diff options
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1bc67995cc8a..b2b17728a7a4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -748,6 +748,7 @@ void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault) } EXPORT_SYMBOL_GPL(kvm_inject_page_fault); +/* Returns true if the page fault was immediately morphed into a VM-Exit. */ bool kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault) { @@ -766,8 +767,26 @@ bool kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu, kvm_mmu_invalidate_gva(vcpu, fault_mmu, fault->address, fault_mmu->root.hpa); + /* + * A workaround for KVM's bad exception handling. If KVM injected an + * exception into L2, and L2 encountered a #PF while vectoring the + * injected exception, manually check to see if L1 wants to intercept + * #PF, otherwise queuing the #PF will lead to #DF or a lost exception. + * In all other cases, defer the check to nested_ops->check_events(), + * which will correctly handle priority (this does not). Note, other + * exceptions, e.g. #GP, are theoretically affected, #PF is simply the + * most problematic, e.g. when L0 and L1 are both intercepting #PF for + * shadow paging. + * + * TODO: Rewrite exception handling to track injected and pending + * (VM-Exit) exceptions separately. + */ + if (unlikely(vcpu->arch.exception.injected && is_guest_mode(vcpu)) && + kvm_x86_ops.nested_ops->handle_page_fault_workaround(vcpu, fault)) + return true; + fault_mmu->inject_page_fault(vcpu, fault); - return fault->nested_page_fault; + return false; } EXPORT_SYMBOL_GPL(kvm_inject_emulated_page_fault); |