On Thu, 23 Jun 2016 07:28:48 +0800
Wanpeng Li <kernellwp@xxxxxxxxx> wrote:
> 2016-06-14 5:20 GMT+08:00 Yunhong Jiang
> <yunhong.jiang@xxxxxxxxxxxxxxx>: [...]
> > +
> > +void kvm_lapic_switch_to_sw_timer(struct kvm_vcpu *vcpu)
> > +{
> > + struct kvm_lapic *apic = vcpu->arch.apic;
> > +
> > + /* Possibly the TSC deadline timer is not enabled yet */
> > + if (!apic->lapic_timer.hv_timer_in_use)
> > + return;
> > +
> > + kvm_x86_ops->cancel_hv_timer(vcpu);
> > + apic->lapic_timer.hv_timer_in_use = false;
> > +
> > + if (atomic_read(&apic->lapic_timer.pending))
> > + return;
> > +
> > + start_sw_tscdeadline(apic);
>
> I have one question here. For example, tsc deadline is set to 10us in
> kvm_set_lapic_tscdeadline_msr(), and 1us past in preemption timer,
> then 9us should be set to hrtimer expire during switch to sw timer,
> however, apic->lapic_timer.tscdeadline is still 10us, so the current
> codes set 10us to hrtimer expire. Where I miss?
I think the tscdeadline is the absolute value, instead of relative value. The
sw timer should set the hrtimer to be deadlinetimer-guest_tsc, like what's done
in start_sw-tscdeadline, right?
Thanks
--jyh
>
> Regards,
> Wanpeng Li
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
