From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44990) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YQIWF-0006hm-K0 for qemu-devel@nongnu.org; Tue, 24 Feb 2015 11:39:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YQIWA-0004He-Iq for qemu-devel@nongnu.org; Tue, 24 Feb 2015 11:39:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:58832) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YQIWA-0004Ha-Bb for qemu-devel@nongnu.org; Tue, 24 Feb 2015 11:39:30 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t1OGdT15015663 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Tue, 24 Feb 2015 11:39:29 -0500 Message-ID: <54ECA940.9050405@redhat.com> Date: Tue, 24 Feb 2015 11:39:28 -0500 From: John Snow MIME-Version: 1.0 References: <54ECA75E.30105@redhat.com> In-Reply-To: <54ECA75E.30105@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] QMP events and the migration of halted machines List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "quint >> juan quin >> Juan Jose Quintela Carreira" Cc: "Dr. David Alan Gilbert" , qemu-devel On 02/24/2015 11:31 AM, John Snow wrote: > In writing migration tests for qtest and ahci-test, I ran into an > interesting pattern and wanted to know if this was expected: > > 1) Using blkdebug, I inject an error to execute once for the first flush > request. > 2) Executing the command, I get a STOP event. > 3) I migrate the VM, and poll the source until it reports that it is > completed. > > So far, so good. > > 4) I receive a RESUME event from the destination, even though the > machine wasn't started. Small correction: BLOCK_IO_ERROR and STOP occur here. > 5) Naively, my script assumes the machine is stopped and sends > {"execute": "cont"} to resume execution from the failed flush command. > 6) I then see BLOCK_IO_ERROR, STOP, and then RESUME events in order. ...and not here. > 7) The command appears to then execute and finish successfully. > > Is this the expected flow? I perhaps naively assumed that the machine > would stay stopped during migration and wait for me to resume it, and > not what appears to happen, which is resume automatically and then stop. > > This flow seems *very* odd to me. >