[PATCH Part2 RFC v3 02/37] KVM: SVM: Provide the Hypervisor Feature support VMGEXIT

[Brijesh Singh <brijesh.singh@xxxxxxx>]

Version 2 of the GHCB specification introduced advertisement of features
that are supported by the Hypervisor.

Now that KVM supports version 2 of the GHCB specification, bump the
maximum supported protocol version.

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
 arch/x86/include/uapi/asm/svm.h |  2 ++
 arch/x86/kvm/svm/sev.c          | 14 ++++++++++++++
 arch/x86/kvm/svm/svm.h          |  3 ++-
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/uapi/asm/svm.h b/arch/x86/include/uapi/asm/svm.h
index bd64f2b98ac7..de977dd167ca 100644
--- a/arch/x86/include/uapi/asm/svm.h
+++ b/arch/x86/include/uapi/asm/svm.h
@@ -114,6 +114,7 @@
 #define SVM_VMGEXIT_AP_CREATE_ON_INIT		0
 #define SVM_VMGEXIT_AP_CREATE			1
 #define SVM_VMGEXIT_AP_DESTROY			2
+#define SVM_VMGEXIT_HV_FT			0x8000fffd
 #define SVM_VMGEXIT_UNSUPPORTED_EVENT		0x8000ffff
 
 #define SVM_EXIT_ERR           -1
@@ -224,6 +225,7 @@
 	{ SVM_VMGEXIT_PSC,		"vmgexit_page_state_change" }, \
 	{ SVM_VMGEXIT_AP_CREATION,	"vmgexit_ap_creation" }, \
 	{ SVM_VMGEXIT_GUEST_REQUEST,	"vmgexit_guest_request" }, \
+	{ SVM_VMGEXIT_HV_FT,      "vmgexit_hypervisor_feature" }, \
 	{ SVM_EXIT_ERR,         "invalid_guest_state" }
 
 
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 7d0b98dbe523..b8505710c36b 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2173,6 +2173,7 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
 	case SVM_VMGEXIT_AP_HLT_LOOP:
 	case SVM_VMGEXIT_AP_JUMP_TABLE:
 	case SVM_VMGEXIT_UNSUPPORTED_EVENT:
+	case SVM_VMGEXIT_HV_FT:
 		break;
 	default:
 		goto vmgexit_err;
@@ -2427,6 +2428,13 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
 				  GHCB_MSR_INFO_MASK,
 				  GHCB_MSR_INFO_POS);
 		break;
+	case GHCB_MSR_HV_FT_REQ: {
+		set_ghcb_msr_bits(svm, GHCB_HV_FT_SUPPORTED,
+				GHCB_MSR_HV_FT_MASK, GHCB_MSR_HV_FT_POS);
+		set_ghcb_msr_bits(svm, GHCB_MSR_HV_FT_RESP,
+				GHCB_MSR_INFO_MASK, GHCB_MSR_INFO_POS);
+		break;
+	}
 	case GHCB_MSR_TERM_REQ: {
 		u64 reason_set, reason_code;
 
@@ -2542,6 +2550,12 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
 		ret = 1;
 		break;
 	}
+	case SVM_VMGEXIT_HV_FT: {
+		ghcb_set_sw_exit_info_2(ghcb, GHCB_HV_FT_SUPPORTED);
+
+		ret = 1;
+		break;
+	}
 	case SVM_VMGEXIT_UNSUPPORTED_EVENT:
 		vcpu_unimpl(vcpu,
 			    "vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index ad12ca26b2d8..5f874168551b 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -527,9 +527,10 @@ void svm_vcpu_unblocking(struct kvm_vcpu *vcpu);
 
 /* sev.c */
 
-#define GHCB_VERSION_MAX	1ULL
+#define GHCB_VERSION_MAX	2ULL
 #define GHCB_VERSION_MIN	1ULL
 
+#define GHCB_HV_FT_SUPPORTED	0
 
 extern unsigned int max_sev_asid;
 
-- 
2.17.1