[PATCH v4 09/34] KVM: SVM: Do not allow instruction emulation under SEV-ES

From: Tom Lendacky
Date: Tue Nov 17 2020 - 12:09:21 EST


From: Tom Lendacky <thomas.lendacky@xxxxxxx>

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@xxxxxxx>
---
arch/x86/kvm/svm/svm.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 7f805cd5bbe7..0e5f83912b56 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4195,6 +4195,12 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int i
bool smep, smap, is_user;
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.
*
--
2.28.0