[Qemu-devel] [PATCH v2 1/1] Add QMP bits for blockdev-snapshot-sync.

[Jes.Sorensen@redhat.com]

From: Jes Sorensen <Jes.Sorensen@redhat.com>

This is quivalent to snapshot_blkdev in the human monitor, with _sync
added to the command name to make it explicit that the command is
synchronous and leave space for a future async version.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
---
 qmp-commands.hx |   26 ++++++++++++++++++++++++++
 1 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/qmp-commands.hx b/qmp-commands.hx
index fbd98ee..b8f537c 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -667,6 +667,32 @@ Example:
 EQMP
 
     {
+        .name       = "blockdev-snapshot-sync",
+        .args_type  = "device:B,snapshot_file:s?,format:s?",
+        .params     = "device [new-image-file] [format]",
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = do_snapshot_blkdev,
+    },
+
+SQMP
+Synchronous snapshot of block device, using snapshot file as target
+if provided. 
+
+If a new image file is specified, the new image file will become the
+new root image. If format is specified, the snapshot file will be
+created in that format. Otherwise the snapshot will be internal!
+(currently unsupported).
+
+Errors:
+If creating the new snapshot image fails, QEMU will continue running
+on the original image. If switching to the newly created image fails,
+it will be attempted to fall back to the original image and return
+QERR_OPEN_FILE_FAILED with the snapshot filename. If re-opening
+the original image fails, QERR_OPEN_FILE_FAILED will be returned with
+the original image filename.
+EQMP
+
+    {
         .name       = "balloon",
         .args_type  = "value:M",
         .params     = "target",
-- 
1.7.4.4