From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:44836) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QfAj1-0002ur-EQ for qemu-devel@nongnu.org; Fri, 08 Jul 2011 09:04:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QfAiz-00004v-Rp for qemu-devel@nongnu.org; Fri, 08 Jul 2011 09:04:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61982) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QfAiz-0008WH-Gv for qemu-devel@nongnu.org; Fri, 08 Jul 2011 09:04:05 -0400 Message-ID: <4E16FFE0.7050709@redhat.com> Date: Fri, 08 Jul 2011 15:02:24 +0200 From: Jes Sorensen MIME-Version: 1.0 References: <4E148776.4000805@redhat.com> <4E149B3F.2010709@redhat.com> <4E14BF36.3080803@codemonkey.ws> <6E6E2CFC-B5BB-4E1D-945D-1F13C604330B@suse.de> <4E155CB9.4020009@redhat.com> <4E15608D.5000201@redhat.com> In-Reply-To: <4E15608D.5000201@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 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: Avi Kivity Cc: Alexander Graf , Juan Quintela , "qemu-devel@nongnu.org" , Markus Armbruster , Gerd Hoffmann On 07/07/11 09:30, Avi Kivity wrote: > On 07/07/2011 10:14 AM, Gerd Hoffmann wrote: >>> Can't we just implicitly fail migration whenever there's a device in >>> the tree that doesn't have VMSTATE? >> >> >> There are cases where the device doesn't need to save state, so that >> alone doesn't cut it. > > It should then say so by having an empty VMSTATE descriptor. It seems reasonable to me to introduce a situation where devices have to explicitly marked as migration compatible and fail if there are devices in the system which are not. Even for the case like USB devices where migration might simply force a replug of the devices. Cheers, Jes