Re: [PATCH for-5.2 4/4] qemu-option: warn for short-form boolean options

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> On 03/11/20 17:08, Daniel P. Berrangé wrote:
>>> +Short-form boolean options (since 5.2)
>>> +''''''''''''''''''''''''''''''''''''''
>>> +
>>> +Boolean options such as ``share=on``/``share=off`` can be written
>>> +in short form as ``share`` and ``noshare``.  This is deprecated
>>> +for all command-line options except ``-chardev` and ``-spice``, for
>>> +which the short form was in wide use.
>> 
>> So IIUC, the short form was possible to use for absolutely /any/
>> boolean property ?
>
> s/boolean// (yikes)

Yup.  "-device virtio-blk,drive=blk0,serial" gives you the lovely serial
number "on".

>> IMHO if we're going to deprecate short forms, we should do it
>> universally including chardev and spice. Arguably spice/chardev
>> are the most important ones to give an explicit warning about
>> precisely because their widespread usage means a heads up is
>> important to users.
>
> Chardevs will probably become user-creatable objects; for -spice I was
> hoping that it would be QAPIfied as "-display spice" which does not
> support short forms, but I'm not sure if Gerd agrees.  In both cases,
> the problem would be taken care of in a different way.

Taken care of only if we deprecate -chardev and -spice wholesale, not if
we keep them forever as sugar for -object.

> I can certainly warn for all of them, but I was thinking of the
> lowest-impact option for 5.2 since we're already in soft freeze.

I'm quite interested in getting rid of this sugar.  I'm not particular
on how exactly, and I understand your reluctance to mess with 5.2.