[PATCH v14 28/22] [SQUASH] KVM: SEV: Provide support for SNP_EXTENDED_GUEST_REQUEST NAE event

[Michael Roth]

Ensure an error is returned if a non-SNP guest attempts to issue an
Extended Guest Request. Also add input validation for RAX/RBX.

Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
---
 arch/x86/kvm/svm/sev.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 2b30b3b0eec8..ff64ed8df301 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3297,6 +3297,11 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
 			goto vmgexit_err;
 		break;
 	case SVM_VMGEXIT_EXT_GUEST_REQUEST:
+		if (!sev_snp_guest(vcpu->kvm))
+			goto vmgexit_err;
+		if (!kvm_ghcb_rax_is_valid(svm) ||
+		    !kvm_ghcb_rbx_is_valid(svm))
+			goto vmgexit_err;
 		break;
 	default:
 		reason = GHCB_ERR_INVALID_EVENT;
-- 
2.25.1