[libvirt] [PATCH 3/3] qemu: use qemu-xhci USB controller by default for ppc64 and aarch64

[Andrea Bolognani]

On Wed, 2017-04-26 at 18:59 +0200, Pavel Hrdina wrote:
> > If qemu-xhci is not available but usb-nec-xhci is, it would
> > probably be nicer to pick the latter rather than leaving it
> > unspecified (which will result in an error later on).
> 
> This is not true, if the qemu-xhci is not available libvirt will set
> piix3-uhci if available as a default for aarch64.  Only in case that
> piix3-uhci is not available it will fail.

You're technically correct[1]. However, piix3-uhci is
another piece of Intel-derived hardware so in practice
qemu-system-aarch64 is very unlikely to have it compiled
in and most users will end up getting the error instead.

> > So I would basically use the same code as ppc64 here, minus
> > the pci-ohci part of course.
> 
> That should be addressed by a separate patch.

Agreed. I suggest adding a patch at the beginning of the
series that makes nec-xhci the default for aarch64 if
available as in ppc64, and then make qemu-xhci the new
default for both in this patch. Would that work for you?


[1] Which is the best kind of correct! ;)
-- 
Andrea Bolognani / Red Hat / Virtualization