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Date: Fri, 13 Oct 2017 10:46:22 +0200
From: Cornelia Huck <cohuck@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 0/2] monitor: increase the refcount of the
 current CPU
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To: Greg Kurz <groug@kaod.org>
Cc: qemu-devel@nongnu.org, qemu-ppc@nongnu.org, David Gibson <david@gibson.dropbear.id.au>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Igor Mammedov <imammedo@redhat.com>, Markus Armbruster <armbru@redhat.com>

On Fri, 13 Oct 2017 10:35:06 +0200
Greg Kurz <groug@kaod.org> wrote:

> If a CPU selected with the "cpu" command is hot-unplugged then "info cpus"
> causes QEMU to exit:
>     
> (qemu) device_del cpu1
> (qemu) info cpus
> qemu:qemu_cpu_kick_thread: No such process
> 
> I could verify that this happens with x86 and ppc, but I guess s390x is
> also impacted.

Not really, as s390x does not support cpu unplug.

> 
> This series tries to fix the issue by using object_ref() and object_unref()
> in the monitor code. For this to work on ppc, some preliminary work is
> needed to let QOM handle the CPU object lifecycle.
> 
> Please comment.
> 
> --
> Greg
> 
> ---
> 
> Greg Kurz (2):
>       spapr_cpu_core: instantiate CPUs separately
>       monitor: add proper reference counting of the current CPU
> 
> 
>  hw/ppc/spapr.c                  |   10 +++-------
>  hw/ppc/spapr_cpu_core.c         |   29 +++++++++--------------------
>  include/hw/ppc/spapr_cpu_core.h |    2 +-
>  monitor.c                       |   12 ++++++++++++
>  4 files changed, 25 insertions(+), 28 deletions(-)
>