From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36794) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bn0DV-0000M0-U9 for qemu-devel@nongnu.org; Thu, 22 Sep 2016 05:22:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bn0DT-000334-8l for qemu-devel@nongnu.org; Thu, 22 Sep 2016 05:22:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36358) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bn0DT-00032z-2G for qemu-devel@nongnu.org; Thu, 22 Sep 2016 05:22:51 -0400 References: <877fa5aiu4.fsf@dusky.pond.sub.org> <6373e011-5068-b0ae-5672-e3704af556d9@redhat.com> <87h998nvf6.fsf@dusky.pond.sub.org> From: Paolo Bonzini Message-ID: <6280ba63-cbe9-c2d3-ba8f-7de1369f059e@redhat.com> Date: Thu, 22 Sep 2016 11:22:45 +0200 MIME-Version: 1.0 In-Reply-To: <87h998nvf6.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v11 0/8] Add a generic loader List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Alistair Francis , Peter Maydell , Peter Crosthwaite , "qemu-devel@nongnu.org Developers" , Christopher Covington On 22/09/2016 11:19, Markus Armbruster wrote: >> > I think -device is okay for something that isn't a "backend" but is >> > directly guest-visible. > Well, the contents of a block device is just as guest-visible. We split > the device in a frontend and a backend, and the contents comes from the > backend. > > We traditionally don't model memory as a split device. Perhaps we > should. Regardless of whether we actually do, "contents of a memory > device that you need to create by some other means (explicit or > implicit)" feels much more like -object than like -device to me. The closest precedents here are "-bios" (not an object at all), PCI ROMs (a property points to the file), and "-pflash" (split into backend and frontend, the frontend being a device). I think there is a device concept in here, the question is whether you want to split the backend and frontend. For read-only data the precedents favor not splitting it. Paolo