Re: [PATCH v4 6/6] KVM: nVMX: Enable nested posted interrupt processing

[Paolo Bonzini <pbonzini@redhat.com>]

On 02/02/2015 16:33, Wincy Van wrote:
> static void vmx_accomp_nested_posted_intr(struct kvm_vcpu *vcpu)
> {
>         struct vcpu_vmx *vmx = to_vmx(vcpu);
> 
>         if (is_guest_mode(vcpu) &&
>             vmx->nested.posted_intr_nv != -1 &&
>             pi_test_on(vmx->nested.pi_desc))
>                 kvm_apic_set_irr(vcpu,
>                         vmx->nested.posted_intr_nv);
> }
> 
> Then we will get an nested-vmexit in vmx_check_nested_events, that
> posted intr will be handled by L1 immediately.
> This mechanism will also emulate the hardware's behavior: If a posted
> intr was not accomplished by hardware, we will get an interrupt with
> POSTED_INTR_NV.

Yes.

> Would this be better?

I think you do not even need a new bit.  You can use KVM_REQ_EVENT and
(to complete my suggestion, which was not enough) do the above in
vmx_check_nested_events.

Paolo