conf: Introduce codec type 'output'

Introduce support for codec type 'output' ('hda-output' in QEMU) for ich6
and ich9 sound devices, which only advertises a line-out in the guest.
This has been available in QEMU since 0.14.

Signed-off-by: Filip Alac <filipalac@gmail.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>

docs/formatdomain.html.in

@@ -7387,9 +7387,18 @@ qemu-kvm -net nic,model=? /dev/null
       with <code>ich6</code> model can have optional
       sub-elements <code>&lt;codec&gt;</code> to attach various audio
       codecs to the audio device. If not specified, a default codec
-      will be attached to allow playback and recording. Valid values
-      are 'duplex' (advertise a line-in and a line-out) and 'micro'
-      (advertise a speaker and a microphone).
+      will be attached to allow playback and recording.
+      </p>
+      <p>
+      Valid values are:
+      </p>
+      <p>
+      <ul>
+        <li>'duplex' - advertise a line-in and a line-out </li>
+        <li>'micro' -  advertise a speaker and a microphone </li>
+        <li>'output' - advertise a line-out
+            <span class="since">Since 4.4.0</span></li>
+      </ul>
     </p>
 
 <pre>

docs/schemas/domaincommon.rng

@@ -3824,6 +3824,7 @@
         <choice>
           <value>duplex</value>
           <value>micro</value>
+          <value>output</value>
         </choice>
       </attribute>
     </element>

src/conf/domain_conf.c

@@ -529,7 +529,8 @@ VIR_ENUM_IMPL(virDomainSmartcard, VIR_DOMAIN_SMARTCARD_TYPE_LAST,
 
 VIR_ENUM_IMPL(virDomainSoundCodec, VIR_DOMAIN_SOUND_CODEC_TYPE_LAST,
               "duplex",
-              "micro")
+              "micro",
+              "output")
 
 VIR_ENUM_IMPL(virDomainSoundModel, VIR_DOMAIN_SOUND_MODEL_LAST,
               "sb16",

src/conf/domain_conf.h

@@ -1335,6 +1335,7 @@ struct _virDomainInputDef {
 typedef enum {
     VIR_DOMAIN_SOUND_CODEC_TYPE_DUPLEX,
     VIR_DOMAIN_SOUND_CODEC_TYPE_MICRO,
+    VIR_DOMAIN_SOUND_CODEC_TYPE_OUTPUT,
 
     VIR_DOMAIN_SOUND_CODEC_TYPE_LAST
 } virDomainSoundCodecType;

src/qemu/qemu_command.c

@@ -139,7 +139,8 @@ VIR_ENUM_DECL(qemuSoundCodec)
 
 VIR_ENUM_IMPL(qemuSoundCodec, VIR_DOMAIN_SOUND_CODEC_TYPE_LAST,
               "hda-duplex",
-              "hda-micro");
+              "hda-micro",
+              "hda-output");
 
 VIR_ENUM_DECL(qemuControllerModelUSB)