On 20/01/2022 01:07, Sean Christopherson wrote:
WARN if KVM attempts to emulate in response to #UD or #GP for SEV guests,
i.e. if KVM intercepts #UD or #GP, as emulation on any fault except #NPF
is impossible since KVM cannot read guest private memory to get the code
stream, and the CPU's DecodeAssists feature only provides the instruction
bytes on #NPF.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/svm/svm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 994224ae2731..ed2ca875b84b 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4267,6 +4267,9 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
if (!sev_guest(vcpu->kvm))
return true;
+ /* #UD and #GP should never be intercepted for SEV guests. */
+ WARN_ON_ONCE(emul_type & (EMULTYPE_TRAP_UD | EMULTYPE_VMWARE_GP));
What about EMULTYPE_TRAP_UD_FORCED?
Otherwise
Reviewed-by: Liam Merwick <liam.merwick@xxxxxxxxxx>
+
/*
* Emulation is impossible for SEV-ES guests as KVM doesn't have access
* to guest register state.
