Re: [Qemu-devel] [RFC PATCH qemu] qmp: Add qom-list-properties to list QOM object properties

[Andrea Bolognani]

On Mon, 2018-02-05 at 14:30 +1100, Alexey Kardashevskiy wrote:
> On 02/02/18 18:37, Markus Armbruster wrote:
> > > > Likewise for properties created differently (say with a different type)
> > > > in non-default configuration.  We can hope that no such beasts exist.
> > > > Since properties get created by code, and code can do anything, we're
> > > > reduced to hope.  Data is so much easier to reason about than code.
> > > > 
> > > > Three building blocks: instantiate, qom-list, destroy.  Do we want the
> > > > building blocks, or do we want their combination qom-list-properties?
> > > 
> > > Building blocks as QEMU internal helpers to split my
> > > qmp_qom_list_properties() into? These are not going to be huge and
> > > "destroy" is literally object_unref(obj) which does not seem very useful.
> > > Or I missed the point here?
> > 
> > My question is whether the QMP interface should provide the building
> > blocks, or only compositions.
> 
> instantiate but not realize? Not sure we have users for that.

We already have scaffolding for dealing with device-list-properties
in libvirt, so the implementation of qom-list-properties proposed
by Alexey would probably be able to reuse a lot of code and could
be integrated very quickly. So there's that.

Would there be any other known use case for providing the building
blocks?

-- 
Andrea Bolognani / Red Hat / Virtualization