[libvirt] [RFC PATCH 00/12] Support multiple PHBs on pSeries guests

[Andrea Bolognani]

On Wed, 2017-03-01 at 11:47 +0000, Daniel P. Berrange wrote:
> > Note: if you want to try this out, you'll need to make sure
> >       your QEMU binary includes this commit[1]; moreover,
> >       that commit is missing a way for libvirt to detect
> >       whether the new naming scheme is in place, so this
> >       will have to remain an RFC until the QEMU side has
> >       been sorted out.
> 
> [snip]
> 
> > 
> > [1] https://github.com/dgibson/qemu/commit/0a6a9ba2adc48a9a5ea7406d1a5fb3c36f0073e0
> 
> IMHO changing QEMU naming just for sake of making PPC look slightly
> more like non-PPC architecture is not enough justification for making
> an incompatible change like this. As you show above, regardless of
> whether libvirt currently uses this feature or not, it hurts libvirt
> because when we do add support we need to be able to cope with new
> and old QEMU.  I'd suggest that commit is simply dropped unless there
> is a clear functional reason for why the naming must be changed, not
> merely a style reason.

Hm, you have a point. I'll try to see how difficult it
would be to teach PCI devices about the quirkiness in
bus naming when it comes to PHBs.

-- 
Andrea Bolognani / Red Hat / Virtualization