Re: [Qemu-devel] QEMU: PCI bus name on PowerPC platforms

[Alexander Graf <agraf@suse.de>]

On 11.04.14 14:27, Eric Blake wrote:
> On 04/11/2014 05:40 AM, Alexey Kardashevskiy wrote:
>
>>> but AFAICT nothing got merged to change this for all the other boards as
>>> discussed here :-(  This is painful for libvirt since we have todo even
>>> more hacks triggered off machine names now, instead of being able to
>>> rely on pci.0 naming as we hoped.
>> Sorry, I am missing the point.
>> How could making a platform similar to many others force you to do more
>> hacks, not less?
> As mentioned in the thread here:
> https://lists.gnu.org/archive/html/qemu-devel/2014-04/threads.html#01565
>
> If there is a way to query via QMP to see which naming scheme is in
> effect, there are no hacks involved - we just ask and get it right.
>
> If ALL platforms behave identically as of a certain release, we have a
> minimal hack - catering to releases older than that, where a downstream
> backport may have to tweak how we detect older releases, but it is only
> a single place to be hacked.
>
> But with just this patch, you have caused the situation where it is
> neither introspectible, nor consistent across qemu versions.  The only
> way to code that up in libvirt is to do MULTIPLE version checks and
> correlate it with architecture checks - and that's the hack we don't
> want to have to support.  Every single version check done in lieu of
> proper feature introspection is yet one more pain point when features
> get backported across version numbers downstream.

So how do you support -M ppce500 which also uses pci.0 and runs on 
(booke) ppc64?


Alex