diff options
| author | Sean Christopherson <seanjc@google.com> | 2021-03-02 20:45:14 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-03-15 11:43:15 +0300 |
| commit | cb6a32c2b8777ad31a02e585584d869251a790e3 (patch) | |
| tree | ae3bf1dec3a2219aa8068cc0aaf733fbe35c1736 /arch/x86/kvm/svm/nested.c | |
| parent | 63129754178c5514f04bf6bdb891e33dfe58e58d (diff) | |
| download | linux-cb6a32c2b8777ad31a02e585584d869251a790e3.tar.xz | |
KVM: x86: Handle triple fault in L2 without killing L1
Synthesize a nested VM-Exit if L2 triggers an emulated triple fault
instead of exiting to userspace, which likely will kill L1. Any flow
that does KVM_REQ_TRIPLE_FAULT is suspect, but the most common scenario
for L2 killing L1 is if L0 (KVM) intercepts a contributory exception that
is _not_intercepted by L1. E.g. if KVM is intercepting #GPs for the
VMware backdoor, a #GP that occurs in L2 while vectoring an injected #DF
will cause KVM to emulate triple fault.
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210302174515.2812275-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/svm/nested.c')
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 6a368f358b0d..348e1f979dbe 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -661,6 +661,9 @@ int nested_svm_vmexit(struct vcpu_svm *svm) struct kvm_host_map map; int rc; + /* Triple faults in L2 should never escape. */ + WARN_ON_ONCE(kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)); + rc = kvm_vcpu_map(vcpu, gpa_to_gfn(svm->nested.vmcb12_gpa), &map); if (rc) { if (rc == -EINVAL) @@ -782,6 +785,16 @@ int nested_svm_vmexit(struct vcpu_svm *svm) return 0; } +static void nested_svm_triple_fault(struct kvm_vcpu *vcpu) +{ + struct vcpu_svm *svm = to_svm(vcpu); + + svm->vmcb->control.exit_code = SVM_EXIT_SHUTDOWN; + svm->vmcb->control.exit_info_1 = 0; + svm->vmcb->control.exit_info_2 = 0; + nested_svm_vmexit(svm); +} + int svm_allocate_nested(struct vcpu_svm *svm) { struct page *vmcb02_page; @@ -1317,6 +1330,7 @@ out_free: struct kvm_x86_nested_ops svm_nested_ops = { .check_events = svm_check_nested_events, + .triple_fault = nested_svm_triple_fault, .get_nested_state_pages = svm_get_nested_state_pages, .get_state = svm_get_nested_state, .set_state = svm_set_nested_state, |