[PATCH 01/13] ui/vnc: Require audiodev= to enable audio

[Paolo Bonzini <pbonzini@redhat.com>]

From: Martin Kletzander <mkletzan@redhat.com>

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Message-ID: <a07513f1bf6123fef52ff5e7943f5704746b376b.1650874791.git.mkletzan@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 docs/about/deprecated.rst       |  8 +++-----
 docs/about/removed-features.rst |  6 ++++++
 ui/vnc.c                        | 10 ++++++++--
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 8f3fef97bd4..c07bf58dde1 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -45,13 +45,11 @@ backend settings instead of environment variables.  To ease migration to
 the new format, the ``-audiodev-help`` option can be used to convert
 the current values of the environment variables to ``-audiodev`` options.
 
-Creating sound card devices and vnc without ``audiodev=`` property (since 4.2)
-''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+Creating sound card devices without ``audiodev=`` property (since 4.2)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 
 When not using the deprecated legacy audio config, each sound card
-should specify an ``audiodev=`` property.  Additionally, when using
-vnc, you should specify an ``audiodev=`` property if you plan to
-transmit audio through the VNC protocol.
+should specify an ``audiodev=`` property.
 
 Short-form boolean options (since 6.0)
 ''''''''''''''''''''''''''''''''''''''
diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst
index 97ec47f1d25..276060b320c 100644
--- a/docs/about/removed-features.rst
+++ b/docs/about/removed-features.rst
@@ -436,6 +436,12 @@ the process listing. This was replaced by the new ``password-secret``
 option which lets the password be securely provided on the command
 line using a ``secret`` object instance.
 
+Creating vnc without ``audiodev=`` property (removed in 8.2)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+When using vnc, you should specify an ``audiodev=`` property if
+you plan to transmit audio through the VNC protocol.
+
 QEMU Machine Protocol (QMP) commands
 ------------------------------------
 
diff --git a/ui/vnc.c b/ui/vnc.c
index 6fd86996a54..cfa18bbd3e1 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -2508,11 +2508,17 @@ static int protocol_client_msg(VncState *vs, uint8_t *data, size_t len)
             switch (read_u16 (data, 2)) {
             case VNC_MSG_CLIENT_QEMU_AUDIO_ENABLE:
                 trace_vnc_msg_client_audio_enable(vs, vs->ioc);
-                audio_add(vs);
+                if (vs->vd->audio_state) {
+                    audio_add(vs);
+                } else {
+                    error_report("audio not available, use audiodev= option for vnc");
+                }
                 break;
             case VNC_MSG_CLIENT_QEMU_AUDIO_DISABLE:
                 trace_vnc_msg_client_audio_disable(vs, vs->ioc);
-                audio_del(vs);
+                if (vs->vd->audio_state) {
+                    audio_del(vs);
+                }
                 break;
             case VNC_MSG_CLIENT_QEMU_AUDIO_SET_FORMAT:
                 if (len == 4)
-- 
2.41.0