* [PATCH v12 20/46] arm64: RMI: Allow populating initial contents
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
The VMM needs to populate the realm with some data before starting (e.g.
a kernel and initrd). This is measured by the RMM and used as part of
the attestation later on.
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
* The multiplex CAP is gone and there's a new ioctl which makes use of
the generic kvm_gmem_populate() functionality.
Changes since v7:
* Improve the error codes.
* Other minor changes from review.
Changes since v6:
* Handle host potentially having a larger page size than the RMM
granule.
* Drop historic "par" (protected address range) from
populate_par_region() - it doesn't exist within the current
architecture.
* Add a cond_resched() call in kvm_populate_realm().
Changes since v5:
* Refactor to use PFNs rather than tracking struct page in
realm_create_protected_data_page().
* Pull changes from a later patch (in the v5 series) for accessing
pages from a guest memfd.
* Do the populate in chunks to avoid holding locks for too long and
triggering RCU stall warnings.
---
arch/arm64/include/asm/kvm_rmi.h | 4 +
arch/arm64/kvm/Kconfig | 1 +
arch/arm64/kvm/arm.c | 9 ++
arch/arm64/kvm/rmi.c | 175 +++++++++++++++++++++++++++++++
4 files changed, 189 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 8a862fc1a99d..b5e36344975c 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -99,6 +99,10 @@ int kvm_rec_enter(struct kvm_vcpu *vcpu);
int kvm_rec_pre_enter(struct kvm_vcpu *vcpu);
int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status);
+struct kvm_arm_rmi_populate;
+
+int kvm_arm_rmi_populate(struct kvm *kvm,
+ struct kvm_arm_rmi_populate *arg);
void kvm_realm_unmap_range(struct kvm *kvm,
unsigned long ipa,
unsigned long size,
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 1cac6dfc0972..b495dfd3a8b4 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -39,6 +39,7 @@ menuconfig KVM
select GUEST_PERF_EVENTS if PERF_EVENTS
select KVM_GUEST_MEMFD
select KVM_GENERIC_MEMORY_ATTRIBUTES
+ select HAVE_KVM_ARCH_GMEM_POPULATE
help
Support hosting virtualized guest machines.
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 7927181887cf..0a06ed9d1a64 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2037,6 +2037,15 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
return -EFAULT;
return kvm_vm_ioctl_get_reg_writable_masks(kvm, &range);
}
+ case KVM_ARM_RMI_POPULATE: {
+ struct kvm_arm_rmi_populate req;
+
+ if (!kvm_is_realm(kvm))
+ return -EPERM;
+ if (copy_from_user(&req, argp, sizeof(req)))
+ return -EFAULT;
+ return kvm_arm_rmi_populate(kvm, &req);
+ }
default:
return -EINVAL;
}
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index fe15b400091c..39577e956a59 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -558,6 +558,150 @@ void kvm_realm_unmap_range(struct kvm *kvm, unsigned long start,
realm_unmap_private_range(kvm, start, end, may_block);
}
+static int realm_create_protected_data_granule(struct realm *realm,
+ unsigned long ipa,
+ phys_addr_t dst_phys,
+ phys_addr_t src_phys,
+ unsigned long flags)
+{
+ phys_addr_t rd = virt_to_phys(realm->rd);
+ int ret;
+
+ if (rmi_granule_delegate(dst_phys))
+ return -ENXIO;
+
+ ret = rmi_data_create(rd, dst_phys, ipa, src_phys, flags);
+ if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
+ /* Create missing RTTs and retry */
+ int level = RMI_RETURN_INDEX(ret);
+
+ WARN_ON(level == RMM_RTT_MAX_LEVEL);
+
+ ret = realm_create_rtt_levels(realm, ipa, level,
+ RMM_RTT_MAX_LEVEL, NULL);
+ if (ret)
+ return -EIO;
+
+ ret = rmi_data_create(rd, dst_phys, ipa, src_phys, flags);
+ }
+ if (ret)
+ return -EIO;
+
+ return 0;
+}
+
+static int realm_create_protected_data_page(struct realm *realm,
+ unsigned long ipa,
+ kvm_pfn_t dst_pfn,
+ kvm_pfn_t src_pfn,
+ unsigned long flags)
+{
+ unsigned long rd = virt_to_phys(realm->rd);
+ phys_addr_t dst_phys, src_phys;
+ bool undelegate_failed = false;
+ int ret, offset;
+
+ dst_phys = __pfn_to_phys(dst_pfn);
+ src_phys = __pfn_to_phys(src_pfn);
+
+ for (offset = 0; offset < PAGE_SIZE; offset += RMM_PAGE_SIZE) {
+ ret = realm_create_protected_data_granule(realm,
+ ipa,
+ dst_phys,
+ src_phys,
+ flags);
+ if (ret)
+ goto err;
+
+ ipa += RMM_PAGE_SIZE;
+ dst_phys += RMM_PAGE_SIZE;
+ src_phys += RMM_PAGE_SIZE;
+ }
+
+ return 0;
+
+err:
+ if (ret == -EIO) {
+ /* current offset needs undelegating */
+ if (WARN_ON(rmi_granule_undelegate(dst_phys)))
+ undelegate_failed = true;
+ }
+ while (offset > 0) {
+ ipa -= RMM_PAGE_SIZE;
+ offset -= RMM_PAGE_SIZE;
+ dst_phys -= RMM_PAGE_SIZE;
+
+ rmi_data_destroy(rd, ipa, NULL, NULL);
+
+ if (WARN_ON(rmi_granule_undelegate(dst_phys)))
+ undelegate_failed = true;
+ }
+
+ if (undelegate_failed) {
+ /*
+ * A granule could not be undelegated,
+ * so the page has to be leaked
+ */
+ get_page(pfn_to_page(dst_pfn));
+ }
+
+ return -ENXIO;
+}
+
+static int populate_region_cb(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
+ void __user *src, int order, void *opaque)
+{
+ struct realm *realm = &kvm->arch.realm;
+ unsigned long data_flags = *(unsigned long *)opaque;
+ phys_addr_t ipa = gfn_to_gpa(gfn);
+ int npages = (1 << order);
+ int i;
+
+ for (i = 0; i < npages; i++) {
+ struct page *src_page;
+ int ret;
+
+ ret = get_user_pages((unsigned long)src, 1, 0, &src_page);
+ if (ret < 0)
+ return ret;
+ if (ret != 1)
+ return -ENOMEM;
+
+ ret = realm_create_protected_data_page(realm, ipa, pfn,
+ page_to_pfn(src_page),
+ data_flags);
+
+ put_page(src_page);
+
+ if (ret)
+ return ret;
+
+ ipa += PAGE_SIZE;
+ pfn++;
+ src += PAGE_SIZE;
+ }
+
+ return 0;
+}
+
+static long populate_region(struct kvm *kvm,
+ gfn_t base_gfn,
+ unsigned long pages,
+ u64 uaddr,
+ unsigned long data_flags)
+{
+ long ret = 0;
+
+ mutex_lock(&kvm->slots_lock);
+ mmap_read_lock(current->mm);
+ ret = kvm_gmem_populate(kvm, base_gfn, u64_to_user_ptr(uaddr), pages,
+ populate_region_cb, &data_flags);
+ mmap_read_unlock(current->mm);
+ mutex_unlock(&kvm->slots_lock);
+
+ return ret;
+}
+
enum ripas_action {
RIPAS_INIT,
RIPAS_SET,
@@ -655,6 +799,37 @@ static int realm_ensure_created(struct kvm *kvm)
return -ENXIO;
}
+int kvm_arm_rmi_populate(struct kvm *kvm,
+ struct kvm_arm_rmi_populate *args)
+{
+ unsigned long data_flags = 0;
+ unsigned long ipa_start = args->base;
+ unsigned long ipa_end = ipa_start + args->size;
+ int ret;
+
+ if (args->reserved ||
+ (args->flags & ~KVM_ARM_RMI_POPULATE_FLAGS_MEASURE) ||
+ !IS_ALIGNED(ipa_start, PAGE_SIZE) ||
+ !IS_ALIGNED(ipa_end, PAGE_SIZE))
+ return -EINVAL;
+
+ ret = realm_ensure_created(kvm);
+ if (ret)
+ return ret;
+
+ if (args->flags & KVM_ARM_RMI_POPULATE_FLAGS_MEASURE)
+ data_flags |= RMI_MEASURE_CONTENT;
+
+ ret = populate_region(kvm, gpa_to_gfn(ipa_start),
+ args->size >> PAGE_SHIFT,
+ args->source_uaddr, args->flags);
+
+ if (ret < 0)
+ return ret;
+
+ return ret * PAGE_SIZE;
+}
+
static void kvm_complete_ripas_change(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
--
2.43.0
^ permalink raw reply related
* [PATCH v12 19/46] KVM: arm64: Expose support for private memory
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
Select KVM_GENERIC_MEMORY_ATTRIBUTES and provide the necessary support
functions.
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v10:
* KVM_GENERIC_PRIVATE_MEM replacd with KVM_GENERIC_MEMORY_ATTRIBUTES.
Changes since v9:
* Drop the #ifdef CONFIG_KVM_PRIVATE_MEM guard from the definition of
kvm_arch_has_private_mem()
Changes since v2:
* Switch kvm_arch_has_private_mem() to a macro to avoid overhead of a
function call.
* Guard definitions of kvm_arch_{pre,post}_set_memory_attributes() with
#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES.
* Early out in kvm_arch_post_set_memory_attributes() if the WARN_ON
should trigger.
---
arch/arm64/include/asm/kvm_host.h | 2 ++
arch/arm64/kvm/Kconfig | 1 +
arch/arm64/kvm/mmu.c | 24 ++++++++++++++++++++++++
3 files changed, 27 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 5a24227088c1..7590d86c78a5 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1462,6 +1462,8 @@ struct kvm *kvm_arch_alloc_vm(void);
#define vcpu_is_protected(vcpu) kvm_vm_is_protected((vcpu)->kvm)
+#define kvm_arch_has_private_mem(kvm) ((kvm)->arch.is_realm)
+
int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);
bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 4f803fd1c99a..1cac6dfc0972 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -38,6 +38,7 @@ menuconfig KVM
select SCHED_INFO
select GUEST_PERF_EVENTS if PERF_EVENTS
select KVM_GUEST_MEMFD
+ select KVM_GENERIC_MEMORY_ATTRIBUTES
help
Support hosting virtualized guest machines.
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index cac3d7b73b3d..f2ac01c1de04 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -2503,6 +2503,30 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
return ret;
}
+#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
+bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
+ struct kvm_gfn_range *range)
+{
+ WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm));
+ return false;
+}
+
+bool kvm_arch_post_set_memory_attributes(struct kvm *kvm,
+ struct kvm_gfn_range *range)
+{
+ if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm)))
+ return false;
+
+ if (range->arg.attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE)
+ range->attr_filter = KVM_FILTER_SHARED;
+ else
+ range->attr_filter = KVM_FILTER_PRIVATE;
+ kvm_unmap_gfn_range(kvm, range);
+
+ return false;
+}
+#endif
+
void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
{
}
--
2.43.0
^ permalink raw reply related
* [PATCH v12 18/46] KVM: arm64: Handle realm MMIO emulation
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
MMIO emulation for a realm cannot be done directly with the VM's
registers as they are protected from the host. However, for emulatable
data aborts, the RMM uses GPRS[0] to provide the read/written value.
We can transfer this from/to the equivalent VCPU's register entry and
then depend on the generic MMIO handling code in KVM.
For a MMIO read, the value is placed in the shared RecExit structure
during kvm_handle_mmio_return() rather than in the VCPU's register
entry.
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Changes since v7:
* New comment for rec_exit_sync_dabt() explaining the call to
vcpu_set_reg().
Changes since v5:
* Inject SEA to the guest is an emulatable MMIO access triggers a data
abort.
* kvm_handle_mmio_return() - disable kvm_incr_pc() for a REC (as the PC
isn't under the host's control) and move the REC_ENTER_EMULATED_MMIO
flag setting to this location (as that tells the RMM to skip the
instruction).
---
arch/arm64/kvm/inject_fault.c | 4 +++-
arch/arm64/kvm/mmio.c | 16 ++++++++++++----
arch/arm64/kvm/rmi-exit.c | 14 ++++++++++++++
3 files changed, 29 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index dfcd66c65517..5e00f7a69bcc 100644
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -224,7 +224,9 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr)
static void __kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr)
{
- if (vcpu_el1_is_32bit(vcpu))
+ if (unlikely(vcpu_is_rec(vcpu)))
+ vcpu->arch.rec.run->enter.flags |= REC_ENTER_FLAG_INJECT_SEA;
+ else if (vcpu_el1_is_32bit(vcpu))
inject_abt32(vcpu, iabt, addr);
else
inject_abt64(vcpu, iabt, addr);
diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c
index 54f9358c9e0e..d7ad291b5357 100644
--- a/arch/arm64/kvm/mmio.c
+++ b/arch/arm64/kvm/mmio.c
@@ -6,6 +6,7 @@
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
+#include <asm/rmi_smc.h>
#include <trace/events/kvm.h>
#include "trace.h"
@@ -138,14 +139,21 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu)
trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
&data);
data = vcpu_data_host_to_guest(vcpu, data, len);
- vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data);
+
+ if (vcpu_is_rec(vcpu))
+ vcpu->arch.rec.run->enter.gprs[0] = data;
+ else
+ vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data);
}
/*
* The MMIO instruction is emulated and should not be re-executed
* in the guest.
*/
- kvm_incr_pc(vcpu);
+ if (vcpu_is_rec(vcpu))
+ vcpu->arch.rec.run->enter.flags |= REC_ENTER_FLAG_EMULATED_MMIO;
+ else
+ kvm_incr_pc(vcpu);
return 1;
}
@@ -164,14 +172,14 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
* No valid syndrome? Ask userspace for help if it has
* volunteered to do so, and bail out otherwise.
*
- * In the protected VM case, there isn't much userspace can do
+ * In the protected/realm VM case, there isn't much userspace can do
* though, so directly deliver an exception to the guest.
*/
if (!kvm_vcpu_dabt_isvalid(vcpu)) {
trace_kvm_mmio_nisv(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu),
kvm_vcpu_get_hfar(vcpu), fault_ipa);
- if (vcpu_is_protected(vcpu))
+ if (vcpu_is_protected(vcpu) || vcpu_is_rec(vcpu))
return kvm_inject_sea_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
if (test_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER,
diff --git a/arch/arm64/kvm/rmi-exit.c b/arch/arm64/kvm/rmi-exit.c
index f5701153dec0..b4843f094615 100644
--- a/arch/arm64/kvm/rmi-exit.c
+++ b/arch/arm64/kvm/rmi-exit.c
@@ -25,6 +25,20 @@ static int rec_exit_reason_notimpl(struct kvm_vcpu *vcpu)
static int rec_exit_sync_dabt(struct kvm_vcpu *vcpu)
{
+ struct realm_rec *rec = &vcpu->arch.rec;
+
+ /*
+ * In the case of a write, copy over gprs[0] to the target GPR,
+ * preparing to handle MMIO write fault. The content to be written has
+ * been saved to gprs[0] by the RMM (even if another register was used
+ * by the guest). In the case of normal memory access this is redundant
+ * (the guest will replay the instruction), but the overhead is
+ * minimal.
+ */
+ if (kvm_vcpu_dabt_iswrite(vcpu) && kvm_vcpu_dabt_isvalid(vcpu))
+ vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu),
+ rec->run->exit.gprs[0]);
+
return kvm_handle_guest_abort(vcpu);
}
--
2.43.0
^ permalink raw reply related
* [PATCH v12 17/46] arm64: RMI: Handle RMI_EXIT_RIPAS_CHANGE
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
The guest can request that a region of it's protected address space is
switched between RIPAS_RAM and RIPAS_EMPTY (and back) using
RSI_IPA_STATE_SET. This causes a guest exit with the
RMI_EXIT_RIPAS_CHANGE code. We treat this as a request to convert a
protected region to unprotected (or back), exiting to the VMM to make
the necessary changes to the guest_memfd and memslot mappings. On the
next entry the RIPAS changes are committed by making RMI_RTT_SET_RIPAS
calls.
The VMM may wish to reject the RIPAS change requested by the guest. For
now it can only do with by no longer scheduling the VCPU as we don't
currently have a usecase for returning that rejection to the guest, but
by postponing the RMI_RTT_SET_RIPAS changes to entry we leave the door
open for adding a new ioctl in the future for this purpose.
There's a FIXME for the case where the RMM rejects a RIPAS change when
(a portion of) the region. The current RMM API makes this difficult to
handle efficiently, but it should be fixed in a later version of the
spec.
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
* Combine the "Allow VMM to set RIPAS" patch into this one to avoid
adding functions before they are used.
* Drop the CAP for setting RIPAS and adapt to changes from previous
patches.
Changes since v10:
* Add comment explaining the assignment of rec->run->exit.ripas_base in
kvm_complete_ripas_change().
Changes since v8:
* Make use of ripas_change() from a previous patch to implement
realm_set_ipa_state().
* Update exit.ripas_base after a RIPAS change so that, if instead of
entering the guest we exit to user space, we don't attempt to repeat
the RIPAS change (triggering an error from the RMM).
Changes since v7:
* Rework the loop in realm_set_ipa_state() to make it clear when the
'next' output value of rmi_rtt_set_ripas() is used.
New patch for v7: The code was previously split awkwardly between two
other patches.
---
arch/arm64/include/asm/kvm_rmi.h | 6 +
arch/arm64/kvm/mmu.c | 8 +-
arch/arm64/kvm/rmi.c | 459 +++++++++++++++++++++++++++++++
3 files changed, 470 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index faf0af563210..8a862fc1a99d 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -99,6 +99,12 @@ int kvm_rec_enter(struct kvm_vcpu *vcpu);
int kvm_rec_pre_enter(struct kvm_vcpu *vcpu);
int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status);
+void kvm_realm_unmap_range(struct kvm *kvm,
+ unsigned long ipa,
+ unsigned long size,
+ bool unmap_private,
+ bool may_block);
+
static inline bool kvm_realm_is_private_address(struct realm *realm,
unsigned long addr)
{
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 68e6cefe1135..cac3d7b73b3d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -319,6 +319,7 @@ static void invalidate_icache_guest_page(void *va, size_t size)
* @start: The intermediate physical base address of the range to unmap
* @size: The size of the area to unmap
* @may_block: Whether or not we are permitted to block
+ * @only_shared: If true then protected mappings should not be unmapped
*
* Clear a range of stage-2 mappings, lowering the various ref-counts. Must
* be called while holding mmu_lock (unless for freeing the stage2 pgd before
@@ -326,7 +327,7 @@ static void invalidate_icache_guest_page(void *va, size_t size)
* with things behind our backs.
*/
static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size,
- bool may_block)
+ bool may_block, bool only_shared)
{
struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
phys_addr_t end = start + size;
@@ -340,7 +341,7 @@ static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64
void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start,
u64 size, bool may_block)
{
- __unmap_stage2_range(mmu, start, size, may_block);
+ __unmap_stage2_range(mmu, start, size, may_block, false);
}
void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
@@ -2230,7 +2231,8 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
__unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT,
(range->end - range->start) << PAGE_SHIFT,
- range->may_block);
+ range->may_block,
+ !(range->attr_filter & KVM_FILTER_PRIVATE));
kvm_nested_s2_unmap(kvm, range->may_block);
return false;
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 215eb4f4fc47..fe15b400091c 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -91,6 +91,59 @@ static int get_start_level(struct realm *realm)
return 4 - ((realm->ia_bits - 8) / (RMM_PAGE_SHIFT - 3));
}
+static int find_map_level(struct realm *realm,
+ unsigned long start,
+ unsigned long end)
+{
+ int level = RMM_RTT_MAX_LEVEL;
+
+ while (level > get_start_level(realm)) {
+ unsigned long map_size = rmi_rtt_level_mapsize(level - 1);
+
+ if (!IS_ALIGNED(start, map_size) ||
+ (start + map_size) > end)
+ break;
+
+ level--;
+ }
+
+ return level;
+}
+
+static phys_addr_t alloc_delegated_granule(struct kvm_mmu_memory_cache *mc)
+{
+ phys_addr_t phys;
+ void *virt;
+
+ if (mc) {
+ virt = kvm_mmu_memory_cache_alloc(mc);
+ } else {
+ virt = (void *)__get_free_page(GFP_ATOMIC | __GFP_ZERO |
+ __GFP_ACCOUNT);
+ }
+
+ if (!virt)
+ return PHYS_ADDR_MAX;
+
+ phys = virt_to_phys(virt);
+ if (rmi_granule_delegate(phys)) {
+ free_page((unsigned long)virt);
+ return PHYS_ADDR_MAX;
+ }
+
+ return phys;
+}
+
+static phys_addr_t alloc_rtt(struct kvm_mmu_memory_cache *mc)
+{
+ phys_addr_t phys = alloc_delegated_granule(mc);
+
+ if (phys != PHYS_ADDR_MAX)
+ kvm_account_pgtable_pages(phys_to_virt(phys), 1);
+
+ return phys;
+}
+
static int free_delegated_granule(phys_addr_t phys)
{
if (WARN_ON(rmi_granule_undelegate(phys))) {
@@ -111,6 +164,32 @@ static void free_rtt(phys_addr_t phys)
kvm_account_pgtable_pages(phys_to_virt(phys), -1);
}
+static int realm_rtt_create(struct realm *realm,
+ unsigned long addr,
+ int level,
+ phys_addr_t phys)
+{
+ addr = ALIGN_DOWN(addr, rmi_rtt_level_mapsize(level - 1));
+ return rmi_rtt_create(virt_to_phys(realm->rd), phys, addr, level);
+}
+
+static int realm_rtt_fold(struct realm *realm,
+ unsigned long addr,
+ int level,
+ phys_addr_t *rtt_granule)
+{
+ unsigned long out_rtt;
+ int ret;
+
+ addr = ALIGN_DOWN(addr, rmi_rtt_level_mapsize(level - 1));
+ ret = rmi_rtt_fold(virt_to_phys(realm->rd), addr, level, &out_rtt);
+
+ if (rtt_granule)
+ *rtt_granule = out_rtt;
+
+ return ret;
+}
+
static int realm_rtt_destroy(struct realm *realm, unsigned long addr,
int level, phys_addr_t *rtt_granule,
unsigned long *next_addr)
@@ -126,6 +205,38 @@ static int realm_rtt_destroy(struct realm *realm, unsigned long addr,
return ret;
}
+static int realm_create_rtt_levels(struct realm *realm,
+ unsigned long ipa,
+ int level,
+ int max_level,
+ struct kvm_mmu_memory_cache *mc)
+{
+ while (level++ < max_level) {
+ phys_addr_t rtt = alloc_rtt(mc);
+ int ret;
+
+ if (rtt == PHYS_ADDR_MAX)
+ return -ENOMEM;
+
+ ret = realm_rtt_create(realm, ipa, level, rtt);
+ if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT &&
+ RMI_RETURN_INDEX(ret) == level - 1) {
+ /* The RTT already exists, continue */
+ free_rtt(rtt);
+ continue;
+ }
+
+ if (ret) {
+ WARN(1, "Failed to create RTT at level %d: %d\n",
+ level, ret);
+ free_rtt(rtt);
+ return -ENXIO;
+ }
+ }
+
+ return 0;
+}
+
static int realm_tear_down_rtt_level(struct realm *realm, int level,
unsigned long start, unsigned long end)
{
@@ -220,6 +331,62 @@ static int realm_tear_down_rtt_range(struct realm *realm,
start, end);
}
+/*
+ * Returns 0 on successful fold, a negative value on error, a positive value if
+ * we were not able to fold all tables at this level.
+ */
+static int realm_fold_rtt_level(struct realm *realm, int level,
+ unsigned long start, unsigned long end)
+{
+ int not_folded = 0;
+ ssize_t map_size;
+ unsigned long addr, next_addr;
+
+ if (WARN_ON(level > RMM_RTT_MAX_LEVEL))
+ return -EINVAL;
+
+ map_size = rmi_rtt_level_mapsize(level - 1);
+
+ for (addr = start; addr < end; addr = next_addr) {
+ phys_addr_t rtt_granule;
+ int ret;
+ unsigned long align_addr = ALIGN(addr, map_size);
+
+ next_addr = ALIGN(addr + 1, map_size);
+
+ ret = realm_rtt_fold(realm, align_addr, level, &rtt_granule);
+
+ switch (RMI_RETURN_STATUS(ret)) {
+ case RMI_SUCCESS:
+ free_rtt(rtt_granule);
+ break;
+ case RMI_ERROR_RTT:
+ if (level == RMM_RTT_MAX_LEVEL ||
+ RMI_RETURN_INDEX(ret) < level) {
+ not_folded++;
+ break;
+ }
+ /* Recurse a level deeper */
+ ret = realm_fold_rtt_level(realm,
+ level + 1,
+ addr,
+ next_addr);
+ if (ret < 0) {
+ return ret;
+ } else if (ret == 0) {
+ /* Try again at this level */
+ next_addr = addr;
+ }
+ break;
+ default:
+ WARN_ON(1);
+ return -ENXIO;
+ }
+ }
+
+ return not_folded;
+}
+
void kvm_realm_destroy_rtts(struct kvm *kvm)
{
struct realm *realm = &kvm->arch.realm;
@@ -228,12 +395,301 @@ void kvm_realm_destroy_rtts(struct kvm *kvm)
WARN_ON(realm_tear_down_rtt_range(realm, 0, (1UL << ia_bits)));
}
+static int realm_destroy_private_granule(struct realm *realm,
+ unsigned long ipa,
+ unsigned long *next_addr)
+{
+ unsigned long rd = virt_to_phys(realm->rd);
+ unsigned long phy_addr;
+ phys_addr_t rtt;
+ int ret;
+
+retry:
+ ret = rmi_data_destroy(rd, ipa, &phy_addr, next_addr);
+ if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
+ if (*next_addr > ipa)
+ return 0; /* UNASSIGNED */
+ rtt = alloc_rtt(NULL);
+ if (WARN_ON(rtt == PHYS_ADDR_MAX))
+ return -ENOMEM;
+ /*
+ * ASSIGNED - ipa is mapped as a block, so split. The index
+ * from the return code should be 2 otherwise it appears
+ * there's a huge page bigger than KVM currently supports
+ */
+ WARN_ON(RMI_RETURN_INDEX(ret) != 2);
+ ret = realm_rtt_create(realm, ipa, 3, rtt);
+ if (WARN_ON(ret)) {
+ free_rtt(rtt);
+ return -ENXIO;
+ }
+ goto retry;
+ } else if (WARN_ON(ret)) {
+ return -ENXIO;
+ }
+
+ ret = rmi_granule_undelegate(phy_addr);
+ if (WARN_ON(ret))
+ return -ENXIO;
+
+ return 0;
+}
+
+static void realm_unmap_shared_range(struct kvm *kvm,
+ int level,
+ unsigned long start,
+ unsigned long end,
+ bool may_block)
+{
+ struct realm *realm = &kvm->arch.realm;
+ unsigned long rd = virt_to_phys(realm->rd);
+ ssize_t map_size = rmi_rtt_level_mapsize(level);
+ unsigned long next_addr, addr;
+ unsigned long shared_bit = BIT(realm->ia_bits - 1);
+
+ if (WARN_ON(level > RMM_RTT_MAX_LEVEL))
+ return;
+
+ start |= shared_bit;
+ end |= shared_bit;
+
+ for (addr = start; addr < end; addr = next_addr) {
+ unsigned long align_addr = ALIGN(addr, map_size);
+ int ret;
+
+ next_addr = ALIGN(addr + 1, map_size);
+
+ if (align_addr != addr || next_addr > end) {
+ /* Need to recurse deeper */
+ if (addr < align_addr)
+ next_addr = align_addr;
+ realm_unmap_shared_range(kvm, level + 1, addr,
+ min(next_addr, end),
+ may_block);
+ continue;
+ }
+
+ ret = rmi_rtt_unmap_unprotected(rd, addr, level, &next_addr);
+ switch (RMI_RETURN_STATUS(ret)) {
+ case RMI_SUCCESS:
+ break;
+ case RMI_ERROR_RTT:
+ if (next_addr == addr) {
+ /*
+ * There's a mapping here, but it's not a block
+ * mapping, so reset next_addr to the next block
+ * boundary and recurse to clear out the pages
+ * one level deeper.
+ */
+ next_addr = ALIGN(addr + 1, map_size);
+ realm_unmap_shared_range(kvm, level + 1, addr,
+ next_addr,
+ may_block);
+ }
+ break;
+ default:
+ WARN_ON(1);
+ return;
+ }
+
+ if (may_block)
+ cond_resched_rwlock_write(&kvm->mmu_lock);
+ }
+
+ realm_fold_rtt_level(realm, get_start_level(realm) + 1,
+ start, end);
+}
+
+static int realm_unmap_private_page(struct realm *realm,
+ unsigned long ipa,
+ unsigned long *next_addr)
+{
+ unsigned long end = ALIGN(ipa + 1, PAGE_SIZE);
+ unsigned long addr;
+ int ret;
+
+ for (addr = ipa; addr < end; addr = *next_addr) {
+ ret = realm_destroy_private_granule(realm, addr, next_addr);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static void realm_unmap_private_range(struct kvm *kvm,
+ unsigned long start,
+ unsigned long end,
+ bool may_block)
+{
+ struct realm *realm = &kvm->arch.realm;
+ unsigned long next_addr, addr;
+ int ret;
+
+ for (addr = start; addr < end; addr = next_addr) {
+ ret = realm_unmap_private_page(realm, addr, &next_addr);
+
+ if (ret)
+ break;
+
+ if (may_block)
+ cond_resched_rwlock_write(&kvm->mmu_lock);
+ }
+
+ realm_fold_rtt_level(realm, get_start_level(realm) + 1,
+ start, end);
+}
+
+void kvm_realm_unmap_range(struct kvm *kvm, unsigned long start,
+ unsigned long size, bool unmap_private,
+ bool may_block)
+{
+ unsigned long end = start + size;
+ struct realm *realm = &kvm->arch.realm;
+
+ end = min(BIT(realm->ia_bits - 1), end);
+
+ if (!kvm_realm_is_created(kvm))
+ return;
+
+ realm_unmap_shared_range(kvm, find_map_level(realm, start, end),
+ start, end, may_block);
+ if (unmap_private)
+ realm_unmap_private_range(kvm, start, end, may_block);
+}
+
+enum ripas_action {
+ RIPAS_INIT,
+ RIPAS_SET,
+};
+
+static int ripas_change(struct kvm *kvm,
+ struct kvm_vcpu *vcpu,
+ unsigned long ipa,
+ unsigned long end,
+ enum ripas_action action,
+ unsigned long *top_ipa)
+{
+ struct realm *realm = &kvm->arch.realm;
+ phys_addr_t rd_phys = virt_to_phys(realm->rd);
+ phys_addr_t rec_phys;
+ struct kvm_mmu_memory_cache *memcache = NULL;
+ int ret = 0;
+
+ if (vcpu) {
+ rec_phys = virt_to_phys(vcpu->arch.rec.rec_page);
+ memcache = &vcpu->arch.mmu_page_cache;
+
+ WARN_ON(action != RIPAS_SET);
+ } else {
+ WARN_ON(action != RIPAS_INIT);
+ }
+
+ while (ipa < end) {
+ unsigned long next = ~0;
+
+ switch (action) {
+ case RIPAS_INIT:
+ ret = rmi_rtt_init_ripas(rd_phys, ipa, end, &next);
+ break;
+ case RIPAS_SET:
+ ret = rmi_rtt_set_ripas(rd_phys, rec_phys, ipa, end,
+ &next);
+ break;
+ }
+
+ switch (RMI_RETURN_STATUS(ret)) {
+ case RMI_SUCCESS:
+ ipa = next;
+ break;
+ case RMI_ERROR_RTT: {
+ int err_level = RMI_RETURN_INDEX(ret);
+ int level = find_map_level(realm, ipa, end);
+
+ if (err_level >= level) {
+ /* FIXME: Ugly hack to skip regions which are
+ * already RIPAS_RAM
+ */
+ ipa += PAGE_SIZE;
+ break;
+ return -EINVAL;
+ }
+
+ ret = realm_create_rtt_levels(realm, ipa, err_level,
+ level, memcache);
+ if (ret)
+ return ret;
+ /* Retry with the RTT levels in place */
+ break;
+ }
+ default:
+ WARN_ON(1);
+ return -ENXIO;
+ }
+ }
+
+ if (top_ipa)
+ *top_ipa = ipa;
+
+ return 0;
+}
+
+static int realm_set_ipa_state(struct kvm_vcpu *vcpu,
+ unsigned long start,
+ unsigned long end,
+ unsigned long ripas,
+ unsigned long *top_ipa)
+{
+ struct kvm *kvm = vcpu->kvm;
+ int ret = ripas_change(kvm, vcpu, start, end, RIPAS_SET, top_ipa);
+
+ if (ripas == RMI_EMPTY && *top_ipa != start)
+ realm_unmap_private_range(kvm, start, *top_ipa, false);
+
+ return ret;
+}
+
static int realm_ensure_created(struct kvm *kvm)
{
/* Provided in later patch */
return -ENXIO;
}
+static void kvm_complete_ripas_change(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct realm_rec *rec = &vcpu->arch.rec;
+ unsigned long base = rec->run->exit.ripas_base;
+ unsigned long top = rec->run->exit.ripas_top;
+ unsigned long ripas = rec->run->exit.ripas_value;
+ unsigned long top_ipa;
+ int ret;
+
+ do {
+ kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_cache,
+ kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu));
+ write_lock(&kvm->mmu_lock);
+ ret = realm_set_ipa_state(vcpu, base, top, ripas, &top_ipa);
+ write_unlock(&kvm->mmu_lock);
+
+ if (WARN_RATELIMIT(ret && ret != -ENOMEM,
+ "Unable to satisfy RIPAS_CHANGE for %#lx - %#lx, ripas: %#lx\n",
+ base, top, ripas))
+ break;
+
+ base = top_ipa;
+ } while (base < top);
+
+ /*
+ * If this function is called again before the REC_ENTER call then
+ * avoid calling realm_set_ipa_state() again by changing to the value
+ * of ripas_base for the part that has already been covered. The RMM
+ * ignores the contains of the rec_exit structure so this doesn't
+ * affect the RMM.
+ */
+ rec->run->exit.ripas_base = base;
+}
+
/*
* kvm_rec_pre_enter - Complete operations before entering a REC
*
@@ -259,6 +715,9 @@ int kvm_rec_pre_enter(struct kvm_vcpu *vcpu)
for (int i = 0; i < REC_RUN_GPRS; i++)
rec->run->enter.gprs[i] = vcpu_get_reg(vcpu, i);
break;
+ case RMI_EXIT_RIPAS_CHANGE:
+ kvm_complete_ripas_change(vcpu);
+ break;
}
return 1;
--
2.43.0
^ permalink raw reply related
* [PATCH v12 16/46] arm64: RMI: Handle realm enter/exit
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
Entering a realm is done using a SMC call to the RMM. On exit the
exit-codes need to be handled slightly differently to the normal KVM
path so define our own functions for realm enter/exit and hook them
in if the guest is a realm guest.
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
---
Changes since v8:
* Introduce kvm_rec_pre_enter() called before entering an atomic
section to handle operations that might require memory allocation
(specifically completing a RIPAS change introduced in a later patch).
* Updates to align with upstream changes to hpfar_el2 which now (ab)uses
HPFAR_EL2_NS as a valid flag.
* Fix exit reason when racing with PSCI shutdown to return
KVM_EXIT_SHUTDOWN rather than KVM_EXIT_UNKNOWN.
Changes since v7:
* A return of 0 from kvm_handle_sys_reg() doesn't mean the register has
been read (although that can never happen in the current code). Tidy
up the condition to handle any future refactoring.
Changes since v6:
* Use vcpu_err() rather than pr_err/kvm_err when there is an associated
vcpu to the error.
* Return -EFAULT for KVM_EXIT_MEMORY_FAULT as per the documentation for
this exit type.
* Split code handling a RIPAS change triggered by the guest to the
following patch.
Changes since v5:
* For a RIPAS_CHANGE request from the guest perform the actual RIPAS
change on next entry rather than immediately on the exit. This allows
the VMM to 'reject' a RIPAS change by refusing to continue
scheduling.
Changes since v4:
* Rename handle_rme_exit() to handle_rec_exit()
* Move the loop to copy registers into the REC enter structure from the
to rec_exit_handlers callbacks to kvm_rec_enter(). This fixes a bug
where the handler exits to user space and user space wants to modify
the GPRS.
* Some code rearrangement in rec_exit_ripas_change().
Changes since v2:
* realm_set_ipa_state() now provides an output parameter for the
top_iap that was changed. Use this to signal the VMM with the correct
range that has been transitioned.
* Adapt to previous patch changes.
---
arch/arm64/include/asm/kvm_rmi.h | 4 +
arch/arm64/kvm/Makefile | 2 +-
arch/arm64/kvm/arm.c | 22 +++-
arch/arm64/kvm/rmi-exit.c | 178 +++++++++++++++++++++++++++++++
arch/arm64/kvm/rmi.c | 38 +++++++
5 files changed, 239 insertions(+), 5 deletions(-)
create mode 100644 arch/arm64/kvm/rmi-exit.c
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 6190d75cc615..faf0af563210 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -95,6 +95,10 @@ void kvm_destroy_realm(struct kvm *kvm);
void kvm_realm_destroy_rtts(struct kvm *kvm);
void kvm_destroy_rec(struct kvm_vcpu *vcpu);
+int kvm_rec_enter(struct kvm_vcpu *vcpu);
+int kvm_rec_pre_enter(struct kvm_vcpu *vcpu);
+int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status);
+
static inline bool kvm_realm_is_private_address(struct realm *realm,
unsigned long addr)
{
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index e17c4077d8e7..4b103bcbe760 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -16,7 +16,7 @@ CFLAGS_handle_exit.o += -Wno-override-init
kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \
inject_fault.o va_layout.o handle_exit.o config.o \
guest.o debug.o reset.o sys_regs.o stacktrace.o \
- vgic-sys-reg-v3.o fpsimd.o pkvm.o rmi.o \
+ vgic-sys-reg-v3.o fpsimd.o pkvm.o rmi.o rmi-exit.o \
arch_timer.o trng.o vmid.o emulate-nested.o nested.o at.o \
vgic/vgic.o vgic/vgic-init.o \
vgic/vgic-irqfd.o vgic/vgic-v2.o \
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 66f23b8b3144..7927181887cf 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1264,6 +1264,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
if (ret > 0)
ret = check_vcpu_requests(vcpu);
+ if (ret > 0 && vcpu_is_rec(vcpu))
+ ret = kvm_rec_pre_enter(vcpu);
+
/*
* Preparing the interrupts to be injected also
* involves poking the GIC, which must be done in a
@@ -1311,7 +1314,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
trace_kvm_entry(*vcpu_pc(vcpu));
guest_timing_enter_irqoff();
- ret = kvm_arm_vcpu_enter_exit(vcpu);
+ if (vcpu_is_rec(vcpu))
+ ret = kvm_rec_enter(vcpu);
+ else
+ ret = kvm_arm_vcpu_enter_exit(vcpu);
vcpu->mode = OUTSIDE_GUEST_MODE;
vcpu->stat.exits++;
@@ -1369,8 +1375,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
- /* Exit types that need handling before we can be preempted */
- handle_exit_early(vcpu, ret);
+ if (!vcpu_is_rec(vcpu)) {
+ /*
+ * Exit types that need handling before we can be
+ * preempted
+ */
+ handle_exit_early(vcpu, ret);
+ }
kvm_nested_sync_hwstate(vcpu);
@@ -1395,7 +1406,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
ret = ARM_EXCEPTION_IL;
}
- ret = handle_exit(vcpu, ret);
+ if (vcpu_is_rec(vcpu))
+ ret = handle_rec_exit(vcpu, ret);
+ else
+ ret = handle_exit(vcpu, ret);
}
/* Tell userspace about in-kernel device output levels */
diff --git a/arch/arm64/kvm/rmi-exit.c b/arch/arm64/kvm/rmi-exit.c
new file mode 100644
index 000000000000..f5701153dec0
--- /dev/null
+++ b/arch/arm64/kvm/rmi-exit.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 ARM Ltd.
+ */
+
+#include <linux/kvm_host.h>
+#include <kvm/arm_hypercalls.h>
+#include <kvm/arm_psci.h>
+
+#include <asm/rmi_smc.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_rmi.h>
+#include <asm/kvm_mmu.h>
+
+typedef int (*exit_handler_fn)(struct kvm_vcpu *vcpu);
+
+static int rec_exit_reason_notimpl(struct kvm_vcpu *vcpu)
+{
+ struct realm_rec *rec = &vcpu->arch.rec;
+
+ vcpu_err(vcpu, "Unhandled exit reason from realm (ESR: %#llx)\n",
+ rec->run->exit.esr);
+ return -ENXIO;
+}
+
+static int rec_exit_sync_dabt(struct kvm_vcpu *vcpu)
+{
+ return kvm_handle_guest_abort(vcpu);
+}
+
+static int rec_exit_sync_iabt(struct kvm_vcpu *vcpu)
+{
+ struct realm_rec *rec = &vcpu->arch.rec;
+
+ vcpu_err(vcpu, "Unhandled instruction abort (ESR: %#llx).\n",
+ rec->run->exit.esr);
+ return -ENXIO;
+}
+
+static int rec_exit_sys_reg(struct kvm_vcpu *vcpu)
+{
+ struct realm_rec *rec = &vcpu->arch.rec;
+ unsigned long esr = kvm_vcpu_get_esr(vcpu);
+ int rt = kvm_vcpu_sys_get_rt(vcpu);
+ bool is_write = !(esr & 1);
+ int ret;
+
+ if (is_write)
+ vcpu_set_reg(vcpu, rt, rec->run->exit.gprs[0]);
+
+ ret = kvm_handle_sys_reg(vcpu);
+ if (!is_write)
+ rec->run->enter.gprs[0] = vcpu_get_reg(vcpu, rt);
+
+ return ret;
+}
+
+static exit_handler_fn rec_exit_handlers[] = {
+ [0 ... ESR_ELx_EC_MAX] = rec_exit_reason_notimpl,
+ [ESR_ELx_EC_SYS64] = rec_exit_sys_reg,
+ [ESR_ELx_EC_DABT_LOW] = rec_exit_sync_dabt,
+ [ESR_ELx_EC_IABT_LOW] = rec_exit_sync_iabt
+};
+
+static int rec_exit_psci(struct kvm_vcpu *vcpu)
+{
+ struct realm_rec *rec = &vcpu->arch.rec;
+ int i;
+
+ for (i = 0; i < REC_RUN_GPRS; i++)
+ vcpu_set_reg(vcpu, i, rec->run->exit.gprs[i]);
+
+ return kvm_smccc_call_handler(vcpu);
+}
+
+static int rec_exit_ripas_change(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct realm *realm = &kvm->arch.realm;
+ struct realm_rec *rec = &vcpu->arch.rec;
+ unsigned long base = rec->run->exit.ripas_base;
+ unsigned long top = rec->run->exit.ripas_top;
+ unsigned long ripas = rec->run->exit.ripas_value;
+
+ if (!kvm_realm_is_private_address(realm, base) ||
+ !kvm_realm_is_private_address(realm, top - 1)) {
+ vcpu_err(vcpu, "Invalid RIPAS_CHANGE for %#lx - %#lx, ripas: %#lx\n",
+ base, top, ripas);
+ /* Set RMI_REJECT bit */
+ rec->run->enter.flags = REC_ENTER_FLAG_RIPAS_RESPONSE;
+ return -EINVAL;
+ }
+
+ /* Exit to VMM, the actual RIPAS change is done on next entry */
+ kvm_prepare_memory_fault_exit(vcpu, base, top - base, false, false,
+ ripas == RMI_RAM);
+
+ /*
+ * KVM_EXIT_MEMORY_FAULT requires an return code of -EFAULT, see the
+ * API documentation
+ */
+ return -EFAULT;
+}
+
+static void update_arch_timer_irq_lines(struct kvm_vcpu *vcpu)
+{
+ struct realm_rec *rec = &vcpu->arch.rec;
+
+ __vcpu_assign_sys_reg(vcpu, CNTV_CTL_EL0, rec->run->exit.cntv_ctl);
+ __vcpu_assign_sys_reg(vcpu, CNTV_CVAL_EL0, rec->run->exit.cntv_cval);
+ __vcpu_assign_sys_reg(vcpu, CNTP_CTL_EL0, rec->run->exit.cntp_ctl);
+ __vcpu_assign_sys_reg(vcpu, CNTP_CVAL_EL0, rec->run->exit.cntp_cval);
+
+ kvm_realm_timers_update(vcpu);
+}
+
+/*
+ * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
+ * proper exit to userspace.
+ */
+int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)
+{
+ struct realm_rec *rec = &vcpu->arch.rec;
+ u8 esr_ec = ESR_ELx_EC(rec->run->exit.esr);
+ unsigned long status, index;
+
+ status = RMI_RETURN_STATUS(rec_run_ret);
+ index = RMI_RETURN_INDEX(rec_run_ret);
+
+ /*
+ * If a PSCI_SYSTEM_OFF request raced with a vcpu executing, we might
+ * see the following status code and index indicating an attempt to run
+ * a REC when the RD state is SYSTEM_OFF. In this case, we just need to
+ * return to user space which can deal with the system event or will try
+ * to run the KVM VCPU again, at which point we will no longer attempt
+ * to enter the Realm because we will have a sleep request pending on
+ * the VCPU as a result of KVM's PSCI handling.
+ */
+ if (status == RMI_ERROR_REALM && index == 1) {
+ vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
+ return 0;
+ }
+
+ if (rec_run_ret)
+ return -ENXIO;
+
+ vcpu->arch.fault.esr_el2 = rec->run->exit.esr;
+ vcpu->arch.fault.far_el2 = rec->run->exit.far;
+ /* HPFAR_EL2 is only valid for RMI_EXIT_SYNC */
+ vcpu->arch.fault.hpfar_el2 = 0;
+
+ update_arch_timer_irq_lines(vcpu);
+
+ /* Reset the emulation flags for the next run of the REC */
+ rec->run->enter.flags = 0;
+
+ switch (rec->run->exit.exit_reason) {
+ case RMI_EXIT_SYNC:
+ /*
+ * HPFAR_EL2_NS is hijacked to indicate a valid HPFAR value,
+ * see __get_fault_info()
+ */
+ vcpu->arch.fault.hpfar_el2 = rec->run->exit.hpfar | HPFAR_EL2_NS;
+ return rec_exit_handlers[esr_ec](vcpu);
+ case RMI_EXIT_IRQ:
+ case RMI_EXIT_FIQ:
+ return 1;
+ case RMI_EXIT_PSCI:
+ return rec_exit_psci(vcpu);
+ case RMI_EXIT_RIPAS_CHANGE:
+ return rec_exit_ripas_change(vcpu);
+ }
+
+ kvm_pr_unimpl("Unsupported exit reason: %u\n",
+ rec->run->exit.exit_reason);
+ vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ return 0;
+}
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 275b266c6614..215eb4f4fc47 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -234,6 +234,44 @@ static int realm_ensure_created(struct kvm *kvm)
return -ENXIO;
}
+/*
+ * kvm_rec_pre_enter - Complete operations before entering a REC
+ *
+ * Some operations require work to be completed before entering a realm. That
+ * work may require memory allocation so cannot be done in the kvm_rec_enter()
+ * call.
+ *
+ * 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
+ */
+int kvm_rec_pre_enter(struct kvm_vcpu *vcpu)
+{
+ struct realm_rec *rec = &vcpu->arch.rec;
+
+ if (kvm_realm_state(vcpu->kvm) != REALM_STATE_ACTIVE)
+ return -EINVAL;
+
+ switch (rec->run->exit.exit_reason) {
+ case RMI_EXIT_HOST_CALL:
+ case RMI_EXIT_PSCI:
+ for (int i = 0; i < REC_RUN_GPRS; i++)
+ rec->run->enter.gprs[i] = vcpu_get_reg(vcpu, i);
+ break;
+ }
+
+ return 1;
+}
+
+int kvm_rec_enter(struct kvm_vcpu *vcpu)
+{
+ struct realm_rec *rec = &vcpu->arch.rec;
+
+ return rmi_rec_enter(virt_to_phys(rec->rec_page),
+ virt_to_phys(rec->run));
+}
+
static void free_rec_aux(struct page **aux_pages,
unsigned int num_aux)
{
--
2.43.0
^ permalink raw reply related
* [PATCH v12 15/46] KVM: arm64: Support timers in realm RECs
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
The RMM keeps track of the timer while the realm REC is running, but on
exit to the normal world KVM is responsible for handling the timers.
A later patch adds the support for propagating the timer values from the
exit data structure and calling kvm_realm_timers_update().
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
* Drop the kvm_is_realm() check from timer_set_offset(). We already
ensure that the offset is 0 when calling the function.
Changes since v10:
* KVM_CAP_COUNTER_OFFSET is now already hidden by a previous patch.
Changes since v9:
* No need to move the call to kvm_timer_unblocking() in
kvm_timer_vcpu_load().
Changes since v7:
* Hide KVM_CAP_COUNTER_OFFSET for realm guests.
---
arch/arm64/kvm/arch_timer.c | 37 ++++++++++++++++++++++++++++++++++--
include/kvm/arm_arch_timer.h | 2 ++
2 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 99a07972068d..99308bde2a05 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -453,6 +453,21 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
timer_ctx);
}
+void kvm_realm_timers_update(struct kvm_vcpu *vcpu)
+{
+ struct arch_timer_cpu *arch_timer = &vcpu->arch.timer_cpu;
+ int i;
+
+ for (i = 0; i < NR_KVM_EL0_TIMERS; i++) {
+ struct arch_timer_context *timer = &arch_timer->timers[i];
+ bool status = timer_get_ctl(timer) & ARCH_TIMER_CTRL_IT_STAT;
+ bool level = kvm_timer_irq_can_fire(timer) && status;
+
+ if (level != timer->irq.level)
+ kvm_timer_update_irq(vcpu, level, timer);
+ }
+}
+
/* Only called for a fully emulated timer */
static void timer_emulate(struct arch_timer_context *ctx)
{
@@ -1056,7 +1071,9 @@ static void timer_context_init(struct kvm_vcpu *vcpu, int timerid)
ctxt->timer_id = timerid;
- if (timerid == TIMER_VTIMER)
+ if (kvm_is_realm(vcpu->kvm))
+ ctxt->offset.vm_offset = NULL;
+ else if (timerid == TIMER_VTIMER)
ctxt->offset.vm_offset = &kvm->arch.timer_data.voffset;
else
ctxt->offset.vm_offset = &kvm->arch.timer_data.poffset;
@@ -1078,13 +1095,19 @@ static void timer_context_init(struct kvm_vcpu *vcpu, int timerid)
void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = vcpu_timer(vcpu);
+ u64 cntvoff;
for (int i = 0; i < NR_KVM_TIMERS; i++)
timer_context_init(vcpu, i);
+ if (kvm_is_realm(vcpu->kvm))
+ cntvoff = 0;
+ else
+ cntvoff = kvm_phys_timer_read();
+
/* Synchronize offsets across timers of a VM if not already provided */
if (!test_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET, &vcpu->kvm->arch.flags)) {
- timer_set_offset(vcpu_vtimer(vcpu), kvm_phys_timer_read());
+ timer_set_offset(vcpu_vtimer(vcpu), cntvoff);
timer_set_offset(vcpu_ptimer(vcpu), 0);
}
@@ -1556,6 +1579,13 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
return -EINVAL;
}
+ /*
+ * We don't use mapped IRQs for Realms because the RMI doesn't allow
+ * us setting the LR.HW bit in the VGIC.
+ */
+ if (vcpu_is_rec(vcpu))
+ return 0;
+
get_timer_map(vcpu, &map);
ret = kvm_vgic_map_phys_irq(vcpu,
@@ -1687,6 +1717,9 @@ int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm,
if (offset->reserved)
return -EINVAL;
+ if (kvm_is_realm(kvm))
+ return -EINVAL;
+
mutex_lock(&kvm->lock);
if (!kvm_trylock_all_vcpus(kvm)) {
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index 7310841f4512..bab0daafc6b1 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -111,6 +111,8 @@ int kvm_arm_timer_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
int kvm_arm_timer_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
int kvm_arm_timer_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
+void kvm_realm_timers_update(struct kvm_vcpu *vcpu);
+
u64 kvm_phys_timer_read(void);
void kvm_timer_vcpu_load(struct kvm_vcpu *vcpu);
--
2.43.0
^ permalink raw reply related
* [PATCH v12 14/46] arm64: RMI: Support for the VGIC in realms
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
The RMM provides emulation of a VGIC to the realm guest but delegates
much of the handling to the host. Implement support in KVM for
saving/restoring state to/from the REC structure.
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes from v11:
* Minor changes to align with the previous patches. Note that the VGIC
handling will change with RMM v2.0.
Changes from v10:
* Make sure we sync the VGIC v4 state, and only populate valid lrs from
the list.
Changes from v9:
* Copy gicv3_vmcr from the RMM at the same time as gicv3_hcr rather
than having to handle that as a special case.
Changes from v8:
* Propagate gicv3_hcr to from the RMM.
Changes from v5:
* Handle RMM providing fewer GIC LRs than the hardware supports.
---
arch/arm64/include/asm/kvm_rmi.h | 1 +
arch/arm64/kvm/arm.c | 11 +++++--
arch/arm64/kvm/rmi.c | 5 ++++
arch/arm64/kvm/vgic/vgic-init.c | 2 +-
arch/arm64/kvm/vgic/vgic-v3.c | 6 ++--
arch/arm64/kvm/vgic/vgic.c | 49 +++++++++++++++++++++++++++++---
arch/arm64/kvm/vgic/vgic.h | 2 ++
7 files changed, 65 insertions(+), 11 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index dbb4b97d5d42..6190d75cc615 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -87,6 +87,7 @@ struct realm_rec {
void kvm_init_rmi(void);
u32 kvm_realm_ipa_limit(void);
+u32 kvm_realm_vgic_nr_lr(void);
int kvm_init_realm_vm(struct kvm *kvm);
int kvm_activate_realm(struct kvm *kvm);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 512d0ec9de60..66f23b8b3144 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -723,19 +723,24 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
kvm_call_hyp_nvhe(__pkvm_vcpu_put);
}
+ kvm_timer_vcpu_put(vcpu);
+ kvm_vgic_put(vcpu);
+
+ vcpu->cpu = -1;
+
+ if (vcpu_is_rec(vcpu))
+ return;
+
kvm_vcpu_put_debug(vcpu);
kvm_arch_vcpu_put_fp(vcpu);
if (has_vhe())
kvm_vcpu_put_vhe(vcpu);
- kvm_timer_vcpu_put(vcpu);
- kvm_vgic_put(vcpu);
kvm_vcpu_pmu_restore_host(vcpu);
if (vcpu_has_nv(vcpu))
kvm_vcpu_put_hw_mmu(vcpu);
kvm_arm_vmid_clear_active();
vcpu_clear_on_unsupported_cpu(vcpu);
- vcpu->cpu = -1;
}
static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 27ecd7d9f757..275b266c6614 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -77,6 +77,11 @@ u32 kvm_realm_ipa_limit(void)
return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_S2SZ);
}
+u32 kvm_realm_vgic_nr_lr(void)
+{
+ return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_GICV3_NUM_LRS);
+}
+
static int get_start_level(struct realm *realm)
{
/*
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index dc9f9db31026..bb1a876bf298 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -82,7 +82,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
* the proper checks already.
*/
if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
- !kvm_vgic_global_state.can_emulate_gicv2)
+ (!kvm_vgic_global_state.can_emulate_gicv2 || kvm_is_realm(kvm)))
return -ENODEV;
/*
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index c9ff4f90c975..f01dd30330e3 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -982,10 +982,10 @@ void vgic_v3_load(struct kvm_vcpu *vcpu)
return;
}
- if (likely(!is_protected_kvm_enabled()))
+ if (likely(!is_protected_kvm_enabled()) && !vcpu_is_rec(vcpu))
kvm_call_hyp(__vgic_v3_restore_vmcr_aprs, cpu_if);
- if (has_vhe())
+ if (has_vhe() && !vcpu_is_rec(vcpu))
__vgic_v3_activate_traps(cpu_if);
WARN_ON(vgic_v4_load(vcpu));
@@ -1004,6 +1004,6 @@ void vgic_v3_put(struct kvm_vcpu *vcpu)
kvm_call_hyp(__vgic_v3_save_aprs, cpu_if);
WARN_ON(vgic_v4_put(vcpu));
- if (has_vhe())
+ if (has_vhe() && !vcpu_is_rec(vcpu))
__vgic_v3_deactivate_traps(cpu_if);
}
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index 2fdcef3d28d1..b317b2a9815f 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -10,6 +10,7 @@
#include <linux/list_sort.h>
#include <linux/nospec.h>
+#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include "vgic.h"
@@ -994,10 +995,26 @@ static inline bool can_access_vgic_from_kernel(void)
return !static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif) || has_vhe();
}
+static inline void vgic_rmm_save_state(struct kvm_vcpu *vcpu)
+{
+ struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
+ int i;
+
+ for (i = 0; i < kvm_vcpu_vgic_nr_lr(vcpu); i++) {
+ cpu_if->vgic_lr[i] = vcpu->arch.rec.run->exit.gicv3_lrs[i];
+ vcpu->arch.rec.run->enter.gicv3_lrs[i] = 0;
+ }
+
+ cpu_if->vgic_hcr = vcpu->arch.rec.run->exit.gicv3_hcr;
+ cpu_if->vgic_vmcr = vcpu->arch.rec.run->exit.gicv3_vmcr;
+}
+
static inline void vgic_save_state(struct kvm_vcpu *vcpu)
{
if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
vgic_v2_save_state(vcpu);
+ else if (vcpu_is_rec(vcpu))
+ vgic_rmm_save_state(vcpu);
else
__vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3);
}
@@ -1032,10 +1049,30 @@ void kvm_vgic_process_async_update(struct kvm_vcpu *vcpu)
local_irq_restore(flags);
}
+static inline void vgic_rmm_restore_state(struct kvm_vcpu *vcpu)
+{
+ struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
+ int i;
+
+ for (i = 0; i < cpu_if->used_lrs; i++) {
+ vcpu->arch.rec.run->enter.gicv3_lrs[i] = cpu_if->vgic_lr[i];
+ /*
+ * Also populate the rec.run->exit copies so that a late
+ * decision to back out from entering the realm doesn't cause
+ * the state to be lost
+ */
+ vcpu->arch.rec.run->exit.gicv3_lrs[i] = cpu_if->vgic_lr[i];
+ }
+
+ vcpu->arch.rec.run->enter.gicv3_hcr = cpu_if->vgic_hcr & RMI_PERMITTED_GICV3_HCR_BITS;
+}
+
static inline void vgic_restore_state(struct kvm_vcpu *vcpu)
{
if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
vgic_v2_restore_state(vcpu);
+ else if (vcpu_is_rec(vcpu))
+ vgic_rmm_restore_state(vcpu);
else
__vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3);
}
@@ -1088,8 +1125,10 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
void kvm_vgic_load(struct kvm_vcpu *vcpu)
{
- if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
- if (has_vhe() && static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ if (unlikely(!irqchip_in_kernel(vcpu->kvm) ||
+ !vgic_initialized(vcpu->kvm))) {
+ if (has_vhe() && !vcpu_is_rec(vcpu) &&
+ static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
return;
}
@@ -1102,8 +1141,10 @@ void kvm_vgic_load(struct kvm_vcpu *vcpu)
void kvm_vgic_put(struct kvm_vcpu *vcpu)
{
- if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
- if (has_vhe() && static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+ if (unlikely(!irqchip_in_kernel(vcpu->kvm) ||
+ !vgic_initialized(vcpu->kvm))) {
+ if (has_vhe() && !vcpu_is_rec(vcpu) &&
+ static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
return;
}
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 55a1142efc6f..282a9701dea6 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -245,6 +245,8 @@ struct ap_list_summary {
static inline int kvm_vcpu_vgic_nr_lr(struct kvm_vcpu *vcpu)
{
+ if (unlikely(vcpu_is_rec(vcpu)))
+ return kvm_realm_vgic_nr_lr();
return kvm_vgic_global_state.nr_lr;
}
--
2.43.0
^ permalink raw reply related
* [PATCH v12 13/46] KVM: arm64: vgic: Provide helper for number of list registers
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
Currently the number of list registers available is stored in a global
(kvm_vgic_global_state.nr_lr). With Arm CCA the RMM is permitted to
reserve list registers for its own use and so the number of available
list registers can be fewer for a realm VM. Provide wrapper functions
to fetch the global in preparation for restricting nr_lr when dealing
with a realm VM.
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes in v12:
* Upstream changes mean that vcpu isn't available everywhere we need
it, so update helpers to take vcpu.
* Note that the VGIC handling will be reworked for the RMM 2.0 spec.
New patch for v6
---
arch/arm64/kvm/vgic/vgic-v2.c | 6 +++---
arch/arm64/kvm/vgic/vgic-v3.c | 8 ++++----
arch/arm64/kvm/vgic/vgic.c | 6 +++---
arch/arm64/kvm/vgic/vgic.h | 18 ++++++++++++------
4 files changed, 22 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c
index 585491fbda80..990bf693f65d 100644
--- a/arch/arm64/kvm/vgic/vgic-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-v2.c
@@ -34,11 +34,11 @@ void vgic_v2_configure_hcr(struct kvm_vcpu *vcpu,
cpuif->vgic_hcr = GICH_HCR_EN;
- if (irqs_pending_outside_lrs(als))
+ if (irqs_pending_outside_lrs(als, vcpu))
cpuif->vgic_hcr |= GICH_HCR_NPIE;
- if (irqs_active_outside_lrs(als))
+ if (irqs_active_outside_lrs(als, vcpu))
cpuif->vgic_hcr |= GICH_HCR_LRENPIE;
- if (irqs_outside_lrs(als))
+ if (irqs_outside_lrs(als, vcpu))
cpuif->vgic_hcr |= GICH_HCR_UIE;
cpuif->vgic_hcr |= (cpuif->vgic_vmcr & GICH_VMCR_ENABLE_GRP0_MASK) ?
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 1d6dd1b545bd..c9ff4f90c975 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -31,11 +31,11 @@ void vgic_v3_configure_hcr(struct kvm_vcpu *vcpu,
cpuif->vgic_hcr = ICH_HCR_EL2_En;
- if (irqs_pending_outside_lrs(als))
+ if (irqs_pending_outside_lrs(als, vcpu))
cpuif->vgic_hcr |= ICH_HCR_EL2_NPIE;
- if (irqs_active_outside_lrs(als))
+ if (irqs_active_outside_lrs(als, vcpu))
cpuif->vgic_hcr |= ICH_HCR_EL2_LRENPIE;
- if (irqs_outside_lrs(als))
+ if (irqs_outside_lrs(als, vcpu))
cpuif->vgic_hcr |= ICH_HCR_EL2_UIE;
if (!als->nr_sgi)
@@ -60,7 +60,7 @@ void vgic_v3_configure_hcr(struct kvm_vcpu *vcpu,
* can change behind our back without any warning...
*/
if (!cpus_have_final_cap(ARM64_HAS_ICH_HCR_EL2_TDIR) ||
- irqs_active_outside_lrs(als) ||
+ irqs_active_outside_lrs(als, vcpu) ||
atomic_read(&vcpu->kvm->arch.vgic.active_spis))
cpuif->vgic_hcr |= ICH_HCR_EL2_TDIR;
}
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index 430aa98888fd..2fdcef3d28d1 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -957,7 +957,7 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
summarize_ap_list(vcpu, &als);
- if (irqs_outside_lrs(&als))
+ if (irqs_outside_lrs(&als, vcpu))
vgic_sort_ap_list(vcpu);
list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
@@ -967,12 +967,12 @@ static void vgic_flush_lr_state(struct kvm_vcpu *vcpu)
}
}
- if (count == kvm_vgic_global_state.nr_lr)
+ if (count == kvm_vcpu_vgic_nr_lr(vcpu))
break;
}
/* Nuke remaining LRs */
- for (int i = count ; i < kvm_vgic_global_state.nr_lr; i++)
+ for (int i = count ; i < kvm_vcpu_vgic_nr_lr(vcpu); i++)
vgic_clear_lr(vcpu, i);
if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 5f0fc96b4dc2..55a1142efc6f 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -7,6 +7,7 @@
#include <linux/irqchip/arm-gic-common.h>
#include <asm/kvm_mmu.h>
+#include <asm/kvm_rmi.h>
#define PRODUCT_ID_KVM 0x4b /* ASCII code K */
#define IMPLEMENTER_ARM 0x43b
@@ -242,14 +243,19 @@ struct ap_list_summary {
unsigned int nr_sgi; /* any SGI */
};
-#define irqs_outside_lrs(s) \
- (((s)->nr_pend + (s)->nr_act) > kvm_vgic_global_state.nr_lr)
+static inline int kvm_vcpu_vgic_nr_lr(struct kvm_vcpu *vcpu)
+{
+ return kvm_vgic_global_state.nr_lr;
+}
+
+#define irqs_outside_lrs(s, vcpu) \
+ (((s)->nr_pend + (s)->nr_act) > kvm_vcpu_vgic_nr_lr(vcpu))
-#define irqs_pending_outside_lrs(s) \
- ((s)->nr_pend > kvm_vgic_global_state.nr_lr)
+#define irqs_pending_outside_lrs(s, vcpu) \
+ ((s)->nr_pend > kvm_vcpu_vgic_nr_lr(vcpu))
-#define irqs_active_outside_lrs(s) \
- ((s)->nr_act && irqs_outside_lrs(s))
+#define irqs_active_outside_lrs(s, vcpu) \
+ ((s)->nr_act && irqs_outside_lrs(s, vcpu))
int vgic_v3_parse_attr(struct kvm_device *dev, struct kvm_device_attr *attr,
struct vgic_reg_attr *reg_attr);
--
2.43.0
^ permalink raw reply related
* [PATCH v12 12/46] arm64: RMI: Allocate/free RECs to match vCPUs
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
The RMM maintains a data structure known as the Realm Execution Context
(or REC). It is similar to struct kvm_vcpu and tracks the state of the
virtual CPUs. KVM must delegate memory and request the structures are
created when vCPUs are created, and suitably tear down on destruction.
RECs must also be supplied with addition pages - auxiliary (or AUX)
granules - for storing the larger registers state (e.g. for SVE). The
number of AUX granules for a REC depends on the parameters with which
the Realm was created - the RMM makes this information available via the
RMI_REC_AUX_COUNT call performed after creating the Realm Descriptor (RD).
Note that only some of register state for the REC can be set by KVM, the
rest is defined by the RMM (zeroed). The register state then cannot be
changed by KVM after the REC is created (except when the guest
explicitly requests this e.g. by performing a PSCI call).
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
* Remove the KVM_ARM_VCPU_REC feature. User space no longer needs to
configure each VCPU separately, RECs are created on the first VCPU
run of the guest.
Changes since v9:
* Size the aux_pages array according to the PAGE_SIZE of the host.
Changes since v7:
* Add comment explaining the aux_pages array.
* Rename "undeleted_failed" variable to "should_free" to avoid a
confusing double negative.
Changes since v6:
* Avoid reporting the KVM_ARM_VCPU_REC feature if the guest isn't a
realm guest.
* Support host page size being larger than RMM's granule size when
allocating/freeing aux granules.
Changes since v5:
* Separate the concept of vcpu_is_rec() and
kvm_arm_vcpu_rec_finalized() by using the KVM_ARM_VCPU_REC feature as
the indication that the VCPU is a REC.
Changes since v2:
* Free rec->run earlier in kvm_destroy_realm() and adapt to previous patches.
---
arch/arm64/include/asm/kvm_emulate.h | 2 +-
arch/arm64/include/asm/kvm_host.h | 3 +
arch/arm64/include/asm/kvm_rmi.h | 21 +++
arch/arm64/kvm/arm.c | 10 +-
arch/arm64/kvm/reset.c | 1 +
arch/arm64/kvm/rmi.c | 185 +++++++++++++++++++++++++++
6 files changed, 219 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index e7e9364ae118..f884bac43c06 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -716,7 +716,7 @@ static inline bool kvm_realm_is_created(struct kvm *kvm)
static inline bool vcpu_is_rec(struct kvm_vcpu *vcpu)
{
- return false;
+ return kvm_is_realm(vcpu->kvm);
}
#endif /* __ARM64_KVM_EMULATE_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index da913fee70b6..5a24227088c1 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -900,6 +900,9 @@ struct kvm_vcpu_arch {
/* Per-vcpu TLB for VNCR_EL2 -- NULL when !NV */
struct vncr_tlb *vncr_tlb;
+
+ /* Realm meta data */
+ struct realm_rec rec;
};
/*
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index e4534af06d96..dbb4b97d5d42 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -65,6 +65,26 @@ struct realm {
unsigned int ia_bits;
};
+/**
+ * struct realm_rec - Additional per VCPU data for a Realm
+ *
+ * @mpidr: MPIDR (Multiprocessor Affinity Register) value to identify this VCPU
+ * @rec_page: Kernel VA of the RMM's private page for this REC
+ * @aux_pages: Additional pages private to the RMM for this REC
+ * @run: Kernel VA of the RmiRecRun structure shared with the RMM
+ */
+struct realm_rec {
+ unsigned long mpidr;
+ void *rec_page;
+ /*
+ * REC_PARAMS_AUX_GRANULES is the maximum number of 4K granules that
+ * the RMM can require. The array is sized to be large enough for the
+ * maximum number of host sized pages that could be required.
+ */
+ struct page *aux_pages[(REC_PARAMS_AUX_GRANULES * SZ_4K) >> PAGE_SHIFT];
+ struct rec_run *run;
+};
+
void kvm_init_rmi(void);
u32 kvm_realm_ipa_limit(void);
@@ -72,6 +92,7 @@ int kvm_init_realm_vm(struct kvm *kvm);
int kvm_activate_realm(struct kvm *kvm);
void kvm_destroy_realm(struct kvm *kvm);
void kvm_realm_destroy_rtts(struct kvm *kvm);
+void kvm_destroy_rec(struct kvm_vcpu *vcpu);
static inline bool kvm_realm_is_private_address(struct realm *realm,
unsigned long addr)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 542df37b9e82..512d0ec9de60 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -529,6 +529,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
/* Force users to call KVM_ARM_VCPU_INIT */
vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
+ vcpu->arch.rec.mpidr = INVALID_HWID;
+
vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
/* Set up the timer */
@@ -1502,7 +1504,7 @@ int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
return -EINVAL;
}
-static unsigned long system_supported_vcpu_features(void)
+static unsigned long system_supported_vcpu_features(struct kvm *kvm)
{
unsigned long features = KVM_VCPU_VALID_FEATURES;
@@ -1540,7 +1542,7 @@ static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu,
return -ENOENT;
}
- if (features & ~system_supported_vcpu_features())
+ if (features & ~system_supported_vcpu_features(vcpu->kvm))
return -EINVAL;
/*
@@ -1562,6 +1564,10 @@ static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu,
if (test_bit(KVM_ARM_VCPU_HAS_EL2, &features))
return -EINVAL;
+ /* Realms are incompatible with AArch32 */
+ if (vcpu_is_rec(vcpu))
+ return -EINVAL;
+
return 0;
}
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 959532422d3a..4bbf58892928 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -161,6 +161,7 @@ void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu)
free_page((unsigned long)vcpu->arch.ctxt.vncr_array);
kfree(vcpu->arch.vncr_tlb);
kfree(vcpu->arch.ccsidr);
+ kvm_destroy_rec(vcpu);
}
static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 98929382c365..27ecd7d9f757 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -229,9 +229,188 @@ static int realm_ensure_created(struct kvm *kvm)
return -ENXIO;
}
+static void free_rec_aux(struct page **aux_pages,
+ unsigned int num_aux)
+{
+ unsigned int i, j;
+ unsigned int page_count = 0;
+
+ for (i = 0; i < num_aux;) {
+ struct page *aux_page = aux_pages[page_count++];
+ phys_addr_t aux_page_phys = page_to_phys(aux_page);
+ bool should_free = true;
+
+ for (j = 0; j < PAGE_SIZE && i < num_aux; j += RMM_PAGE_SIZE) {
+ if (WARN_ON(rmi_granule_undelegate(aux_page_phys)))
+ should_free = false;
+ aux_page_phys += RMM_PAGE_SIZE;
+ i++;
+ }
+ /* Only free if all the undelegate calls were successful */
+ if (should_free)
+ __free_page(aux_page);
+ }
+}
+
+static int alloc_rec_aux(struct page **aux_pages,
+ u64 *aux_phys_pages,
+ unsigned int num_aux)
+{
+ struct page *aux_page;
+ int page_count = 0;
+ unsigned int i, j;
+ int ret;
+
+ for (i = 0; i < num_aux;) {
+ phys_addr_t aux_page_phys;
+
+ aux_page = alloc_page(GFP_KERNEL);
+ if (!aux_page) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ aux_page_phys = page_to_phys(aux_page);
+ for (j = 0; j < PAGE_SIZE && i < num_aux; j += RMM_PAGE_SIZE) {
+ if (rmi_granule_delegate(aux_page_phys)) {
+ ret = -ENXIO;
+ goto err_undelegate;
+ }
+ aux_phys_pages[i++] = aux_page_phys;
+ aux_page_phys += RMM_PAGE_SIZE;
+ }
+ aux_pages[page_count++] = aux_page;
+ }
+
+ return 0;
+err_undelegate:
+ while (j > 0) {
+ j -= RMM_PAGE_SIZE;
+ i--;
+ if (WARN_ON(rmi_granule_undelegate(aux_phys_pages[i]))) {
+ /* Leak the page if the undelegate fails */
+ goto out_err;
+ }
+ }
+ __free_page(aux_page);
+out_err:
+ free_rec_aux(aux_pages, i);
+ return ret;
+}
+
+static int kvm_create_rec(struct kvm_vcpu *vcpu)
+{
+ struct user_pt_regs *vcpu_regs = vcpu_gp_regs(vcpu);
+ unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
+ struct realm *realm = &vcpu->kvm->arch.realm;
+ struct realm_rec *rec = &vcpu->arch.rec;
+ unsigned long rec_page_phys;
+ struct rec_params *params;
+ int r, i;
+
+ if (rec->run)
+ return -EBUSY;
+
+ /*
+ * The RMM will report PSCI v1.0 to Realms and the KVM_ARM_VCPU_PSCI_0_2
+ * flag covers v0.2 and onwards.
+ */
+ if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_PSCI_0_2))
+ return -EINVAL;
+
+ BUILD_BUG_ON(sizeof(*params) > PAGE_SIZE);
+ BUILD_BUG_ON(sizeof(*rec->run) > PAGE_SIZE);
+
+ params = (struct rec_params *)get_zeroed_page(GFP_KERNEL);
+ rec->rec_page = (void *)__get_free_page(GFP_KERNEL);
+ rec->run = (void *)get_zeroed_page(GFP_KERNEL);
+ if (!params || !rec->rec_page || !rec->run) {
+ r = -ENOMEM;
+ goto out_free_pages;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(params->gprs); i++)
+ params->gprs[i] = vcpu_regs->regs[i];
+
+ params->pc = vcpu_regs->pc;
+
+ if (vcpu->vcpu_id == 0)
+ params->flags |= REC_PARAMS_FLAG_RUNNABLE;
+
+ rec_page_phys = virt_to_phys(rec->rec_page);
+
+ if (rmi_granule_delegate(rec_page_phys)) {
+ r = -ENXIO;
+ goto out_free_pages;
+ }
+
+ r = alloc_rec_aux(rec->aux_pages, params->aux, realm->num_aux);
+ if (r)
+ goto out_undelegate_rmm_rec;
+
+ params->num_rec_aux = realm->num_aux;
+ params->mpidr = mpidr;
+
+ if (rmi_rec_create(virt_to_phys(realm->rd),
+ rec_page_phys,
+ virt_to_phys(params))) {
+ r = -ENXIO;
+ goto out_free_rec_aux;
+ }
+
+ rec->mpidr = mpidr;
+
+ free_page((unsigned long)params);
+ return 0;
+
+out_free_rec_aux:
+ free_rec_aux(rec->aux_pages, realm->num_aux);
+out_undelegate_rmm_rec:
+ if (WARN_ON(rmi_granule_undelegate(rec_page_phys)))
+ rec->rec_page = NULL;
+out_free_pages:
+ free_page((unsigned long)rec->run);
+ free_page((unsigned long)rec->rec_page);
+ free_page((unsigned long)params);
+ return r;
+}
+
+void kvm_destroy_rec(struct kvm_vcpu *vcpu)
+{
+ struct realm *realm = &vcpu->kvm->arch.realm;
+ struct realm_rec *rec = &vcpu->arch.rec;
+ unsigned long rec_page_phys;
+
+ if (!vcpu_is_rec(vcpu))
+ return;
+
+ if (!rec->run) {
+ /* Nothing to do if the VCPU hasn't been finalized */
+ return;
+ }
+
+ free_page((unsigned long)rec->run);
+
+ rec_page_phys = virt_to_phys(rec->rec_page);
+
+ /*
+ * The REC and any AUX pages cannot be reclaimed until the REC is
+ * destroyed. So if the REC destroy fails then the REC page and any AUX
+ * pages will be leaked.
+ */
+ if (WARN_ON(rmi_rec_destroy(rec_page_phys)))
+ return;
+
+ free_rec_aux(rec->aux_pages, realm->num_aux);
+
+ free_delegated_granule(rec_page_phys);
+}
+
int kvm_activate_realm(struct kvm *kvm)
{
struct realm *realm = &kvm->arch.realm;
+ struct kvm_vcpu *vcpu;
+ unsigned long i;
int ret;
if (!kvm_is_realm(kvm))
@@ -257,6 +436,12 @@ int kvm_activate_realm(struct kvm *kvm)
return -EOPNOTSUPP;
}
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ ret = kvm_create_rec(vcpu);
+ if (ret)
+ return ret;
+ }
+
ret = rmi_realm_activate(virt_to_phys(realm->rd));
if (ret)
return -ENXIO;
--
2.43.0
^ permalink raw reply related
* [PATCH v12 11/46] arm64: RMI: Activate realm on first VCPU run
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
When a VCPU migrates to another physical CPU check if this is the first
time the guest has run, and if so activate the realm.
Before the realm can be activated it must first be created, this is a
stub in this patch and will be filled in by a later patch.
Signed-off-by: Steven Price <steven.price@arm.com>
---
New patch for v12
---
arch/arm64/include/asm/kvm_rmi.h | 1 +
arch/arm64/kvm/arm.c | 6 +++++
arch/arm64/kvm/rmi.c | 42 ++++++++++++++++++++++++++++++++
3 files changed, 49 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index cb7350f8a01a..e4534af06d96 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -69,6 +69,7 @@ void kvm_init_rmi(void);
u32 kvm_realm_ipa_limit(void);
int kvm_init_realm_vm(struct kvm *kvm);
+int kvm_activate_realm(struct kvm *kvm);
void kvm_destroy_realm(struct kvm *kvm);
void kvm_realm_destroy_rtts(struct kvm *kvm);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 941d1bec8e77..542df37b9e82 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -951,6 +951,12 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
return ret;
}
+ if (kvm_is_realm(vcpu->kvm)) {
+ ret = kvm_activate_realm(kvm);
+ if (ret)
+ return ret;
+ }
+
mutex_lock(&kvm->arch.config_lock);
set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags);
mutex_unlock(&kvm->arch.config_lock);
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index e57e8b7eafa9..98929382c365 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -223,6 +223,48 @@ void kvm_realm_destroy_rtts(struct kvm *kvm)
WARN_ON(realm_tear_down_rtt_range(realm, 0, (1UL << ia_bits)));
}
+static int realm_ensure_created(struct kvm *kvm)
+{
+ /* Provided in later patch */
+ return -ENXIO;
+}
+
+int kvm_activate_realm(struct kvm *kvm)
+{
+ struct realm *realm = &kvm->arch.realm;
+ int ret;
+
+ if (!kvm_is_realm(kvm))
+ return -ENXIO;
+
+ if (kvm_realm_state(kvm) == REALM_STATE_ACTIVE)
+ return 0;
+
+ guard(mutex)(&kvm->arch.config_lock);
+ /* Check again with the lock held */
+ if (kvm_realm_state(kvm) == REALM_STATE_ACTIVE)
+ return 0;
+
+ ret = realm_ensure_created(kvm);
+ if (ret)
+ return ret;
+
+ /* Mark state as dead in case we fail */
+ WRITE_ONCE(realm->state, REALM_STATE_DEAD);
+
+ if (!irqchip_in_kernel(kvm)) {
+ /* Userspace irqchip not yet supported with realms */
+ return -EOPNOTSUPP;
+ }
+
+ ret = rmi_realm_activate(virt_to_phys(realm->rd));
+ if (ret)
+ return -ENXIO;
+
+ WRITE_ONCE(realm->state, REALM_STATE_ACTIVE);
+ return 0;
+}
+
void kvm_destroy_realm(struct kvm *kvm)
{
struct realm *realm = &kvm->arch.realm;
--
2.43.0
^ permalink raw reply related
* [PATCH v12 10/46] arm64: RMI: RTT tear down
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
The RMM owns the stage 2 page tables for a realm, and KVM must request
that the RMM creates/destroys entries as necessary. The physical pages
to store the page tables are delegated to the realm as required, and can
be undelegated when no longer used.
Creating new RTTs is the easy part, tearing down is a little more
tricky. The result of realm_rtt_destroy() can be used to effectively
walk the tree and destroy the entries (undelegating pages that were
given to the realm).
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
* Moved some code from earlier in the series to this one so that it's
added when it's first used.
Changes since v10:
* RME->RMI rename.
* Some code to handle freeing stage 2 PGD moved into this patch where
it belongs.
Changes since v9:
* Add a comment clarifying that root level RTTs are not destroyed until
after the RD is destroyed.
Changes since v8:
* Introduce free_rtt() wrapper which calls free_delegated_granule()
followed by kvm_account_pgtable_pages(). This makes it clear where an
RTT is being freed rather than just a delegated granule.
Changes since v6:
* Move rme_rtt_level_mapsize() and supporting defines from kvm_rme.h
into rme.c as they are only used in that file.
Changes since v5:
* Rename some RME_xxx defines to do with page sizes as RMM_xxx - they are
a property of the RMM specification not the RME architecture.
Changes since v2:
* Moved {alloc,free}_delegated_page() and ensure_spare_page() to a
later patch when they are actually used.
* Some simplifications now rmi_xxx() functions allow NULL as an output
parameter.
* Improved comments and code layout.
---
arch/arm64/include/asm/kvm_rmi.h | 7 ++
arch/arm64/kvm/mmu.c | 15 ++-
arch/arm64/kvm/rmi.c | 151 +++++++++++++++++++++++++++++++
3 files changed, 172 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 7f06aa5b0550..cb7350f8a01a 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -70,5 +70,12 @@ u32 kvm_realm_ipa_limit(void);
int kvm_init_realm_vm(struct kvm *kvm);
void kvm_destroy_realm(struct kvm *kvm);
+void kvm_realm_destroy_rtts(struct kvm *kvm);
+
+static inline bool kvm_realm_is_private_address(struct realm *realm,
+ unsigned long addr)
+{
+ return !(addr & BIT(realm->ia_bits - 1));
+}
#endif /* __ASM_KVM_RMI_H */
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index ed86a10f08e0..68e6cefe1135 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1098,10 +1098,23 @@ void stage2_unmap_vm(struct kvm *kvm)
void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
{
struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
- struct kvm_pgtable *pgt = NULL;
+ struct kvm_pgtable *pgt;
write_lock(&kvm->mmu_lock);
pgt = mmu->pgt;
+ if (kvm_is_realm(kvm) &&
+ (kvm_realm_state(kvm) != REALM_STATE_DEAD &&
+ kvm_realm_state(kvm) != REALM_STATE_NONE)) {
+ write_unlock(&kvm->mmu_lock);
+ kvm_realm_destroy_rtts(kvm);
+
+ /*
+ * The PGD pages can be reclaimed only after the realm (RD) is
+ * destroyed. We call this again from kvm_destroy_realm() after
+ * the RD is destroyed.
+ */
+ return;
+ }
if (pgt) {
mmu->pgd_phys = 0;
mmu->pgt = NULL;
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index c2b13fecfd11..e57e8b7eafa9 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -17,6 +17,22 @@ static unsigned long rmm_feat_reg0;
#define RMM_PAGE_SHIFT 12
#define RMM_PAGE_SIZE BIT(RMM_PAGE_SHIFT)
+#define RMM_RTT_BLOCK_LEVEL 2
+#define RMM_RTT_MAX_LEVEL 3
+
+/* See ARM64_HW_PGTABLE_LEVEL_SHIFT() */
+#define RMM_RTT_LEVEL_SHIFT(l) \
+ ((RMM_PAGE_SHIFT - 3) * (4 - (l)) + 3)
+#define RMM_L2_BLOCK_SIZE BIT(RMM_RTT_LEVEL_SHIFT(2))
+
+static inline unsigned long rmi_rtt_level_mapsize(int level)
+{
+ if (WARN_ON(level > RMM_RTT_MAX_LEVEL))
+ return RMM_PAGE_SIZE;
+
+ return (1UL << RMM_RTT_LEVEL_SHIFT(level));
+}
+
static int rmi_check_version(void)
{
struct arm_smccc_res res;
@@ -61,6 +77,15 @@ u32 kvm_realm_ipa_limit(void)
return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_S2SZ);
}
+static int get_start_level(struct realm *realm)
+{
+ /*
+ * Open coded version of 4 - stage2_pgtable_levels(ia_bits) but using
+ * the RMM's page size rather than the host's.
+ */
+ return 4 - ((realm->ia_bits - 8) / (RMM_PAGE_SHIFT - 3));
+}
+
static int free_delegated_granule(phys_addr_t phys)
{
if (WARN_ON(rmi_granule_undelegate(phys))) {
@@ -73,6 +98,131 @@ static int free_delegated_granule(phys_addr_t phys)
return 0;
}
+static void free_rtt(phys_addr_t phys)
+{
+ if (free_delegated_granule(phys))
+ return;
+
+ kvm_account_pgtable_pages(phys_to_virt(phys), -1);
+}
+
+static int realm_rtt_destroy(struct realm *realm, unsigned long addr,
+ int level, phys_addr_t *rtt_granule,
+ unsigned long *next_addr)
+{
+ unsigned long out_rtt;
+ int ret;
+
+ ret = rmi_rtt_destroy(virt_to_phys(realm->rd), addr, level,
+ &out_rtt, next_addr);
+
+ *rtt_granule = out_rtt;
+
+ return ret;
+}
+
+static int realm_tear_down_rtt_level(struct realm *realm, int level,
+ unsigned long start, unsigned long end)
+{
+ ssize_t map_size;
+ unsigned long addr, next_addr;
+
+ if (WARN_ON(level > RMM_RTT_MAX_LEVEL))
+ return -EINVAL;
+
+ map_size = rmi_rtt_level_mapsize(level - 1);
+
+ for (addr = start; addr < end; addr = next_addr) {
+ phys_addr_t rtt_granule;
+ int ret;
+ unsigned long align_addr = ALIGN(addr, map_size);
+
+ next_addr = ALIGN(addr + 1, map_size);
+
+ if (next_addr > end || align_addr != addr) {
+ /*
+ * The target range is smaller than what this level
+ * covers, recurse deeper.
+ */
+ ret = realm_tear_down_rtt_level(realm,
+ level + 1,
+ addr,
+ min(next_addr, end));
+ if (ret)
+ return ret;
+ continue;
+ }
+
+ ret = realm_rtt_destroy(realm, addr, level,
+ &rtt_granule, &next_addr);
+
+ switch (RMI_RETURN_STATUS(ret)) {
+ case RMI_SUCCESS:
+ free_rtt(rtt_granule);
+ break;
+ case RMI_ERROR_RTT:
+ if (next_addr > addr) {
+ /* Missing RTT, skip */
+ break;
+ }
+ /*
+ * We tear down the RTT range for the full IPA
+ * space, after everything is unmapped. Also we
+ * descend down only if we cannot tear down a
+ * top level RTT. Thus RMM must be able to walk
+ * to the requested level. e.g., a block mapping
+ * exists at L1 or L2.
+ */
+ if (WARN_ON(RMI_RETURN_INDEX(ret) != level))
+ return -EBUSY;
+ if (WARN_ON(level == RMM_RTT_MAX_LEVEL))
+ return -EBUSY;
+
+ /*
+ * The table has active entries in it, recurse deeper
+ * and tear down the RTTs.
+ */
+ next_addr = ALIGN(addr + 1, map_size);
+ ret = realm_tear_down_rtt_level(realm,
+ level + 1,
+ addr,
+ next_addr);
+ if (ret)
+ return ret;
+ /*
+ * Now that the child RTTs are destroyed,
+ * retry at this level.
+ */
+ next_addr = addr;
+ break;
+ default:
+ WARN_ON(1);
+ return -ENXIO;
+ }
+ }
+
+ return 0;
+}
+
+static int realm_tear_down_rtt_range(struct realm *realm,
+ unsigned long start, unsigned long end)
+{
+ /*
+ * Root level RTTs can only be destroyed after the RD is destroyed. So
+ * tear down everything below the root level
+ */
+ return realm_tear_down_rtt_level(realm, get_start_level(realm) + 1,
+ start, end);
+}
+
+void kvm_realm_destroy_rtts(struct kvm *kvm)
+{
+ struct realm *realm = &kvm->arch.realm;
+ unsigned int ia_bits = realm->ia_bits;
+
+ WARN_ON(realm_tear_down_rtt_range(realm, 0, (1UL << ia_bits)));
+}
+
void kvm_destroy_realm(struct kvm *kvm)
{
struct realm *realm = &kvm->arch.realm;
@@ -83,6 +233,7 @@ void kvm_destroy_realm(struct kvm *kvm)
kvm_stage2_unmap_range(&kvm->arch.mmu, 0,
BIT(realm->ia_bits - 1), true);
write_unlock(&kvm->mmu_lock);
+ kvm_realm_destroy_rtts(kvm);
if (realm->params) {
free_page((unsigned long)realm->params);
--
2.43.0
^ permalink raw reply related
* [PATCH v12 09/46] KVM: arm64: Allow passing machine type in KVM creation
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
Previously machine type was used purely for specifying the physical
address size of the guest. Reserve the higher bits to specify an ARM
specific machine type and declare a new type 'KVM_VM_TYPE_ARM_REALM'
used to create a realm guest.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v9:
* Explictly set realm.state to REALM_STATE_NONE rather than rely on the
zeroing of the structure.
Changes since v7:
* Add some documentation explaining the new machine type.
Changes since v6:
* Make the check for kvm_rme_is_available more visible and report an
error code of -EPERM (instead of -EINVAL) to make it explicit that
the kernel supports RME, but the platform doesn't.
---
Documentation/virt/kvm/api.rst | 16 ++++++++++++++--
arch/arm64/kvm/arm.c | 16 ++++++++++++++++
arch/arm64/kvm/mmu.c | 3 ---
include/uapi/linux/kvm.h | 19 +++++++++++++++----
4 files changed, 45 insertions(+), 9 deletions(-)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 2d5dc7e48954..d7ebf42933e8 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -181,8 +181,20 @@ flag KVM_VM_MIPS_VZ.
ARM64:
^^^^^^
-On arm64, the physical address size for a VM (IPA Size limit) is limited
-to 40bits by default. The limit can be configured if the host supports the
+On arm64, the machine type identifier is used to encode a type and the
+physical address size for the VM. The lower byte (bits[7-0]) encode the
+address size and the upper bits[11-8] encode a machine type. The machine
+types that might be available are:
+
+ ====================== ============================================
+ KVM_VM_TYPE_ARM_NORMAL A standard VM
+ KVM_VM_TYPE_ARM_REALM A "Realm" VM using the Arm Confidential
+ Compute extensions, the VM's memory is
+ protected from the host.
+ ====================== ============================================
+
+The physical address size for a VM (IPA Size limit) is limited to 40bits
+by default. The limit can be configured if the host supports the
extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use
KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type
identifier, where IPA_Bits is the maximum width of any physical
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 345d9f56e98e..941d1bec8e77 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -170,6 +170,22 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
mutex_unlock(&kvm->lock);
#endif
+ if (type & ~(KVM_VM_TYPE_ARM_MASK | KVM_VM_TYPE_ARM_IPA_SIZE_MASK))
+ return -EINVAL;
+
+ switch (type & KVM_VM_TYPE_ARM_MASK) {
+ case KVM_VM_TYPE_ARM_NORMAL:
+ break;
+ case KVM_VM_TYPE_ARM_REALM:
+ if (!static_branch_unlikely(&kvm_rmi_is_available))
+ return -EINVAL;
+ WRITE_ONCE(kvm->arch.realm.state, REALM_STATE_NONE);
+ kvm->arch.is_realm = true;
+ break;
+ default:
+ return -EINVAL;
+ }
+
kvm_init_nested(kvm);
ret = kvm_share_hyp(kvm, kvm + 1);
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index d91e7eb2c8d3..ed86a10f08e0 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -882,9 +882,6 @@ static int kvm_init_ipa_range(struct kvm *kvm,
if (kvm_is_realm(kvm))
kvm_ipa_limit = kvm_realm_ipa_limit();
- if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
- return -EINVAL;
-
phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
if (is_protected_kvm_enabled()) {
phys_shift = kvm_ipa_limit;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 8e66ba9c81db..c51fd88feedf 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -681,14 +681,25 @@ struct kvm_enable_cap {
#define KVM_S390_SIE_PAGE_OFFSET 1
/*
- * On arm64, machine type can be used to request the physical
- * address size for the VM. Bits[7-0] are reserved for the guest
- * PA size shift (i.e, log2(PA_Size)). For backward compatibility,
- * value 0 implies the default IPA size, 40bits.
+ * On arm64, machine type can be used to request both the machine type and
+ * the physical address size for the VM.
+ *
+ * Bits[11-8] are reserved for the ARM specific machine type.
+ *
+ * Bits[7-0] are reserved for the guest PA size shift (i.e, log2(PA_Size)).
+ * For backward compatibility, value 0 implies the default IPA size, 40bits.
*/
+#define KVM_VM_TYPE_ARM_SHIFT 8
+#define KVM_VM_TYPE_ARM_MASK (0xfULL << KVM_VM_TYPE_ARM_SHIFT)
+#define KVM_VM_TYPE_ARM(_type) \
+ (((_type) << KVM_VM_TYPE_ARM_SHIFT) & KVM_VM_TYPE_ARM_MASK)
+#define KVM_VM_TYPE_ARM_NORMAL KVM_VM_TYPE_ARM(0)
+#define KVM_VM_TYPE_ARM_REALM KVM_VM_TYPE_ARM(1)
+
#define KVM_VM_TYPE_ARM_IPA_SIZE_MASK 0xffULL
#define KVM_VM_TYPE_ARM_IPA_SIZE(x) \
((x) & KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
+
/*
* ioctls for /dev/kvm fds:
*/
--
2.43.0
^ permalink raw reply related
* [PATCH v12 08/46] kvm: arm64: Don't expose unsupported capabilities for realm guests
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Suzuki K Poulose, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Zenghui Yu, linux-arm-kernel,
linux-kernel, Joey Gouly, Alexandru Elisei, Christoffer Dall,
Fuad Tabba, linux-coco, Ganapatrao Kulkarni, Gavin Shan,
Shanker Donthineni, Alper Gun, Aneesh Kumar K . V, Emi Kisanuki,
Vishal Annapurve, Steven Price
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
From: Suzuki K Poulose <suzuki.poulose@arm.com>
RMM v1.0 provides no mechanism for the host to perform debug operations
on the guest. So limit the extensions that are visible to an allowlist
so that only those capabilities we can support are advertised.
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v10:
* Add a kvm_realm_ext_allowed() function which limits which extensions
are exposed to an allowlist. This removes the need for special casing
various extensions.
Changes since v7:
* Remove the helper functions and inline the kvm_is_realm() check with
a ternary operator.
* Rewrite the commit message to explain this patch.
---
arch/arm64/kvm/arm.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 4ce3ad1d69b0..345d9f56e98e 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -310,6 +310,26 @@ static bool kvm_has_full_ptr_auth(void)
(apa + api + apa3) == 1);
}
+static bool kvm_realm_ext_allowed(long ext)
+{
+ switch (ext) {
+ case KVM_CAP_IRQCHIP:
+ case KVM_CAP_ARM_PSCI:
+ case KVM_CAP_ARM_PSCI_0_2:
+ case KVM_CAP_NR_VCPUS:
+ case KVM_CAP_MAX_VCPUS:
+ case KVM_CAP_MAX_VCPU_ID:
+ case KVM_CAP_MSI_DEVID:
+ case KVM_CAP_ARM_VM_IPA_SIZE:
+ case KVM_CAP_ARM_PMU_V3:
+ case KVM_CAP_ARM_PTRAUTH_ADDRESS:
+ case KVM_CAP_ARM_PTRAUTH_GENERIC:
+ case KVM_CAP_ARM_RMI:
+ return true;
+ }
+ return false;
+}
+
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
int r;
@@ -317,6 +337,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
if (kvm && kvm_vm_is_protected(kvm) && !kvm_pvm_ext_allowed(ext))
return 0;
+ if (kvm && kvm_is_realm(kvm) && !kvm_realm_ext_allowed(ext))
+ return 0;
+
switch (ext) {
case KVM_CAP_IRQCHIP:
r = vgic_present;
--
2.43.0
^ permalink raw reply related
* [PATCH v12 07/46] arm64: RMI: Basic infrastructure for creating a realm.
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
Introduce the skeleton functions for creating and destroying a realm.
The IPA size requested is checked against what the RMM supports.
The actual work of constructing the realm will be added in future
patches.
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
* Major rework to drop the realm configuration and make the
construction of realms implicit rather than driven by the VMM
directly.
* The code to create RDs, handle VMIDs etc is moved to later patches.
Changes since v10:
* Rename from RME to RMI.
* Move the stage2 cleanup to a later patch.
Changes since v9:
* Avoid walking the stage 2 page tables when destroying the realm -
the real ones are not accessible to the non-secure world, and the RMM
may leave junk in the physical pages when returning them.
* Fix an error path in realm_create_rd() to actually return an error value.
Changes since v8:
* Fix free_delegated_granule() to not call kvm_account_pgtable_pages();
a separate wrapper will be introduced in a later patch to deal with
RTTs.
* Minor code cleanups following review.
Changes since v7:
* Minor code cleanup following Gavin's review.
Changes since v6:
* Separate RMM RTT calculations from host PAGE_SIZE. This allows the
host page size to be larger than 4k while still communicating with an
RMM which uses 4k granules.
Changes since v5:
* Introduce free_delegated_granule() to replace many
undelegate/free_page() instances and centralise the comment on
leaking when the undelegate fails.
* Several other minor improvements suggested by reviews - thanks for
the feedback!
Changes since v2:
* Improved commit description.
* Improved return failures for rmi_check_version().
* Clear contents of PGD after it has been undelegated in case the RMM
left stale data.
* Minor changes to reflect changes in previous patches.
---
arch/arm64/include/asm/kvm_emulate.h | 5 ++
arch/arm64/include/asm/kvm_rmi.h | 18 +++++++
arch/arm64/kvm/arm.c | 11 ++++
arch/arm64/kvm/mmu.c | 11 ++--
arch/arm64/kvm/rmi.c | 81 ++++++++++++++++++++++++++++
5 files changed, 123 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 67f75678e489..e7e9364ae118 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -709,6 +709,11 @@ static inline enum realm_state kvm_realm_state(struct kvm *kvm)
return READ_ONCE(kvm->arch.realm.state);
}
+static inline bool kvm_realm_is_created(struct kvm *kvm)
+{
+ return kvm_is_realm(kvm) && kvm_realm_state(kvm) != REALM_STATE_NONE;
+}
+
static inline bool vcpu_is_rec(struct kvm_vcpu *vcpu)
{
return false;
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 3506f50b05cd..7f06aa5b0550 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -6,6 +6,8 @@
#ifndef __ASM_KVM_RMI_H
#define __ASM_KVM_RMI_H
+#include <asm/rmi_smc.h>
+
/**
* enum realm_state - State of a Realm
*/
@@ -46,11 +48,27 @@ enum realm_state {
* struct realm - Additional per VM data for a Realm
*
* @state: The lifetime state machine for the realm
+ * @rd: Kernel mapping of the Realm Descriptor (RD)
+ * @params: Parameters for the RMI_REALM_CREATE command
+ * @num_aux: The number of auxiliary pages required by the RMM
+ * @vmid: VMID to be used by the RMM for the realm
+ * @ia_bits: Number of valid Input Address bits in the IPA
*/
struct realm {
enum realm_state state;
+
+ void *rd;
+ struct realm_params *params;
+
+ unsigned long num_aux;
+ unsigned int vmid;
+ unsigned int ia_bits;
};
void kvm_init_rmi(void);
+u32 kvm_realm_ipa_limit(void);
+
+int kvm_init_realm_vm(struct kvm *kvm);
+void kvm_destroy_realm(struct kvm *kvm);
#endif /* __ASM_KVM_RMI_H */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index a537f56f97db..4ce3ad1d69b0 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -207,6 +207,13 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
bitmap_zero(kvm->arch.vcpu_features, KVM_VCPU_MAX_FEATURES);
+ /* Initialise the realm bits after the generic bits are enabled */
+ if (kvm_is_realm(kvm)) {
+ ret = kvm_init_realm_vm(kvm);
+ if (ret)
+ goto err_free_cpumask;
+ }
+
return 0;
err_free_cpumask:
@@ -266,6 +273,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
kvm_unshare_hyp(kvm, kvm + 1);
kvm_arm_teardown_hypercalls(kvm);
+ kvm_destroy_realm(kvm);
}
static bool kvm_has_full_ptr_auth(void)
@@ -427,6 +435,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
else
r = kvm_supports_cacheable_pfnmap();
break;
+ case KVM_CAP_ARM_RMI:
+ r = static_key_enabled(&kvm_rmi_is_available);
+ break;
default:
r = 0;
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 48d7c372a4cd..d91e7eb2c8d3 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -872,12 +872,16 @@ static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = {
.icache_inval_pou = invalidate_icache_guest_page,
};
-static int kvm_init_ipa_range(struct kvm_s2_mmu *mmu, unsigned long type)
+static int kvm_init_ipa_range(struct kvm *kvm,
+ struct kvm_s2_mmu *mmu, unsigned long type)
{
u32 kvm_ipa_limit = get_kvm_ipa_limit();
u64 mmfr0, mmfr1;
u32 phys_shift;
+ if (kvm_is_realm(kvm))
+ kvm_ipa_limit = kvm_realm_ipa_limit();
+
if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
return -EINVAL;
@@ -974,7 +978,7 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
return -EINVAL;
}
- err = kvm_init_ipa_range(mmu, type);
+ err = kvm_init_ipa_range(kvm, mmu, type);
if (err)
return err;
@@ -1113,7 +1117,8 @@ void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
write_unlock(&kvm->mmu_lock);
if (pgt) {
- kvm_stage2_destroy(pgt);
+ if (!kvm_is_realm(kvm))
+ kvm_stage2_destroy(pgt);
kfree(pgt);
}
}
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 629ace10cacc..c2b13fecfd11 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -5,9 +5,18 @@
#include <linux/kvm_host.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_mmu.h>
#include <asm/rmi_cmds.h>
#include <asm/virt.h>
+#include <asm/kvm_pgtable.h>
+
+static unsigned long rmm_feat_reg0;
+
+#define RMM_PAGE_SHIFT 12
+#define RMM_PAGE_SIZE BIT(RMM_PAGE_SHIFT)
+
static int rmi_check_version(void)
{
struct arm_smccc_res res;
@@ -47,6 +56,75 @@ static int rmi_check_version(void)
return 0;
}
+u32 kvm_realm_ipa_limit(void)
+{
+ return u64_get_bits(rmm_feat_reg0, RMI_FEATURE_REGISTER_0_S2SZ);
+}
+
+static int free_delegated_granule(phys_addr_t phys)
+{
+ if (WARN_ON(rmi_granule_undelegate(phys))) {
+ /* Undelegate failed: leak the page */
+ return -EBUSY;
+ }
+
+ free_page((unsigned long)phys_to_virt(phys));
+
+ return 0;
+}
+
+void kvm_destroy_realm(struct kvm *kvm)
+{
+ struct realm *realm = &kvm->arch.realm;
+ size_t pgd_size = kvm_pgtable_stage2_pgd_size(kvm->arch.mmu.vtcr);
+ int i;
+
+ write_lock(&kvm->mmu_lock);
+ kvm_stage2_unmap_range(&kvm->arch.mmu, 0,
+ BIT(realm->ia_bits - 1), true);
+ write_unlock(&kvm->mmu_lock);
+
+ if (realm->params) {
+ free_page((unsigned long)realm->params);
+ realm->params = NULL;
+ }
+
+ if (!kvm_realm_is_created(kvm))
+ return;
+
+ WRITE_ONCE(realm->state, REALM_STATE_DYING);
+
+ if (realm->rd) {
+ phys_addr_t rd_phys = virt_to_phys(realm->rd);
+
+ if (WARN_ON(rmi_realm_destroy(rd_phys)))
+ return;
+ free_delegated_granule(rd_phys);
+ realm->rd = NULL;
+ }
+
+ for (i = 0; i < pgd_size; i += RMM_PAGE_SIZE) {
+ phys_addr_t pgd_phys = kvm->arch.mmu.pgd_phys + i;
+
+ if (WARN_ON(rmi_granule_undelegate(pgd_phys)))
+ return;
+ }
+
+ WRITE_ONCE(realm->state, REALM_STATE_DEAD);
+
+ /* Now that the Realm is destroyed, free the entry level RTTs */
+ kvm_free_stage2_pgd(&kvm->arch.mmu);
+}
+
+int kvm_init_realm_vm(struct kvm *kvm)
+{
+ kvm->arch.realm.params = (void *)get_zeroed_page(GFP_KERNEL);
+
+ if (!kvm->arch.realm.params)
+ return -ENOMEM;
+ return 0;
+}
+
void kvm_init_rmi(void)
{
/* Only 4k page size on the host is supported */
@@ -57,5 +135,8 @@ void kvm_init_rmi(void)
if (rmi_check_version())
return;
+ if (WARN_ON(rmi_features(0, &rmm_feat_reg0)))
+ return;
+
/* Future patch will enable static branch kvm_rmi_is_available */
}
--
2.43.0
^ permalink raw reply related
* [PATCH v12 06/46] arm64: RMI: Define the user ABI
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
There is one CAP which identified the presence of CCA, and two ioctls.
One ioctl is used to populate memory and the other is used when user
space is providing the PSCI implementation to identify the target of the
operation.
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
* Completely reworked to be more implicit. Rather than having explicit
CAP operations to progress the realm construction these operations
are done when needed (on populating and on first vCPU run).
* Populate and PSCI complete are promoted to proper ioctls.
Changes since v10:
* Rename symbols from RME to RMI.
Changes since v9:
* Improvements to documentation.
* Bump the magic number for KVM_CAP_ARM_RME to avoid conflicts.
Changes since v8:
* Minor improvements to documentation following review.
* Bump the magic numbers to avoid conflicts.
Changes since v7:
* Add documentation of new ioctls
* Bump the magic numbers to avoid conflicts
Changes since v6:
* Rename some of the symbols to make their usage clearer and avoid
repetition.
Changes from v5:
* Actually expose the new VCPU capability (KVM_ARM_VCPU_REC) by bumping
KVM_VCPU_MAX_FEATURES - note this also exposes KVM_ARM_VCPU_HAS_EL2!
---
Documentation/virt/kvm/api.rst | 57 ++++++++++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 23 ++++++++++++++
2 files changed, 80 insertions(+)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 01a3abef8abb..2d5dc7e48954 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6517,6 +6517,54 @@ the capability to be present.
`flags` must currently be zero.
+4.144 KVM_ARM_VCPU_RMI_PSCI_COMPLETE
+------------------------------------
+
+:Capability: KVM_CAP_ARM_RMI
+:Architectures: arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_arm_rmi_psci_complete (in)
+:Returns: 0 if successful, < 0 on error
+
+::
+
+ struct kvm_arm_rmi_psci_complete {
+ __u64 target_mpidr;
+ __u32 psci_status;
+ __u32 padding[3];
+ };
+
+Where PSCI functions are handled by user space, the RMM needs to be informed of
+the target of the operation using `target_mpidr`, along with the status
+(`psci_status`). The RMM v1.0 specification defines two functions that require
+this call: PSCI_CPU_ON and PSCI_AFFINITY_INFO.
+
+If the kernel is handling PSCI then this is done automatically and the VMM
+doesn't need to call this ioctl.
+
+4.145 KVM_ARM_RMI_POPULATE
+--------------------------
+
+:Capability: KVM_CAP_ARM_RMI
+:Architectures: arm64
+:Type: vm ioctl
+:Parameters: struct kvm_arm_rmi_populate (in)
+:Returns: number of bytes populated, < 0 on error
+
+::
+
+ struct kvm_arm_rmi_populate {
+ __u64 base;
+ __u64 size;
+ __u64 source_uaddr;
+ __u32 flags;
+ __u32 reserved;
+ };
+
+Populate a region of protected address space by copying the data from the user
+space pointer provided. This is only valid before any VCPUs have been run.
+The ioctl might not populate the entire region and user space may have to
+repeatedly call it (with updated pointers) to populate the entire region.
.. _kvm_run:
@@ -8765,6 +8813,15 @@ helpful if user space wants to emulate instructions which are not
This capability can be enabled dynamically even if VCPUs were already
created and are running.
+7.47 KVM_CAP_ARM_RMI
+--------------------
+
+:Architectures: arm64
+:Target: VM
+:Parameters: None
+
+This capability indicates that support for CCA realms is available.
+
8. Other capabilities.
======================
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index dddb781b0507..8e66ba9c81db 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -974,6 +974,7 @@ struct kvm_enable_cap {
#define KVM_CAP_GUEST_MEMFD_FLAGS 244
#define KVM_CAP_ARM_SEA_TO_USER 245
#define KVM_CAP_S390_USER_OPEREXEC 246
+#define KVM_CAP_ARM_RMI 247
struct kvm_irq_routing_irqchip {
__u32 irqchip;
@@ -1628,4 +1629,26 @@ struct kvm_pre_fault_memory {
__u64 padding[5];
};
+/* Available with KVM_CAP_ARM_RMI, only for VMs with KVM_VM_TYPE_ARM_REALM */
+struct kvm_arm_rmi_psci_complete {
+ __u64 target_mpidr;
+ __u32 psci_status;
+ __u32 padding[3];
+};
+
+#define KVM_ARM_VCPU_RMI_PSCI_COMPLETE _IOW(KVMIO, 0xd6, struct kvm_arm_rmi_psci_complete)
+
+/* Available with KVM_CAP_ARM_RMI, only for VMs with KVM_VM_TYPE_ARM_REALM */
+struct kvm_arm_rmi_populate {
+ __u64 base;
+ __u64 size;
+ __u64 source_uaddr;
+ __u32 flags;
+ __u32 reserved;
+};
+
+#define KVM_ARM_RMI_POPULATE_FLAGS_MEASURE (1 << 0)
+
+#define KVM_ARM_RMI_POPULATE _IOW(KVMIO, 0xd7, struct kvm_arm_rmi_populate)
+
#endif /* __LINUX_KVM_H */
--
2.43.0
^ permalink raw reply related
* [PATCH v12 05/46] arm64: RMI: Check for RMI support at KVM init
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
Query the RMI version number and check if it is a compatible version. A
static key is also provided to signal that a supported RMM is available.
Functions are provided to query if a VM or VCPU is a realm (or rec)
which currently will always return false.
Later patches make use of struct realm and the states as the ioctls
interfaces are added to support realm and REC creation and destruction.
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
* Reword slightly the comments on the realm states.
Changes since v10:
* kvm_is_realm() no longer has a NULL check.
* Rename from "rme" to "rmi" when referring to the RMM interface.
* Check for RME (hardware) support before probing for RMI support.
Changes since v8:
* No need to guard kvm_init_rme() behind 'in_hyp_mode'.
Changes since v6:
* Improved message for an unsupported RMI ABI version.
Changes since v5:
* Reword "unsupported" message from "host supports" to "we want" to
clarify that 'we' are the 'host'.
Changes since v2:
* Drop return value from kvm_init_rme(), it was always 0.
* Rely on the RMM return value to identify whether the RSI ABI is
compatible.
---
arch/arm64/include/asm/kvm_emulate.h | 18 ++++++++
arch/arm64/include/asm/kvm_host.h | 4 ++
arch/arm64/include/asm/kvm_rmi.h | 56 +++++++++++++++++++++++++
arch/arm64/include/asm/virt.h | 1 +
arch/arm64/kernel/cpufeature.c | 1 +
arch/arm64/kvm/Makefile | 2 +-
arch/arm64/kvm/arm.c | 5 +++
arch/arm64/kvm/rmi.c | 61 ++++++++++++++++++++++++++++
8 files changed, 147 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/include/asm/kvm_rmi.h
create mode 100644 arch/arm64/kvm/rmi.c
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index c9eab316398e..67f75678e489 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -696,4 +696,22 @@ static inline void vcpu_set_hcrx(struct kvm_vcpu *vcpu)
vcpu->arch.hcrx_el2 |= HCRX_EL2_SCTLR2En;
}
}
+
+static inline bool kvm_is_realm(struct kvm *kvm)
+{
+ if (static_branch_unlikely(&kvm_rmi_is_available))
+ return kvm->arch.is_realm;
+ return false;
+}
+
+static inline enum realm_state kvm_realm_state(struct kvm *kvm)
+{
+ return READ_ONCE(kvm->arch.realm.state);
+}
+
+static inline bool vcpu_is_rec(struct kvm_vcpu *vcpu)
+{
+ return false;
+}
+
#endif /* __ARM64_KVM_EMULATE_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index ac7f970c7883..da913fee70b6 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -27,6 +27,7 @@
#include <asm/fpsimd.h>
#include <asm/kvm.h>
#include <asm/kvm_asm.h>
+#include <asm/kvm_rmi.h>
#include <asm/vncr_mapping.h>
#define __KVM_HAVE_ARCH_INTC_INITIALIZED
@@ -408,6 +409,9 @@ struct kvm_arch {
* the associated pKVM instance in the hypervisor.
*/
struct kvm_protected_vm pkvm;
+
+ bool is_realm;
+ struct realm realm;
};
struct kvm_vcpu_fault_info {
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
new file mode 100644
index 000000000000..3506f50b05cd
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023-2025 ARM Ltd.
+ */
+
+#ifndef __ASM_KVM_RMI_H
+#define __ASM_KVM_RMI_H
+
+/**
+ * enum realm_state - State of a Realm
+ */
+enum realm_state {
+ /**
+ * @REALM_STATE_NONE:
+ * Realm has not yet been created. rmi_realm_create() has not
+ * yet been called.
+ */
+ REALM_STATE_NONE,
+ /**
+ * @REALM_STATE_NEW:
+ * Realm is under construction, rmi_realm_create() has been
+ * called, but it is not yet activated. Pages may be populated.
+ */
+ REALM_STATE_NEW,
+ /**
+ * @REALM_STATE_ACTIVE:
+ * Realm has been created and is eligible for execution with
+ * rmi_rec_enter(). Pages may no longer be populated with
+ * rmi_data_create().
+ */
+ REALM_STATE_ACTIVE,
+ /**
+ * @REALM_STATE_DYING:
+ * Realm is in the process of being destroyed or has already been
+ * destroyed.
+ */
+ REALM_STATE_DYING,
+ /**
+ * @REALM_STATE_DEAD:
+ * Realm has been destroyed.
+ */
+ REALM_STATE_DEAD
+};
+
+/**
+ * struct realm - Additional per VM data for a Realm
+ *
+ * @state: The lifetime state machine for the realm
+ */
+struct realm {
+ enum realm_state state;
+};
+
+void kvm_init_rmi(void);
+
+#endif /* __ASM_KVM_RMI_H */
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index b51ab6840f9c..dc9b2899e0b2 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -87,6 +87,7 @@ void __hyp_reset_vectors(void);
bool is_kvm_arm_initialised(void);
DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
+DECLARE_STATIC_KEY_FALSE(kvm_rmi_is_available);
static inline bool is_pkvm_initialized(void)
{
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c840a93b9ef9..fa5ef83af7de 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -288,6 +288,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar3[] = {
static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV3_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV2_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_RME_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_DIT_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_AMU_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_MPAM_SHIFT, 4, 0),
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 3ebc0570345c..e17c4077d8e7 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -16,7 +16,7 @@ CFLAGS_handle_exit.o += -Wno-override-init
kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \
inject_fault.o va_layout.o handle_exit.o config.o \
guest.o debug.o reset.o sys_regs.o stacktrace.o \
- vgic-sys-reg-v3.o fpsimd.o pkvm.o \
+ vgic-sys-reg-v3.o fpsimd.o pkvm.o rmi.o \
arch_timer.o trng.o vmid.o emulate-nested.o nested.o at.o \
vgic/vgic.o vgic/vgic-init.o \
vgic/vgic-irqfd.o vgic/vgic-v2.o \
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 4f80da0c0d1d..a537f56f97db 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -39,6 +39,7 @@
#include <asm/kvm_nested.h>
#include <asm/kvm_pkvm.h>
#include <asm/kvm_ptrauth.h>
+#include <asm/kvm_rmi.h>
#include <asm/sections.h>
#include <kvm/arm_hypercalls.h>
@@ -58,6 +59,8 @@ enum kvm_wfx_trap_policy {
static enum kvm_wfx_trap_policy kvm_wfi_trap_policy __read_mostly = KVM_WFX_NOTRAP_SINGLE_TASK;
static enum kvm_wfx_trap_policy kvm_wfe_trap_policy __read_mostly = KVM_WFX_NOTRAP_SINGLE_TASK;
+DEFINE_STATIC_KEY_FALSE(kvm_rmi_is_available);
+
DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_base);
@@ -2865,6 +2868,8 @@ static __init int kvm_arm_init(void)
in_hyp_mode = is_kernel_in_hyp_mode();
+ kvm_init_rmi();
+
if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||
cpus_have_final_cap(ARM64_WORKAROUND_1508412))
kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
new file mode 100644
index 000000000000..629ace10cacc
--- /dev/null
+++ b/arch/arm64/kvm/rmi.c
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023-2025 ARM Ltd.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <asm/rmi_cmds.h>
+#include <asm/virt.h>
+
+static int rmi_check_version(void)
+{
+ struct arm_smccc_res res;
+ unsigned short version_major, version_minor;
+ unsigned long host_version = RMI_ABI_VERSION(RMI_ABI_MAJOR_VERSION,
+ RMI_ABI_MINOR_VERSION);
+ unsigned long aa64pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
+
+ /* If RME isn't supported, then RMI can't be */
+ if (cpuid_feature_extract_unsigned_field(aa64pfr0, ID_AA64PFR0_EL1_RME_SHIFT) == 0)
+ return -ENXIO;
+
+ arm_smccc_1_1_invoke(SMC_RMI_VERSION, host_version, &res);
+
+ if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+ return -ENXIO;
+
+ version_major = RMI_ABI_VERSION_GET_MAJOR(res.a1);
+ version_minor = RMI_ABI_VERSION_GET_MINOR(res.a1);
+
+ if (res.a0 != RMI_SUCCESS) {
+ unsigned short high_version_major, high_version_minor;
+
+ high_version_major = RMI_ABI_VERSION_GET_MAJOR(res.a2);
+ high_version_minor = RMI_ABI_VERSION_GET_MINOR(res.a2);
+
+ kvm_err("Unsupported RMI ABI (v%d.%d - v%d.%d) we want v%d.%d\n",
+ version_major, version_minor,
+ high_version_major, high_version_minor,
+ RMI_ABI_MAJOR_VERSION,
+ RMI_ABI_MINOR_VERSION);
+ return -ENXIO;
+ }
+
+ kvm_info("RMI ABI version %d.%d\n", version_major, version_minor);
+
+ return 0;
+}
+
+void kvm_init_rmi(void)
+{
+ /* Only 4k page size on the host is supported */
+ if (PAGE_SIZE != SZ_4K)
+ return;
+
+ /* Continue without realm support if we can't agree on a version */
+ if (rmi_check_version())
+ return;
+
+ /* Future patch will enable static branch kvm_rmi_is_available */
+}
--
2.43.0
^ permalink raw reply related
* [PATCH v12 04/46] arm64: RMI: Add wrappers for RMI calls
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
The wrappers make the call sites easier to read and deal with the
boiler plate of handling the error codes from the RMM.
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes from v8:
* Switch from arm_smccc_1_2_smc() to arm_smccc_1_2_invoke() in
rmi_rtt_read_entry() for consistency.
Changes from v7:
* Minor renaming of parameters and updated comments
Changes from v5:
* Further improve comments
Changes from v4:
* Improve comments
Changes from v2:
* Make output arguments optional.
* Mask RIPAS value rmi_rtt_read_entry()
* Drop unused rmi_rtt_get_phys()
---
arch/arm64/include/asm/rmi_cmds.h | 508 ++++++++++++++++++++++++++++++
1 file changed, 508 insertions(+)
create mode 100644 arch/arm64/include/asm/rmi_cmds.h
diff --git a/arch/arm64/include/asm/rmi_cmds.h b/arch/arm64/include/asm/rmi_cmds.h
new file mode 100644
index 000000000000..ef53147c1984
--- /dev/null
+++ b/arch/arm64/include/asm/rmi_cmds.h
@@ -0,0 +1,508 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023 ARM Ltd.
+ */
+
+#ifndef __ASM_RMI_CMDS_H
+#define __ASM_RMI_CMDS_H
+
+#include <linux/arm-smccc.h>
+
+#include <asm/rmi_smc.h>
+
+struct rtt_entry {
+ unsigned long walk_level;
+ unsigned long desc;
+ int state;
+ int ripas;
+};
+
+/**
+ * rmi_data_create() - Create a data granule
+ * @rd: PA of the RD
+ * @data: PA of the target granule
+ * @ipa: IPA at which the granule will be mapped in the guest
+ * @src: PA of the source granule
+ * @flags: RMI_MEASURE_CONTENT if the contents should be measured
+ *
+ * Create a new data granule, copying contents from a non-secure granule.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_data_create(unsigned long rd, unsigned long data,
+ unsigned long ipa, unsigned long src,
+ unsigned long flags)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_DATA_CREATE, rd, data, ipa, src,
+ flags, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_data_create_unknown() - Create a data granule with unknown contents
+ * @rd: PA of the RD
+ * @data: PA of the target granule
+ * @ipa: IPA at which the granule will be mapped in the guest
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_data_create_unknown(unsigned long rd,
+ unsigned long data,
+ unsigned long ipa)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_DATA_CREATE_UNKNOWN, rd, data, ipa, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_data_destroy() - Destroy a data granule
+ * @rd: PA of the RD
+ * @ipa: IPA at which the granule is mapped in the guest
+ * @data_out: PA of the granule which was destroyed
+ * @top_out: Top IPA of non-live RTT entries
+ *
+ * Unmap a protected IPA from stage 2, transitioning it to DESTROYED.
+ * The IPA cannot be used by the guest unless it is transitioned to RAM again
+ * by the realm guest.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_data_destroy(unsigned long rd, unsigned long ipa,
+ unsigned long *data_out,
+ unsigned long *top_out)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_DATA_DESTROY, rd, ipa, &res);
+
+ if (data_out)
+ *data_out = res.a1;
+ if (top_out)
+ *top_out = res.a2;
+
+ return res.a0;
+}
+
+/**
+ * rmi_features() - Read feature register
+ * @index: Feature register index
+ * @out: Feature register value is written to this pointer
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_features(unsigned long index, unsigned long *out)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_FEATURES, index, &res);
+
+ if (out)
+ *out = res.a1;
+ return res.a0;
+}
+
+/**
+ * rmi_granule_delegate() - Delegate a granule
+ * @phys: PA of the granule
+ *
+ * Delegate a granule for use by the realm world.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_granule_delegate(unsigned long phys)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_GRANULE_DELEGATE, phys, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_granule_undelegate() - Undelegate a granule
+ * @phys: PA of the granule
+ *
+ * Undelegate a granule to allow use by the normal world. Will fail if the
+ * granule is in use.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_granule_undelegate(unsigned long phys)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_GRANULE_UNDELEGATE, phys, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_psci_complete() - Complete pending PSCI command
+ * @calling_rec: PA of the calling REC
+ * @target_rec: PA of the target REC
+ * @status: Status of the PSCI request
+ *
+ * Completes a pending PSCI command which was called with an MPIDR argument, by
+ * providing the corresponding REC.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_psci_complete(unsigned long calling_rec,
+ unsigned long target_rec,
+ unsigned long status)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_PSCI_COMPLETE, calling_rec, target_rec,
+ status, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_realm_activate() - Active a realm
+ * @rd: PA of the RD
+ *
+ * Mark a realm as Active signalling that creation is complete and allowing
+ * execution of the realm.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_realm_activate(unsigned long rd)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_REALM_ACTIVATE, rd, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_realm_create() - Create a realm
+ * @rd: PA of the RD
+ * @params: PA of realm parameters
+ *
+ * Create a new realm using the given parameters.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_realm_create(unsigned long rd, unsigned long params)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_REALM_CREATE, rd, params, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_realm_destroy() - Destroy a realm
+ * @rd: PA of the RD
+ *
+ * Destroys a realm, all objects belonging to the realm must be destroyed first.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_realm_destroy(unsigned long rd)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_REALM_DESTROY, rd, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_rec_aux_count() - Get number of auxiliary granules required
+ * @rd: PA of the RD
+ * @aux_count: Number of granules written to this pointer
+ *
+ * A REC may require extra auxiliary granules to be delegated for the RMM to
+ * store metadata (not visible to the normal world) in. This function provides
+ * the number of granules that are required.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rec_aux_count(unsigned long rd, unsigned long *aux_count)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_REC_AUX_COUNT, rd, &res);
+
+ if (aux_count)
+ *aux_count = res.a1;
+ return res.a0;
+}
+
+/**
+ * rmi_rec_create() - Create a REC
+ * @rd: PA of the RD
+ * @rec: PA of the target REC
+ * @params: PA of REC parameters
+ *
+ * Create a REC using the parameters specified in the struct rec_params pointed
+ * to by @params.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rec_create(unsigned long rd, unsigned long rec,
+ unsigned long params)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_REC_CREATE, rd, rec, params, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_rec_destroy() - Destroy a REC
+ * @rec: PA of the target REC
+ *
+ * Destroys a REC. The REC must not be running.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rec_destroy(unsigned long rec)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_REC_DESTROY, rec, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_rec_enter() - Enter a REC
+ * @rec: PA of the target REC
+ * @run_ptr: PA of RecRun structure
+ *
+ * Starts (or continues) execution within a REC.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rec_enter(unsigned long rec, unsigned long run_ptr)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_REC_ENTER, rec, run_ptr, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_rtt_create() - Creates an RTT
+ * @rd: PA of the RD
+ * @rtt: PA of the target RTT
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ *
+ * Creates an RTT (Realm Translation Table) at the specified level for the
+ * translation of the specified address within the realm.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_create(unsigned long rd, unsigned long rtt,
+ unsigned long ipa, long level)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_RTT_CREATE, rd, rtt, ipa, level, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_rtt_destroy() - Destroy an RTT
+ * @rd: PA of the RD
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ * @out_rtt: Pointer to write the PA of the RTT which was destroyed
+ * @out_top: Pointer to write the top IPA of non-live RTT entries
+ *
+ * Destroys an RTT. The RTT must be non-live, i.e. none of the entries in the
+ * table are in ASSIGNED or TABLE state.
+ *
+ * Return: RMI return code.
+ */
+static inline int rmi_rtt_destroy(unsigned long rd,
+ unsigned long ipa,
+ long level,
+ unsigned long *out_rtt,
+ unsigned long *out_top)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_RTT_DESTROY, rd, ipa, level, &res);
+
+ if (out_rtt)
+ *out_rtt = res.a1;
+ if (out_top)
+ *out_top = res.a2;
+
+ return res.a0;
+}
+
+/**
+ * rmi_rtt_fold() - Fold an RTT
+ * @rd: PA of the RD
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ * @out_rtt: Pointer to write the PA of the RTT which was destroyed
+ *
+ * Folds an RTT. If all entries with the RTT are 'homogeneous' the RTT can be
+ * folded into the parent and the RTT destroyed.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_fold(unsigned long rd, unsigned long ipa,
+ long level, unsigned long *out_rtt)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_RTT_FOLD, rd, ipa, level, &res);
+
+ if (out_rtt)
+ *out_rtt = res.a1;
+
+ return res.a0;
+}
+
+/**
+ * rmi_rtt_init_ripas() - Set RIPAS for new realm
+ * @rd: PA of the RD
+ * @base: Base of target IPA region
+ * @top: Top of target IPA region
+ * @out_top: Top IPA of range whose RIPAS was modified
+ *
+ * Sets the RIPAS of a target IPA range to RAM, for a realm in the NEW state.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_init_ripas(unsigned long rd, unsigned long base,
+ unsigned long top, unsigned long *out_top)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_RTT_INIT_RIPAS, rd, base, top, &res);
+
+ if (out_top)
+ *out_top = res.a1;
+
+ return res.a0;
+}
+
+/**
+ * rmi_rtt_map_unprotected() - Map NS granules into a realm
+ * @rd: PA of the RD
+ * @ipa: Base IPA of the mapping
+ * @level: Depth within the RTT tree
+ * @desc: RTTE descriptor
+ *
+ * Create a mapping from an Unprotected IPA to a Non-secure PA.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_map_unprotected(unsigned long rd,
+ unsigned long ipa,
+ long level,
+ unsigned long desc)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_RTT_MAP_UNPROTECTED, rd, ipa, level,
+ desc, &res);
+
+ return res.a0;
+}
+
+/**
+ * rmi_rtt_read_entry() - Read an RTTE
+ * @rd: PA of the RD
+ * @ipa: IPA for which to read the RTTE
+ * @level: RTT level at which to read the RTTE
+ * @rtt: Output structure describing the RTTE
+ *
+ * Reads a RTTE (Realm Translation Table Entry).
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_read_entry(unsigned long rd, unsigned long ipa,
+ long level, struct rtt_entry *rtt)
+{
+ struct arm_smccc_1_2_regs regs = {
+ SMC_RMI_RTT_READ_ENTRY,
+ rd, ipa, level
+ };
+
+ arm_smccc_1_2_invoke(®s, ®s);
+
+ rtt->walk_level = regs.a1;
+ rtt->state = regs.a2 & 0xFF;
+ rtt->desc = regs.a3;
+ rtt->ripas = regs.a4 & 0xFF;
+
+ return regs.a0;
+}
+
+/**
+ * rmi_rtt_set_ripas() - Set RIPAS for an running realm
+ * @rd: PA of the RD
+ * @rec: PA of the REC making the request
+ * @base: Base of target IPA region
+ * @top: Top of target IPA region
+ * @out_top: Pointer to write top IPA of range whose RIPAS was modified
+ *
+ * Completes a request made by the realm to change the RIPAS of a target IPA
+ * range.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_set_ripas(unsigned long rd, unsigned long rec,
+ unsigned long base, unsigned long top,
+ unsigned long *out_top)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_RTT_SET_RIPAS, rd, rec, base, top, &res);
+
+ if (out_top)
+ *out_top = res.a1;
+
+ return res.a0;
+}
+
+/**
+ * rmi_rtt_unmap_unprotected() - Remove a NS mapping
+ * @rd: PA of the RD
+ * @ipa: Base IPA of the mapping
+ * @level: Depth within the RTT tree
+ * @out_top: Pointer to write top IPA of non-live RTT entries
+ *
+ * Removes a mapping at an Unprotected IPA.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rtt_unmap_unprotected(unsigned long rd,
+ unsigned long ipa,
+ long level,
+ unsigned long *out_top)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_invoke(SMC_RMI_RTT_UNMAP_UNPROTECTED, rd, ipa,
+ level, &res);
+
+ if (out_top)
+ *out_top = res.a1;
+
+ return res.a0;
+}
+
+#endif /* __ASM_RMI_CMDS_H */
--
2.43.0
^ permalink raw reply related
* [PATCH v12 03/46] arm64: RMI: Add SMC definitions for calling the RMM
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
The RMM (Realm Management Monitor) provides functionality that can be
accessed by SMC calls from the host.
The SMC definitions are based on DEN0137[1] version 1.0-rel0
[1] https://developer.arm.com/documentation/den0137/1-0rel0/
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v9:
* Corrected size of 'ripas_value' in struct rec_exit. The spec states
this is an 8-bit type with padding afterwards (rather than a u64).
Changes since v8:
* Added RMI_PERMITTED_GICV3_HCR_BITS to define which bits the RMM
permits to be modified.
Changes since v6:
* Renamed REC_ENTER_xxx defines to include 'FLAG' to make it obvious
these are flag values.
Changes since v5:
* Sorted the SMC #defines by value.
* Renamed SMI_RxI_CALL to SMI_RMI_CALL since the macro is only used for
RMI calls.
* Renamed REC_GIC_NUM_LRS to REC_MAX_GIC_NUM_LRS since the actual
number of available list registers could be lower.
* Provided a define for the reserved fields of FeatureRegister0.
* Fix inconsistent names for padding fields.
Changes since v4:
* Update to point to final released RMM spec.
* Minor rearrangements.
Changes since v3:
* Update to match RMM spec v1.0-rel0-rc1.
Changes since v2:
* Fix specification link.
* Rename rec_entry->rec_enter to match spec.
* Fix size of pmu_ovf_status to match spec.
---
arch/arm64/include/asm/rmi_smc.h | 269 +++++++++++++++++++++++++++++++
1 file changed, 269 insertions(+)
create mode 100644 arch/arm64/include/asm/rmi_smc.h
diff --git a/arch/arm64/include/asm/rmi_smc.h b/arch/arm64/include/asm/rmi_smc.h
new file mode 100644
index 000000000000..1000368f1bca
--- /dev/null
+++ b/arch/arm64/include/asm/rmi_smc.h
@@ -0,0 +1,269 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023-2024 ARM Ltd.
+ *
+ * The values and structures in this file are from the Realm Management Monitor
+ * specification (DEN0137) version 1.0-rel0:
+ * https://developer.arm.com/documentation/den0137/1-0rel0/
+ */
+
+#ifndef __ASM_RMI_SMC_H
+#define __ASM_RMI_SMC_H
+
+#include <linux/arm-smccc.h>
+
+#define SMC_RMI_CALL(func) \
+ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+ ARM_SMCCC_SMC_64, \
+ ARM_SMCCC_OWNER_STANDARD, \
+ (func))
+
+#define SMC_RMI_VERSION SMC_RMI_CALL(0x0150)
+#define SMC_RMI_GRANULE_DELEGATE SMC_RMI_CALL(0x0151)
+#define SMC_RMI_GRANULE_UNDELEGATE SMC_RMI_CALL(0x0152)
+#define SMC_RMI_DATA_CREATE SMC_RMI_CALL(0x0153)
+#define SMC_RMI_DATA_CREATE_UNKNOWN SMC_RMI_CALL(0x0154)
+#define SMC_RMI_DATA_DESTROY SMC_RMI_CALL(0x0155)
+
+#define SMC_RMI_REALM_ACTIVATE SMC_RMI_CALL(0x0157)
+#define SMC_RMI_REALM_CREATE SMC_RMI_CALL(0x0158)
+#define SMC_RMI_REALM_DESTROY SMC_RMI_CALL(0x0159)
+#define SMC_RMI_REC_CREATE SMC_RMI_CALL(0x015a)
+#define SMC_RMI_REC_DESTROY SMC_RMI_CALL(0x015b)
+#define SMC_RMI_REC_ENTER SMC_RMI_CALL(0x015c)
+#define SMC_RMI_RTT_CREATE SMC_RMI_CALL(0x015d)
+#define SMC_RMI_RTT_DESTROY SMC_RMI_CALL(0x015e)
+#define SMC_RMI_RTT_MAP_UNPROTECTED SMC_RMI_CALL(0x015f)
+
+#define SMC_RMI_RTT_READ_ENTRY SMC_RMI_CALL(0x0161)
+#define SMC_RMI_RTT_UNMAP_UNPROTECTED SMC_RMI_CALL(0x0162)
+
+#define SMC_RMI_PSCI_COMPLETE SMC_RMI_CALL(0x0164)
+#define SMC_RMI_FEATURES SMC_RMI_CALL(0x0165)
+#define SMC_RMI_RTT_FOLD SMC_RMI_CALL(0x0166)
+#define SMC_RMI_REC_AUX_COUNT SMC_RMI_CALL(0x0167)
+#define SMC_RMI_RTT_INIT_RIPAS SMC_RMI_CALL(0x0168)
+#define SMC_RMI_RTT_SET_RIPAS SMC_RMI_CALL(0x0169)
+
+#define RMI_ABI_MAJOR_VERSION 1
+#define RMI_ABI_MINOR_VERSION 0
+
+#define RMI_ABI_VERSION_GET_MAJOR(version) ((version) >> 16)
+#define RMI_ABI_VERSION_GET_MINOR(version) ((version) & 0xFFFF)
+#define RMI_ABI_VERSION(major, minor) (((major) << 16) | (minor))
+
+#define RMI_UNASSIGNED 0
+#define RMI_ASSIGNED 1
+#define RMI_TABLE 2
+
+#define RMI_RETURN_STATUS(ret) ((ret) & 0xFF)
+#define RMI_RETURN_INDEX(ret) (((ret) >> 8) & 0xFF)
+
+#define RMI_SUCCESS 0
+#define RMI_ERROR_INPUT 1
+#define RMI_ERROR_REALM 2
+#define RMI_ERROR_REC 3
+#define RMI_ERROR_RTT 4
+
+enum rmi_ripas {
+ RMI_EMPTY = 0,
+ RMI_RAM = 1,
+ RMI_DESTROYED = 2,
+};
+
+#define RMI_NO_MEASURE_CONTENT 0
+#define RMI_MEASURE_CONTENT 1
+
+#define RMI_FEATURE_REGISTER_0_S2SZ GENMASK(7, 0)
+#define RMI_FEATURE_REGISTER_0_LPA2 BIT(8)
+#define RMI_FEATURE_REGISTER_0_SVE_EN BIT(9)
+#define RMI_FEATURE_REGISTER_0_SVE_VL GENMASK(13, 10)
+#define RMI_FEATURE_REGISTER_0_NUM_BPS GENMASK(19, 14)
+#define RMI_FEATURE_REGISTER_0_NUM_WPS GENMASK(25, 20)
+#define RMI_FEATURE_REGISTER_0_PMU_EN BIT(26)
+#define RMI_FEATURE_REGISTER_0_PMU_NUM_CTRS GENMASK(31, 27)
+#define RMI_FEATURE_REGISTER_0_HASH_SHA_256 BIT(32)
+#define RMI_FEATURE_REGISTER_0_HASH_SHA_512 BIT(33)
+#define RMI_FEATURE_REGISTER_0_GICV3_NUM_LRS GENMASK(37, 34)
+#define RMI_FEATURE_REGISTER_0_MAX_RECS_ORDER GENMASK(41, 38)
+#define RMI_FEATURE_REGISTER_0_Reserved GENMASK(63, 42)
+
+#define RMI_REALM_PARAM_FLAG_LPA2 BIT(0)
+#define RMI_REALM_PARAM_FLAG_SVE BIT(1)
+#define RMI_REALM_PARAM_FLAG_PMU BIT(2)
+
+/*
+ * Note many of these fields are smaller than u64 but all fields have u64
+ * alignment, so use u64 to ensure correct alignment.
+ */
+struct realm_params {
+ union { /* 0x0 */
+ struct {
+ u64 flags;
+ u64 s2sz;
+ u64 sve_vl;
+ u64 num_bps;
+ u64 num_wps;
+ u64 pmu_num_ctrs;
+ u64 hash_algo;
+ };
+ u8 padding0[0x400];
+ };
+ union { /* 0x400 */
+ u8 rpv[64];
+ u8 padding1[0x400];
+ };
+ union { /* 0x800 */
+ struct {
+ u64 vmid;
+ u64 rtt_base;
+ s64 rtt_level_start;
+ u64 rtt_num_start;
+ };
+ u8 padding2[0x800];
+ };
+};
+
+/*
+ * The number of GPRs (starting from X0) that are
+ * configured by the host when a REC is created.
+ */
+#define REC_CREATE_NR_GPRS 8
+
+#define REC_PARAMS_FLAG_RUNNABLE BIT_ULL(0)
+
+#define REC_PARAMS_AUX_GRANULES 16
+
+struct rec_params {
+ union { /* 0x0 */
+ u64 flags;
+ u8 padding0[0x100];
+ };
+ union { /* 0x100 */
+ u64 mpidr;
+ u8 padding1[0x100];
+ };
+ union { /* 0x200 */
+ u64 pc;
+ u8 padding2[0x100];
+ };
+ union { /* 0x300 */
+ u64 gprs[REC_CREATE_NR_GPRS];
+ u8 padding3[0x500];
+ };
+ union { /* 0x800 */
+ struct {
+ u64 num_rec_aux;
+ u64 aux[REC_PARAMS_AUX_GRANULES];
+ };
+ u8 padding4[0x800];
+ };
+};
+
+#define REC_ENTER_FLAG_EMULATED_MMIO BIT(0)
+#define REC_ENTER_FLAG_INJECT_SEA BIT(1)
+#define REC_ENTER_FLAG_TRAP_WFI BIT(2)
+#define REC_ENTER_FLAG_TRAP_WFE BIT(3)
+#define REC_ENTER_FLAG_RIPAS_RESPONSE BIT(4)
+
+#define REC_RUN_GPRS 31
+#define REC_MAX_GIC_NUM_LRS 16
+
+#define RMI_PERMITTED_GICV3_HCR_BITS (ICH_HCR_EL2_UIE | \
+ ICH_HCR_EL2_LRENPIE | \
+ ICH_HCR_EL2_NPIE | \
+ ICH_HCR_EL2_VGrp0EIE | \
+ ICH_HCR_EL2_VGrp0DIE | \
+ ICH_HCR_EL2_VGrp1EIE | \
+ ICH_HCR_EL2_VGrp1DIE | \
+ ICH_HCR_EL2_TDIR)
+
+struct rec_enter {
+ union { /* 0x000 */
+ u64 flags;
+ u8 padding0[0x200];
+ };
+ union { /* 0x200 */
+ u64 gprs[REC_RUN_GPRS];
+ u8 padding1[0x100];
+ };
+ union { /* 0x300 */
+ struct {
+ u64 gicv3_hcr;
+ u64 gicv3_lrs[REC_MAX_GIC_NUM_LRS];
+ };
+ u8 padding2[0x100];
+ };
+ u8 padding3[0x400];
+};
+
+#define RMI_EXIT_SYNC 0x00
+#define RMI_EXIT_IRQ 0x01
+#define RMI_EXIT_FIQ 0x02
+#define RMI_EXIT_PSCI 0x03
+#define RMI_EXIT_RIPAS_CHANGE 0x04
+#define RMI_EXIT_HOST_CALL 0x05
+#define RMI_EXIT_SERROR 0x06
+
+struct rec_exit {
+ union { /* 0x000 */
+ u8 exit_reason;
+ u8 padding0[0x100];
+ };
+ union { /* 0x100 */
+ struct {
+ u64 esr;
+ u64 far;
+ u64 hpfar;
+ };
+ u8 padding1[0x100];
+ };
+ union { /* 0x200 */
+ u64 gprs[REC_RUN_GPRS];
+ u8 padding2[0x100];
+ };
+ union { /* 0x300 */
+ struct {
+ u64 gicv3_hcr;
+ u64 gicv3_lrs[REC_MAX_GIC_NUM_LRS];
+ u64 gicv3_misr;
+ u64 gicv3_vmcr;
+ };
+ u8 padding3[0x100];
+ };
+ union { /* 0x400 */
+ struct {
+ u64 cntp_ctl;
+ u64 cntp_cval;
+ u64 cntv_ctl;
+ u64 cntv_cval;
+ };
+ u8 padding4[0x100];
+ };
+ union { /* 0x500 */
+ struct {
+ u64 ripas_base;
+ u64 ripas_top;
+ u8 ripas_value;
+ u8 padding8[7];
+ };
+ u8 padding5[0x100];
+ };
+ union { /* 0x600 */
+ u16 imm;
+ u8 padding6[0x100];
+ };
+ union { /* 0x700 */
+ struct {
+ u8 pmu_ovf_status;
+ };
+ u8 padding7[0x100];
+ };
+};
+
+struct rec_run {
+ struct rec_enter enter;
+ struct rec_exit exit;
+};
+
+#endif /* __ASM_RMI_SMC_H */
--
2.43.0
^ permalink raw reply related
* [PATCH v12 02/46] arm64: RME: Handle Granule Protection Faults (GPFs)
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
If the host attempts to access granules that have been delegated for use
in a realm these accesses will be caught and will trigger a Granule
Protection Fault (GPF).
A fault during a page walk signals a bug in the kernel and is handled by
oopsing the kernel. A non-page walk fault could be caused by user space
having access to a page which has been delegated to the kernel and will
trigger a SIGBUS to allow debugging why user space is trying to access a
delegated page.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v10:
* Don't call arm64_notify_die() in do_gpf() but simply return 1.
Changes since v2:
* Include missing "Granule Protection Fault at level -1"
---
arch/arm64/mm/fault.c | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index be9dab2c7d6a..13b1d5de6d77 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -858,6 +858,22 @@ static int do_tag_check_fault(unsigned long far, unsigned long esr,
return 0;
}
+static int do_gpf_ptw(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+ const struct fault_info *inf = esr_to_fault_info(esr);
+
+ die_kernel_fault(inf->name, far, esr, regs);
+ return 0;
+}
+
+static int do_gpf(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+ if (!is_el1_instruction_abort(esr) && fixup_exception(regs, esr))
+ return 0;
+
+ return 1;
+}
+
static const struct fault_info fault_info[] = {
{ do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" },
{ do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" },
@@ -894,12 +910,12 @@ static const struct fault_info fault_info[] = {
{ do_bad, SIGKILL, SI_KERNEL, "unknown 32" },
{ do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 34" },
- { do_bad, SIGKILL, SI_KERNEL, "unknown 35" },
- { do_bad, SIGKILL, SI_KERNEL, "unknown 36" },
- { do_bad, SIGKILL, SI_KERNEL, "unknown 37" },
- { do_bad, SIGKILL, SI_KERNEL, "unknown 38" },
- { do_bad, SIGKILL, SI_KERNEL, "unknown 39" },
- { do_bad, SIGKILL, SI_KERNEL, "unknown 40" },
+ { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level -1" },
+ { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 0" },
+ { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 1" },
+ { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 2" },
+ { do_gpf_ptw, SIGKILL, SI_KERNEL, "Granule Protection Fault at level 3" },
+ { do_gpf, SIGBUS, SI_KERNEL, "Granule Protection Fault not on table walk" },
{ do_bad, SIGKILL, SI_KERNEL, "level -1 address size fault" },
{ do_bad, SIGKILL, SI_KERNEL, "unknown 42" },
{ do_translation_fault, SIGSEGV, SEGV_MAPERR, "level -1 translation fault" },
--
2.43.0
^ permalink raw reply related
* [PATCH v12 01/46] kvm: arm64: Include kvm_emulate.h in kvm/arm_psci.h
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Suzuki K Poulose, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Zenghui Yu, linux-arm-kernel,
linux-kernel, Joey Gouly, Alexandru Elisei, Christoffer Dall,
Fuad Tabba, linux-coco, Ganapatrao Kulkarni, Gavin Shan,
Shanker Donthineni, Alper Gun, Aneesh Kumar K . V, Emi Kisanuki,
Vishal Annapurve, Steven Price
In-Reply-To: <20251217101125.91098-1-steven.price@arm.com>
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Fix a potential build error (like below, when asm/kvm_emulate.h gets
included after the kvm/arm_psci.h) by including the missing header file
in kvm/arm_psci.h:
./include/kvm/arm_psci.h: In function ‘kvm_psci_version’:
./include/kvm/arm_psci.h:29:13: error: implicit declaration of function
‘vcpu_has_feature’; did you mean ‘cpu_have_feature’? [-Werror=implicit-function-declaration]
29 | if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_PSCI_0_2)) {
| ^~~~~~~~~~~~~~~~
| cpu_have_feature
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
include/kvm/arm_psci.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h
index cbaec804eb83..38dab7add79b 100644
--- a/include/kvm/arm_psci.h
+++ b/include/kvm/arm_psci.h
@@ -10,6 +10,8 @@
#include <linux/kvm_host.h>
#include <uapi/linux/psci.h>
+#include <asm/kvm_emulate.h>
+
#define KVM_ARM_PSCI_0_1 PSCI_VERSION(0, 1)
#define KVM_ARM_PSCI_0_2 PSCI_VERSION(0, 2)
#define KVM_ARM_PSCI_1_0 PSCI_VERSION(1, 0)
--
2.43.0
^ permalink raw reply related
* [PATCH v12 00/46] arm64: Support for Arm CCA in KVM
From: Steven Price @ 2025-12-17 10:10 UTC (permalink / raw)
To: kvm, kvmarm
Cc: Steven Price, Catalin Marinas, Marc Zyngier, Will Deacon,
James Morse, Oliver Upton, Suzuki K Poulose, Zenghui Yu,
linux-arm-kernel, linux-kernel, Joey Gouly, Alexandru Elisei,
Christoffer Dall, Fuad Tabba, linux-coco, Ganapatrao Kulkarni,
Gavin Shan, Shanker Donthineni, Alper Gun, Aneesh Kumar K . V,
Emi Kisanuki, Vishal Annapurve
This series adds support for running protected VMs using KVM under the
Arm Confidential Compute Architecture (CCA). I've changed the uAPI
following feedback from Marc.
The main change is that rather than providing a multiplex CAP and
expecting the VMM to drive the different stages of realm construction,
there's now just a minimal interface and KVM performs the necessary
operations when needed.
This series is lightly tested and is meant as a demonstration of the new
uAPI. There are a number of (known) rough corners in the implementation
that I haven't dealt with properly.
In particular please note that this series is still targetting RMM v1.0.
There is an alpha quality version of RMM v2.0 available[1]. Feedback was
that there are a number of blockers for merging with RMM v1.0 and so I
expect to rework this series to support RMM v2.0 before it is merged.
That will necessarily involve reworking the implementation.
Specifically I'm expecting improvements in:
* GIC handling - passing state in registers, and allowing the host to
fully emulate the GIC by allowing trap bits to be set.
* PMU handling - again providing flexibility to the host's emulation.
* Page size/granule size mismatch. RMM v1.0 defines the granule as 4k,
RMM v2.0 provide the option for the host to change the granule size.
The intention is that Linux would simply set the granule size equal
to its page size which will significantly simplify the management of
granules.
* Some performance improvement from the use of range-based map/unmap
RMI calls.
This series is based on v6.19-rc1. It is also available as a git
repository:
https://gitlab.arm.com/linux-arm/linux-cca cca-host/v12
Work in progress changes for kvmtool are available from the git
repository below:
https://gitlab.arm.com/linux-arm/kvmtool-cca cca/v10
[1] https://developer.arm.com/documentation/den0137/latest/
Jean-Philippe Brucker (7):
arm64: RMI: Propagate number of breakpoints and watchpoints to
userspace
arm64: RMI: Set breakpoint parameters through SET_ONE_REG
arm64: RMI: Initialize PMCR.N with number counter supported by RMM
arm64: RMI: Propagate max SVE vector length from RMM
arm64: RMI: Configure max SVE vector length for a Realm
arm64: RMI: Provide register list for unfinalized RMI RECs
arm64: RMI: Provide accurate register list
Joey Gouly (2):
arm64: RMI: allow userspace to inject aborts
arm64: RMI: support RSI_HOST_CALL
Steven Price (34):
arm64: RME: Handle Granule Protection Faults (GPFs)
arm64: RMI: Add SMC definitions for calling the RMM
arm64: RMI: Add wrappers for RMI calls
arm64: RMI: Check for RMI support at KVM init
arm64: RMI: Define the user ABI
arm64: RMI: Basic infrastructure for creating a realm.
KVM: arm64: Allow passing machine type in KVM creation
arm64: RMI: RTT tear down
arm64: RMI: Activate realm on first VCPU run
arm64: RMI: Allocate/free RECs to match vCPUs
KVM: arm64: vgic: Provide helper for number of list registers
arm64: RMI: Support for the VGIC in realms
KVM: arm64: Support timers in realm RECs
arm64: RMI: Handle realm enter/exit
arm64: RMI: Handle RMI_EXIT_RIPAS_CHANGE
KVM: arm64: Handle realm MMIO emulation
KVM: arm64: Expose support for private memory
arm64: RMI: Allow populating initial contents
arm64: RMI: Set RIPAS of initial memslots
arm64: RMI: Create the realm descriptor
arm64: RMI: Add a VMID allocator for realms
arm64: RMI: Runtime faulting of memory
KVM: arm64: Handle realm VCPU load
KVM: arm64: Validate register access for a Realm VM
KVM: arm64: Handle Realm PSCI requests
KVM: arm64: WARN on injected undef exceptions
arm64: Don't expose stolen time for realm guests
arm64: RMI: Always use 4k pages for realms
arm64: RMI: Prevent Device mappings for Realms
HACK: Restore per-CPU cpu_armpmu pointer
arm_pmu: Provide a mechanism for disabling the physical IRQ
arm64: RMI: Enable PMU support with a realm guest
KVM: arm64: Expose KVM_ARM_VCPU_REC to user space
arm64: RMI: Enable realms to be created
Suzuki K Poulose (3):
kvm: arm64: Include kvm_emulate.h in kvm/arm_psci.h
kvm: arm64: Don't expose unsupported capabilities for realm guests
arm64: RMI: Allow checking SVE on VM instance
Documentation/virt/kvm/api.rst | 78 +-
arch/arm64/include/asm/kvm_emulate.h | 31 +
arch/arm64/include/asm/kvm_host.h | 13 +-
arch/arm64/include/asm/kvm_rmi.h | 137 +++
arch/arm64/include/asm/rmi_cmds.h | 508 ++++++++
arch/arm64/include/asm/rmi_smc.h | 269 +++++
arch/arm64/include/asm/virt.h | 1 +
arch/arm64/kernel/cpufeature.c | 1 +
arch/arm64/kvm/Kconfig | 2 +
arch/arm64/kvm/Makefile | 2 +-
arch/arm64/kvm/arch_timer.c | 37 +-
arch/arm64/kvm/arm.c | 179 ++-
arch/arm64/kvm/guest.c | 95 +-
arch/arm64/kvm/hypercalls.c | 4 +-
arch/arm64/kvm/inject_fault.c | 5 +-
arch/arm64/kvm/mmio.c | 16 +-
arch/arm64/kvm/mmu.c | 214 +++-
arch/arm64/kvm/pmu-emul.c | 6 +
arch/arm64/kvm/psci.c | 30 +
arch/arm64/kvm/reset.c | 13 +-
arch/arm64/kvm/rmi-exit.c | 207 ++++
arch/arm64/kvm/rmi.c | 1663 ++++++++++++++++++++++++++
arch/arm64/kvm/sys_regs.c | 53 +-
arch/arm64/kvm/vgic/vgic-init.c | 2 +-
arch/arm64/kvm/vgic/vgic-v2.c | 6 +-
arch/arm64/kvm/vgic/vgic-v3.c | 14 +-
arch/arm64/kvm/vgic/vgic.c | 55 +-
arch/arm64/kvm/vgic/vgic.h | 20 +-
arch/arm64/mm/fault.c | 28 +-
drivers/perf/arm_pmu.c | 20 +
include/kvm/arm_arch_timer.h | 2 +
include/kvm/arm_pmu.h | 4 +
include/kvm/arm_psci.h | 2 +
include/linux/perf/arm_pmu.h | 7 +
include/uapi/linux/kvm.h | 42 +-
35 files changed, 3650 insertions(+), 116 deletions(-)
create mode 100644 arch/arm64/include/asm/kvm_rmi.h
create mode 100644 arch/arm64/include/asm/rmi_cmds.h
create mode 100644 arch/arm64/include/asm/rmi_smc.h
create mode 100644 arch/arm64/kvm/rmi-exit.c
create mode 100644 arch/arm64/kvm/rmi.c
--
2.43.0
^ permalink raw reply
* Re: [PATCH v2 2/7] KVM: x86: Extract VMXON and EFER.SVME enablement to kernel
From: Xu Yilun @ 2025-12-17 6:57 UTC (permalink / raw)
To: Chao Gao
Cc: Sean Christopherson, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, Dave Hansen, x86, Kiryl Shutsemau, Paolo Bonzini,
linux-kernel, linux-coco, kvm, Dan Williams
In-Reply-To: <aTe4QyE3h8LHOAMb@intel.com>
> >+#define x86_virt_call(fn) \
> >+({ \
> >+ int __r; \
> >+ \
> >+ if (IS_ENABLED(CONFIG_KVM_INTEL) && \
> >+ cpu_feature_enabled(X86_FEATURE_VMX)) \
> >+ __r = x86_vmx_##fn(); \
> >+ else if (IS_ENABLED(CONFIG_KVM_AMD) && \
> >+ cpu_feature_enabled(X86_FEATURE_SVM)) \
> >+ __r = x86_svm_##fn(); \
> >+ else \
> >+ __r = -EOPNOTSUPP; \
> >+ \
> >+ __r; \
> >+})
> >+
> >+int x86_virt_get_cpu(int feat)
> >+{
> >+ int r;
> >+
> >+ if (!x86_virt_feature || x86_virt_feature != feat)
> >+ return -EOPNOTSUPP;
> >+
> >+ if (this_cpu_inc_return(virtualization_nr_users) > 1)
> >+ return 0;
>
> Should we assert that preemption is disabled? Calling this API when preemption
> is enabled is wrong.
>
> Maybe use __this_cpu_inc_return(), which already verifies preemption status.
>
Is it better we explicitly assert the preemption for x86_virt_get_cpu()
rather than embed the check in __this_cpu_inc_return()? We are not just
protecting the racing for the reference counter. We should ensure the
"counter increase + x86_virt_call(get_cpu)" can't be preempted.
Thanks,
Yilun
^ permalink raw reply
* SVSM Development Call December 17th, 2025
From: Jörg Rödel @ 2025-12-16 17:17 UTC (permalink / raw)
To: coconut-svsm, linux-coco
Hi,
Here is the call for agenda items for the the last SVSM development call this
year. Yes, time runs fast :) Please send me any agenda items you have in mind
or raise them in the meeting.
We will use the LF Zoom instance. Details of the meeting can be found in our
governance repository at:
https://github.com/coconut-svsm/governance
The link to the COCONUT-SVSM calendar is:
https://zoom-lfx.platform.linuxfoundation.org/meetings/coconut-svsm?view=week
The meeting will be recorded and the recording eventually published.
Regards,
Jörg
^ permalink raw reply
* Re: [PATCH v2 2/5] KVM: guest_memfd: Remove preparation tracking
From: Gupta, Pankaj @ 2025-12-16 3:29 UTC (permalink / raw)
To: Michael Roth, kvm
Cc: linux-coco, linux-mm, linux-kernel, thomas.lendacky, pbonzini,
seanjc, vbabka, ashish.kalra, liam.merwick, david, vannapurve,
ackerleytng, aik, ira.weiny, yan.y.zhao
In-Reply-To: <20251215153411.3613928-3-michael.roth@amd.com>
> guest_memfd currently uses the folio uptodate flag to track:
>
> 1) whether or not a page has been cleared before initial usage
> 2) whether or not the architecture hooks have been issued to put the
> page in a private state as defined by the architecture
>
> In practice, 2) is only actually being tracked for SEV-SNP VMs, and
> there do not seem to be any plans/reasons that would suggest this will
> change in the future, so this additional tracking/complexity is not
> really providing any general benefit to guest_memfd users. Future plans
> around in-place conversion and hugepage support, where the per-folio
> uptodate flag is planned to be used purely to track the initial clearing
> of folios, whereas conversion operations could trigger multiple
> transitions between 'prepared' and 'unprepared' and thus need separate
> tracking, will make the burden of tracking this information within
> guest_memfd even more complex, since preparation generally happens
> during fault time, on the "read-side" of any global locks that might
> protect state tracked by guest_memfd, and so may require more complex
> locking schemes to allow for concurrent handling of page faults for
> multiple vCPUs where the "preparedness" state tracked by guest_memfd
> might need to be updated as part of handling the fault.
>
> Instead of keeping this current/future complexity within guest_memfd for
> what is essentially just SEV-SNP, just drop the tracking for 2) and have
> the arch-specific preparation hooks get triggered unconditionally on
> every fault so the arch-specific hooks can check the preparation state
> directly and decide whether or not a folio still needs additional
> preparation. In the case of SEV-SNP, the preparation state is already
> checked again via the preparation hooks to avoid double-preparation, so
> nothing extra needs to be done to update the handling of things there.
>
> Signed-off-by: Michael Roth <michael.roth@amd.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
> ---
> virt/kvm/guest_memfd.c | 44 ++++++++++++------------------------------
> 1 file changed, 12 insertions(+), 32 deletions(-)
>
> diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
> index 9dafa44838fe..8b1248f42aae 100644
> --- a/virt/kvm/guest_memfd.c
> +++ b/virt/kvm/guest_memfd.c
> @@ -76,11 +76,6 @@ static int __kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slo
> return 0;
> }
>
> -static inline void kvm_gmem_mark_prepared(struct folio *folio)
> -{
> - folio_mark_uptodate(folio);
> -}
> -
> /*
> * Process @folio, which contains @gfn, so that the guest can use it.
> * The folio must be locked and the gfn must be contained in @slot.
> @@ -90,13 +85,7 @@ static inline void kvm_gmem_mark_prepared(struct folio *folio)
> static int kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slot,
> gfn_t gfn, struct folio *folio)
> {
> - unsigned long nr_pages, i;
> pgoff_t index;
> - int r;
> -
> - nr_pages = folio_nr_pages(folio);
> - for (i = 0; i < nr_pages; i++)
> - clear_highpage(folio_page(folio, i));
>
> /*
> * Preparing huge folios should always be safe, since it should
> @@ -114,11 +103,8 @@ static int kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slot,
> WARN_ON(!IS_ALIGNED(slot->gmem.pgoff, folio_nr_pages(folio)));
> index = kvm_gmem_get_index(slot, gfn);
> index = ALIGN_DOWN(index, folio_nr_pages(folio));
> - r = __kvm_gmem_prepare_folio(kvm, slot, index, folio);
> - if (!r)
> - kvm_gmem_mark_prepared(folio);
>
> - return r;
> + return __kvm_gmem_prepare_folio(kvm, slot, index, folio);
> }
>
> /*
> @@ -429,7 +415,7 @@ static vm_fault_t kvm_gmem_fault_user_mapping(struct vm_fault *vmf)
>
> if (!folio_test_uptodate(folio)) {
> clear_highpage(folio_page(folio, 0));
> - kvm_gmem_mark_prepared(folio);
> + folio_mark_uptodate(folio);
> }
>
> vmf->page = folio_file_page(folio, vmf->pgoff);
> @@ -766,7 +752,7 @@ void kvm_gmem_unbind(struct kvm_memory_slot *slot)
> static struct folio *__kvm_gmem_get_pfn(struct file *file,
> struct kvm_memory_slot *slot,
> pgoff_t index, kvm_pfn_t *pfn,
> - bool *is_prepared, int *max_order)
> + int *max_order)
> {
> struct file *slot_file = READ_ONCE(slot->gmem.file);
> struct gmem_file *f = file->private_data;
> @@ -796,7 +782,6 @@ static struct folio *__kvm_gmem_get_pfn(struct file *file,
> if (max_order)
> *max_order = 0;
>
> - *is_prepared = folio_test_uptodate(folio);
> return folio;
> }
>
> @@ -806,19 +791,22 @@ int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
> {
> pgoff_t index = kvm_gmem_get_index(slot, gfn);
> struct folio *folio;
> - bool is_prepared = false;
> int r = 0;
>
> CLASS(gmem_get_file, file)(slot);
> if (!file)
> return -EFAULT;
>
> - folio = __kvm_gmem_get_pfn(file, slot, index, pfn, &is_prepared, max_order);
> + folio = __kvm_gmem_get_pfn(file, slot, index, pfn, max_order);
> if (IS_ERR(folio))
> return PTR_ERR(folio);
>
> - if (!is_prepared)
> - r = kvm_gmem_prepare_folio(kvm, slot, gfn, folio);
> + if (!folio_test_uptodate(folio)) {
> + clear_highpage(folio_page(folio, 0));
> + folio_mark_uptodate(folio);
> + }
> +
> + r = kvm_gmem_prepare_folio(kvm, slot, gfn, folio);
>
> folio_unlock(folio);
>
> @@ -861,7 +849,6 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long
> struct folio *folio;
> gfn_t gfn = start_gfn + i;
> pgoff_t index = kvm_gmem_get_index(slot, gfn);
> - bool is_prepared = false;
> kvm_pfn_t pfn;
>
> if (signal_pending(current)) {
> @@ -869,19 +856,12 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long
> break;
> }
>
> - folio = __kvm_gmem_get_pfn(file, slot, index, &pfn, &is_prepared, NULL);
> + folio = __kvm_gmem_get_pfn(file, slot, index, &pfn, NULL);
> if (IS_ERR(folio)) {
> ret = PTR_ERR(folio);
> break;
> }
>
> - if (is_prepared) {
> - folio_unlock(folio);
> - folio_put(folio);
> - ret = -EEXIST;
> - break;
> - }
> -
> folio_unlock(folio);
>
> ret = -EINVAL;
> @@ -893,7 +873,7 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t start_gfn, void __user *src, long
> p = src ? src + i * PAGE_SIZE : NULL;
> ret = post_populate(kvm, gfn, pfn, p, opaque);
> if (!ret)
> - kvm_gmem_mark_prepared(folio);
> + folio_mark_uptodate(folio);
>
> put_folio_and_exit:
> folio_put(folio);
^ permalink raw reply
* Re: [PATCH v2 4/5] KVM: TDX: Document alignment requirements for KVM_TDX_INIT_MEM_REGION
From: Vishal Annapurve @ 2025-12-16 0:19 UTC (permalink / raw)
To: Michael Roth
Cc: kvm, linux-coco, linux-mm, linux-kernel, thomas.lendacky,
pbonzini, seanjc, vbabka, ashish.kalra, liam.merwick, david,
ackerleytng, aik, ira.weiny, yan.y.zhao
In-Reply-To: <20251215153411.3613928-5-michael.roth@amd.com>
On Mon, Dec 15, 2025 at 7:36 AM Michael Roth <michael.roth@amd.com> wrote:
>
> Since it was never possible to use a non-PAGE_SIZE-aligned @source_addr,
> go ahead and document this as a requirement. This is in preparation for
> enforcing page-aligned @source_addr for all architectures in
> guest_memfd.
>
> Signed-off-by: Michael Roth <michael.roth@amd.com>
> ---
> Documentation/virt/kvm/x86/intel-tdx.rst | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Documentation/virt/kvm/x86/intel-tdx.rst b/Documentation/virt/kvm/x86/intel-tdx.rst
> index 5efac62c92c7..6a222e9d0954 100644
> --- a/Documentation/virt/kvm/x86/intel-tdx.rst
> +++ b/Documentation/virt/kvm/x86/intel-tdx.rst
> @@ -156,7 +156,7 @@ KVM_TDX_INIT_MEM_REGION
> :Returns: 0 on success, <0 on error
>
> Initialize @nr_pages TDX guest private memory starting from @gpa with userspace
> -provided data from @source_addr.
> +provided data from @source_addr. @source_addr must be PAGE_SIZE-aligned.
Reviewed-By: Vishal Annapurve <vannapurve@google.com>
^ permalink raw reply
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