qcow2: Add list of bitmaps to ImageInfoSpecificQCow2

In the 'Format specific information' section of the 'qemu-img info'
command output, the supplemental information about existing QCOW2
bitmaps will be shown, such as a bitmap name, flags and granularity:

image: /vz/vmprivate/VM1/harddisk.hdd
file format: qcow2
virtual size: 64G (68719476736 bytes)
disk size: 3.0M
cluster_size: 1048576
Format specific information:
    compat: 1.1
    lazy refcounts: true
    bitmaps:
        [0]:
            flags:
                [0]: in-use
                [1]: auto
            name: back-up1
            granularity: 65536
        [1]:
            flags:
                [0]: in-use
                [1]: auto
            name: back-up2
            granularity: 65536
    refcount bits: 16
    corrupt: false

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1549638368-530182-3-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 5f17d67..0f349d4 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -69,6 +69,8 @@
 # @encrypt: details about encryption parameters; only set if image
 #           is encrypted (since 2.10)
 #
+# @bitmaps: A list of qcow2 bitmap details (since 4.0)
+#
 # Since: 1.7
 ##
 { 'struct': 'ImageInfoSpecificQCow2',
@@ -77,7 +79,8 @@
       '*lazy-refcounts': 'bool',
       '*corrupt': 'bool',
       'refcount-bits': 'int',
-      '*encrypt': 'ImageInfoSpecificQCow2Encryption'
+      '*encrypt': 'ImageInfoSpecificQCow2Encryption',
+      '*bitmaps': ['Qcow2BitmapInfo']
   } }
 
 ##
@@ -454,6 +457,42 @@
            'status': 'DirtyBitmapStatus'} }
 
 ##
+# @Qcow2BitmapInfoFlags:
+#
+# An enumeration of flags that a bitmap can report to the user.
+#
+# @in-use: This flag is set by any process actively modifying the qcow2 file,
+#          and cleared when the updated bitmap is flushed to the qcow2 image.
+#          The presence of this flag in an offline image means that the bitmap
+#          was not saved correctly after its last usage, and may contain
+#          inconsistent data.
+#
+# @auto: The bitmap must reflect all changes of the virtual disk by any
+#        application that would write to this qcow2 file.
+#
+# Since: 4.0
+##
+{ 'enum': 'Qcow2BitmapInfoFlags',
+  'data': ['in-use', 'auto'] }
+
+##
+# @Qcow2BitmapInfo:
+#
+# Qcow2 bitmap information.
+#
+# @name: the name of the bitmap
+#
+# @granularity: granularity of the bitmap in bytes
+#
+# @flags: flags of the bitmap
+#
+# Since: 4.0
+##
+{ 'struct': 'Qcow2BitmapInfo',
+  'data': {'name': 'str', 'granularity': 'uint32',
+           'flags': ['Qcow2BitmapInfoFlags'] } }
+
+##
 # @BlockLatencyHistogramInfo:
 #
 # Block latency histogram.