Re: [Qemu-devel] [libvirt] [PULL 04/14] audio: -audiodev command line option basic implementation

[Markus Armbruster]

Pavel Hrdina <address@hidden> writes:

> On Tue, Mar 12, 2019 at 08:12:40AM +0100, Gerd Hoffmann wrote:
>> From: Kővágó, Zoltán <address@hidden>
>> 
>> Audio drivers now get an Audiodev * as config paramters, instead of the
>> global audio_option structs.  There is some code in audio/audio_legacy.c
>> that converts the old environment variables to audiodev options (this
>> way backends do not have to worry about legacy options).  It also
>> contains a replacement of -audio-help, which prints out the equivalent
>> -audiodev based config of the currently specified environment variables.
>> 
>> Note that backends are not updated and still rely on environment
>> variables.
>> 
>> Also note that (due to moving try-poll from global to backend specific
>> option) currently ALSA and OSS will always try poll mode, regardless of
>> environment variables or -audiodev options.
>
> Hi,
>
> I'm glad that this is merged now and I wanted to start working on
> libvirt patches, but there is one big issue with this command,
> it's not introspectable by query-command-line-options.
>
> My guess based on the QEMU code is that it uses the new function that
> allows you to use JSON on qemu command line.
>
> Without the introspection libvirt cannot implement the new option in
> sensible way (without version check).
>
> Adding Markus to CC so we can figure out how to wire up the
> introspection for such command line options.

query-command-line-options has always been woefully incomplete.  Sadly,
my replacement is still not ready.

A reliable "witness" could serve a stop gap.  Unfortunately,
query-qmp-schema doesn't provide one: the series does not change
generated qapi-introspect.c.

Need to think some more.