1 files changed, 32 insertions, 3 deletions

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 00256fa318..ded0c10453 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -345,6 +345,35 @@ end:
     return G_SOURCE_REMOVE;
 }
 
+static gboolean slave_read(QIOChannel *ioc, GIOCondition condition,
+                           gpointer opaque);
+
+/*
+ * This updates the read handler to use a new event loop context.
+ * Event sources are removed from the previous context : this ensures
+ * that events detected in the previous context are purged. They will
+ * be re-detected and processed in the new context.
+ */
+static void slave_update_read_handler(struct vhost_dev *dev,
+                                      GMainContext *ctxt)
+{
+    struct vhost_user *u = dev->opaque;
+
+    if (!u->slave_ioc) {
+        return;
+    }
+
+    if (u->slave_src) {
+        g_source_destroy(u->slave_src);
+        g_source_unref(u->slave_src);
+    }
+
+    u->slave_src = qio_channel_add_watch_source(u->slave_ioc,
+                                                G_IO_IN | G_IO_HUP,
+                                                slave_read, dev, NULL,
+                                                ctxt);
+}
+
 static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
 {
     struct vhost_user *u = dev->opaque;
@@ -366,6 +395,7 @@ static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
      * be prepared for re-entrancy. So we create a new one and switch chr
      * to use it.
      */
+    slave_update_read_handler(dev, ctxt);
     qemu_chr_be_update_read_handlers(chr->chr, ctxt);
     qemu_chr_fe_add_watch(chr, G_IO_IN | G_IO_HUP, vhost_user_read_cb, &data);
 
@@ -377,6 +407,7 @@ static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
      * context that have been processed by the nested loop are purged.
      */
     qemu_chr_be_update_read_handlers(chr->chr, prev_ctxt);
+    slave_update_read_handler(dev, NULL);
 
     g_main_loop_unref(loop);
     g_main_context_unref(ctxt);
@@ -1580,9 +1611,7 @@ static int vhost_setup_slave_channel(struct vhost_dev *dev)
         return -1;
     }
     u->slave_ioc = ioc;
-    u->slave_src = qio_channel_add_watch_source(u->slave_ioc,
-                                                G_IO_IN | G_IO_HUP,
-                                                slave_read, dev, NULL, NULL);
+    slave_update_read_handler(dev, NULL);
 
     if (reply_supported) {
         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;