[PATCH v2] audio: add help option for -audio and -audiodev

[PATCH v2] audio: add help option for -audio and -audiodev

[Claudio Fontana]

add a simple help option for -audio and -audiodev
to show the list of available drivers, and document them.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
---
 audio/audio.c   | 20 ++++++++++++++++++++
 audio/audio.h   |  1 +
 qemu-options.hx | 10 ++++++----
 softmmu/vl.c    |  9 +++++++--
 4 files changed, 34 insertions(+), 6 deletions(-)

v1 -> v2: also extend the help to -audio.

 -audio help
 -audio driver=help
 -audiodev help

will all show the same results.

diff --git a/audio/audio.c b/audio/audio.c
index 4f4bb10cce..ffb09ec825 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -32,6 +32,7 @@
 #include "qapi/qapi-visit-audio.h"
 #include "qemu/cutils.h"
 #include "qemu/module.h"
+#include "qemu/help_option.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/replay.h"
 #include "sysemu/runstate.h"
@@ -2105,10 +2106,29 @@ static void audio_validate_opts(Audiodev *dev, Error **errp)
     }
 }
 
+void audio_help(void)
+{
+    int i;
+
+    printf("Available audio drivers:\n");
+    printf("none\n");
+
+    for (i = 0; audio_prio_list[i]; i++) {
+        audio_driver *driver = audio_driver_lookup(audio_prio_list[i]);
+        if (driver) {
+            printf("%s\n", driver->name);
+        }
+    }
+}
+
 void audio_parse_option(const char *opt)
 {
     Audiodev *dev = NULL;
 
+    if (is_help_option(opt)) {
+        audio_help();
+        exit(EXIT_SUCCESS);
+    }
     Visitor *v = qobject_input_visitor_new_str(opt, "driver", &error_fatal);
     visit_type_Audiodev(v, NULL, &dev, &error_fatal);
     visit_free(v);
diff --git a/audio/audio.h b/audio/audio.h
index 27e67079a0..01bdc567fb 100644
--- a/audio/audio.h
+++ b/audio/audio.h
@@ -171,6 +171,7 @@ void audio_sample_from_uint64(void *samples, int pos,
 void audio_define(Audiodev *audio);
 void audio_parse_option(const char *opt);
 bool audio_init_audiodevs(void);
+void audio_help(void);
 void audio_legacy_help(void);
 
 AudioState *audio_state_by_name(const char *name);
diff --git a/qemu-options.hx b/qemu-options.hx
index 31c04f7eea..04cd4dacfc 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -704,10 +704,11 @@ SRST
 ``-audio [driver=]driver,model=value[,prop[=value][,...]]``
     This option is a shortcut for configuring both the guest audio
     hardware and the host audio backend in one go.
-    The host backend options are the same as with the corresponding
-    ``-audiodev`` options below. The guest hardware model can be set with
-    ``model=modelname``. Use ``model=help`` to list the available device
-    types.
+    The driver option is the same as with the corresponding ``-audiodev`` option below.
+    The guest hardware model can be set with ``model=modelname``.
+
+    Use ``driver=help`` to list the available drivers,
+    and ``model=help`` to list the available device types.
 
     The following two example do exactly the same, to show how ``-audio``
     can be used to shorten the command line length:
@@ -721,6 +722,7 @@ ERST
 DEF("audiodev", HAS_ARG, QEMU_OPTION_audiodev,
     "-audiodev [driver=]driver,id=id[,prop[=value][,...]]\n"
     "                specifies the audio backend to use\n"
+    "                Use ``-audiodev help`` to list the available drivers\n"
     "                id= identifier of the backend\n"
     "                timer-period= timer period in microseconds\n"
     "                in|out.mixing-engine= use mixing engine to mix streams inside QEMU\n"
diff --git a/softmmu/vl.c b/softmmu/vl.c
index dea4005e47..2f8eecf5c1 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -2842,11 +2842,16 @@ void qemu_init(int argc, char **argv, char **envp)
                 audio_parse_option(optarg);
                 break;
             case QEMU_OPTION_audio: {
-                QDict *dict = keyval_parse(optarg, "driver", NULL, &error_fatal);
+                bool help;
                 char *model;
                 Audiodev *dev = NULL;
                 Visitor *v;
-
+                QDict *dict = keyval_parse(optarg, "driver", &help, &error_fatal);
+                if (help || (qdict_haskey(dict, "driver") &&
+                             is_help_option(qdict_get_str(dict, "driver")))) {
+                    audio_help();
+                    exit(EXIT_SUCCESS);
+                }
                 if (!qdict_haskey(dict, "id")) {
                     qdict_put_str(dict, "id", "audiodev0");
                 }
-- 
2.26.2

Re: [PATCH v2] audio: add help option for -audio and -audiodev

[Volker Rümelin]

Am 07.09.22 um 19:30 schrieb Claudio Fontana:

> add a simple help option for -audio and -audiodev
> to show the list of available drivers, and document them.
>
> Signed-off-by: Claudio Fontana <cfontana@suse.de>
> ---
>   audio/audio.c   | 20 ++++++++++++++++++++
>   audio/audio.h   |  1 +
>   qemu-options.hx | 10 ++++++----
>   softmmu/vl.c    |  9 +++++++--
>   4 files changed, 34 insertions(+), 6 deletions(-)
>
> v1 -> v2: also extend the help to -audio.
>
>   -audio help
>   -audio driver=help
>   -audiodev help
>
> will all show the same results.
>
> diff --git a/audio/audio.c b/audio/audio.c
> index 4f4bb10cce..ffb09ec825 100644
> --- a/audio/audio.c
> +++ b/audio/audio.c
> @@ -32,6 +32,7 @@
>   #include "qapi/qapi-visit-audio.h"
>   #include "qemu/cutils.h"
>   #include "qemu/module.h"
> +#include "qemu/help_option.h"
>   #include "sysemu/sysemu.h"
>   #include "sysemu/replay.h"
>   #include "sysemu/runstate.h"
> @@ -2105,10 +2106,29 @@ static void audio_validate_opts(Audiodev *dev, Error **errp)
>       }
>   }
>   
> +void audio_help(void)
> +{
> +    int i;
> +
> +    printf("Available audio drivers:\n");
> +    printf("none\n");
> +
> +    for (i = 0; audio_prio_list[i]; i++) {
> +        audio_driver *driver = audio_driver_lookup(audio_prio_list[i]);

Hi Claudio,

there is no guarantee that the audio_prio_list contains all audio 
backend drivers. I would use this

+    for (i = 0; i < AUDIODEV_DRIVER__MAX; i++) {
+        const char *name = AudiodevDriver_str(i);
+        audio_driver *driver = audio_driver_lookup(name);

to enumerate all audio backend drivers.

With best regards,
Volker

> +        if (driver) {
> +            printf("%s\n", driver->name);
> +        }
> +    }
> +}
> +
>

Re: [PATCH v2] audio: add help option for -audio and -audiodev

[Claudio Fontana]

On 9/8/22 07:55, Volker Rümelin wrote:
> Am 07.09.22 um 19:30 schrieb Claudio Fontana:
> 
>> add a simple help option for -audio and -audiodev
>> to show the list of available drivers, and document them.
>>
>> Signed-off-by: Claudio Fontana <cfontana@suse.de>
>> ---
>>   audio/audio.c   | 20 ++++++++++++++++++++
>>   audio/audio.h   |  1 +
>>   qemu-options.hx | 10 ++++++----
>>   softmmu/vl.c    |  9 +++++++--
>>   4 files changed, 34 insertions(+), 6 deletions(-)
>>
>> v1 -> v2: also extend the help to -audio.
>>
>>   -audio help
>>   -audio driver=help
>>   -audiodev help
>>
>> will all show the same results.
>>
>> diff --git a/audio/audio.c b/audio/audio.c
>> index 4f4bb10cce..ffb09ec825 100644
>> --- a/audio/audio.c
>> +++ b/audio/audio.c
>> @@ -32,6 +32,7 @@
>>   #include "qapi/qapi-visit-audio.h"
>>   #include "qemu/cutils.h"
>>   #include "qemu/module.h"
>> +#include "qemu/help_option.h"
>>   #include "sysemu/sysemu.h"
>>   #include "sysemu/replay.h"
>>   #include "sysemu/runstate.h"
>> @@ -2105,10 +2106,29 @@ static void audio_validate_opts(Audiodev *dev, Error **errp)
>>       }
>>   }
>>   
>> +void audio_help(void)
>> +{
>> +    int i;
>> +
>> +    printf("Available audio drivers:\n");
>> +    printf("none\n");
>> +
>> +    for (i = 0; audio_prio_list[i]; i++) {
>> +        audio_driver *driver = audio_driver_lookup(audio_prio_list[i]);
> 
> Hi Claudio,
> 
> there is no guarantee that the audio_prio_list contains all audio 
> backend drivers. I would use this
> 
> +    for (i = 0; i < AUDIODEV_DRIVER__MAX; i++) {
> +        const char *name = AudiodevDriver_str(i);
> +        audio_driver *driver = audio_driver_lookup(name);
> 
> to enumerate all audio backend drivers.

Thanks Volker, will update accordingly.

Claudio

> 
> With best regards,
> Volker
> 
>> +        if (driver) {
>> +            printf("%s\n", driver->name);
>> +        }
>> +    }
>> +}
>> +
>>
>