From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36098) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZuKWJ-0002e0-If for qemu-devel@nongnu.org; Thu, 05 Nov 2015 08:24:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZuKWG-0004pl-F5 for qemu-devel@nongnu.org; Thu, 05 Nov 2015 08:24:03 -0500 Received: from e06smtp14.uk.ibm.com ([195.75.94.110]:59003) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZuKWG-0004ob-5V for qemu-devel@nongnu.org; Thu, 05 Nov 2015 08:24:00 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 5 Nov 2015 13:23:57 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 251C52190056 for ; Thu, 5 Nov 2015 13:23:51 +0000 (GMT) Received: from d06av05.portsmouth.uk.ibm.com (d06av05.portsmouth.uk.ibm.com [9.149.37.229]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id tA5DNtAf41615570 for ; Thu, 5 Nov 2015 13:23:55 GMT Received: from d06av05.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av05.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id tA5DNshV002000 for ; Thu, 5 Nov 2015 06:23:54 -0700 References: <1446725610.30393.23.camel@redhat.com> From: Christian Borntraeger Message-ID: <563B586A.1060908@de.ibm.com> Date: Thu, 5 Nov 2015 14:23:54 +0100 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] virtio-gpu doesn't build if you do a linux-headers update from kvm/next List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , Gerd Hoffmann Cc: Paolo Bonzini , QEMU Developers Am 05.11.2015 um 13:32 schrieb Peter Maydell: > On 5 November 2015 at 12:13, Gerd Hoffmann wrote: >>> etc, because all the virtio_gpu definitions disappear from >>> include/standard-headers/linux/virtio_gpu.h. >> >> Updates not yet in mainline, they are sitting in drm-next and should >> land during the merge window (i.e. 4.4-rc1 should have them). >> >> I'd suggest to exclude virtio_gpu.h changes when updating linux headers >> for the time being. > > I would strongly prefer it if we could get to a point where > we can say "kernel headers must only be updated from this tree" > and be guaranteed that it always works. This used to be true > with the tree in question being kvm/next, but it doesn't seem > to be so now. If it's going to be common that we have header > changes that don't go via kvm/next, maybe we need to coordinate > a tree that merges together the abi-guaranteed-stable changes > from different places before they hit mainline? Yes I agree. In the end this might imply to only use Linus tree to merge things in qemu. This is probably fine regarding the Linux tree, as it has a 63/70 day cadence and we only synced from kvm/next after rc4 or so. So this might defer for 4,5, or 6 weeks. One problem why people won't like that is that the QEMU releases are not often enough, though, as missing the deadline will defer the feature for 4 or 5 month. 2014-04-17 Tag v2.0.0 2014-08-01 Tag v2.1.0 2014-12-09 Tag v2.2.0 2015-04-24 Tag v2.3.0 2015-08-11 Tag v2.4.0 2015-12-10 Tag v2.5.0 Maybe we should try to aim for a 3 month cadence for QEMU to reduce the pain of missing soft/hard freeze. -> maybe a topic for the next QEMU summit? Christian