[Spice-devel] [RFC PATCH 14/15] stream-device: Start supporting resetting device when close/open on guest

[Frediano Ziglio]

When guest close the device the host device has to be reset too.
This make easier to restart the guest device which can happen in case
of reboot, agent issues or if we want to update the agent.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 server/stream-channel.c | 30 ++++++++++++++++++++++++++++++
 server/stream-channel.h |  7 ++++++-
 server/stream-device.c  | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 85 insertions(+), 1 deletion(-)

diff --git a/server/stream-channel.c b/server/stream-channel.c
index 5e59335..58c550e 100644
--- a/server/stream-channel.c
+++ b/server/stream-channel.c
@@ -477,3 +477,33 @@ stream_channel_register_start_cb(StreamChannel *channel,
     channel->start_cb = cb;
     channel->start_opaque = opaque;
 }
+
+void
+stream_channel_reset(StreamChannel *channel)
+{
+    RedChannel *red_channel = RED_CHANNEL(channel);
+
+    // send destroy old stream
+    red_channel_pipes_add_type(red_channel, RED_PIPE_ITEM_TYPE_STREAM_DESTROY);
+
+    // destroy display surface
+    if (channel->width != 0 && channel->height != 0) {
+        red_channel_pipes_add_type(red_channel, RED_PIPE_ITEM_TYPE_SURFACE_DESTROY);
+    }
+
+    channel->stream_id = -1;
+    channel->width = 0;
+    channel->height = 0;
+
+    if (!red_channel_is_connected(red_channel)) {
+        return;
+    }
+
+    // try to ask new stream, this should start a new stream
+    // if the guest connect to the device and a client is already connected
+    StreamMsgStartStop* start = stream_channel_get_supported_codecs(channel);
+    // send in any case, even if list is not changed
+    // notify device about changes
+    ask_new_stream(channel, start);
+    free(start);
+}
diff --git a/server/stream-channel.h b/server/stream-channel.h
index d48c3c8..8c9c0f1 100644
--- a/server/stream-channel.h
+++ b/server/stream-channel.h
@@ -48,7 +48,12 @@ GType stream_channel_get_type(void) G_GNUC_CONST;
  */
 StreamChannel* stream_channel_new(RedsState *server);
 
-struct StreamMsgFormat;
+/**
+ * Reset channel at initial state
+ */
+void stream_channel_reset(StreamChannel *channel);
+
+struct StreamMsgStreamFormat;
 struct StreamMsgStartStop;
 
 void stream_channel_change_format(StreamChannel *channel,
diff --git a/server/stream-device.c b/server/stream-device.c
index fdc9c34..df28ffc 100644
--- a/server/stream-device.c
+++ b/server/stream-device.c
@@ -47,6 +47,7 @@ struct StreamDevice {
     StreamDevHeader hdr;
     uint8_t hdr_pos;
     bool has_error;
+    bool opened;
     StreamChannel *channel;
 };
 
@@ -192,6 +193,35 @@ stream_device_remove_client(RedCharDevice *self, RedClient *client)
 {
 }
 
+static void
+stream_device_stream_start(void *opaque, StreamMsgStartStop *start,
+                           StreamChannel *channel G_GNUC_UNUSED)
+{
+    StreamDevice *dev = (StreamDevice *) opaque;
+
+    if (!dev->opened) {
+        return;
+    }
+
+    int msg_size = sizeof(*start) + sizeof(start->codecs[0]) * start->num_codecs;
+    int total_size = sizeof(StreamDevHeader) + msg_size;
+
+    RedCharDevice *char_dev = RED_CHAR_DEVICE(dev);
+    RedCharDeviceWriteBuffer *buf =
+        red_char_device_write_buffer_get_server_no_token(char_dev, total_size);
+    buf->buf_used = total_size;
+
+    StreamDevHeader *hdr = (StreamDevHeader *)buf->buf;
+    hdr->protocol_version = STREAM_DEVICE_PROTOCOL;
+    hdr->padding = 0;
+    hdr->type = GUINT16_TO_LE(STREAM_TYPE_START_STOP);
+    hdr->size = GUINT32_TO_LE(msg_size);
+
+    memcpy(&hdr[1], start, msg_size);
+
+    red_char_device_write_buffer_add(char_dev, buf);
+}
+
 RedCharDevice *
 stream_device_connect(RedsState *reds, SpiceCharDeviceInstance *sin)
 {
@@ -201,6 +231,7 @@ stream_device_connect(RedsState *reds, SpiceCharDeviceInstance *sin)
 
     StreamDevice *dev = stream_device_new(sin, reds);
     dev->channel = channel;
+    stream_channel_register_start_cb(channel, stream_device_stream_start, dev);
 
     sif = spice_char_device_get_interface(sin);
     if (sif->state) {
@@ -229,6 +260,23 @@ stream_device_dispose(GObject *object)
 }
 
 static void
+stream_device_port_event(RedCharDevice *char_dev, uint8_t event)
+{
+    if (event != SPICE_PORT_EVENT_OPENED && event != SPICE_PORT_EVENT_CLOSED) {
+        return;
+    }
+
+    StreamDevice *device = STREAM_DEVICE(char_dev);
+
+    // reset device and channel on close/open
+    device->opened = (event == SPICE_PORT_EVENT_OPENED);
+    device->hdr_pos = 0;
+    device->has_error = false;
+    red_char_device_reset(char_dev);
+    stream_channel_reset(device->channel);
+}
+
+static void
 stream_device_class_init(StreamDeviceClass *klass)
 {
     GObjectClass *object_class = G_OBJECT_CLASS(klass);
@@ -240,6 +288,7 @@ stream_device_class_init(StreamDeviceClass *klass)
     char_dev_class->send_msg_to_client = stream_device_send_msg_to_client;
     char_dev_class->send_tokens_to_client = stream_device_send_tokens_to_client;
     char_dev_class->remove_client = stream_device_remove_client;
+    char_dev_class->port_event = stream_device_port_event;
 }
 
 static void
-- 
2.9.3