From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=36032 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OdPb8-0005Hk-3c for qemu-devel@nongnu.org; Mon, 26 Jul 2010 11:28:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OdPb3-0001Yl-3P for qemu-devel@nongnu.org; Mon, 26 Jul 2010 11:28:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29146) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OdPb2-0001YO-PV for qemu-devel@nongnu.org; Mon, 26 Jul 2010 11:28:05 -0400 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o6QFS2TC005769 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 26 Jul 2010 11:28:03 -0400 Message-ID: <4C4DA97F.2060003@redhat.com> Date: Mon, 26 Jul 2010 11:27:59 -0400 From: Laine Stump MIME-Version: 1.0 References: <20100723150818.69cde489@redhat.com> <20100724073124.GB5254@amit-laptop.redhat.com> <20100726112353.4771b3cd@redhat.com> In-Reply-To: <20100726112353.4771b3cd@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH] migration: Issue 'cont' only on successful incoming migration List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: Amit Shah , Paolo Bonzini , qemu list , quintela@redhat.com On 07/26/2010 10:23 AM, Luiz Capitulino wrote: > On Sat, 24 Jul 2010 13:01:24 +0530 > Amit Shah wrote: > >> On (Fri) Jul 23 2010 [15:08:18], Luiz Capitulino wrote: >>>> diff --git a/monitor.c b/monitor.c >>>> index 45fd482..d12a7b5 100644 >>>> --- a/monitor.c >>>> +++ b/monitor.c >>>> @@ -1056,6 +1056,10 @@ static int do_cont(Monitor *mon, const QDict *qdict, QObject **ret_data) >>>> { >>>> struct bdrv_iterate_context context = { mon, 0 }; >>>> >>>> + if (incoming_expected&& !incoming_done) { >>>> + autostart = 1; >>> Why do we need to set autostart? We should just fail if we're unable to run. >>> >>>> + return 1; /* Waiting for incoming migration */ >>> You should return -1 and use qerror_report(), so that we have a meaningful >>> error in the user Monitor and QMP (otherwise we'll get UndefinedError). >> That would mean old/existing libvirt will be confused on why guests >> wouldn't start even though it issued cont. > Yes, although delaying to start could cause a problem too and this is > also introducing an new error in QMP already. > > I really would like to avoid adding weird semantics, specially in QMP where > cont will return an error but will put the VM to run later. We could fix this > there only, but then it will get complex w/o reason. > > We should fix it properly right now, IMO. > >> If it's not a problem for the libvirt folks, I can do that. > Laine, could you please check that? That should really be answered by someone who better understands the implications (I'm a newcomer to that part of the code). Dan Berrange or Chris Lalancette maybe? (I am setting up to test the current version of the patch on the system where I can reproduce the problem. Haven't flipped the switch yet, though.)