From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51772) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YDW5K-00061p-UZ for qemu-devel@nongnu.org; Tue, 20 Jan 2015 05:30:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YDW5F-0000oy-WC for qemu-devel@nongnu.org; Tue, 20 Jan 2015 05:30:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60230) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YDW5F-0000oN-Px for qemu-devel@nongnu.org; Tue, 20 Jan 2015 05:30:53 -0500 Date: Tue, 20 Jan 2015 16:00:37 +0530 From: Amit Shah Message-ID: <20150120103037.GH31174@grmbl.mre> References: <1419604968-87437-1-git-send-email-agraf@suse.de> <1419604968-87437-5-git-send-email-agraf@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1419604968-87437-5-git-send-email-agraf@suse.de> Subject: Re: [Qemu-devel] [PATCH v3 4/5] migration: Append JSON description of migration stream List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: pbonzini@redhat.com, quintela@redhat.com, qemu-devel@nongnu.org, afaerber@suse.de On (Fri) 26 Dec 2014 [15:42:47], Alexander Graf wrote: > One of the annoyances of the current migration format is the fact that > it's not self-describing. In fact, it's not properly describing at all. > Some code randomly scattered throughout QEMU elaborates roughly how to > read and write a stream of bytes. > > We discussed an idea during KVM Forum 2013 to add a JSON description of > the migration protocol itself to the migration stream. This patch > adds a section after the VM_END migration end marker that contains > description data on what the device sections of the stream are composed of. Can you add a note saying why this is safe for migrations to qemu versions that don't expect this new json data? Amit