2017-06-29 16:17 GMT+08:00 Wanpeng Li <kernellwp@xxxxxxxxx>:
> 2017-06-29 15:55 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>:
>>> +
>>> + /* In case the sw timer triggered in the window */
>>> + if (atomic_read(&apic->lapic_timer.pending) &&
>>> + !apic_lvtt_period(apic))
>>> + need_cancel = true;
>>> + else if (r && (apic_lvtt_oneshot(apic) ||
>>> apic_lvtt_tscdeadline(apic)))
>>> + apic_timer_expired(apic);
>>> + }
>>> + }
>
> [...]
>
>>
>> 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?
Regards,
Wanpeng Li
