block: Add AioContextNotifier functions to BB

Because all BlockDriverStates behind a single BlockBackend reside in a
single AioContext, it is fine to just pass these functions
(blk_add_aio_context_notifier() and blk_remove_aio_context_notifier())
through to the root BlockDriverState.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 1416309679-333-3-git-send-email-mreitz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/block-backend.c

@@ -624,6 +624,24 @@ void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
     bdrv_set_aio_context(blk->bs, new_context);
 }
 
+void blk_add_aio_context_notifier(BlockBackend *blk,
+        void (*attached_aio_context)(AioContext *new_context, void *opaque),
+        void (*detach_aio_context)(void *opaque), void *opaque)
+{
+    bdrv_add_aio_context_notifier(blk->bs, attached_aio_context,
+                                  detach_aio_context, opaque);
+}
+
+void blk_remove_aio_context_notifier(BlockBackend *blk,
+                                     void (*attached_aio_context)(AioContext *,
+                                                                  void *),
+                                     void (*detach_aio_context)(void *),
+                                     void *opaque)
+{
+    bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context,
+                                     detach_aio_context, opaque);
+}
+
 void blk_io_plug(BlockBackend *blk)
 {
     bdrv_io_plug(blk->bs);

include/sysemu/block-backend.h

@@ -135,6 +135,14 @@ void blk_op_block_all(BlockBackend *blk, Error *reason);
 void blk_op_unblock_all(BlockBackend *blk, Error *reason);
 AioContext *blk_get_aio_context(BlockBackend *blk);
 void blk_set_aio_context(BlockBackend *blk, AioContext *new_context);
+void blk_add_aio_context_notifier(BlockBackend *blk,
+        void (*attached_aio_context)(AioContext *new_context, void *opaque),
+        void (*detach_aio_context)(void *opaque), void *opaque);
+void blk_remove_aio_context_notifier(BlockBackend *blk,
+                                     void (*attached_aio_context)(AioContext *,
+                                                                  void *),
+                                     void (*detach_aio_context)(void *),
+                                     void *opaque);
 void blk_io_plug(BlockBackend *blk);
 void blk_io_unplug(BlockBackend *blk);
 BlockAcctStats *blk_get_stats(BlockBackend *blk);