[Qemu-block] [PATCH for-2.8] qapi: Document introduction of gluster's 'debug' option

[Eric Blake]

We intentionally renamed 'debug-level' to 'debug' in the QMP
schema for 'blockdev-add' related to gluster, in order to
match the command line (commit 1a417e46).  However, since
'debug-level' was visible in 2.7, that means that we should
document that 'debug' was not available until 2.8.

The change was intentional because 'blockdev-add' itself
underwent incompatible changes (such as commit 0153d2f) for
the same release; our intent is that after 2.8, these
interfaces will now be stable.  [In hindsight, we should have
used the name x-blockdev-add when we first introduced it]

Signed-off-by: Eric Blake <address@hidden>
---
 qapi/block-core.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index a298e76..6b42216 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2196,6 +2196,7 @@
 # @server:      gluster servers description
 #
 # @debug:       #optional libgfapi log level (default '4' which is Error)
+#               (Since 2.8)
 #
 # @logfile:     #optional libgfapi log file (default /dev/stderr) (Since 2.8)
 #
-- 
2.9.3