From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38787) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bQLze-0006eD-8y for qemu-devel@nongnu.org; Thu, 21 Jul 2016 17:58:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bQLzb-0006UO-K2 for qemu-devel@nongnu.org; Thu, 21 Jul 2016 17:58:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47515) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bQLzb-0006UK-EZ for qemu-devel@nongnu.org; Thu, 21 Jul 2016 17:58:55 -0400 Message-ID: <1469138332.3363.66.camel@redhat.com> From: Gerd Hoffmann Date: Thu, 21 Jul 2016 23:58:52 +0200 In-Reply-To: <20160722003618-mutt-send-email-mst@kernel.org> References: <1469028501-23780-1-git-send-email-marcel@redhat.com> <20160722003618-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH V3] hw/virtio-pci: fix virtio behaviour List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Marcel Apfelbaum , qemu-devel@nongnu.org, cornelia.huck@de.ibm.com Hi, > Actually this can still break existing scripts: > stick a device on express bus but add disable-modern=3Don > Gave you a legacy device previously but it no longer does. Unlikely to happen in practice because there is little reason to use disable-modern=3Don in 2.6 & older because that is the default ... Still we can default to legacy=3Dyes in case disable-modern=3Don + disable-legacy=3Dauto. And throw and error in case both modern and legacy are explicitly disabled (as already suggested elsewhere in this thread). cheers, Gerd