Re: [PATCH 00/18] qapi/qom: QAPIfy object-add

[Gerd Hoffmann]

  Hi,

> It would be much nicer to do the wrapper the other way round, i.e.
> setting properties before the device is realized would update a
> configuration struct and realize would then call .create() with that
> struct. To me, this sounds much harder, though also a more useful state.

Well, in some places we already have separate config structs.  We have
NICConf for example, which is typically used like this:

        struct USBNetState {
           USBDevice dev;
           [ ... ]
           NICConf conf;
           [ ... ]
        };

and

        static Property net_properties[] = {
            DEFINE_NIC_PROPERTIES(USBNetState, conf),
            DEFINE_PROP_END_OF_LIST(),
        };

So I think we could:

  (1) move *all* properties into structs.
  (2) generate those structs from qapi schemas.
  (3) generate Property lists (or functions with
      object_class_property_add_*() calls) from qapi
      schema.

We could then convert devices one-by-one without breaking anything
or needing two code paths essentially doing the same thing in two
different ways.

take care,
  Gerd