Re: ObjectPropertyInfo design

[Markus Armbruster <armbru@redhat.com>]

Markus Armbruster <armbru@redhat.com> writes:

> Marc-André Lureau <marcandre.lureau@redhat.com> writes:
>
> [Possible improvement to the QAPI/QMP QOM introspection interface...]
>
>>> Thoughts?
>>
>> I like it overall.
>>
>> But this goes beyond the intended scope of the series.
>> Blending/merging QOM type & QAPI type would warrant more design
>> research. So covering child<> & link<> are out of scope of the current
>> qom-qapi series. I think the addition of qapi-type shouldn't be
>> incompatible with a future proposal, after all all properties should
>> have some 'wire' type (link/child are paths). But we can drop it for
>> now or just rename it x-qapi-type until we agree on the new
>> introspection.
>>
>> my2c
>
> Adding @qapi-type with feature unstable means we don't have to worry
> about the external interface now.  One less hurdle for merging.  I like
> it.
>
> Whether changing the @type values is safe remains somewhat unclear.  See
>
>     Subject: Property types changed in this series (was: [PATCH v7 00/65] Hi)
>     Date: Wed, 21 Oct 2026 18:29:40 +0200
>     Message-ID: <87tsmfkoej.fsf@pond.sub.org>

We're about to miss the soft freeze.  Not your fault; I've been awfully
slow reviewing this.

The series is quite big.  If we can't get it merged, we'll have to
rebase and update it.  Not good.

Here's a possible way forward:

1. We tweak this series to retain the existing @type values.

   As is, the series changes @type to the QAPI type where applicable.
   This is an improvement, and *probably* safe enough, but I'm reluctant
   to accept the risk this late in the development cycle.

   I can do the tweaking.  It'll be mildly icky, but should go away
   fairly soon.

2. We mark @qapi-type unstable for now.

3. Try hard to get it merged in time for 11.2.

We can then improve on top at our leisure:

* If we convince ourselves that changing @type values is worthwhile and
  safe enough, do so early in a development cycle.

* Hunt down the remaining properties that don't use a QAPI type.

* Explore more comprehensive improvements to QOM introspection.

* Settle on a new QOM introspection interface, deprecate the old crap.

What do you think, Marc-André?