[Libguestfs] FYI: virtio-pci will be the default with libvirt 3.0.0, aarch64 & -M virt

[Andrea Bolognani]

On Mon, 2017-01-16 at 14:19 +0000, Richard W.M. Jones wrote:
> I previously wrote a patch to make this happen in libguestfs:
> 
>   https://www.redhat.com/archives/libguestfs/2016-October/thread.html#00078
> 
> However the change was still being finalized in qemu & libvirt at that
> time, so I think that patch is probably not quite right for the final
> qemu/libvirt.  In any case nothing is upstream.

The patch you wrote in October looks still applicable to me,
but with libvirt 3.0.0 you won't even need to change anything
in libguestfs to get virtio-pci on aarch64, as it's the new
default.

You might still want to manually assign PCI addresses in
libguestfs in order to minimize the number of PCI controllers,
but maybe the difference will not big enough to offset the
disadvantage of having to take the matter into your own hands
instead of relying on libvirt.

> This is just a note that things will probably be broken for
> LIBGUESTFS_BACKEND=libvirt + libvirt 3.0.0 + aarch64 until we fix this
> in libguestfs.

As long as you're sticking with upstream components, the
change should be mostly transparent to users; on RHELSA,
the combination you listed will indeed stop working until
https://bugzilla.redhat.com/1337510 has been taken care of,
with once again no need to change libguestfs AFAICT.

-- 
Andrea Bolognani / Red Hat / Virtualization