Add KVM_CAP_ARM_CPU_FEATURE extension for userpace to check whether KVM
supports to set CPU features in AArch64.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@xxxxxxxxxx>
Signed-off-by: Peng Liang <liangpeng10@xxxxxxxxxx>
---
Documentation/virt/kvm/api.rst | 8 ++++++++
arch/arm64/kvm/arm.c | 1 +
include/uapi/linux/kvm.h | 1 +
3 files changed, 10 insertions(+)
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index d2b733dc7892..50214ed8f50e 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6173,3 +6173,11 @@ specific interfaces must be consistent, i.e. if one says the feature
is supported, than the other should as well and vice versa. For arm64
see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL".
For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME".
+
+8.25 KVM_CAP_ARM_CPU_FEATURE
+-----------------------------------
+
+:Architecture: arm64
+
+This capability indicates that userspace can modify the ID registers via
+KVM_SET_ONE_REG ioctl.
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 6d961e192268..918a7a56b224 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -178,6 +178,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_ARM_IRQ_LINE_LAYOUT_2:
case KVM_CAP_ARM_NISV_TO_USER:
case KVM_CAP_ARM_INJECT_EXT_DABT:
+ case KVM_CAP_ARM_CPU_FEATURE:
r = 1;
break;
case KVM_CAP_ARM_SET_DEVICE_ADDR:
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 7d8eced6f459..12356beadd5a 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1037,6 +1037,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_SMALLER_MAXPHYADDR 185
#define KVM_CAP_S390_DIAG318 186
#define KVM_CAP_STEAL_TIME 187
+#define KVM_CAP_ARM_CPU_FEATURE 188
#ifdef KVM_CAP_IRQ_ROUTING
--
2.26.2
