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)); + /* * Emulation is impossible for SEV-ES guests as KVM doesn't have access * to guest register state. -- 2.34.1.703.g22d0c6ccf7-goog
