libvhost-user-glib: fix VugDev main fd cleanup

If you try to make a device implementation that can handle multiple
connections and allow disconnections (which requires overriding the
VHOST_USER_NONE handling), then glib will warn that we remove a src
while it's still on the mainloop, and will poll() an FD that doesn't
exist anymore.

Fix this by making vug_source_new() require pairing with the new
vug_source_destroy() so we can keep the GSource referenced in the
meantime.

Note that this requires calling the new API in vhost-user-input.
vhost-user-gpu also uses vug_source_new(), but never seems to free
the result at all, so I haven't changed anything there.

Fixes: 8bb7ddb78a1c ("libvhost-user: add glib source helper")
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Message-Id: <20200123081708.7817-3-johannes@sipsolutions.net>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/contrib/vhost-user-input/main.c b/contrib/vhost-user-input/main.c
index ef4b7769f2..6020c6f33a 100644
--- a/contrib/vhost-user-input/main.c
+++ b/contrib/vhost-user-input/main.c
@@ -187,7 +187,7 @@ vi_queue_set_started(VuDev *dev, int qidx, bool started)
     }
 
     if (!started && vi->evsrc) {
-        g_source_destroy(vi->evsrc);
+        vug_source_destroy(vi->evsrc);
         vi->evsrc = NULL;
     }
 }
@@ -401,9 +401,7 @@ main(int argc, char *argv[])
 
     vug_deinit(&vi.dev);
 
-    if (vi.evsrc) {
-        g_source_unref(vi.evsrc);
-    }
+    vug_source_destroy(vi.evsrc);
     g_array_free(vi.config, TRUE);
     g_free(vi.queue);
     return 0;