[libvirt] [PATCH v2 0/4] New mdev type handling for aggregated resources

[Erik Skultety]

On Thu, Jul 26, 2018 at 06:04:10PM +0200, Cornelia Huck wrote:
> On Thu, 26 Jul 2018 17:43:45 +0200
> Erik Skultety <eskultet at redhat.com> wrote:
>
> > On Thu, Jul 26, 2018 at 05:30:07PM +0200, Cornelia Huck wrote:
> > > One thing I noticed is that we have seem to have an optional (?)
> > > vendor-driver created "aggregation" attribute (which always prints
> > > "true" in the Intel driver). Would it be better or worse for libvirt if
> > > it contained some kind of upper boundary or so? Additionally, would it
> >
> > Can you be more specific? Although, I wouldn't argue against data that conveys
> > some information, since I would treat the mere presence of the optional
> > attribute as a supported feature that we can expose. Therefore, additional
> > *structured* data which sets clear limits to a certain feature is only a plus
> > that we can expose to the users/management layer.
>
> My question is what would be easiest for libvirt:
>
> - "aggregation" attribute only present when driver supports aggregation
>   (possibly containing max number of resources to be aggregated)
> - "aggregation" attribute always present; contains '1' if driver does
>   not support aggregation and 'm' if driver can aggregate 'm' resources

Both are fine from libvirt's POV, but IMHO the former makes a bit more sense
and I'm in favour of that one, IOW the presence of an attribute denotes a new
functionality which we can report, if it's missing, the feature is clearly
lacking- I don't think we (libvirt) should be reporting the value 1 explicitly
in the XML if the feature is missing, we can assume 1 as the default.

Erik