Paolo Bonzini wrote on 2014-12-18: > > > On 18/12/2014 04:14, Wu, Feng wrote: >> >> >> linux-kernel-owner@xxxxxxxxxxxxxxx wrote on mailto:linux-kernel-owner@xxxxxxxxxxxxxxx] On Behalf Of Paolo: >>> x86@xxxxxxxxxx; Gleb Natapov; Paolo Bonzini; dwmw2@xxxxxxxxxxxxx; >>> joro-zLv9SwRftAIdnm+yROfE0A@xxxxxxxxxxxxxxxx; Alex Williamson; >>> joro-zLv9SwRftAIdnm+Jiang >>> Liu >>> Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; >>> linux-kernel-u79uwXL29TY76Z2rM5mHXA@xxxxxxxxxxxxxxxx; KVM list; >>> Eric Auger >>> Subject: Re: [v3 25/26] KVM: Suppress posted-interrupt when 'SN' is >>> set >>> >>> >>> >>> On 12/12/2014 16:14, Feng Wu wrote: >>>> Currently, we don't support urgent interrupt, all interrupts are >>>> recognized as non-urgent interrupt, so we cannot send >>>> posted-interrupt when 'SN' is set. >>> >>> Can this happen? If the vcpu is in guest mode, it cannot have been >>> scheduled out, and that's the only case when SN is set. >>> >>> Paolo >> >> Currently, the only place where SN is set is vCPU is preempted and If the vCPU is preempted, shouldn't the subsequent be ignored? What happens if a PI is occurs when vCPU is preempted? >> waiting for the next scheduling in the runqueue. But I am not sure >> whether we need to set SN for other purpose in future. Adding SN >> checking here is just to follow the Spec. non-urgent interrupts are >> suppressed > when SN is set. > > I would change that to a WARN_ON_ONCE then. Best regards, Yang -- 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
