Re: [PATCH v1 13/23] KVM: VMX: Handle VMX nested exception for FRED

[Chao Gao]

> 	/* Require Write-Back (WB) memory type for VMCS accesses. */
>@@ -7313,11 +7328,12 @@ static void __vmx_complete_interrupts(struct kvm_vcpu *vcpu,
> 			}
> 		}
> 
>-		if (idt_vectoring_info & VECTORING_INFO_DELIVER_CODE_MASK) {
>-			u32 err = vmcs_read32(error_code_field);
>-			kvm_requeue_exception_e(vcpu, vector, err);
>-		} else
>-			kvm_requeue_exception(vcpu, vector);
>+		if (idt_vectoring_info & VECTORING_INFO_DELIVER_CODE_MASK)
>+			kvm_requeue_exception_e(vcpu, vector, vmcs_read32(error_code_field),
>+						idt_vectoring_info & INTR_INFO_NESTED_EXCEPTION_MASK);
>+		else
>+			kvm_requeue_exception(vcpu, vector,
>+					      idt_vectoring_info & INTR_INFO_NESTED_EXCEPTION_MASK);

Exiting-event identification can also have bit 13 set, indicating a nested
exception encountered and caused VM-exit. when reinjecting the exception to
guests, kvm needs to set the "nested" bit, right? I suspect some changes
to e.g., handle_exception_nmi() are needed.