qapi, audio: add query-audiodev command

Way back in QEMU 4.0, the -audiodev command line option was introduced
for configuring audio backends. This CLI option does not use QemuOpts
so it is not visible for introspection in 'query-command-line-options',
instead using the QAPI Audiodev type.  Unfortunately there is also no
QMP command that uses the Audiodev type, so it is not introspectable
with 'query-qmp-schema' either.

This introduces a 'query-audiodev' command that simply reflects back
the list of configured -audiodev command line options. This alone is
maybe not very useful by itself, but it makes Audiodev introspectable
via 'query-qmp-schema', so that libvirt (and other upper layer tools)
can discover the available audiodevs.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
[thuth: Update for upcoming QEMU v8.0, and use QAPI_LIST_PREPEND]
Message-Id: <20230123083957.20349-2-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/qapi/audio.json b/qapi/audio.json
index 1e0a24b..c7aafa2 100644
--- a/qapi/audio.json
+++ b/qapi/audio.json
@@ -443,3 +443,16 @@
     'sndio':     'AudiodevSndioOptions',
     'spice':     'AudiodevGenericOptions',
     'wav':       'AudiodevWavOptions' } }
+
+##
+# @query-audiodevs:
+#
+# Returns information about audiodev configuration
+#
+# Returns: array of @Audiodev
+#
+# Since: 8.0
+#
+##
+{ 'command': 'query-audiodevs',
+  'returns': ['Audiodev'] }