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. Berrangé 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. > > > > > > We can make the solution to be more extensible and solve other > > > problems as well, but my original goal is the one above. > > > > Configuring the machine type is just one thing that users > > would do with OpenStack though. A simple example might be > > > > openstack image set \ > > --property hw_disk_bus=scsi \ > > --property hw_vif_model=e1000e [...] > > Setting a non-default machine type is one extra prop > > > > openstack image set \ > > --property hw_machine_type=q35 > > --property os_distro=fedora26 > > 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=x86_64=pc-q35-2.9 The above means _all_ QEMU instances launched on that Compute node will get 'pc-q35-2.9' machine type. [...] -- /kashyap