From: "Daniel P. Berrange" <berrange@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 3/3] deal with guest panicked event
Date: Tue, 12 Jun 2012 13:40:45 +0100
Message-ID: <20120612124045.GK10153@redhat.com>
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Reply-To: "Daniel P. Berrange" <berrange@redhat.com>
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Cc: Wen Congyang <wency@cn.fujitsu.com>,
	kvm list <kvm@vger.kernel.org>,
	qemu-devel <qemu-devel@nongnu.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Avi Kivity <avi@redhat.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	Gleb Natapov <gleb@redhat.com>
To: Luiz Capitulino <lcapitulino@redhat.com>
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On Tue, Jun 12, 2012 at 09:35:04AM -0300, Luiz Capitulino wrote:
> On Tue, 12 Jun 2012 14:55:37 +0800
> Wen Congyang <wency@cn.fujitsu.com> wrote:
> 
> > >> +static void panicked_perform_action(void)
> > >> +{
> > >> +    switch(panicked_action) {
> > >> +    case PANICKED_REPORT:
> > >> +        panicked_mon_event("report");
> > >> +        break;
> > >> +
> > >> +    case PANICKED_PAUSE:
> > >> +        panicked_mon_event("pause");
> > >> +        vm_stop(RUN_STATE_GUEST_PANICKED);
> > >> +        break;
> > >> +
> > >> +    case PANICKED_QUIT:
> > >> +        panicked_mon_event("quit");
> > >> +        exit(0);
> > >> +        break;
> > >> +    }
> > > 
> > > Having the data argument is not needed/wanted. The mngt app can guess it if it
> > > needs to know it, but I think it doesn't want to.
> > 
> > Libvirt will do something when the kernel is panicked, so it should know the action
> > in qemu side.
> 
> But the action will be set by libvirt itself, no?

Sure, but the whole world isn't libvirt. If the process listening to the
monitor is not the same as the process which launched the VM, then I
think including the action is worthwhile. Besides, the way Wen has done
this is identical to what we already do with QEVENT_WATCHDOG and I think
it is desirable to keep consistency here.

Daniel
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