From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:53032) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QeqQr-0001Xd-6f for qemu-devel@nongnu.org; Thu, 07 Jul 2011 11:24:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QeqQo-0006x6-1z for qemu-devel@nongnu.org; Thu, 07 Jul 2011 11:24:01 -0400 Received: from mail-ww0-f41.google.com ([74.125.82.41]:54545) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QeqQn-0006wh-KF for qemu-devel@nongnu.org; Thu, 07 Jul 2011 11:23:57 -0400 Received: by wwi14 with SMTP id 14so4317477wwi.4 for ; Thu, 07 Jul 2011 08:23:56 -0700 (PDT) Sender: Paolo Bonzini Message-ID: <4E15CF88.8080404@redhat.com> Date: Thu, 07 Jul 2011 17:23:52 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <4E148776.4000805@redhat.com> <4E1497C6.4060505@codemonkey.ws> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] migration: new sections and backward compatibility. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: "qemu-devel@nongnu.org" , jes sorensen , Gerd Hoffmann , Markus Armbruster , Juan Quintela On 07/07/2011 01:02 PM, Alexander Graf wrote: > I'd guess the best would be to have a special VMSTATE that means > "broken old version doesn't send a section" which we can set for > special -M? No, the best would be to have a serious migration format, based for example on ASN.1 which Michael Tsirkin was playing with. We cannot keep bolting more and more stuff on top of the current protocol, especially since adding a new protocol is not that hard (old machine types can keep the old protocol). > That would of course not help with RHEL:). At least for RHEL6 we can live with adding a few hacks here and there. Paolo