Messages in this thread Patch in this message | | | Date | Thu, 20 Jan 2022 01:07:13 +0000 | Subject | [PATCH 3/9] KVM: SVM: Don't intercept #GP for SEV guests | From | Sean Christopherson <> |
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Never intercept #GP for SEV guests as reading SEV guest private memory will return cyphertext, i.e. emulating on #GP can't work as intended.
Cc: stable@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/svm/svm.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 85703145eb0a..edea52be6c01 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -312,7 +312,11 @@ int svm_set_efer(struct kvm_vcpu *vcpu, u64 efer) return ret; } - if (svm_gp_erratum_intercept) + /* + * Never intercept #GP for SEV guests, KVM can't + * decrypt guest memory to workaround the erratum. + */ + if (svm_gp_erratum_intercept && !sev_guest(vcpu->kvm)) set_exception_intercept(svm, GP_VECTOR); } } @@ -1010,9 +1014,10 @@ static void init_vmcb(struct kvm_vcpu *vcpu) * Guest access to VMware backdoor ports could legitimately * trigger #GP because of TSS I/O permission bitmap. * We intercept those #GP and allow access to them anyway - * as VMware does. + * as VMware does. Don't intercept #GP for SEV guests as KVM can't + * decrypt guest memory to decode the faulting instruction. */ - if (enable_vmware_backdoor) + if (enable_vmware_backdoor && !sev_guest(vcpu->kvm)) set_exception_intercept(svm, GP_VECTOR); svm_set_intercept(svm, INTERCEPT_INTR); -- 2.34.1.703.g22d0c6ccf7-goog
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