[Qemu-devel] [RFC V3 3/7] qapi: Add skeletton of command to query a drive bs graph.

["Benoît Canet" <benoit@irqsave.net>]

---
 blockdev.c       |  8 ++++++++
 qapi-schema.json | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index a474bb5..824e718 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1940,6 +1940,14 @@ void qmp_drive_backup(const char *device, const char *target,
     }
 }
 
+BlockGraphNode * qmp_query_drive_graph(const char *device, Error **errp)
+{
+    /* the implementation of this function would recurse through the
+     * BlockDriverState graph to build it's result
+     */
+    return NULL;
+}
+
 #define DEFAULT_MIRROR_BUF_SIZE   (10 << 20)
 
 void qmp_drive_mirror(const char *device, const char *target,
diff --git a/qapi-schema.json b/qapi-schema.json
index 8630eb5..938f8b9 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2008,6 +2008,38 @@
 { 'command': 'drive-backup', 'data': 'DriveBackup' }
 
 ##
+# @BlockGraphNode
+#
+# Information about a node of the block driver state graph
+#
+# @node-name: the name of the node in the graph
+#
+# @drv: the name of the block format used by this node as described in
+#       @BlockDeviceInfo.
+#
+# @children: a list of @BlockGraphNode being the children of this node
+#
+# Since 1.8
+##
+{ 'type': 'BlockGraphNode',
+  'data': { 'node-name': 'str', 'drv': 'str', 'children': ['BlockGraphNode'] } }
+
+##
+# @query-drive-graph
+#
+# Get the block driver states graph for a given drive
+#
+# @device: the name of the device to get the graph from
+#
+# Returns: the root @BlockGraphNode
+#
+# Since 1.8
+##
+{ 'command': 'query-drive-graph',
+  'data': { 'device': 'str' },
+  'returns': 'BlockGraphNode' }
+
+##
 # @drive-mirror
 #
 # Start mirroring a block device's writes to a new destination.
-- 
1.8.3.2