blkif: add placeholder for packet extension to block interface

While the corresponding implementation has been in our trees for quite
a while, it's in a state that doesn't make it suitable for submission,
and the original author having left the company leaves open to find
someone to complete this work. Yet to prevent problems with other
interface extensions we'd like to keep the slot in the number space
reserved for the purpose it has been serving here.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

diff --git a/xen/include/public/io/blkif.h b/xen/include/public/io/blkif.h
index 3e0c5abae3957dada775027ed288a86f9b709f9e..52ad36a7b1d8505f88db40a813723bab8251cc79 100644 (file)
--- a/xen/include/public/io/blkif.h
+++ b/xen/include/public/io/blkif.h
@@ -76,6 +76,11 @@
  * "feature-flush-cache" node!
  */
 #define BLKIF_OP_FLUSH_DISKCACHE   3
+/*
+ * Used in SLES sources for device specific command packet
+ * contained within the request. Reserved for that purpose.
+ */
+#define BLKIF_OP_RESERVED_1        4
 
 /*
  * Maximum scatter/gather segments per request.