block-backend: expose bs->bl.max_transfer_length

Signed-off-by: NPeter Lieven <pl@kamp.de>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/block-backend.c

@@ -580,6 +580,11 @@ int blk_get_flags(BlockBackend *blk)
     return bdrv_get_flags(blk->bs);
 }
 
+int blk_get_max_transfer_length(BlockBackend *blk)
+{
+    return blk->bs->bl.max_transfer_length;
+}
+
 void blk_set_guest_block_size(BlockBackend *blk, int align)
 {
     bdrv_set_guest_block_size(blk->bs, align);

include/sysemu/block-backend.h

@@ -127,6 +127,7 @@ int blk_is_inserted(BlockBackend *blk);
 void blk_lock_medium(BlockBackend *blk, bool locked);
 void blk_eject(BlockBackend *blk, bool eject_flag);
 int blk_get_flags(BlockBackend *blk);
+int blk_get_max_transfer_length(BlockBackend *blk);
 void blk_set_guest_block_size(BlockBackend *blk, int align);
 void *blk_blockalign(BlockBackend *blk, size_t size);
 bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);