Re: [PATCH 2/3] qapi, audio: respect build time conditions in audio schema

[Eric Blake <eblake@redhat.com>]

On 3/2/21 11:55 AM, Daniel P. Berrangé wrote:
> Currently the -audiodev accepts any audiodev type regardless of what is
> built in to QEMU. An error only occurs later at runtime when a sound
> device tries to use the audio backend.
> 
> With this change QEMU will immediately reject -audiodev args that are
> not compiled into the binary. The QMP schema will also be introspectable
> to identify what is compiled in.

Nice!

> 
> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>  audio/audio.c          | 16 +++++++++++++++
>  audio/audio_legacy.c   | 41 ++++++++++++++++++++++++++++++++++++++-
>  audio/audio_template.h | 16 +++++++++++++++
>  qapi/audio.json        | 44 ++++++++++++++++++++++++++++++++----------
>  4 files changed, 106 insertions(+), 11 deletions(-)
> 

> +++ b/qapi/audio.json
> @@ -386,8 +386,24 @@
>  # Since: 4.0
>  ##
>  { 'enum': 'AudiodevDriver',
> -  'data': [ 'none', 'alsa', 'coreaudio', 'dsound', 'jack', 'oss', 'pa',
> -            'sdl', 'spice', 'wav' ] }
> +  'data': [ 'none',
> +            { 'name': 'alsa',
> +              'if': 'defined(CONFIG_AUDIO_ALSA)' },
> +            { 'name': 'coreaudio',
> +              'if': 'defined(CONFIG_AUDIO_COREAUDIO)' },
> +            { 'name': 'dsound',
> +              'if': 'defined(CONFIG_AUDIO_DSOUND)' },
> +            { 'name': 'jack',
> +              'if': 'defined(CONFIG_AUDIO_JACK)' },
> +            { 'name': 'oss',
> +              'if': 'defined(CONFIG_AUDIO_OSS)' },
> +            { 'name': 'pa',
> +              'if': 'defined(CONFIG_AUDIO_PA)' },
> +            { 'name': 'sdl',
> +              'if': 'defined(CONFIG_AUDIO_SDL)' },
> +            { 'name': 'spice',
> +              'if': 'defined(CONFIG_SPICE)' },
> +            'wav' ] }

I'll trust that you compiled multiple times to test the various
interplays between options.

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org