From 132627c64d94b1561ba5a444824e46c9f84c3d5b Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc@google.com> Date: Thu, 20 Jan 2022 01:07:16 +0000 Subject: KVM: SVM: WARN if KVM attempts emulation on #UD or #GP for SEV guests 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@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-7-seanjc@google.com> [Warn on EMULTYPE_TRAP_UD_FORCED according to Liam Merwick's review. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/svm/svm.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch') diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 115743e250bb..85bbfba1fa07 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4268,6 +4268,11 @@ 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_TRAP_UD_FORCED | + EMULTYPE_VMWARE_GP)); + /* * Emulation is impossible for SEV-ES guests as KVM doesn't have access * to guest register state. -- cgit v1.2.3-70-g09d2