Commit 132627c6 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

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: default avatarSean Christopherson <seanjc@google.com>
Reviewed-by: default avatarLiam 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: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4d31d9ef

arch/x86/kvm/svm/svm.c

+5 −0
Original line number Diff line number Diff line
@@ -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.