From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43320) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cELig-0006q1-Al for qemu-devel@nongnu.org; Tue, 06 Dec 2016 14:48:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cELid-0007xY-NZ for qemu-devel@nongnu.org; Tue, 06 Dec 2016 14:48:06 -0500 Date: Tue, 6 Dec 2016 17:48:00 -0200 From: Eduardo Habkost Message-ID: <20161206194800.GH4027@thinpad.lan.raisama.net> References: <148104617887.7699.984921868108236415.stgit@bahia.lab.toulouse-stg.fr.ibm.com> <20161206213023-mutt-send-email-mst@kernel.org> <20161206193349.GF4027@thinpad.lan.raisama.net> <20161206213545-mutt-send-email-mst@kernel.org> <20161206194029.GG4027@thinpad.lan.raisama.net> <20161206214217-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161206214217-mutt-send-email-mst@kernel.org> Subject: Re: [Qemu-devel] [PATCH] virtio: fix HW_COMPAT_2_6 macro for virtio-*-pci drivers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Greg Kurz , qemu-devel@nongnu.org, Halil Pasic , qemu-stable@nongnu.org, Stefan Hajnoczi , Cornelia Huck , Paolo Bonzini On Tue, Dec 06, 2016 at 09:44:11PM +0200, Michael S. Tsirkin wrote: > On Tue, Dec 06, 2016 at 05:40:29PM -0200, Eduardo Habkost wrote: > > On Tue, Dec 06, 2016 at 09:36:07PM +0200, Michael S. Tsirkin wrote: > > > On Tue, Dec 06, 2016 at 05:33:49PM -0200, Eduardo Habkost wrote: > > > > On Tue, Dec 06, 2016 at 09:31:43PM +0200, Michael S. Tsirkin wrote: > > > > > On Tue, Dec 06, 2016 at 06:50:47PM +0100, Greg Kurz wrote: > > > > > > Since commit "9a4c0e220d8a hw/virtio-pci: fix virtio behaviour", passing > > > > > > -device virtio-blk-pci.disable-modern=off has no effect on 2.6 machine > > > > > > types because the internal virtio-pci.disable-modern=on compat property > > > > > > always prevail. > > > > > > > > > > > > This should ideally be fixed in the qdev properties core code, but it is > > > > > > too late in the QEMU 2.8 schedule. So this patch fixes the issue by setting > > > > > > the compat properties for every virtio-*-pci subtypes instead of the base > > > > > > virtio-pci type. > > > > > > > > > > > > Signed-off-by: Greg Kurz > > > > > > > > > > What's the rush? Either the issue is or isn't 2.8 material. If it is, > > > > > let's fix it in qdev core now. If it isn't no need for quick fixes, > > > > > just wait a bit and merge qdev core fix after 2.8 is out. > > > > > > > > Because it is a regression, > > > > > > Regression in 2.7 though, isn't it? > > > > Yes. Does that mean we don't mind leaving a regression unfixed in > > 2.8 because it was introduced in 2.7? > > Not necessarily, it's a judgement call. But there will always be > another release. I would say don't rush it. My judgement is that it won't hurt to include the HW_COMPAT_* fix for virtio-pci (this patch, after including the missing classes I pointed out), because it is simple and obvious. But I agree that this means we don't need the more complex hack I just sent as RFC. -- Eduardo