Re: [PATCH 7/8] qmp: add filtering of statistics by name

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Paolo Bonzini (pbonzini@redhat.com) wrote:
> On 4/27/22 17:16, Dr. David Alan Gilbert wrote:
> > * Paolo Bonzini (pbonzini@redhat.com) wrote:
> > > On 4/27/22 14:34, Dr. David Alan Gilbert wrote:
> > > > If I specify a 'vm' it's not obvious to me whether I'd get NICs and
> > > > block devices in the future?
> > > 
> > > VM would not get those (it's global statistics), but the size could balloon
> > > if you specify no target at all.
> > > 
> > > > Adding a syntax for 'all' into the vcpus list would fix that?
> > > 
> > > I don't like having special syntax.  The current QAPI just doesn't filter
> > > what is not in the arguments.
> > 
> > Is there a object that represents the set of all vcpus?
> 
> No.

If it was easy to create one then you could remove all the special
casing of vCPUs/VM target?
(It feels really like you should call a 'stats' method on the target)

> > > Yes, those would have different providers.  But a single target can support
> > > multiple providers.
> > 
> > Is that just for different implementations - kvm/hcf/tcg etc or do you
> > envisage multiple providers on an object in a running VM?
> 
> I think multiple providers are possible for a single object, for example a
> device could expose both PCI (how many MSIs, etc.) and SCSI (how many
> commands sent/succeeded/failed) statistics.

Yeh fair enough.

Dave

> Paolo
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK