qcow2: Add refcount_bits to format-specific info

Add the bit width of every refcount entry to the format-specific
information.

In contrast to lazy_refcounts and the corrupt flag, this should be
always emitted, even for compat=0.10 although it does not support any
refcount width other than 16 bits. This is because if a boolean is
optional, one normally assumes it to be false when omitted; but if an
integer is not specified, it is rather difficult to guess its value.

This new field breaks some test outputs, fix them.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/qapi/block-core.json b/qapi/block-core.json
index a3fdaf0..90586a5 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -41,13 +41,16 @@
 # @corrupt: #optional true if the image has been marked corrupt; only valid for
 #           compat >= 1.1 (since 2.2)
 #
+# @refcount-bits: width of a refcount entry in bits (since 2.3)
+#
 # Since: 1.7
 ##
 { 'type': 'ImageInfoSpecificQCow2',
   'data': {
       'compat': 'str',
       '*lazy-refcounts': 'bool',
-      '*corrupt': 'bool'
+      '*corrupt': 'bool',
+      'refcount-bits': 'int'
   } }
 
 ##