Re: [PATCH] KVM: nVMX: Fix the NMI IDT-vectoring info handling

From: Paolo Bonzini
Date: Thu Sep 22 2016 - 05:37:48 EST




On 22/09/2016 05:34, Wanpeng Li wrote:
> - if (vmx->rmode.vm86_active) {
> - if (kvm_inject_realmode_interrupt(vcpu, NMI_VECTOR, 0) != EMULATE_DONE)
> - kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
> - return;
> + ++vcpu->stat.nmi_injections;
> + vmx->nmi_known_unmasked = false;
> + if (vmx->rmode.vm86_active) {
> + if (kvm_inject_realmode_interrupt(vcpu, NMI_VECTOR, 0) != EMULATE_DONE)
> + kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
> + return;
> + }
> }
> vmcs_write32(VM_ENTRY_INTR_INFO_FIELD,
> INTR_TYPE_NMI_INTR | INTR_INFO_VALID_MASK | NMI_VECTOR);

Hi,

the patch is mostly okay but the "if (vmx->rmode.vm86_active)" part
should be done also if the VCPU is in guest mode. See
vmx_queue_exception for a similar example.

I would like to know which processors lack virtual NMI support. I'd
rather rip that code out...

Thanks,

Paolo