| Message ID | 20221103141351.50662-8-mlevitsk@redhat.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 92e7d5c83aff124f49082585e57939ed24b59c5c |
| Headers | show |
| Series | nSVM: Security and correctness fixes | expand |
On 03/11/2022 14:13, Maxim Levitsky wrote: > This is SVM correctness fix - although a sane L1 would intercept > SHUTDOWN event, it doesn't have to, so we have to honour this. > > Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> > --- > arch/x86/kvm/svm/nested.c | 6 ++++++ > arch/x86/kvm/vmx/nested.c | 1 + > arch/x86/kvm/x86.c | 11 ++++++----- > 3 files changed, 13 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c > index bcc4f6620f8aec..3aa9184d1e4ed7 100644 > --- a/arch/x86/kvm/svm/nested.c > +++ b/arch/x86/kvm/svm/nested.c > @@ -1092,6 +1092,12 @@ int nested_svm_vmexit(struct vcpu_svm *svm) > > static void nested_svm_triple_fault(struct kvm_vcpu *vcpu) > { > + struct vcpu_svm *svm = to_svm(vcpu); > + > + if (!vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SHUTDOWN)) > + return; > + > + kvm_clear_request(KVM_REQ_TRIPLE_FAULT, vcpu); > nested_svm_simple_vmexit(to_svm(vcpu), SVM_EXIT_SHUTDOWN); You could replace 'to_svm(vcpu)' with 'svm' here But LGTM either way. Reviewed-by: Liam Merwick <liam.merwick@oracle.com> > } > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 1ebe141a0a015f..7924dea9367813 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -4855,6 +4855,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason, > > static void nested_vmx_triple_fault(struct kvm_vcpu *vcpu) > { > + kvm_clear_request(KVM_REQ_TRIPLE_FAULT, vcpu); > nested_vmx_vmexit(vcpu, EXIT_REASON_TRIPLE_FAULT, 0, 0); > } > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 3fd900504e683b..f0a0102a78f5c3 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -9741,7 +9741,7 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu) > > int kvm_check_nested_events(struct kvm_vcpu *vcpu) > { > - if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { > + if (kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { > kvm_x86_ops.nested_ops->triple_fault(vcpu); > return 1; > } > @@ -10255,15 +10255,16 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) > r = 0; > goto out; > } > - if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { > - if (is_guest_mode(vcpu)) { > + if (kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { > + if (is_guest_mode(vcpu)) > kvm_x86_ops.nested_ops->triple_fault(vcpu); > - } else { > + > + if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { > vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN; > vcpu->mmio_needed = 0; > r = 0; > - goto out; > } > + goto out; > } > if (kvm_check_request(KVM_REQ_APF_HALT, vcpu)) { > /* Page is swapped out. Do synthetic halt */
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index bcc4f6620f8aec..3aa9184d1e4ed7 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1092,6 +1092,12 @@ int nested_svm_vmexit(struct vcpu_svm *svm) static void nested_svm_triple_fault(struct kvm_vcpu *vcpu) { + struct vcpu_svm *svm = to_svm(vcpu); + + if (!vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_SHUTDOWN)) + return; + + kvm_clear_request(KVM_REQ_TRIPLE_FAULT, vcpu); nested_svm_simple_vmexit(to_svm(vcpu), SVM_EXIT_SHUTDOWN); } diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 1ebe141a0a015f..7924dea9367813 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4855,6 +4855,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason, static void nested_vmx_triple_fault(struct kvm_vcpu *vcpu) { + kvm_clear_request(KVM_REQ_TRIPLE_FAULT, vcpu); nested_vmx_vmexit(vcpu, EXIT_REASON_TRIPLE_FAULT, 0, 0); } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3fd900504e683b..f0a0102a78f5c3 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9741,7 +9741,7 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu) int kvm_check_nested_events(struct kvm_vcpu *vcpu) { - if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { + if (kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { kvm_x86_ops.nested_ops->triple_fault(vcpu); return 1; } @@ -10255,15 +10255,16 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) r = 0; goto out; } - if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { - if (is_guest_mode(vcpu)) { + if (kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { + if (is_guest_mode(vcpu)) kvm_x86_ops.nested_ops->triple_fault(vcpu); - } else { + + if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN; vcpu->mmio_needed = 0; r = 0; - goto out; } + goto out; } if (kvm_check_request(KVM_REQ_APF_HALT, vcpu)) { /* Page is swapped out. Do synthetic halt */
This is SVM correctness fix - although a sane L1 would intercept SHUTDOWN event, it doesn't have to, so we have to honour this. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> --- arch/x86/kvm/svm/nested.c | 6 ++++++ arch/x86/kvm/vmx/nested.c | 1 + arch/x86/kvm/x86.c | 11 ++++++----- 3 files changed, 13 insertions(+), 5 deletions(-)