Roman Kagan <rkagan@xxxxxxxxxxxxx> writes:
> On Mon, Nov 26, 2018 at 04:47:31PM +0100, Vitaly Kuznetsov wrote:
>> @@ -379,6 +398,14 @@ void kvm_hv_synic_send_eoi(struct kvm_vcpu *vcpu, int vector)
>> for (i = 0; i < ARRAY_SIZE(synic->sint); i++)
>> if (synic_get_sint_vector(synic_read_sint(synic, i)) == vector)
>> kvm_hv_notify_acked_sint(vcpu, i);
>> +
>> + for (i = 0; i < ARRAY_SIZE(hv_vcpu->stimer); i++) {
>> + stimer = &hv_vcpu->stimer[i];
>> + if (stimer->msg_pending && stimer->config.enable &&
>> + stimer->config.direct_mode &&
>> + stimer->config.apic_vector == vector)
>> + stimer_mark_pending(stimer, false);
>> + }
>> }
>
> While debugging another issue with synic timers, it just occurred to me
> that with direct timers no extra processing is necessary on EOI: unlike
> traditional synic timers which may have failed to deliver a message and
> want to be notified when they can retry, direct timers just set the irq
> directly in the apic.
>
> So this hunk shouldn't be needed, should it?
Hm, you're probably right: kvm_apic_set_irq() fails only when apic is
disabled (see APIC_DM_FIXED case in __apic_accept_irq()) and I'm not
convinced we should re-try in this synthetic case.
Let me test the hypothesis with Hyper-V on KVM, I'll come back with
either a patch removing this over-engineered part or a reson for it to
stay. Will do later this week.
Thanks!
--
Vitaly
