KVM: x86: allow L1 to not intercept triple fault

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>
Message-Id: <20221103141351.50662-8-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 7354f00..995bc0f 100644 (file)
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1091,6 +1091,12 @@ 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 f7333b9..5b0d485 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4854,6 +4854,7 @@ 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 597d7f8..5384c56 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9811,7 +9811,7 @@ 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;
        }
@@ -10566,15 +10566,16 @@ 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 */