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Date: Wed, 21 Aug 2013 10:17:49 -0400
From: Luiz Capitulino <lcapitulino@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] vl: allow "cont" from panicked state
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: pkrempa@redhat.com, marcel.a@redhat.com, libvir-list@redhat.com, hutao@cn.fujitsu.com, mst@redhat.com, qemu-stable@nongnu.org, qemu-devel@nongnu.org, rhod@redhat.com, kraxel@redhat.com, anthony@codemonkey.ws, Laszlo Ersek <lersek@redhat.com>, afaerber@suse.de

On Wed, 21 Aug 2013 14:43:11 +0200
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Il 21/08/2013 14:42, Laszlo Ersek ha scritto:
> > (*) Hm I think I understand why. main_loop_should_exit(), when a reset
> > was requested *and* runstate_needs_reset() evaluated to true, used to
> > set the runstate to PAUSED -- I guess temporarily.
> 
> Yes, this is the code that does the PANICKED -> PAUSED transition:
> 
>         if (runstate_needs_reset()) {
>             runstate_set(RUN_STATE_PAUSED);
>         }
> 
> This is to move the system out of a runstate that needs_reset(), and
> make the subsequent "cont" work instead of hitting this:
> 
>     if (runstate_needs_reset()) {
>         error_set(errp, QERR_RESET_REQUIRED);
>         return;
>     }

Yes. For those states issuing 'cont' won't put the guest to run again,
so you're required to reset the guest first.

I think the same reasoning went behind the PANICKED state, and for most
cases it's going to be disastrous to put the guest to run again, but
I can understand that this is up user/mngt to decide this, not QEMU.