[vfio-users] Switching to Q35

[Patrick O'Callaghan]

On Sat, 2018-12-29 at 08:31 -0700, Alex Williamson wrote:
> On Sat, 29 Dec 2018 11:51:57 +0000
> "Patrick O'Callaghan" <poc at usb.ve> wrote:
> 
> > I'm interested in switching to Q35 but it isn't entirely trivial.
> > Simply editing the machine-type line in the XML file doesn't do it:
> > 
> > If I change:
> > 
> >    <type arch='x86_64' machine='pc-i440fx-3.0'>hvm</type>
> > 
> > to:
> > 
> >    <type arch='x86_64' machine='Q35'>hvm</type>
> > 
> > I get:
> > 
> >    Error: unsupported configuration: IDE controllers are unsupported
> > for this QEMU binary or machine type
> > 
> > I created the VM using Virtual Machine Manager under Fedora over a year
> > ago, so most of the settings were defaults at the time. Is there a
> > Dummy's Guide to changing this, or would it be easier to just create a
> > new VM (keeping the existing storage of course)? The man pages are
> > pretty unhelpful.
> 
> Use virtual machine manager again to create a Q35 VM and re-use your
> disk image.  Note that this is the same as moving your disk from one
> machine to another with potentially different disk and network
> controllers.  If you're using virtio for both, you're probably fine
> otherwise you might need to go back to the 440fx machine type and
> install extra drivers to make it work.  Also be sure to maintain the
> same firmware type in the VM, SeaBIOS or OVMF.  Switching between the
> two for an existing VM image is non-trivial.  Thanks,

Thanks Alex. I use virtio and OVMF so hopefully it should be
straightforward. I have a separate physical drive for this VM, so under
'storage' in VMM I gave the full drive rather than a partition. However
I immediately ran into this bug:

https://bugzilla.redhat.com/show_bug.cgi?id=1644848

The suggested fix is to delete .osxsave from the XML, but there is no
such string in the file.

BTW