[PATCH 1/9] qapi: New special feature flag "unstable"

[Markus Armbruster]

Daniel P. Berrangé <berrange at redhat.com> writes:

> On Tue, Oct 26, 2021 at 05:15:10PM +0200, Markus Armbruster wrote:
>> Daniel P. Berrangé <berrange at redhat.com> writes:
>> 
>> > On Tue, Oct 26, 2021 at 11:37:19AM +0200, Markus Armbruster wrote:

[...]

>> >> Management applications are better off with a feature flag than with a
>> >> naming convention we sometimes ignore.
>> >
>> > We will sometimes ignore/forget the feature flag too though, so I'm
>> > not convinced there's much difference there.
>> 
>> -compat unstable-input=reject,unstable-output=hide should help you stay
>> on the straight & narrow :)
>
> That's from the pov of the mgmt app. I meant from the POV of QEMU
> maintainers forgetting to add "unstable" flag, just as they might
> forget to add a "x-" prefix.

Got it.

My point was that feature flag "unstable" is an unequivocal signal for
"this thing is unstable", while a name starting with "x-" isn't: there
are exceptions.

The converse is a wash: we can forget to mark something unstable no
matter how the mark works.