[v8,54/69] KVM: arm64: nv: Allow userspace to request KVM_ARM_VCPU_NESTED_VIRT

Commit Message

Marc Zyngier Jan. 31, 2023, 9:24 a.m. UTC

Since we're (almost) feature complete, let's allow userspace to
request KVM_ARM_VCPU_NESTED_VIRT by bumping the KVM_VCPU_MAX_FEATURES
up. We also now advertise the feature to userspace with a new capability.

It's going to be great...

Signed-off-by: Marc Zyngier <[e-mail]>
---
 arch/arm64/include/asm/kvm_host.h | 2 +-
 arch/arm64/kvm/arm.c              | 3 +++
 include/uapi/linux/kvm.h          | 1 +
 3 files changed, 5 insertions(+), 1 deletion(-)

Patch

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 5db9e74b86f6..a1fc3b893af8 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -37,7 +37,7 @@ 
 
 #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS
 
-#define KVM_VCPU_MAX_FEATURES 7
+#define KVM_VCPU_MAX_FEATURES 8
 
 #define KVM_REQ_SLEEP \
 	KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 505cb72d8535..bfcf6db27448 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -269,6 +269,9 @@  int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_ARM_EL1_32BIT:
 		r = cpus_have_const_cap(ARM64_HAS_32BIT_EL1);
 		break;
+	case KVM_CAP_ARM_EL2:
+		r = cpus_have_const_cap(ARM64_HAS_NESTED_VIRT);
+		break;
 	case KVM_CAP_GUEST_DEBUG_HW_BPS:
 		r = get_num_brps();
 		break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 55155e262646..573fa03bb002 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1175,6 +1175,7 @@  struct kvm_ppc_resize_hpt {
 #define KVM_CAP_DIRTY_LOG_RING_ACQ_REL 223
 #define KVM_CAP_S390_PROTECTED_ASYNC_DISABLE 224
 #define KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP 225
+#define KVM_CAP_ARM_EL2 226
 
 #ifdef KVM_CAP_IRQ_ROUTING