hmp: Allow using a qdev id in block_set_io_throttle

The QMP version of this command can take a qdev ID since 7a9877a026,
but the HMP version is still using the deprecated block device name so
there's no way to refer to a block device added like this:

  -blockdev node-name=disk0,driver=qcow2,file.driver=file,file.filename=hd.qcow2
  -device virtio-blk-pci,id=virtio-blk-pci0,drive=disk0

This patch works around this problem by using the specified name as a
qdev ID if the block device name is not found.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

hmp-commands.hx

@@ -1647,7 +1647,8 @@ ETEXI
 STEXI
 @item block_set_io_throttle @var{device} @var{bps} @var{bps_rd} @var{bps_wr} @var{iops} @var{iops_rd} @var{iops_wr}
 @findex block_set_io_throttle
-Change I/O throttle limits for a block drive to @var{bps} @var{bps_rd} @var{bps_wr} @var{iops} @var{iops_rd} @var{iops_wr}
+Change I/O throttle limits for a block drive to @var{bps} @var{bps_rd} @var{bps_wr} @var{iops} @var{iops_rd} @var{iops_wr}.
+@var{device} can be a block device name, a qdev ID or a QOM path.
 ETEXI
 
     {

hmp.c

@@ -1789,9 +1789,8 @@ void hmp_change(Monitor *mon, const QDict *qdict)
 void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict)
 {
     Error *err = NULL;
+    char *device = (char *) qdict_get_str(qdict, "device");
     BlockIOThrottle throttle = {
-        .has_device = true,
-        .device = (char *) qdict_get_str(qdict, "device"),
         .bps = qdict_get_int(qdict, "bps"),
         .bps_rd = qdict_get_int(qdict, "bps_rd"),
         .bps_wr = qdict_get_int(qdict, "bps_wr"),
@@ -1800,6 +1799,17 @@ void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict)
         .iops_wr = qdict_get_int(qdict, "iops_wr"),
     };
 
+    /* qmp_block_set_io_throttle has separate parameters for the
+     * (deprecated) block device name and the qdev ID but the HMP
+     * version has only one, so we must decide which one to pass. */
+    if (blk_by_name(device)) {
+        throttle.has_device = true;
+        throttle.device = device;
+    } else {
+        throttle.has_id = true;
+        throttle.id = device;
+    }
+
     qmp_block_set_io_throttle(&throttle, &err);
     hmp_handle_error(mon, &err);
 }