diff options
| author | Jim Mattson <jmattson@google.com> | 2018-10-16 14:29:22 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-10-17 19:07:43 +0200 |
| commit | da998b46d244767505e41d050dcac5e4d03ba96f (patch) | |
| tree | 8e719071b6732577b306b04dfb6fe886a244e51f /arch/x86/kvm/svm.c | |
| parent | 91e86d225ef3da80d33a8fd7695316c31c0810c9 (diff) | |
kvm: x86: Defer setting of CR2 until #PF delivery
When exception payloads are enabled by userspace (which is not yet
possible) and a #PF is raised in L2, defer the setting of CR2 until
the #PF is delivered. This allows the L1 hypervisor to intercept the
fault before CR2 is modified.
For backwards compatibility, when exception payloads are not enabled
by userspace, kvm_multiple_exception modifies CR2 when the #PF
exception is raised.
Reported-by: Jim Mattson <jmattson@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 47b07211c5b1..1086bebaeea3 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -805,6 +805,8 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu) nested_svm_check_exception(svm, nr, has_error_code, error_code)) return; + kvm_deliver_exception_payload(&svm->vcpu); + if (nr == BP_VECTOR && !static_cpu_has(X86_FEATURE_NRIPS)) { unsigned long rip, old_rip = kvm_rip_read(&svm->vcpu); @@ -2965,16 +2967,13 @@ static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr, svm->vmcb->control.exit_info_1 = error_code; /* - * FIXME: we should not write CR2 when L1 intercepts an L2 #PF exception. - * The fix is to add the ancillary datum (CR2 or DR6) to structs - * kvm_queued_exception and kvm_vcpu_events, so that CR2 and DR6 can be - * written only when inject_pending_event runs (DR6 would written here - * too). This should be conditional on a new capability---if the - * capability is disabled, kvm_multiple_exception would write the - * ancillary information to CR2 or DR6, for backwards ABI-compatibility. + * EXITINFO2 is undefined for all exception intercepts other + * than #PF. */ if (svm->vcpu.arch.exception.nested_apf) svm->vmcb->control.exit_info_2 = svm->vcpu.arch.apf.nested_apf_token; + else if (svm->vcpu.arch.exception.has_payload) + svm->vmcb->control.exit_info_2 = svm->vcpu.arch.exception.payload; else svm->vmcb->control.exit_info_2 = svm->vcpu.arch.cr2; |