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Date: Wed, 21 Sep 2016 10:50:49 -0400
From: Luiz Capitulino <lcapitulino@redhat.com>
Message-ID: <20160921105049.55ede6b1@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] monitor: fix crash for platforms without a
 CPU 0
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To: David Gibson <david@gibson.dropbear.id.au>
Cc: qemu-trivial@nongnu.org, qemu-ppc@nongnu.org, qemu-devel@nongnu.org, ehabkost@redhat.com, armbru@redhat.com, imammedo@redhat.com, =?UTF-8?B?Q8OpZHJpYw==?= Le Goater <clg@kaod.org>

On Wed, 21 Sep 2016 15:29:26 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> Now that we allow CPU hot unplug on a few platforms, we can end up in a
> situation where we don't have a CPU with index 0.  Or at least we could,
> if we didn't have code to explicitly prohibit unplug of CPU 0.
>=20
> Longer term we want to allow CPU 0 unplug, this patch is an early step in
> allowing this, by removing an assumption in the monitor code that CPU 0
> always exists.
>=20
> Signed-off-by: C=C3=A9dric Le Goater <clg@kaod.org>
> [dwg: Rewrote commit message to better explain background]
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  monitor.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>=20
> Anyone want to volunteer to take this through their tree?  If not, I
> can take it through my ppc tree.

Please do.

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>

>=20
> diff --git a/monitor.c b/monitor.c
> index 8bb8bbf..83c4edf 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -1025,7 +1025,7 @@ int monitor_set_cpu(int cpu_index)
>  CPUState *mon_get_cpu(void)
>  {
>      if (!cur_mon->mon_cpu) {
> -        monitor_set_cpu(0);
> +        monitor_set_cpu(first_cpu->cpu_index);
>      }
>      cpu_synchronize_state(cur_mon->mon_cpu);
>      return cur_mon->mon_cpu;