KVM: SVM: Do not allow instruction emulation under SEV-ES

When a guest is running as an SEV-ES guest, it is not possible to emulate
instructions. Add support to prevent instruction emulation.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-Id: <f6355ea3024fda0a3eb5eb99c6b62dca10d792bd.1607620209.git.thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index bec427a..cade703 100644 (file)
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4158,6 +4158,12 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int i
        unsigned long cr4;
 
        /*
+        * When the guest is an SEV-ES guest, emulation is not possible.
+        */
+       if (sev_es_guest(vcpu->kvm))
+               return false;
+
+       /*
         * Detect and workaround Errata 1096 Fam_17h_00_0Fh.
         *
         * Errata: