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

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(a)redhat.com&gt; 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.