From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:34211) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tiklg-0001S2-Tc for qemu-devel@nongnu.org; Wed, 12 Dec 2012 06:46:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tikla-0004jc-KW for qemu-devel@nongnu.org; Wed, 12 Dec 2012 06:46:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:14020) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tikla-0004jU-D5 for qemu-devel@nongnu.org; Wed, 12 Dec 2012 06:46:22 -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 qBCBkL6F024428 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 12 Dec 2012 06:46:21 -0500 Message-ID: <50C86E8B.5020705@redhat.com> Date: Wed, 12 Dec 2012 12:46:19 +0100 From: Gerd Hoffmann MIME-Version: 1.0 References: <1354808473-7634-1-git-send-email-alevy@redhat.com> In-Reply-To: <1354808473-7634-1-git-send-email-alevy@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] qxl: use correct rom size for revision < 4 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alon Levy Cc: qemu-devel@nongnu.org On 12/06/12 16:41, Alon Levy wrote: > RHBZ 869981 > > Before this patch revision < 4 (4 is the default) would result in a wrong > qxl_rom size of 16384 instead of 8192 when building with > spice-protocol-0.12, due to the addition of fields in > the rom for client capabilities and monitors config that were added > between spice-protocol 0.10 and 0.12. > > The solution is a bit involved, since I decided not to change QXLRom > which is defined externally in spice-protocol. Instead for revision < 4 > we allocate 72 bytes for the QXLRom on the qxl_rom bar (bytes [0,71]) > and make sure no fields out of that range are accessed, via checking of > the revision and nop-ing. Ok, I see we tackle two issues here. Number one is qxl accessing the new fields with revision being < 4. That needs fixing indeed. But separate patch please. Number two is breaking migration due to the rom size change. Can't we just get the rom below 8k again instead? I think we can throw away a whole bunch of modes. Each mode is four times in the list, for orientation = { 0, 1, 2, 3 }. orientation is never ever used anywhere, looks like historic leftover or something planned which was never actually implemented. So keeping orientation = 0 only and kick out everything else should give us plenty of room ... cheers, Gerd