docs, qapi: document qemu-img map

Eric Blake also requested including the output in qapi-schema.json,
so that it is published through the introspection mechanism.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/qapi-schema.json b/qapi-schema.json
index 5d5164f9e2..2b2c8bce07 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -831,6 +831,35 @@
 { 'enum': 'BlockDeviceIoStatus', 'data': [ 'ok', 'failed', 'nospace' ] }
 
 ##
+# @BlockDeviceMapEntry:
+#
+# Entry in the metadata map of the device (returned by "qemu-img map")
+#
+# @start: Offset in the image of the first byte described by this entry
+#         (in bytes)
+#
+# @length: Length of the range described by this entry (in bytes)
+#
+# @depth: Number of layers (0 = top image, 1 = top image's backing file, etc.)
+#         before reaching one for which the range is allocated.  The value is
+#         in the range 0 to the depth of the image chain - 1.
+#
+# @zero: the sectors in this range read as zeros
+#
+# @data: reading the image will actually read data from a file (in particular,
+#        if @offset is present this means that the sectors are not simply
+#        preallocated, but contain actual data in raw format)
+#
+# @offset: if present, the image file stores the data for this range in
+#          raw format at the given offset.
+#
+# Since 1.7
+##
+{ 'type': 'BlockDeviceMapEntry',
+  'data': { 'start': 'int', 'length': 'int', 'depth': 'int', 'zero': 'bool',
+            'data': 'bool', '*offset': 'int' } }
+
+##
 # @BlockDirtyInfo:
 #
 # Block dirty bitmap information.