[PATCH 2/2][RFC] KVM: Emulate MSI-X table and PBA in kernel

Sheng Yang
2010-12-22T08:44:37Z

Then we can support mask bit operation of assigned devices now.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
arch/x86/kvm/Makefile | 2 +-
arch/x86/kvm/x86.c | 8 +-
include/linux/kvm.h | 22 ++++
include/linux/kvm_host.h | 25 +++++
virt/kvm/assigned-dev.c | 30 ++++++
virt/kvm/kvm_main.c | 38 +++++++-
virt/kvm/msix_mmio.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++
virt/kvm/msix_mmio.h | 24 +++++
8 files changed, 386 insertions(+), 7 deletions(-)
create mode 100644 virt/kvm/msix_mmio.c
create mode 100644 virt/kvm/msix_mmio.h

diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index f15501f..3a0d851 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -7,7 +7,7 @@ CFLAGS_vmx.o := -I.

kvm-y += $(addprefix ../../../virt/kvm/, kvm_main.o ioapic.o \
coalesced_mmio.o irq_comm.o eventfd.o \
- assigned-dev.o)
+ assigned-dev.o msix_mmio.o)
kvm-$(CONFIG_IOMMU_API) += $(addprefix ../../../virt/kvm/, iommu.o)
kvm-$(CONFIG_KVM_ASYNC_PF) += $(addprefix ../../../virt/kvm/, async_pf.o)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ed373ba..0be5837 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1965,6 +1965,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_X86_ROBUST_SINGLESTEP:
case KVM_CAP_XSAVE:
case KVM_CAP_ASYNC_PF:
+ case KVM_CAP_MSIX_MMIO:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
@@ -3802,6 +3803,7 @@ static int emulator_write_emulated_onepage(unsigned long addr,
struct kvm_vcpu *vcpu)
{
gpa_t gpa;
+ int r;

gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, exception);

@@ -3817,14 +3819,16 @@ static int emulator_write_emulated_onepage(unsigned long addr,

mmio:
trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, bytes, gpa, *(u64 *)val);
+ r = vcpu_mmio_write(vcpu, gpa, bytes, val);
/*
* Is this MMIO handled locally?
*/
- if (!vcpu_mmio_write(vcpu, gpa, bytes, val))
+ if (!r)
return X86EMUL_CONTINUE;

vcpu->mmio_needed = 1;
- vcpu->run->exit_reason = KVM_EXIT_MMIO;
+ vcpu->run->exit_reason = (r == -ENOTSYNC) ?
+ KVM_EXIT_MSIX_ROUTING_UPDATE : KVM_EXIT_MMIO;
vcpu->run->mmio.phys_addr = vcpu->mmio_phys_addr = gpa;
vcpu->run->mmio.len = vcpu->mmio_size = bytes;
vcpu->run->mmio.is_write = vcpu->mmio_is_write = 1;
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index ea2dc1a..44838fe 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -161,6 +161,7 @@ struct kvm_pit_config {
#define KVM_EXIT_NMI 16
#define KVM_EXIT_INTERNAL_ERROR 17
#define KVM_EXIT_OSI 18
+#define KVM_EXIT_MSIX_ROUTING_UPDATE 19

/* For KVM_EXIT_INTERNAL_ERROR */
#define KVM_INTERNAL_ERROR_EMULATION 1
@@ -541,6 +542,7 @@ struct kvm_ppc_pvinfo {
#define KVM_CAP_PPC_GET_PVINFO 57
#define KVM_CAP_PPC_IRQ_LEVEL 58
#define KVM_CAP_ASYNC_PF 59
+#define KVM_CAP_MSIX_MMIO 60

#ifdef KVM_CAP_IRQ_ROUTING

@@ -672,6 +674,9 @@ struct kvm_clock_data {
#define KVM_XEN_HVM_CONFIG _IOW(KVMIO, 0x7a, struct kvm_xen_hvm_config)
#define KVM_SET_CLOCK _IOW(KVMIO, 0x7b, struct kvm_clock_data)
#define KVM_GET_CLOCK _IOR(KVMIO, 0x7c, struct kvm_clock_data)
+/* Available with KVM_CAP_MSIX_MMIO */
+#define KVM_REGISTER_MSIX_MMIO _IOW(KVMIO, 0x7d, struct kvm_msix_mmio_user)
+#define KVM_UNREGISTER_MSIX_MMIO _IOW(KVMIO, 0x7e, struct kvm_msix_mmio_user)
/* Available with KVM_CAP_PIT_STATE2 */
#define KVM_GET_PIT2 _IOR(KVMIO, 0x9f, struct kvm_pit_state2)
#define KVM_SET_PIT2 _IOW(KVMIO, 0xa0, struct kvm_pit_state2)
@@ -795,4 +800,21 @@ struct kvm_assigned_msix_entry {
__u16 padding[3];
};

+#define KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV (1 << 0)
+
+#define KVM_MSIX_MMIO_TYPE_BASE_TABLE (1 << 8)
+#define KVM_MSIX_MMIO_TYPE_BASE_PBA (1 << 9)
+
+#define KVM_MSIX_MMIO_TYPE_DEV_MASK 0x00ff
+#define KVM_MSIX_MMIO_TYPE_BASE_MASK 0xff00
+struct kvm_msix_mmio_user {
+ __u32 dev_id;
+ __u16 type;
+ __u16 max_entries_nr;
+ __u64 base_addr;
+ __u64 base_va;
+ __u64 flags;
+ __u64 reserved[4];
+};
+
#endif /* __LINUX_KVM_H */
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ac026ad..15fdd0d 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -231,6 +231,27 @@ struct kvm_memslots {
KVM_PRIVATE_MEM_SLOTS];
};

+#define KVM_MSIX_MMIO_MAX 32
+
+struct kvm_msix_mmio {
+ u32 dev_id;
+ u16 type;
+ u16 max_entries_nr;
+ u64 flags;
+ gpa_t table_base_addr;
+ hva_t table_base_va;
+ gpa_t pba_base_addr;
+ hva_t pba_base_va;
+};
+
+struct kvm_msix_mmio_dev {
+ struct kvm *kvm;
+ struct kvm_io_device table_dev;
+ int mmio_nr;
+ struct kvm_msix_mmio mmio[KVM_MSIX_MMIO_MAX];
+ struct mutex lock;
+};
+
struct kvm {
spinlock_t mmu_lock;
raw_spinlock_t requests_lock;
@@ -279,6 +300,7 @@ struct kvm {
long mmu_notifier_count;
long tlbs_dirty;
#endif
+ struct kvm_msix_mmio_dev msix_mmio_dev;
};

/* The guest did something we don't support. */
@@ -551,6 +573,9 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
int kvm_request_irq_source_id(struct kvm *kvm);
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);

+int kvm_assigned_device_update_msix_mask_bit(struct kvm *kvm,
+ int assigned_dev_id, int entry, u32 flag);
+
/* For vcpu->arch.iommu_flags */
#define KVM_IOMMU_CACHE_COHERENCY 0x1

diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index ae72ae6..ec48bfe 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -785,3 +785,33 @@ out:
return r;
}

+int kvm_assigned_device_update_msix_mask_bit(struct kvm *kvm,
+ int assigned_dev_id, int entry, u32 flag)
+{
+ int r = -EFAULT;
+ struct kvm_assigned_dev_kernel *adev;
+ int i;
+
+ if (!irqchip_in_kernel(kvm))
+ return r;
+
+ mutex_lock(&kvm->lock);
+ adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
+ assigned_dev_id);
+ if (!adev)
+ goto out;
+
+ for (i = 0; i < adev->entries_nr; i++)
+ if (adev->host_msix_entries[i].entry == entry) {
+ if (flag)
+ disable_irq_nosync(
+ adev->host_msix_entries[i].vector);
+ else
+ enable_irq(adev->host_msix_entries[i].vector);
+ r = 0;
+ break;
+ }
+out:
+ mutex_unlock(&kvm->lock);
+ return r;
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 83f5bf6..4be7cfe 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -56,6 +56,7 @@

#include "coalesced_mmio.h"
#include "async_pf.h"
+#include "msix_mmio.h"

#define CREATE_TRACE_POINTS
#include <trace/events/kvm.h>
@@ -521,6 +522,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
#else
kvm_arch_flush_shadow(kvm);
#endif
+ kvm_unregister_msix_mmio_dev(kvm);
kvm_arch_destroy_vm(kvm);
kvm_free_physmem(kvm);
cleanup_srcu_struct(&kvm->srcu);
@@ -1877,6 +1879,24 @@ static long kvm_vm_ioctl(struct file *filp,
mutex_unlock(&kvm->lock);
break;
#endif
+ case KVM_REGISTER_MSIX_MMIO: {
+ struct kvm_msix_mmio_user mmio_user;
+
+ r = -EFAULT;
+ if (copy_from_user(&mmio_user, argp, sizeof mmio_user))
+ goto out;
+ r = kvm_vm_ioctl_register_msix_mmio(kvm, &mmio_user);
+ break;
+ }
+ case KVM_UNREGISTER_MSIX_MMIO: {
+ struct kvm_msix_mmio_user mmio_user;
+
+ r = -EFAULT;
+ if (copy_from_user(&mmio_user, argp, sizeof mmio_user))
+ goto out;
+ r = kvm_vm_ioctl_unregister_msix_mmio(kvm, &mmio_user);
+ break;
+ }
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
if (r == -ENOTTY)
@@ -1988,6 +2008,12 @@ static int kvm_dev_ioctl_create_vm(void)
return r;
}
#endif
+ r = kvm_register_msix_mmio_dev(kvm);
+ if (r < 0) {
+ kvm_put_kvm(kvm);
+ return r;
+ }
+
r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
if (r < 0)
kvm_put_kvm(kvm);
@@ -2223,14 +2249,18 @@ static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
int len, const void *val)
{
- int i;
+ int i, r = -EOPNOTSUPP;
struct kvm_io_bus *bus;

bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
- for (i = 0; i < bus->dev_count; i++)
- if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
+ for (i = 0; i < bus->dev_count; i++) {
+ r = kvm_iodevice_write(bus->devs[i], addr, len, val);
+ if (r == -ENOTSYNC)
+ break;
+ else if (!r)
return 0;
- return -EOPNOTSUPP;
+ }
+ return r;
}

/* kvm_io_bus_read - called under kvm->slots_lock */
diff --git a/virt/kvm/msix_mmio.c b/virt/kvm/msix_mmio.c
new file mode 100644
index 0000000..e6064e0
--- /dev/null
+++ b/virt/kvm/msix_mmio.c
@@ -0,0 +1,244 @@
+/*
+ * MSI-X MMIO emulation
+ *
+ * Copyright (c) 2010 Intel Corporation
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ * Author:
+ * Sheng Yang <sheng.yang@intel.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+
+#include "msix_mmio.h"
+#include "iodev.h"
+
+static int update_msix_mask_bit(struct kvm *kvm, struct kvm_msix_mmio *mmio,
+ int entry, u32 flag)
+{
+ if (mmio->type & KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV)
+ return kvm_assigned_device_update_msix_mask_bit(kvm,
+ mmio->dev_id, entry, flag);
+ return -EFAULT;
+}
+
+/* Caller must hold dev->lock */
+static int get_mmio_table_index(struct kvm_msix_mmio_dev *dev,
+ gpa_t addr, int len)
+{
+ gpa_t start, end;
+ int i, r = -EINVAL;
+
+ for (i = 0; i < dev->mmio_nr; i++) {
+ start = dev->mmio[i].table_base_addr;
+ end = dev->mmio[i].table_base_addr + PCI_MSIX_ENTRY_SIZE *
+ dev->mmio[i].max_entries_nr;
+ if (addr >= start && addr + len <= end) {
+ r = i;
+ break;
+ }
+ }
+
+ return r;
+}
+
+static int msix_table_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
+ void *val)
+{
+ struct kvm_msix_mmio_dev *mmio_dev =
+ container_of(this, struct kvm_msix_mmio_dev, table_dev);
+ struct kvm_msix_mmio *mmio;
+ int idx, ret = 0, entry, offset, r;
+
+ mutex_lock(&mmio_dev->lock);
+ idx = get_mmio_table_index(mmio_dev, addr, len);
+ if (idx < 0) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ if ((addr & 0x3) || (len != 4 && len != 8))
+ goto out;
+ mmio = &mmio_dev->mmio[idx];
+
+ entry = (addr - mmio->table_base_addr) / PCI_MSIX_ENTRY_SIZE;
+ offset = addr & 0xf;
+ r = copy_from_user(val, (void *)(mmio->table_base_va +
+ entry * PCI_MSIX_ENTRY_SIZE + offset), len);
+ if (r)
+ goto out;
+out:
+ mutex_unlock(&mmio_dev->lock);
+ return ret;
+}
+
+static int msix_table_mmio_write(struct kvm_io_device *this, gpa_t addr,
+ int len, const void *val)
+{
+ struct kvm_msix_mmio_dev *mmio_dev =
+ container_of(this, struct kvm_msix_mmio_dev, table_dev);
+ struct kvm_msix_mmio *mmio;
+ int idx, entry, offset, ret = 0, r = 0;
+ gpa_t entry_base;
+ u32 old_ctrl, new_ctrl;
+
+ mutex_lock(&mmio_dev->lock);
+ idx = get_mmio_table_index(mmio_dev, addr, len);
+ if (idx < 0) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }
+ if ((addr & 0x3) || (len != 4 && len != 8))
+ goto out;
+ mmio = &mmio_dev->mmio[idx];
+ entry = (addr - mmio->table_base_addr) / PCI_MSIX_ENTRY_SIZE;
+ entry_base = mmio->table_base_va + entry * PCI_MSIX_ENTRY_SIZE;
+ offset = addr & 0xF;
+
+ if (copy_from_user(&old_ctrl,
+ entry_base + PCI_MSIX_ENTRY_VECTOR_CTRL,
+ sizeof old_ctrl))
+ goto out;
+
+ /* No allow writing to other fields when entry is unmasked */
+ if (!(old_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT) &&
+ offset != PCI_MSIX_ENTRY_VECTOR_CTRL)
+ goto out;
+
+ if (copy_to_user(entry_base + offset, val, len))
+ goto out;
+
+ if (copy_from_user(&new_ctrl,
+ entry_base + PCI_MSIX_ENTRY_VECTOR_CTRL,
+ sizeof new_ctrl))
+ goto out;
+
+ if ((offset < PCI_MSIX_ENTRY_VECTOR_CTRL && len == 4) ||
+ (offset < PCI_MSIX_ENTRY_DATA && len == 8))
+ ret = -ENOTSYNC;
+ if (old_ctrl == new_ctrl)
+ goto out;
+ if (!(old_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT) &&
+ (new_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT))
+ r = update_msix_mask_bit(mmio_dev->kvm, mmio, entry, 1);
+ else if ((old_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT) &&
+ !(new_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT))
+ r = update_msix_mask_bit(mmio_dev->kvm, mmio, entry, 0);
+ if (r || ret)
+ ret = -ENOTSYNC;
+out:
+ mutex_unlock(&mmio_dev->lock);
+ return ret;
+}
+static const struct kvm_io_device_ops msix_mmio_table_ops = {
+ .read = msix_table_mmio_read,
+ .write = msix_table_mmio_write,
+};
+
+int kvm_register_msix_mmio_dev(struct kvm *kvm)
+{
+ int ret;
+
+ kvm_iodevice_init(&kvm->msix_mmio_dev.table_dev, &msix_mmio_table_ops);
+ mutex_init(&kvm->msix_mmio_dev.lock);
+ kvm->msix_mmio_dev.kvm = kvm;
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS,
+ &kvm->msix_mmio_dev.table_dev);
+ mutex_unlock(&kvm->slots_lock);
+ return ret;
+}
+
+int kvm_unregister_msix_mmio_dev(struct kvm *kvm)
+{
+ int ret;
+
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
+ &kvm->msix_mmio_dev.table_dev);
+ mutex_unlock(&kvm->slots_lock);
+ return ret;
+}
+
+int kvm_vm_ioctl_register_msix_mmio(struct kvm *kvm,
+ struct kvm_msix_mmio_user *mmio_user)
+{
+ struct kvm_msix_mmio_dev *mmio_dev = &kvm->msix_mmio_dev;
+ struct kvm_msix_mmio *mmio = NULL;
+ int r = 0, i;
+
+ mutex_lock(&mmio_dev->lock);
+ for (i = 0; i < mmio_dev->mmio_nr; i++) {
+ if (mmio_dev->mmio[i].dev_id == mmio_user->dev_id &&
+ (mmio_dev->mmio[i].type & KVM_MSIX_MMIO_TYPE_DEV_MASK) ==
+ (mmio_user->type & KVM_MSIX_MMIO_TYPE_DEV_MASK)) {
+ mmio = &mmio_dev->mmio[i];
+ if (mmio->max_entries_nr != mmio_user->max_entries_nr) {
+ r = -EINVAL;
+ goto out;
+ }
+ break;
+ }
+ }
+ if (!mmio) {
+ if (mmio_dev->mmio_nr == KVM_MSIX_MMIO_MAX) {
+ r = -ENOSPC;
+ goto out;
+ }
+ mmio = &mmio_dev->mmio[mmio_dev->mmio_nr];
+ mmio_dev->mmio_nr++;
+ }
+ mmio->max_entries_nr = mmio_user->max_entries_nr;
+ mmio->dev_id = mmio_user->dev_id;
+ mmio->flags = mmio_user->flags;
+ if ((mmio_user->type & KVM_MSIX_MMIO_TYPE_DEV_MASK) ==
+ KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV)
+ mmio->type = KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV;
+
+ if ((mmio_user->type & KVM_MSIX_MMIO_TYPE_BASE_MASK) ==
+ KVM_MSIX_MMIO_TYPE_BASE_TABLE) {
+ mmio->type |= KVM_MSIX_MMIO_TYPE_BASE_TABLE;
+ mmio->table_base_addr = mmio_user->base_addr;
+ mmio->table_base_va = mmio_user->base_va;
+ } else if ((mmio_user->type & KVM_MSIX_MMIO_TYPE_BASE_MASK) ==
+ KVM_MSIX_MMIO_TYPE_BASE_PBA) {
+ mmio->type |= KVM_MSIX_MMIO_TYPE_BASE_PBA;
+ mmio->pba_base_addr = mmio_user->base_addr;
+ mmio->pba_base_va = mmio_user->base_va;
+ }
+out:
+ mutex_unlock(&mmio_dev->lock);
+ return r;
+}
+
+int kvm_vm_ioctl_unregister_msix_mmio(struct kvm *kvm,
+ struct kvm_msix_mmio_user *mmio)
+{
+ struct kvm_msix_mmio_dev *mmio_dev = &kvm->msix_mmio_dev;
+ int r = 0, i, j;
+ bool found = 0;
+
+ mutex_lock(&mmio_dev->lock);
+ BUG_ON(mmio_dev->mmio_nr >= KVM_MSIX_MMIO_MAX);
+ for (i = 0; i < mmio_dev->mmio_nr; i++) {
+ if (mmio_dev->mmio[i].max_entries_nr != 0 &&
+ mmio_dev->mmio[i].dev_id == mmio->dev_id &&
+ mmio_dev->mmio[i].type == mmio->type) {
+ found = true;
+ for (j = i; j < mmio_dev->mmio_nr - 1; j++)
+ mmio_dev->mmio[j] = mmio_dev->mmio[j + 1];
+ mmio_dev->mmio[mmio_dev->mmio_nr].max_entries_nr = 0;
+ mmio_dev->mmio[mmio_dev->mmio_nr].dev_id = 0;
+ mmio_dev->mmio[mmio_dev->mmio_nr].type = 0;
+ mmio_dev->mmio_nr--;
+ break;
+ }
+ }
+ if (!found)
+ r = -EINVAL;
+ mutex_unlock(&mmio_dev->lock);
+ return r;
+}
+
diff --git a/virt/kvm/msix_mmio.h b/virt/kvm/msix_mmio.h
new file mode 100644
index 0000000..87caa29
--- /dev/null
+++ b/virt/kvm/msix_mmio.h
@@ -0,0 +1,24 @@
+#ifndef __KVM_MSIX_MMIO_H__
+#define __KVM_MSIX_MMIO_H__
+/*
+ * MSI-X MMIO emulation
+ *
+ * Copyright (c) 2010 Intel Corporation
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ * Author:
+ * Sheng Yang <sheng.yang@intel.com>
+ */
+
+#include <linux/pci.h>
+
+int kvm_register_msix_mmio_dev(struct kvm *kvm);
+int kvm_unregister_msix_mmio_dev(struct kvm *kvm);
+int kvm_vm_ioctl_register_msix_mmio(struct kvm *kvm,
+ struct kvm_msix_mmio_user *mmio);
+int kvm_vm_ioctl_unregister_msix_mmio(struct kvm *kvm,
+ struct kvm_msix_mmio_user *mmio);
+
+#endif
--
1.7.0.1