Re: [PATCH] KVM: x86: Rework INIT and SIPI handling

[Gleb Natapov <gleb@redhat.com>]

On Wed, Mar 13, 2013 at 12:36:58PM +0100, Jan Kiszka wrote:
> On 2013-03-13 12:16, Jan Kiszka wrote:
> >>> @@ -5871,8 +5867,8 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
> >>>                       srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
> >>>                       kvm_vcpu_block(vcpu);
> >>>                       vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
> >>> -                     if (kvm_check_request(KVM_REQ_UNHALT, vcpu))
> >>> -                     {
> >>> +                     if (kvm_check_request(KVM_REQ_UNHALT, vcpu)) {
> >>> +                             kvm_apic_accept_events(vcpu);
> >> I think we can drop this. If INIT happens while vcpu is halted it will
> >> become runnable here and kvm_apic_accept_events() will be called in
> >> vcpu_enter_guest().
> > 
> > I'm not that sure, but I will recheck carefully.
> 
> Doesn't work: If the state was INIT_RECEIVED, we will not process the
> SIPI but reenter kvm_vcpu_block.
Which raises the question. What if vcpu is in INIT_RECEIVED and it
receives NMI. It will make kvm_arch_vcpu_runnable() return true but code
will get back to kvm_vcpu_block() again.

>                                 And it's more consistent to process the
> events here IMHO.
> 
I would like to minimize a number of places kvm_apic_accept_events()
is called, but it looks like we cannot remove it from here indeed. What
about calling it in "case: KVM_MP_STATE_INIT_RECEIVED"?
 
--
			Gleb.