Introduce a new capability KVM_CAP_ARM_ID_REG_WRITABLE to indicate
that ID registers are writable by userspace.
Signed-off-by: Reiji Watanabe <reijiw@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 a6729c8cf063..f7dfb5127310 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7265,3 +7265,11 @@ The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset
of the result of KVM_CHECK_EXTENSION. KVM will forward to userspace
the hypercalls whose corresponding bit is in the argument, and return
ENOSYS for the others.
+
+8.35 KVM_CAP_ARM_ID_REG_WRITABLE
+--------------------------------
+
+:Architectures: 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 820f35051d77..29c13a32dd21 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -197,6 +197,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_SET_GUEST_DEBUG:
case KVM_CAP_VCPU_ATTRIBUTES:
case KVM_CAP_PTP_KVM:
+ case KVM_CAP_ARM_ID_REG_WRITABLE:
r = 1;
break;
case KVM_CAP_SET_GUEST_DEBUG2:
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a067410ebea5..3345a57f05a6 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1112,6 +1112,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_BINARY_STATS_FD 203
#define KVM_CAP_EXIT_ON_EMULATION_FAILURE 204
#define KVM_CAP_ARM_MTE 205
+#define KVM_CAP_ARM_ID_REG_WRITABLE 206
#ifdef KVM_CAP_IRQ_ROUTING
--
2.33.0.882.g93a45727a2-goog
