[RFC 07/33] KVM: x86: hyper-v: Introduce KVM_CAP_HYPERV_VSM

[Nicolas Saenz Julienne]

Introduce a new capability to enable Hyper-V Virtual Secure Mode (VSM)
emulation support.

Signed-off-by: Nicolas Saenz Julienne <nsaenz@xxxxxxxxxx>
---
 arch/x86/include/asm/kvm_host.h | 2 ++
 arch/x86/kvm/hyperv.h           | 5 +++++
 arch/x86/kvm/x86.c              | 5 +++++
 include/uapi/linux/kvm.h        | 1 +
 4 files changed, 13 insertions(+)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 00cd21b09f8c..7712e31b7537 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1118,6 +1118,8 @@ struct kvm_hv {
 
 	struct hv_partition_assist_pg *hv_pa_pg;
 	struct kvm_hv_syndbg hv_syndbg;
+
+	bool hv_enable_vsm;
 };
 
 struct msr_bitmap_range {
diff --git a/arch/x86/kvm/hyperv.h b/arch/x86/kvm/hyperv.h
index f83b8db72b11..2bfed69ba0db 100644
--- a/arch/x86/kvm/hyperv.h
+++ b/arch/x86/kvm/hyperv.h
@@ -238,4 +238,9 @@ static inline int kvm_hv_verify_vp_assist(struct kvm_vcpu *vcpu)
 
 int kvm_hv_vcpu_flush_tlb(struct kvm_vcpu *vcpu);
 
+static inline bool kvm_hv_vsm_enabled(struct kvm *kvm)
+{
+       return kvm->arch.hyperv.hv_enable_vsm;
+}
+
 #endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4cd3f00475c1..b0512e433032 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4485,6 +4485,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_HYPERV_CPUID:
 	case KVM_CAP_HYPERV_ENFORCE_CPUID:
 	case KVM_CAP_SYS_HYPERV_CPUID:
+	case KVM_CAP_HYPERV_VSM:
 	case KVM_CAP_PCI_SEGMENT:
 	case KVM_CAP_DEBUGREGS:
 	case KVM_CAP_X86_ROBUST_SINGLESTEP:
@@ -6519,6 +6520,10 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 		}
 		mutex_unlock(&kvm->lock);
 		break;
+	case KVM_CAP_HYPERV_VSM:
+		kvm->arch.hyperv.hv_enable_vsm = true;
+		r = 0;
+		break;
 	default:
 		r = -EINVAL;
 		break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 5ce06a1eee2b..168b6ac6ebe5 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1226,6 +1226,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_GUEST_MEMFD 233
 #define KVM_CAP_VM_TYPES 234
 #define KVM_CAP_APIC_ID_GROUPS 235
+#define KVM_CAP_HYPERV_VSM 237
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
-- 
2.40.1