvm/arm64/mmio.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kvm_host.h>
+#include <linux/bitfield.h>
+
+#include <trace/events/kvm.h>
+
+#include <arm64/kvm_emulate.h>
+#include <arm64/sysreg.h>
+
+#include "trace.h"
+
+#define __INCL_GEN_ARM_FILE
+#include "generated/mmio.inc"
+#undef __INCL_GEN_ARM_FILE
diff --git a/arch/s390/kvm/arm64/mmu.c b/arch/s390/kvm/arm64/mmu.c
new file mode 100644
index 000000000000..71cd582f24ff
--- /dev/null
+++ b/arch/s390/kvm/arm64/mmu.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kvm_host.h>
+
+#include <arm64/kvm_emulate.h>
+
+#include <faultin.h>
+
+static inline bool kvm_s390_cur_gmap_fault_is_write(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.sae_block.hai.pic == PGM_PROTECTION ||
+ vcpu->arch.sae_block.hai.teid.fsi == TEID_FSI_STORE;
+}
+
+/*
+ * user_mem_abort() - handle a dat fault for the gmap of a vcpu
+ *
+ * Return: 0 on success, < 0 in case of error.
+ * Context: The mm lock must not be held before calling. May sleep.
+ */
+static int user_mem_abort(struct kvm_vcpu *vcpu, gpa_t fault_ipa,
+ struct kvm_memory_slot *slot, hva_t hva)
+{
+ struct guest_fault f = { };
+ int ret;
+
+ if (kvm_s390_cur_gmap_fault_is_write(vcpu))
+ f.write_attempt = FOLL_WRITE;
+ f.gfn = gpa_to_gfn(fault_ipa);
+
+ ret = kvm_s390_faultin_gfn(vcpu, NULL, &f);
+ if (ret <= 0)
+ return ret;
+ if (ret == PGM_ADDRESSING)
+ /*
+ * Without the relevant sysregs we cannot do anything for now.
+ * Go back to userspace with an error. TODO sysreg handling
+ */
+ return -ENOEXEC;
+ KVM_BUG_ON(ret, vcpu->kvm);
+ return -EINVAL;
+}
+
+static int kvm_handle_pic(struct kvm_vcpu *vcpu, bool *translation)
+{
+ switch (kvm_vcpu_fault_pic(vcpu)) {
+ /* expected cases: */
+ case PGM_ASCE_TYPE:
+ case PGM_REGION_FIRST_TRANS:
+ case PGM_REGION_SECOND_TRANS:
+ case PGM_REGION_THIRD_TRANS:
+ case PGM_SEGMENT_TRANSLATION:
+ case PGM_PAGE_TRANSLATION:
+ *translation = true;
+ break;
+ case PGM_PROTECTION:
+ break;
+ /* unexpected cases: */
+ case 0:
+ KVM_BUG(1, vcpu->kvm, "On MMU fault path but no fault occurred");
+ return -EFAULT;
+ default:
+ KVM_BUG(1, vcpu->kvm, "Unexpected program interrupt 0x%x, TEID 0x%016lx",
+ vcpu->arch.sae_block.hai.pic, vcpu->arch.sae_block.hai.teid.val);
+ send_sig(SIGSEGV, current, 0);
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
+{
+ struct kvm_memory_slot *memslot;
+ bool translation = false;
+ phys_addr_t fault_ipa;
+ unsigned long esr;
+ unsigned long hva;
+ bool write_fault;
+ bool guest_size_err;
+ bool writable;
+ bool is_iabt;
+ int ret;
+ gfn_t gfn;
+ int idx;
+
+ esr = kvm_vcpu_get_esr(vcpu);
+ fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
+ is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
+ guest_size_err = vcpu->arch.sae_block.icptr == SAE_ICPTR_GUEST_ADDRESS_SIZE;
+
+ if (guest_size_err) {
+ translation = true;
+ } else {
+ ret = kvm_handle_pic(vcpu, &translation);
+ if (ret)
+ return ret;
+ }
+
+ if (translation) {
+ /*
+ * For both cases:
+ * Without the relevant sysregs we cannot do anything for now.
+ * Go back to userspace with an error. TODO sysreg handling
+ */
+ if (fault_ipa >= BIT_ULL(get_kvm_ipa_limit()))
+ return -ENOEXEC;
+
+ if (fault_ipa >= kvm_phys_size(vcpu->kvm))
+ return -ENOEXEC;
+ }
+
+ idx = srcu_read_lock(&vcpu->kvm->srcu);
+
+ gfn = fault_ipa >> PAGE_SHIFT;
+
+ memslot = gfn_to_memslot(vcpu->kvm, gfn);
+ hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
+ write_fault = kvm_is_write_fault(vcpu);
+ if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
+ ret = -ENOEXEC;
+ /*
+ * The guest has put either its instructions or its page-tables
+ * somewhere it shouldn't have. Userspace won't be able to do
+ * anything about this (there's no syndrome for a start).
+ *
+ * Without the relevant sysregs we cannot do anything for now.
+ * Go back to userspace with an error. TODO sysreg handling
+ */
+ if (is_iabt)
+ goto out_unlock;
+
+ if (kvm_vcpu_abt_iss1tw(vcpu)) {
+ /*
+ * Without the relevant sysregs we cannot do anything for now.
+ * Go back to userspace with an error. TODO sysreg handling
+ */
+ goto out_unlock;
+ }
+
+ /*
+ * Check for a cache maintenance operation. Assume the guest is
+ * cautious and skip instruction
+ */
+ if (kvm_is_error_hva(hva) && kvm_vcpu_dabt_is_cm(vcpu)) {
+ kvm_incr_pc(vcpu);
+ ret = 1;
+ goto out_unlock;
+ }
+
+ /*
+ * The IPA is reported as [MAX:12], so we need to
+ * complement it with the bottom 12 bits from the
+ * faulting VA. This is always 12 bits, irrespective
+ * of the page size.
+ */
+ fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
+ ret = io_mem_abort(vcpu, fault_ipa);
+ goto out_unlock;
+ }
+
+ /* Userspace should not be able to register out-of-bounds IPAs */
+ VM_BUG_ON(fault_ipa >= kvm_phys_size(vcpu->kvm));
+ /*
+ * Proper guest size faults have been injected.
+ * In theory it's fine to have device memory higher than MSL,
+ * even if not currently possible, but that would have been handled above.
+ * So if we get here with a guest size intercept, we have a bug somewhere.
+ */
+ VM_BUG_ON(guest_size_err);
+
+ ret = user_mem_abort(vcpu, fault_ipa, memslot, hva);
+ if (!ret)
+ ret = 1;
+out_unlock:
+ srcu_read_unlock(&vcpu->kvm->srcu, idx);
+ return ret;
+}
diff --git a/arch/s390/kvm/arm64/trace.h b/arch/s390/kvm/arm64/trace.h
index 1e3cb6108196..2a205ba0165c 100644
--- a/arch/s390/kvm/arm64/trace.h
+++ b/arch/s390/kvm/arm64/trace.h
@@ -7,6 +7,30 @@
#undef TRACE_SYSTEM
#define TRACE_SYSTEM kvm_arm64
+TRACE_EVENT(kvm_mmio_nisv,
+ TP_PROTO(unsigned long vcpu_pc, unsigned long esr,
+ unsigned long far, unsigned long ipa),
+ TP_ARGS(vcpu_pc, esr, far, ipa),
+
+ TP_STRUCT__entry(
+ __field( unsigned long, vcpu_pc )
+ __field( unsigned long, esr )
+ __field( unsigned long, far )
+ __field( unsigned long, ipa )
+ ),
+
+ TP_fast_assign(
+ __entry->vcpu_pc = vcpu_pc;
+ __entry->esr = esr;
+ __entry->far = far;
+ __entry->ipa = ipa;
+ ),
+
+ TP_printk("ipa %#016lx, esr %#016lx, far %#016lx, pc %#016lx",
+ __entry->ipa, __entry->esr,
+ __entry->far, __entry->vcpu_pc)
+);
+
#endif /* KVM_ARM64_TRACE_KVM_H */
#undef TRACE_INCLUDE_PATH
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 32/33] KVM: s390: arm64: Implement basic page fault handler
2026-08-12 15:36 ` [PATCH v6 32/33] KVM: s390: arm64: Implement basic page fault handler Steffen Eiden
@ 2026-08-12 16:34 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:34 UTC (permalink / raw)
To: Steffen Eiden
Cc: Heiko Carstens, Alexander Gordeev, Oliver Upton,
Christian Borntraeger, Marc Zyngier, linux-s390, kvmarm, kvm,
Vasily Gorbik
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Guest-triggerable KVM_BUG on unexpected program interrupt codes (PICs) causes host denial of service.
--
--- Patch [32]: [PATCH v6 32/33] KVM: s390: arm64: Implement basic page fault handler ---
commit 1cc2a3fc0641697d83c316659559bcf0aaa389a1
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: arm64: Implement basic page fault handler
Add host functionality to page in guest memory. If the guest does
something unexpected or illegal exit to userspace abort guest execution.
> diff --git a/arch/s390/kvm/arm64/mmu.c b/arch/s390/kvm/arm64/mmu.c
> new file mode 100644
> index 0000000000000..71cd582f24ff8
> --- /dev/null
> +++ b/arch/s390/kvm/arm64/mmu.c
[ ... ]
> +static int kvm_handle_pic(struct kvm_vcpu *vcpu, bool *translation)
> +{
> + switch (kvm_vcpu_fault_pic(vcpu)) {
> + /* expected cases: */
> + case PGM_ASCE_TYPE:
> + case PGM_REGION_FIRST_TRANS:
> + case PGM_REGION_SECOND_TRANS:
> + case PGM_REGION_THIRD_TRANS:
> + case PGM_SEGMENT_TRANSLATION:
> + case PGM_PAGE_TRANSLATION:
> + *translation = true;
> + break;
> + case PGM_PROTECTION:
> + break;
> + /* unexpected cases: */
> + case 0:
> + KVM_BUG(1, vcpu->kvm, "On MMU fault path but no fault occurred");
[Severity: High]
Does this KVM_BUG() allow a guest to trigger a host warning?
If a guest performs an action that triggers a hardware exit with an
unexpected program interrupt code (like an alignment fault that exits with
pic == 0), kvm_handle_pic() falls into these branches.
Since KVM_BUG() expands to a WARN_ONCE in the host kernel, this could
cause a host kernel panic on systems configured with panic_on_warn.
Should this cleanly return -EFAULT to userspace to gracefully abort the
guest without asserting instead?
> + return -EFAULT;
> + default:
> + KVM_BUG(1, vcpu->kvm, "Unexpected program interrupt 0x%x, TEID 0x%016lx",
> + vcpu->arch.sae_block.hai.pic, vcpu->arch.sae_block.hai.teid.val);
> + send_sig(SIGSEGV, current, 0);
> + return -EFAULT;
> + }
> +
> + return 0;
> +}
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=32
^ permalink raw reply [flat|nested] 70+ messages in thread
* [PATCH v6 33/33] KVM: s390: arm64: Enable KVM_ARM64 config and Kbuild
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (31 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 32/33] KVM: s390: arm64: Implement basic page fault handler Steffen Eiden
@ 2026-08-12 15:36 ` Steffen Eiden
2026-08-12 16:59 ` sashiko-bot
2026-08-12 16:28 ` [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Christian Borntraeger
33 siblings, 1 reply; 70+ messages in thread
From: Steffen Eiden @ 2026-08-12 15:36 UTC (permalink / raw)
To: kvm, kvmarm, linux-arm-kernel, linux-kernel, linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Christian Borntraeger, Claudio Imbrenda,
David Hildenbrand, Friedrich Welter, Fuad Tabba, Gautam Gala,
Hariharan Mari, Heiko Carstens, Hendrik Brueckner,
Ilya Leoshkevich, Janosch Frank, Joey Gouly, Marc Zyngier,
Nico Boehr, Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Add all Kbuild/Makefile configurations to build a second KVM module on
s390 implementing the arm64-KVM API. To prevent symbol conflicts with
kvm-s390 all internal symbols in kvm-arm64 are mangled if compiled as
built-in. The new module ins named kvm-arm64.
As in this case the build does not go through the normal build process
the module parameter handling would be messed up. By forcing
KBUILD_MODNAME to kvm-arm64 all parameters are at the same location and
not at object/basename of the object file the parameter is introduced.
Co-developed-by: Andreas Grapentin <gra@linux.ibm.com>
Signed-off-by: Andreas Grapentin <gra@linux.ibm.com>
Co-developed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
Co-developed-by: Gautam Gala <ggala@linux.ibm.com>
Signed-off-by: Gautam Gala <ggala@linux.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
arch/s390/configs/debug_defconfig | 1 +
arch/s390/configs/defconfig | 1 +
arch/s390/include/asm/Kbuild | 3 +
arch/s390/kvm/Kconfig | 29 ++++++++++
arch/s390/kvm/Makefile | 1 +
arch/s390/kvm/arm64/Makefile | 91 +++++++++++++++++++++++++++++++
6 files changed, 126 insertions(+)
create mode 100644 arch/s390/kvm/arm64/Makefile
diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig
index 3dae71474333..a05ea2204cdc 100644
--- a/arch/s390/configs/debug_defconfig
+++ b/arch/s390/configs/debug_defconfig
@@ -66,6 +66,7 @@ CONFIG_CMM=m
CONFIG_APPLDATA_BASE=y
CONFIG_S390_HYPFS_FS=y
CONFIG_KVM=m
+CONFIG_KVM_ARM64=m
CONFIG_KVM_S390_UCONTROL=y
CONFIG_S390_UNWIND_SELFTEST=m
CONFIG_S390_KPROBES_SANITY_TEST=m
diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig
index 6f5722634b4d..3497f2959b93 100644
--- a/arch/s390/configs/defconfig
+++ b/arch/s390/configs/defconfig
@@ -64,6 +64,7 @@ CONFIG_CMM=m
CONFIG_APPLDATA_BASE=y
CONFIG_S390_HYPFS_FS=y
CONFIG_KVM=m
+CONFIG_KVM_ARM64=m
CONFIG_S390_UNWIND_SELFTEST=m
CONFIG_S390_KPROBES_SANITY_TEST=m
CONFIG_S390_MODULES_SANITY_TEST=m
diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild
index 0c1fc47c3ba0..40a81419e353 100644
--- a/arch/s390/include/asm/Kbuild
+++ b/arch/s390/include/asm/Kbuild
@@ -8,3 +8,6 @@ generic-y += asm-offsets.h
generic-y += mcs_spinlock.h
generic-y += mmzone.h
generic-y += ring_buffer.h
+
+generated-y += sysreg-defs.h
+generated-y += kvm_arm64_modname.h
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index 8d3ee17a1bcb..ee5c1cdc4580 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -53,4 +53,33 @@ config KVM_S390_UCONTROL
If unsure, say N.
+config KVM_ARM64
+ def_tristate y
+ prompt "KVM support for hardware accelerated arm64 guests"
+ depends on HAS_IOMEM
+ depends on KVM
+ select GUEST_PERF_EVENTS if PERF_EVENTS
+ select HAVE_KVM_CPU_RELAX_INTERCEPT
+ select HAVE_KVM_IRQCHIP
+ select HAVE_KVM_VCPU_RUN_PID_CHANGE
+ select IRQ_BYPASS_MANAGER
+ select KVM_COMMON
+ select KVM_MMIO
+ select KVM_VFIO
+ select SCHED_INFO
+ select XARRAY_MULTI
+ help
+ Enable support for hosting paravirtualized, hardware-accelerated
+ arm64 virtual machines on s390 systems using the Start ARM Execution
+ (SAE) instruction. This requires hardware models that support the Arm
+ execution facility (AEF).
+
+ The module provides a character device named /dev/kvm-arm64 to expose
+ the hardware capabilities.
+
+ To compile this driver as a module, choose M here. The module will
+ be called kvm-arm64.
+
+ If unsure, say N.
+
endif # VIRTUALIZATION
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index a4e3875b5bdd..d00efd58f94f 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -4,3 +4,4 @@
# Copyright IBM Corp. 2008
obj-$(CONFIG_KVM) += s390/
+obj-$(CONFIG_KVM_ARM64) += arm64/
diff --git a/arch/s390/kvm/arm64/Makefile b/arch/s390/kvm/arm64/Makefile
new file mode 100644
index 000000000000..2ae4a5624151
--- /dev/null
+++ b/arch/s390/kvm/arm64/Makefile
@@ -0,0 +1,91 @@
+# SPDX-License-Identifier: GPL-2.0
+
+KVM := ../../../../virt/kvm
+include $(srctree)/virt/kvm/Makefile.kvm
+include $(srctree)/arch/s390/kvm/gmap/Makefile
+include $(src)/Makefile.gen
+
+ccflags-y += -I $(src) -I $(objtree)/$(obj) -I$(srctree)/arch/s390/kvm/gmap -DKVM_S390_ARM64
+
+kvm-arm64-obj := \
+ arm.o \
+ guest.o \
+ handle_exit.o \
+ inject_fault.o \
+ mmu.o \
+ mmio.o \
+ reset.o \
+
+kvm-arm64-obj += $(patsubst %.o,%-arm64.o,$(kvm-y))
+kvm-arm64-obj += $(patsubst %.o,%-arm64.o,$(gmap-y))
+
+targets += $(kvm-arm64-obj)
+
+$(obj)/%-arm64.o: $(src)/%.c FORCE
+ @mkdir -p $(dir $@)
+ $(call if_changed_rule,cc_o_c)
+
+ifeq ($(CONFIG_KVM_ARM64),m)
+
+kvm-arm64-y = $(kvm-arm64-obj)
+
+else ifeq ($(CONFIG_KVM_ARM64),y)
+
+KVM_ARM64_GEN_DIR := $(objtree)/arch/${SRCARCH}/include/generated/asm
+KVM_ARM64_MODNAME_H := $(KVM_ARM64_GEN_DIR)/kvm_arm64_modname.h
+ccflags-y += -include $(KVM_ARM64_MODNAME_H)
+
+targets += $(KVM_ARM64_MODNAME_H)
+
+quiet_cmd_kvm_arm64_modname_h = GEN $@
+ cmd_kvm_arm64_modname_h = { \
+ echo '/* Automatically generated; do not edit. */'; \
+ echo '\#ifndef _KVM_ARM64_MODNAME_H'; \
+ echo '\#define _KVM_ARM64_MODNAME_H'; \
+ echo '\#undef KBUILD_MODNAME'; \
+ echo '\#define KBUILD_MODNAME "kvm_arm64"'; \
+ echo '\#endif /* _KVM_ARM64_MODNAME_H */'; \
+ } > $@
+
+$(addprefix $(obj)/,$(kvm-arm64-obj)): $(KVM_ARM64_MODNAME_H)
+
+$(KVM_ARM64_MODNAME_H):
+ @mkdir -p $(KVM_ARM64_GEN_DIR)
+ $(call cmd,kvm_arm64_modname_h)
+
+prereq-o-cmd = $(foreach o, $(filter %.o, $^), $(dir $(o)).$(notdir $(o)).cmd)
+cmd_gen_symversions_o = \
+ grep --no-filename "^\#SYMVER" $(prereq-o-cmd) >> $(dot-target).cmd || true
+
+define rule_ld_o_o
+ $(call cmd_and_savecmd,ld)
+ $(call cmd,gen_symversions_o)
+endef
+
+LDFLAGS_kvm-unnamespaced.o := -r --whole-archive
+$(obj)/kvm-unnamespaced.o: $(addprefix $(obj)/,$(kvm-arm64-obj)) FORCE
+ $(call if_changed_rule,ld_o_o)
+
+quiet_cmd_nm_filter = NMFLTR $@
+ cmd_nm_filter = $(NM) -jU $< | sort -u > $@
+
+$(obj)/kvm_symbol_list: $(obj)/kvm-unnamespaced.o FORCE
+ $(call if_changed,nm_filter)
+
+define rule_oc_o_o
+ $(call cmd_and_savecmd,objcopy)
+ $(call cmd,gen_objtooldep)
+ $(call cmd,gen_symversions_o)
+endef
+
+OBJCOPYFLAGS_kvm-namespaced.o := -O default --localize-symbols=$(obj)/kvm_symbol_list
+$(obj)/kvm-namespaced.o: $(obj)/kvm-unnamespaced.o $(obj)/kvm_symbol_list FORCE
+ $(call if_changed_rule,oc_o_o)
+
+kvm-arm64-y = kvm-namespaced.o
+
+targets += kvm-unnamespaced.o kvm_symbol_list kvm-namespaced.o
+
+endif
+
+obj-$(CONFIG_KVM_ARM64) += kvm-arm64.o
--
2.53.0
^ permalink raw reply related [flat|nested] 70+ messages in thread* Re: [PATCH v6 33/33] KVM: s390: arm64: Enable KVM_ARM64 config and Kbuild
2026-08-12 15:36 ` [PATCH v6 33/33] KVM: s390: arm64: Enable KVM_ARM64 config and Kbuild Steffen Eiden
@ 2026-08-12 16:59 ` sashiko-bot
0 siblings, 0 replies; 70+ messages in thread
From: sashiko-bot @ 2026-08-12 16:59 UTC (permalink / raw)
To: Steffen Eiden
Cc: Vasily Gorbik, kvm, Oliver Upton, linux-s390, Heiko Carstens,
Christian Borntraeger, Marc Zyngier, Alexander Gordeev, kvmarm
Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [Medium] Trace event name collisions completely break tracing for the kvm-arm64 subsystem.
- [Low] The `$(NM) -jU` command is incompatible with GNU nm, causing build failures.
- [Low] The Makefile passes `-O default` to `objcopy`, which is an invalid BFD target.
--
--- Patch [33]: [PATCH v6 33/33] KVM: s390: arm64: Enable KVM_ARM64 config and Kbuild ---
commit 9d8a545589b9d6b384f0fa20e8bcb8b16fc11bd1
Author: Steffen Eiden <seiden@linux.ibm.com>
KVM: s390: arm64: Enable KVM_ARM64 config and Kbuild
Adds Kbuild/Makefile configurations to build a second KVM module on s390
implementing the arm64-KVM API. To prevent symbol conflicts with kvm-s390,
internal symbols in kvm-arm64 are mangled if compiled as built-in.
> diff --git a/arch/s390/kvm/arm64/Makefile b/arch/s390/kvm/arm64/Makefile
> new file mode 100644
> index 0000000000000..2ae4a5624151d
> --- /dev/null
> +++ b/arch/s390/kvm/arm64/Makefile
> @@ -0,0 +1,91 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +KVM := ../../../../virt/kvm
> +include $(srctree)/virt/kvm/Makefile.kvm
> +include $(srctree)/arch/s390/kvm/gmap/Makefile
> +include $(src)/Makefile.gen
> +
> +ccflags-y += -I $(src) -I $(objtree)/$(obj) -I$(srctree)/arch/s390/kvm/gmap -DKVM_S390_ARM64
> +
> +kvm-arm64-obj := \
> + arm.o \
> + guest.o \
> + handle_exit.o \
> + inject_fault.o \
> + mmu.o \
> + mmio.o \
> + reset.o \
> +
> +kvm-arm64-obj += $(patsubst %.o,%-arm64.o,$(kvm-y))
[Severity: Medium]
Because kvm_main.c is compiled into both the s390 kvm.ko and kvm-arm64.ko
modules, it includes the trace headers with TRACE_SYSTEM kvm. Does this mean
both modules will generate trace event structures mapped to the exact same
system and event names? If eventfs processes these tracepoints during module
load, could the kvm-arm64 trace events be permanently shadowed by the kvm
subsystem's events?
[ ... ]
> +prereq-o-cmd = $(foreach o, $(filter %.o, $^), $(dir $(o)).$(notdir $(o)).cmd)
> +cmd_gen_symversions_o = \
> + grep --no-filename "^\#SYMVER" $(prereq-o-cmd) >> $(dot-target).cmd || true
> +
> +define rule_ld_o_o
> + $(call cmd_and_savecmd,ld)
> + $(call cmd,gen_symversions_o)
> +endef
> +
> +LDFLAGS_kvm-unnamespaced.o := -r --whole-archive
> +$(obj)/kvm-unnamespaced.o: $(addprefix $(obj)/,$(kvm-arm64-obj)) FORCE
> + $(call if_changed_rule,ld_o_o)
> +
> +quiet_cmd_nm_filter = NMFLTR $@
> + cmd_nm_filter = $(NM) -jU $< | sort -u > $@
[Severity: Low]
Are the -j and -U flags compatible with standard GNU nm? GNU nm does not
support these flags natively and requires --defined-only instead. Will this
cause a build failure on systems using standard GCC/binutils toolchains?
> +
> +$(obj)/kvm_symbol_list: $(obj)/kvm-unnamespaced.o FORCE
> + $(call if_changed,nm_filter)
> +
> +define rule_oc_o_o
> + $(call cmd_and_savecmd,objcopy)
> + $(call cmd,gen_objtooldep)
> + $(call cmd,gen_symversions_o)
> +endef
> +
> +OBJCOPYFLAGS_kvm-namespaced.o := -O default --localize-symbols=$(obj)/kvm_symbol_list
[Severity: Low]
Is default a valid BFD architecture/target name for objcopy? GNU objcopy
strictly requires a recognized target like elf64-s390, or for the -O flag to
be omitted entirely to preserve the input format. Could this cause a fatal
invalid bfd target error?
> +$(obj)/kvm-namespaced.o: $(obj)/kvm-unnamespaced.o $(obj)/kvm_symbol_list FORCE
> + $(call if_changed_rule,oc_o_o)
> +
> +kvm-arm64-y = kvm-namespaced.o
> +
> +targets += kvm-unnamespaced.o kvm_symbol_list kvm-namespaced.o
> +
> +endif
> +
> +obj-$(CONFIG_KVM_ARM64) += kvm-arm64.o
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260812153631.3376090-1-seiden@linux.ibm.com?part=33
^ permalink raw reply [flat|nested] 70+ messages in thread
* Re: [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM
2026-08-12 15:35 [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Steffen Eiden
` (32 preceding siblings ...)
2026-08-12 15:36 ` [PATCH v6 33/33] KVM: s390: arm64: Enable KVM_ARM64 config and Kbuild Steffen Eiden
@ 2026-08-12 16:28 ` Christian Borntraeger
2026-08-12 16:36 ` Sean Christopherson
33 siblings, 1 reply; 70+ messages in thread
From: Christian Borntraeger @ 2026-08-12 16:28 UTC (permalink / raw)
To: Steffen Eiden, kvm, kvmarm, linux-arm-kernel, linux-kernel,
linux-s390
Cc: Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Claudio Imbrenda, David Hildenbrand,
Friedrich Welter, Fuad Tabba, Gautam Gala, Hariharan Mari,
Heiko Carstens, Hendrik Brueckner, Ilya Leoshkevich,
Janosch Frank, Joey Gouly, Marc Zyngier, Nico Boehr,
Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Sean Christopherson, Suzuki K Poulose, Sven Schnelle,
Ulrich Weigand, Vasily Gorbik, Will Deacon, Zenghui Yu
Am 12.08.26 um 17:35 schrieb Steffen Eiden:
> C) KVM/s390 reorganization (patches 12-22):
> Prepare s390 for a second KVM module. Move existing s390 KVM code into
> dedicated s390 and gmap subdirectories to make room for a second KVM
> implementation. Refactor gmap to better integrate with the second KVM
> implementation. GMAP hides a few features only required when managing s390
> guests: Storage keys, CMMA, and prefix handling. Those are guarded behind an
> #if KVM_S390_MANAGES_S390_GUEST. Only features which implementation would
> break kvm-arm64 code are guarded. I leave the non-breaking stuff (like
> shadow-gmaps or ucontrol) for the LTO.
I will likely take 12-21 for the next merge window so that we can minimize this
patch set. sashiko and claude are happy. Mostly mechanical moves. I will review
those first and might do small fixups myself if necessary.
^ permalink raw reply [flat|nested] 70+ messages in thread* Re: [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM
2026-08-12 16:28 ` [PATCH v6 00/33] KVM: s390: Introduce arm64 KVM Christian Borntraeger
@ 2026-08-12 16:36 ` Sean Christopherson
0 siblings, 0 replies; 70+ messages in thread
From: Sean Christopherson @ 2026-08-12 16:36 UTC (permalink / raw)
To: Christian Borntraeger
Cc: Steffen Eiden, kvm, kvmarm, linux-arm-kernel, linux-kernel,
linux-s390, Alexander Gordeev, Andreas Grapentin, Arnd Bergmann,
Catalin Marinas, Claudio Imbrenda, David Hildenbrand,
Friedrich Welter, Fuad Tabba, Gautam Gala, Hariharan Mari,
Heiko Carstens, Hendrik Brueckner, Ilya Leoshkevich,
Janosch Frank, Joey Gouly, Marc Zyngier, Nico Boehr,
Nina Schoetterl-Glausch, Oliver Upton, Paolo Bonzini,
Suzuki K Poulose, Sven Schnelle, Ulrich Weigand, Vasily Gorbik,
Will Deacon, Zenghui Yu
On Wed, Aug 12, 2026, Christian Borntraeger wrote:
> Am 12.08.26 um 17:35 schrieb Steffen Eiden:
>
> > C) KVM/s390 reorganization (patches 12-22):
> > Prepare s390 for a second KVM module. Move existing s390 KVM code into
> > dedicated s390 and gmap subdirectories to make room for a second KVM
> > implementation. Refactor gmap to better integrate with the second KVM
> > implementation. GMAP hides a few features only required when managing s390
> > guests: Storage keys, CMMA, and prefix handling. Those are guarded behind an
> > #if KVM_S390_MANAGES_S390_GUEST. Only features which implementation would
> > break kvm-arm64 code are guarded. I leave the non-breaking stuff (like
> > shadow-gmaps or ucontrol) for the LTO.
>
> I will likely take 12-21 for the next merge window so that we can minimize this
> patch set. sashiko and claude are happy. Mostly mechanical moves. I will review
> those first and might do small fixups myself if necessary.
Speaking of trimming down the patch set...
Steffen, can you post patch 1, "vfio: Use file-based reference counting for KVM",
separately? I'd love to get that merged sooner than later.
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