On Mon, Jul 05, 2010 at 11:07:56AM +0200, Jan Kiszka wrote:
> Avi Kivity wrote:
> > On 07/05/2010 10:36 AM, Jan Kiszka wrote:
> >>
> >>> Assumes that CPU with
> >>> lowest index is BSP (that one we can actually guaranty if we want
> >>> to).
> >>>
> >> Well, the generic solution would be returning a bitmap of the CPUs that
> >> were affected, but this is impractical. However, at least x86 should be
> >> fine with the information "state change also on BSP", e.g. like this:
> >> 0 - state change on one or more CPUs, none of them is the BSP
> >> 1 - state change on BSP (and possible more CPUs)
> >>
> >
> > What about ack notifiers? Ask the APIC to notify you when an interrupt
> > is acked. That allows you to track the BSP, all cpus, or some subset.
> > Masking can be seen at the irq controller level.
>
> So, if I understand you correctly, an IRQ state change that is ignored
> due to masking would invoke the ack notifier chain as well?
>
Ack notifiers go with mask notifiers.
> >
> > It's more involved, but provides more information.
>
> Well, it requires to establish ack notifier chains in parallel to the
> existing IRQ delivery routes. Definitely more invasive.
>
> Jan
>
--
Gleb.
