KVM: Unprotect a page if #PF happens during NMI injection.

It is done for exception and interrupt already.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

arch/x86/kvm/svm.c

@@ -1122,8 +1122,7 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
 	if (npt_enabled)
 		svm_flush_tlb(&svm->vcpu);
 	else {
-		if (svm->vcpu.arch.interrupt.pending ||
-				svm->vcpu.arch.exception.pending)
+		if (kvm_event_needs_reinjection(&svm->vcpu))
 			kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
 	}
 	return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code);

arch/x86/kvm/vmx.c

@@ -2615,7 +2615,7 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 		cr2 = vmcs_readl(EXIT_QUALIFICATION);
 		KVMTRACE_3D(PAGE_FAULT, vcpu, error_code, (u32)cr2,
 			    (u32)((u64)cr2 >> 32), handler);
-		if (vcpu->arch.interrupt.pending || vcpu->arch.exception.pending)
+		if (kvm_event_needs_reinjection(vcpu))
 			kvm_mmu_unprotect_page_virt(vcpu, cr2);
 		return kvm_mmu_page_fault(vcpu, cr2, error_code);
 	}

arch/x86/kvm/x86.h

@@ -30,4 +30,10 @@ static inline u8 kvm_pop_irq(struct kvm_vcpu *vcpu)
 		clear_bit(word_index, &vcpu->arch.irq_summary);
 	return irq;
 }
+
+static inline bool kvm_event_needs_reinjection(struct kvm_vcpu *vcpu)
+{
+	return vcpu->arch.exception.pending || vcpu->arch.interrupt.pending ||
+		vcpu->arch.nmi_injected;
+}
 #endif