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

[Andrea Bolognani]

On Tue, 2018-01-23 at 23:49 +1100, David Gibson wrote:
> It's also occurred to me that making a spapr specific approach to this
> might not be quite as horrible as I initially thought.  The
> capabilities table is global (and immutable) so coding up a
> "get-spapr-caps" qapi entry point which encodes the stuff there into
> json giving the names and allowed values of each cap would be fairly
> straightforward.

OTOH, qom-list-properties is a superset of device-list-properties
so it could be used instead of it if supported; plus it would
expose properties of machines which are not also capabilities and
properties of non-pSeries machine types. There could be value in
taking the more generic approach.

> Accurately retreiving default values would be trickier, not sure if
> that's important or not.

Not sure. I think it's okay not to expose that information, since
there are other areas where defaults are not exposed and so all
libvirt can do is document that not *explicitly* setting a feature
will result in the hypervisor default, whatever that might happen
to be, being enforced.

-- 
Andrea Bolognani / Red Hat / Virtualization