From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:45687) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ggQ1A-0001pr-TZ for qemu-devel@nongnu.org; Mon, 07 Jan 2019 03:12:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ggQ1A-00005C-0O for qemu-devel@nongnu.org; Mon, 07 Jan 2019 03:12:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38374) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ggQ19-0008WG-Ov for qemu-devel@nongnu.org; Mon, 07 Jan 2019 03:12:15 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1BA6D58E23 for ; Mon, 7 Jan 2019 08:12:14 +0000 (UTC) Date: Mon, 7 Jan 2019 09:12:06 +0100 From: Cornelia Huck Message-ID: <20190107091206.6b5bd772.cohuck@redhat.com> In-Reply-To: <20190104220050.GK4157@habkost.net> References: <20190104032226.21428-1-ehabkost@redhat.com> <20190103232012-mutt-send-email-mst@kernel.org> <20190104101200.GA2494@work-vm> <20190104175439.GH4157@habkost.net> <20190104200952.GI4157@habkost.net> <20190104154723-mutt-send-email-mst@kernel.org> <20190104210656.GJ4157@habkost.net> <20190104161217-mutt-send-email-mst@kernel.org> <20190104220050.GK4157@habkost.net> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] compat: Use explicit type names on HW_COMPAT_2_6 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: "Michael S. Tsirkin" , "Dr. David Alan Gilbert" , qemu-devel@nongnu.org, Thomas Huth On Fri, 4 Jan 2019 20:00:50 -0200 Eduardo Habkost wrote: > On Fri, Jan 04, 2019 at 04:13:15PM -0500, Michael S. Tsirkin wrote: > > On Fri, Jan 04, 2019 at 07:06:56PM -0200, Eduardo Habkost wrote: > > > On Fri, Jan 04, 2019 at 03:48:02PM -0500, Michael S. Tsirkin wrote: > > > > On Fri, Jan 04, 2019 at 06:09:52PM -0200, Eduardo Habkost wrote: > > > > > Anyway, while writing this I noticed another issue: many of the > > > > > virtio devices in QEMU 2.6 were already modern-only! > > > > > > > > > > Setting disable-modern=off on modern-only devices like virtio-vga > > > > > or virtio-tablet-pci doesn't make sense. This means setting > > > > > virtio-pci.disable-modern=off on HW_COMPAT_2_6 was incorrect even > > > > > before the -non-transitional and -transitional device types were > > > > > introduced. > > > > > > > > > > > > It did create an opportunity to create non working devices. > > > > > > > > Whether that's incorrect as such I'm not sure. > > > > > > This is not just creating the opportunity for an user to > > > disable-modern=on. HW_COMPAT_2_6 is actually setting > > > disable-modern=on on virtio-vga and other modern-only devices. > > > Sounds like a mistake to me. > > > > > > Luckily those modern-only devices silently ignore the > > > disable-modern/disable-legacy properties, but this might change > > > in the future. > > > > Worry about it then? > > Right, we don't need to worry about it today. But if a solution > to the crash reported by Thomas will make the problem go away, > that's even better. It seems your patch with the modern-only devices removed from the list would achieve that?