block: Accept device model name for block_set_io_throttle

In order to remove the need for BlockBackend names in the external API,
we want to allow qdev device names in all device related commands.

This converts block_set_io_throttle to accept a qdev device name.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

blockdev.c

@@ -2647,10 +2647,10 @@ void qmp_block_set_io_throttle(BlockIOThrottle *arg, Error **errp)
     BlockBackend *blk;
     AioContext *aio_context;
 
-    blk = blk_by_name(arg->device);
+    blk = qmp_get_blk(arg->has_device ? arg->device : NULL,
+                      arg->has_id ? arg->id : NULL,
+                      errp);
     if (!blk) {
-        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
-                  "Device '%s' not found", arg->device);
         return;
     }
 
@@ -2659,7 +2659,7 @@ void qmp_block_set_io_throttle(BlockIOThrottle *arg, Error **errp)
 
     bs = blk_bs(blk);
     if (!bs) {
-        error_setg(errp, "Device '%s' has no medium", arg->device);
+        error_setg(errp, "Device has no medium");
         goto out;
     }
 
@@ -2723,7 +2723,9 @@ void qmp_block_set_io_throttle(BlockIOThrottle *arg, Error **errp)
          * just update the throttling group. */
         if (!blk_get_public(blk)->throttle_state) {
             blk_io_limits_enable(blk,
-                                 arg->has_group ? arg->group : arg->device);
+                                 arg->has_group ? arg->group :
+                                 arg->has_device ? arg->device :
+                                 arg->id);
         } else if (arg->has_group) {
             blk_io_limits_update_group(blk, arg->group);
         }

docs/qmp-commands.txt

@@ -1459,7 +1459,9 @@ Change I/O throttle limits for a block drive.
 
 Arguments:
 
-- "device": device name (json-string)
+- "device": block device name (deprecated, use @id instead)
+            (json-string, optional)
+- "id": the name or QOM path of the guest device (json-string, optional)
 - "bps": total throughput limit in bytes per second (json-int)
 - "bps_rd": read throughput limit in bytes per second (json-int)
 - "bps_wr": write throughput limit in bytes per second (json-int)
@@ -1483,7 +1485,7 @@ Arguments:
 
 Example:
 
--> { "execute": "block_set_io_throttle", "arguments": { "device": "virtio0",
+-> { "execute": "block_set_io_throttle", "arguments": { "id": "ide0-1-0",
                                                "bps": 1000000,
                                                "bps_rd": 0,
                                                "bps_wr": 0,

qapi/block-core.json

@@ -1377,7 +1377,9 @@
 #
 # A set of parameters describing block throttling.
 #
-# @device: The name of the device
+# @device: #optional Block device name (deprecated, use @id instead)
+#
+# @id: #optional The name or QOM path of the guest device (since: 2.8)
 #
 # @bps: total throughput limit in bytes per second
 #
@@ -1446,8 +1448,8 @@
 # Since: 1.1
 ##
 { 'struct': 'BlockIOThrottle',
-  'data': { 'device': 'str', 'bps': 'int', 'bps_rd': 'int', 'bps_wr': 'int',
-            'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int',
+  'data': { '*device': 'str', '*id': 'str', 'bps': 'int', 'bps_rd': 'int',
+            'bps_wr': 'int', 'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int',
             '*bps_max': 'int', '*bps_rd_max': 'int',
             '*bps_wr_max': 'int', '*iops_max': 'int',
             '*iops_rd_max': 'int', '*iops_wr_max': 'int',