[Qemu-devel] [PATCH 4/4] qmp: add query-block-jobs

[Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>]

This patch introduces the query-block-jobs HMP/QMP command.  It is
currently unimplemented and returns an empty dict.

query-block-jobs
----------------

Show progress of ongoing block device operations.

Return a json-array of all block device operations.  If no operation is
active then return an empty array.  Each operation is a json-object with
the following data:

- type:     job type ("stream" for image streaming, json-string)
- device:   device name (json-string)
- end:      maximum progress value (json-int)
- position: current progress value (json-int)
- speed:    rate limit, bytes per second (json-int)

Progress can be observed as position increases and it reaches end when
the operation completes.  Position and end have undefined units but can
be used to calculate a percentage indicating the progress that has been
made.

Example:

-> { "execute": "query-block-jobs" }
<- { "return":[
      { "type": "stream", "device": "virtio0",
        "end": 10737418240, "position": 709632,
        "speed": 0 }
   ]
 }

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
---
 blockdev.c      |   10 ++++++++++
 blockdev.h      |    2 ++
 monitor.c       |   16 ++++++++++++++++
 qmp-commands.hx |   32 ++++++++++++++++++++++++++++++++
 4 files changed, 60 insertions(+), 0 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 036b7eb..e9098f6 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -835,3 +835,13 @@ int do_block_job_cancel(Monitor *mon, const QDict *params, QObject **ret_data)
     qerror_report(QERR_DEVICE_NOT_ACTIVE, device);
     return -1;
 }
+
+void monitor_print_block_jobs(Monitor *mon, const QObject *data)
+{
+    monitor_printf(mon, "No active jobs\n");
+}
+
+void do_info_block_jobs(Monitor *mon, QObject **ret_data)
+{
+    *ret_data = QOBJECT(qdict_new());
+}
diff --git a/blockdev.h b/blockdev.h
index a132d36..f199d7a 100644
--- a/blockdev.h
+++ b/blockdev.h
@@ -69,5 +69,7 @@ int do_block_stream(Monitor *mon, const QDict *qdict, QObject **ret_data);
 int do_block_job_set_speed(Monitor *mon, const QDict *qdict,
                            QObject **ret_data);
 int do_block_job_cancel(Monitor *mon, const QDict *qdict, QObject **ret_data);
+void monitor_print_block_jobs(Monitor *mon, const QObject *data);
+void do_info_block_jobs(Monitor *mon, QObject **ret_data);
 
 #endif
diff --git a/monitor.c b/monitor.c
index dc55fca..e832d10 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2907,6 +2907,14 @@ static const mon_cmd_t info_cmds[] = {
         .mhandler.info_new = bdrv_info_stats,
     },
     {
+        .name       = "block-jobs",
+        .args_type  = "",
+        .params     = "",
+        .help       = "show progress of ongoing block device operations",
+        .user_print = monitor_print_block_jobs,
+        .mhandler.info_new = do_info_block_jobs,
+    },
+    {
         .name       = "registers",
         .args_type  = "",
         .params     = "",
@@ -3206,6 +3214,14 @@ static const mon_cmd_t qmp_query_cmds[] = {
         .mhandler.info_new = bdrv_info_stats,
     },
     {
+        .name       = "block-jobs",
+        .args_type  = "",
+        .params     = "",
+        .help       = "show progress of ongoing block device operations",
+        .user_print = monitor_print_block_jobs,
+        .mhandler.info_new = do_info_block_jobs,
+    },
+    {
         .name       = "cpus",
         .args_type  = "",
         .params     = "",
diff --git a/qmp-commands.hx b/qmp-commands.hx
index de442f7..ffac014 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2006,3 +2006,35 @@ Example:
 
 EQMP
 
+SQMP
+
+query-block-jobs
+----------------
+
+Show progress of ongoing block device operations.
+
+Return a json-array of all block device operations.  If no operation is active
+then return an empty array.  Each operation is a json-object with the following
+data:
+
+- type:     job type ("stream" for image streaming, json-string)
+- device:   device name (json-string)
+- end:      maximum progress value (json-int)
+- position: current progress value (json-int)
+- speed:    rate limit, bytes per second (json-int)
+
+Progress can be observed as position increases and it reaches end when the
+operation completes.  Position and end have undefined units but can be used to
+calculate a percentage indicating the progress that has been made.
+
+Example:
+
+-> { "execute": "query-block-jobs" }
+<- { "return":[
+      { "type": "stream", "device": "virtio0",
+        "end": 10737418240, "position": 709632,
+        "speed": 0 }
+   ]
+ }
+
+EQMP
-- 
1.7.5.4