1 files changed, 9 insertions, 0 deletions
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 29cafa4236..99b9190627 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -446,6 +446,15 @@ struct BlockDriver {
                                                 const char *name,
                                                 Error **errp);
 
+    /**
+     * Register/unregister a buffer for I/O. For example, when the driver is
+     * interested to know the memory areas that will later be used in iovs, so
+     * that it can do IOMMU mapping with VFIO etc., in order to get better
+     * performance. In the case of VFIO drivers, this callback is used to do
+     * DMA mapping for hot buffers.
+     */
+    void (*bdrv_register_buf)(BlockDriverState *bs, void *host, size_t size);
+    void (*bdrv_unregister_buf)(BlockDriverState *bs, void *host);
     QLIST_ENTRY(BlockDriver) list;
 };