Commit ae018183 authored by Brijesh Singh's avatar Brijesh Singh Committed by Paolo Bonzini
Browse files

KVM: SEV: Add GHCB handling for Hypervisor Feature Support requests 



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: default avatarBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: default avatarAshish Kalra <ashish.kalra@amd.com>
Signed-off-by: default avatarMichael Roth <michael.roth@amd.com>
Message-ID: <20240501071048.2208265-3-michael.roth@amd.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent d916f003

arch/x86/include/asm/sev-common.h

+2 −0
Original line number Diff line number Diff line
@@ -101,6 +101,8 @@ enum psc_op { 
/* GHCB Hypervisor Feature Request/Response */

#define GHCB_MSR_HV_FT_REQ		0x080

#define GHCB_MSR_HV_FT_RESP		0x081

#define GHCB_MSR_HV_FT_POS		12

#define GHCB_MSR_HV_FT_MASK		GENMASK_ULL(51, 0)

#define GHCB_MSR_HV_FT_RESP_VAL(v)			\

	/* GHCBData[63:12] */				\

	(((u64)(v) & GENMASK_ULL(63, 12)) >> 12)

arch/x86/kvm/svm/sev.c

+14 −0
Original line number Diff line number Diff line
@@ -36,6 +36,8 @@ 
#define GHCB_VERSION_MAX	1ULL

#define GHCB_VERSION_MIN	1ULL



#define GHCB_HV_FT_SUPPORTED	GHCB_HV_FT_SNP



/* enable/disable SEV support */

static bool sev_enabled = true;

module_param_named(sev, sev_enabled, bool, 0444);
@@ -2701,6 +2703,7 @@ 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_FEATURES:

		break;

	default:

		reason = GHCB_ERR_INVALID_EVENT;
@@ -2961,6 +2964,12 @@ 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;
@@ -3085,6 +3094,11 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) 
		ret = 1;

		break;

	}

	case SVM_VMGEXIT_HV_FEATURES:

		ghcb_set_sw_exit_info_2(svm->sev_es.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",