On Mon, Feb 25, 2013 at 11:13:25AM +0000, Zhang, Yang Z wrote: > Gleb Natapov wrote on 2013-02-25: > > On Mon, Feb 25, 2013 at 11:04:25AM +0000, Zhang, Yang Z wrote: > >> Gleb Natapov wrote on 2013-02-25: > >>> On Mon, Feb 25, 2013 at 08:42:52AM +0000, Zhang, Yang Z wrote: > >>>> Avi Kivity wrote on 2013-02-25: > >>>>> I didn't really follow, but is the root cause the need to keep track > >>>>> of interrupt coalescing? If so we can recommend that users use > >>>>> KVM_IRQ_LINE when coalescing is unneeded, and move interrupt > >>>>> injection with irq coalescing support to vcpu context. > >>>> So we can hide the capability KVM_CAP_IRQ_INJECT_STATUS when posted > >>> interrupt is enabled to force users doesn't to use > >>> KVM_IRQ_LINE_STATUS. Does this acceptable? > >>>> > >>>> The only case in KVM that need to know the interrupt injection status is > > vlapic > >>> timer. But since vlapic timer and vcpu are always in same pcpu, so there is no > >>> problem. > >>>> > >>> Not really. The primary user of this interface is RTC interrupt > >>> re-injection for Windows guests. > >> So without KVM_IRQ_LINE_STATUS capability, RTC cannot work well? > >> > > Windows guests may experience timedrift under CPU overcommit scenario. > Ok, I see. Seems we are stuck. :( > Do you have any suggestion to solve or workaround current problem? Depend on knowledge about atomicity (item 5 IIRC) of the sequence in the manual. -- 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
