Re: [PATCH v3] KVM: LAPIC: Fix lapic timer injection delay

[Wanpeng Li]

2017-06-29 19:43 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>:
>
>
> On 29/06/2017 10:44, Wanpeng Li wrote:
>>>> You still need to enable the preemption timer even if you return 1, so
>>>> in lapic.c it becomes
>>>>
>>>>         if (!apic_lvtt_period(apic)) {
>>>>                 if (r)
>>>>                         apic_timer_expired(apic);
>>>>                 if (atomic_read(&apic->lapic_timer.pending))
>>>>                         need_cancel = true;
>>>>         }
>>> I think the codes are more clear but the same as above. We didn't
>>> program preemption timer vmcs field if delta == 0, so how to
>>> understand "need to enable the preemption timer even if return 1"?
>> I guess you mean start_hv_timer() should return true, right?
>
> vmx.c's set_hv_timer callback should set the preemption timer execution
> control.  Otherwise, kvm_lapic_hv_timer_expired is again not called.

I see, this should be set for apic timer periodic mode.

Regards,
Wanpeng Li