1 files changed, 1 insertions, 0 deletions
diff --git a/block.h b/block.h
index 2e2be11071..4d919c249f 100644
--- a/block.h
+++ b/block.h
@@ -80,6 +80,7 @@ typedef struct BlockDevOps {
 #define BDRV_O_COPY_ON_READ 0x0400 /* copy read backing sectors into image */
 #define BDRV_O_INCOMING    0x0800  /* consistency hint for incoming migration */
 #define BDRV_O_CHECK       0x1000  /* open solely for consistency check */
+#define BDRV_O_ALLOW_RDWR  0x2000  /* allow reopen to change from r/o to r/w */
 
 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)