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

[Paolo Bonzini <pbonzini@redhat.com>]

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.

>>>       "providers": [
>>>          { "provider": "kvm",
>>>            "names": [ "l1d_flush", "exits" ] } } }
>>>
>>> It's not clear to me whether the "target" should also be specific
>>> to a given provider.
>>
>> No, the target is a QEMU concept, such as a CPU or a device backend.  It is
>> identified by either a QOM path or a unique id.
> 
> But doesn't 'kvm' as a provider only make sense for vcpus and VMs; if
> you're imagining block devices and other things as targets it would seem
> wrong to have that set of providers separate.

Yes, those would have different providers.  But a single target can 
support multiple providers.

Paolo