Re: [Qemu-devel] [PATCH 10/21 DISGISED v6] acpi_piix4: add infrastructure to send CPU hot-plug GPE to guest

[Igor Mammedov]

On Wed, 24 Apr 2013 18:09:11 +0200
Andreas Färber <address@hidden> wrote:

> Am 24.04.2013 18:03, schrieb Eduardo Habkost:
> > On Wed, Apr 24, 2013 at 05:56:46PM +0200, Igor Mammedov wrote:
> >> On Tue, 23 Apr 2013 18:27:11 +0200
> >> Igor Mammedov <address@hidden> wrote:
> >>
> >> NACK
> >>
> >>
> >>   gpe_cpu.sts isn't need to be migrated, since CPU hotpluging during
> >>   migration just doesn't work, since destination QEMU has to be started
> >>   with all present in guest CPUs (including hotplugged).
> >>   i.e. src-qemu -smp 2,max-cpus=4; cpu-add id=2; dst-qemu -smp 3,max-cpus=4
> >>   Destination QEMU will recreate the same gpe_cpu.sts=t'111' bitmap as
> >>   on source by calling qemu_for_each_cpu(piix4_init_cpu_status, 
> >> &s->gpe_cpu);
> >>   since it has been started with 3 CPUs on command line.
> >>
> >> tested on ping pong migration, It works as expected without gpe_cpu.sts 
> >> migrated.
> >> I'll post v7 to this thread shortly.
> > 
> > Are we going to make the cpu-add command fail in case it gets called
> > during migration?
> 
> I would rather suggest to throw an Error* on realize, if this can be
> detected.
it would be better not to start/allow hot add at all if migration in
progress and let it complete. it probably could be made generic???

> 
> Andreas
> 
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-- 
Regards,
  Igor