Re: [Qemu-devel] [RFC] spice-core: allow setting properties from QMP

[Kevin Pouget <kpouget@redhat.com>]

On Fri, Jun 21, 2019 at 9:16 AM Frediano Ziglio <fziglio@redhat.com> wrote:
>
> >
> > Hello Eric,
> >
> > > A new command may be okay, however,
> >
> > thanks, I've fix the typos and updated the patch to use an Enum, which
> > indeed makes more sense.
> >
> > I've also updated "spice-query" command to provide the current value
> > of the "video-codec" property,
> > but it made me wonder if I should improve this QMP interface with a
> > json list, or keep the current string-based list
> > ("enc1:codec1;enc2:codec2").
> >
> > I CC the spice-devel list to get their point of view
> >
> > The current behavior is:
> >
> > --> { "execute": "set-spice", "arguments": { "property":
> > "video-codecs", "value": "spice:mjpeg;gstreamer:h264" } }
> > <-- {"return":{},"id":"libvirt-23"}
>
> It looks complicated from the user. Why not just
>
> --> { "execute": "set-spice", "arguments": { "video-codecs": "spice:mjpeg;gstreamer:h264" } }

it makes sense indeed, I've updated the code:

# -> { "execute": "set-spice", "arguments": { "video-codecs": "spice:mjpeg;" }
# <- { "returns": {} }

+{ 'command': 'set-spice',
+  'data': {'*video-codecs': 'str'},
+  'if': 'defined(CONFIG_SPICE)' }


---
 qapi/ui.json    | 27 +++++++++++++++++++++++++--
 ui/spice-core.c | 17 +++++++++++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/qapi/ui.json b/qapi/ui.json
index 59e412139a..cdbe04bda0 100644
--- a/qapi/ui.json
+++ b/qapi/ui.json
@@ -211,12 +211,16 @@
 #
 # @channels: a list of @SpiceChannel for each active spice channel
 #
+# @video-codecs: The list of encoders:codecs currently allowed for
+#                video streaming (since: ...)
+#
 # Since: 0.14.0
 ##
 { 'struct': 'SpiceInfo',
   'data': {'enabled': 'bool', 'migrated': 'bool', '*host': 'str',
'*port': 'int',
            '*tls-port': 'int', '*auth': 'str', '*compiled-version': 'str',
-           'mouse-mode': 'SpiceQueryMouseMode', '*channels': ['SpiceChannel']},
+           'mouse-mode': 'SpiceQueryMouseMode', '*channels': ['SpiceChannel'],
+           'video-codecs': 'str'},
   'if': 'defined(CONFIG_SPICE)' }

 ##
@@ -257,7 +261,8 @@
 #                "tls": false
 #             },
 #             [ ... more channels follow ... ]
-#          ]
+#          ],
+#          "video-codecs": "spice:mjpeg;gstreamer:h264;"
 #       }
 #    }
 #
@@ -265,6 +270,24 @@
 { 'command': 'query-spice', 'returns': 'SpiceInfo',
   'if': 'defined(CONFIG_SPICE)' }

+##
+# @set-spice:
+#
+# Set Spice properties.
+# @video-codecs: the ;-separated list of video-codecs allowed for
+#                spice-server video streaming.
+#
+# Since: ...
+#
+# Example:
+#
+# -> { "execute": "set-spice", "arguments": { "video-codecs": "spice:mjpeg;" }
+# <- { "returns": {} }
+##
+{ 'command': 'set-spice',
+  'data': {'*video-codecs': 'str'},
+  'if': 'defined(CONFIG_SPICE)' }
+
 ##
 # @SPICE_CONNECTED:
 #
diff --git a/ui/spice-core.c b/ui/spice-core.c
index 63e8694df8..a4b265b663 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -506,6 +506,21 @@ static QemuOptsList qemu_spice_opts = {
     },
 };

+void qmp_set_spice(bool has_video_codecs, const char *video_codecs,
+                   Error **errp)
+{
+    if (has_video_codecs) {
+        int invalid_codecs = spice_server_set_video_codecs(spice_server,
+                                                           video_codecs);
+
+        if (invalid_codecs) {
+            error_setg(errp, "Found %d invalid video-codecs while setting"
+                       " spice property 'video-codec=%s'", invalid_codecs,
+                       video_codecs);
+        }
+    }
+}
+
 SpiceInfo *qmp_query_spice(Error **errp)
 {
     QemuOpts *opts = QTAILQ_FIRST(&qemu_spice_opts.head);
@@ -555,6 +570,8 @@ SpiceInfo *qmp_query_spice(Error **errp)
                        SPICE_QUERY_MOUSE_MODE_SERVER :
                        SPICE_QUERY_MOUSE_MODE_CLIENT;

+    info->video_codecs = spice_server_get_video_codecs(spice_server);
+
     /* for compatibility with the original command */
     info->has_channels = true;
     info->channels = qmp_query_spice_channels();
-- 
2.21.0