diff options
| author | Sean Christopherson <seanjc@google.com> | 2023-07-21 15:43:37 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-07-29 11:05:27 -0400 |
| commit | b439eb8ab578557263815ba8581d02c1b730e348 (patch) | |
| tree | 8662838f51b8a2bd3093df9ccb5bebf98efb59fb | |
| parent | 3f2739bd1e0b7e9669333852b4e618294d5a1e54 (diff) | |
| download | kvm-s390-vfio-b439eb8ab578557263815ba8581d02c1b730e348.tar.gz | |
Revert "KVM: SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"
Now that handle_fastpath_set_msr_irqoff() acquires kvm->srcu, i.e. allows
dereferencing memslots during WRMSR emulation, drop the requirement that
"next RIP" is valid. In hindsight, acquiring kvm->srcu would have been a
better fix than avoiding the pastpath, but at the time it was thought that
accessing SRCU-protected data in the fastpath was a one-off edge case.
This reverts commit 5c30e8101e8d5d020b1d7119117889756a6ed713.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721224337.2335137-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index d381ad4245542c..cea08e5fa69b3c 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3986,14 +3986,8 @@ static int svm_vcpu_pre_run(struct kvm_vcpu *vcpu) static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu) { - struct vmcb_control_area *control = &to_svm(vcpu)->vmcb->control; - - /* - * Note, the next RIP must be provided as SRCU isn't held, i.e. KVM - * can't read guest memory (dereference memslots) to decode the WRMSR. - */ - if (control->exit_code == SVM_EXIT_MSR && control->exit_info_1 && - nrips && control->next_rip) + if (to_svm(vcpu)->vmcb->control.exit_code == SVM_EXIT_MSR && + to_svm(vcpu)->vmcb->control.exit_info_1) return handle_fastpath_set_msr_irqoff(vcpu); return EXIT_FASTPATH_NONE; |