From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54707) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fqeZJ-0004Uk-Od for qemu-devel@nongnu.org; Fri, 17 Aug 2018 09:13:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fqeZE-0002Zr-Fw for qemu-devel@nongnu.org; Fri, 17 Aug 2018 09:13:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38180) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fqeZE-0002ZT-AJ for qemu-devel@nongnu.org; Fri, 17 Aug 2018 09:13:28 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B57AE3084218 for ; Fri, 17 Aug 2018 13:13:27 +0000 (UTC) From: Markus Armbruster References: <68a98c1b-e6dd-f2df-1499-17c2b8b583be@redhat.com> <20180817092936.GC11124@redhat.com> <20180817104351.GG11124@redhat.com> Date: Fri, 17 Aug 2018 15:13:22 +0200 In-Reply-To: <20180817104351.GG11124@redhat.com> ("Daniel P. =?utf-8?Q?Ber?= =?utf-8?Q?rang=C3=A9=22's?= message of "Fri, 17 Aug 2018 11:43:51 +0100") Message-ID: <878t5516h9.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [libvirt] clean/simple Q35 support in libvirt+QEMU for guest OSes that don't support virtio-1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. =?utf-8?Q?Berrang=C3=A9?=" Cc: Andrea Bolognani , Libvirt , qemu list , Laine Stump Daniel P. Berrang=C3=A9 writes: > On Fri, Aug 17, 2018 at 12:35:11PM +0200, Andrea Bolognani wrote: >> On Fri, 2018-08-17 at 10:29 +0100, Daniel P. Berrang=C3=A9 wrote: >> > On Thu, Aug 16, 2018 at 06:20:29PM -0400, Laine Stump wrote: >> > > 5) Some guest OSes that we still want to support (and which would >> > > otherwise work okay on a Q35 virtual machine) have virtio drivers too >> > > old to support virtio-1.0 (CentOS6 and RHEL6 are examples of such OS= es), >> > > but due to the chain of reasons listed above, the "standard" config = for >> > > a Q35 guest generated by libvirt doesn't support virtio-0.9, hence >> > > doesn't support these guest OSes. >> >=20 >> > Note when talking about "support" you're really saying it from the >> > downstream vendor, specifically RHEL, POV. From upstream or Fedora POV >> > essentially all x86 OS ever made are in scope for running under QEMU >> > if suitable virtual hardware models have been provided. QEMU doesn't >> > maintain any whitelist of "supported" OS that differs from what is >> > technically capable of being run, in the way downstream vendors do. >>=20 >> Well, at least in the case of RHEL 6, "not supported" means that it >> will not boot at all on q35 with the default guest topology created >> by libvirt, so that's not really a downstream-only problem :) > > I mean from an upstream POV we still support RHEL-6 fine in i440fx, > so there's no reason to particularly care about RHEL-6 with q35 > upstream. Only true if Q35 provides nothing of value over i440FX for RHEL-6 guests. Does it? > It is only downstream decision to try to force it to > use q35, despite it not working right today.