From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58426) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fLn1P-0001XL-Md for qemu-devel@nongnu.org; Thu, 24 May 2018 05:59:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fLn1O-00053q-To for qemu-devel@nongnu.org; Thu, 24 May 2018 05:58:59 -0400 Date: Thu, 24 May 2018 11:58:49 +0200 From: Kashyap Chamarthy Message-ID: <20180524095849.GB18277@paraplu> References: <20180518180440-mutt-send-email-mst@kernel.org> <20180518170956.GI8615@redhat.com> <20180518174133.GC25013@localhost.localdomain> <20180521201817.GA10382@redhat.com> <20180521203322.GU25013@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20180521203322.GU25013@localhost.localdomain> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] storing machine data in qcow images? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , kwolf@redhat.com, qemu-block@nongnu.org, "Michael S. Tsirkin" , qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com On Mon, May 21, 2018 at 05:33:22PM -0300, Eduardo Habkost wrote: > On Mon, May 21, 2018 at 09:18:17PM +0100, Daniel P. Berrang=E9 wrote: [...] (Just catching up with this thread.) [...] > > > I have very specific goal here: the goal is to make it less > > > painful to users when OpenStack+libvirt+QEMU switch to using a > > > different machine-type by default (q35), and/or when guest OSes > > > stop supporting pc-i440fx. I assume this is a goal for OpenStack > > > as well. > > >=20 > > > We can make the solution to be more extensible and solve other > > > problems as well, but my original goal is the one above. > >=20 > > Configuring the machine type is just one thing that users > > would do with OpenStack though. A simple example might be > >=20 > > openstack image set \ > > --property hw_disk_bus=3Dscsi \ > > --property hw_vif_model=3De1000e [...] > > Setting a non-default machine type is one extra prop > >=20 > > openstack image set \ > > --property hw_machine_type=3Dq35 > > --property os_distro=3Dfedora26 >=20 > Nice. Are these just hypothetical examples, or something that > already works? No, not hypothetical -- they actually work _today_, and customers actively use it in production as we speak. Machine type could be set in two ways in OpenStack. One is as Dan noted above, which is *per* disk image. The other is per Compute node (where QEMU instances are launched), via setting a config attribute in a file (/etc/nova/nova.conf): [libvirt] ... hw_machine_type=3Dx86_64=3Dpc-q35-2.9 The above means _all_ QEMU instances launched on that Compute node will get 'pc-q35-2.9' machine type. [...] --=20 /kashyap