block: Accept device model name for blockdev-change-medium

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 blockdev-change-medium to accept a qdev device name.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

blockdev.c

@@ -2540,7 +2540,9 @@ void qmp_x_blockdev_insert_medium(bool has_device, const char *device,
     qmp_blockdev_insert_anon_medium(blk, bs, errp);
 }
 
-void qmp_blockdev_change_medium(const char *device, const char *filename,
+void qmp_blockdev_change_medium(bool has_device, const char *device,
+                                bool has_id, const char *id,
+                                const char *filename,
                                 bool has_format, const char *format,
                                 bool has_read_only,
                                 BlockdevChangeReadOnlyMode read_only,
@@ -2553,10 +2555,10 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
     QDict *options = NULL;
     Error *err = NULL;
 
-    blk = blk_by_name(device);
+    blk = qmp_get_blk(has_device ? device : NULL,
+                      has_id ? id : NULL,
+                      errp);
     if (!blk) {
-        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
-                  "Device '%s' not found", device);
         goto fail;
     }
 
@@ -2604,7 +2606,9 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
         goto fail;
     }
 
-    rc = do_open_tray(device, NULL, false, &err);
+    rc = do_open_tray(has_device ? device : NULL,
+                      has_id ? id : NULL,
+                      false, &err);
     if (rc && rc != -ENOSYS) {
         error_propagate(errp, err);
         goto fail;
@@ -2612,7 +2616,7 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
     error_free(err);
     err = NULL;
 
-    qmp_x_blockdev_remove_medium(true, device, false, NULL, errp);
+    qmp_x_blockdev_remove_medium(has_device, device, has_id, id, errp);
     if (err) {
         error_propagate(errp, err);
         goto fail;
@@ -2626,7 +2630,7 @@ void qmp_blockdev_change_medium(const char *device, const char *filename,
 
     blk_apply_root_state(blk, medium_bs);
 
-    qmp_blockdev_close_tray(true, device, false, NULL, errp);
+    qmp_blockdev_close_tray(has_device, device, has_id, id, errp);
 
 fail:
     /* If the medium has been inserted, the device has its own reference, so

docs/qmp-commands.txt

@@ -3458,7 +3458,9 @@ and loading a new image file which is inserted as the new medium.
 
 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)
 - "filename": filename of the new image (json-string)
 - "format": format of the new image (json-string, optional)
 - "read-only-mode": new read-only mode (json-string, optional)
@@ -3469,7 +3471,7 @@ Examples:
 1. Change a removable medium
 
 -> { "execute": "blockdev-change-medium",
-             "arguments": { "device": "ide1-cd0",
+             "arguments": { "id": "ide0-1-0",
                             "filename": "/srv/images/Fedora-12-x86_64-DVD.iso",
                             "format": "raw" } }
 <- { "return": {} }
@@ -3477,7 +3479,7 @@ Examples:
 2. Load a read-only medium into a writable drive
 
 -> { "execute": "blockdev-change-medium",
-             "arguments": { "device": "isa-fd0",
+             "arguments": { "id": "floppyA",
                             "filename": "/srv/images/ro.img",
                             "format": "raw",
                             "read-only-mode": "retain" } }
@@ -3487,7 +3489,7 @@ Examples:
        "desc": "Could not open '/srv/images/ro.img': Permission denied" } }
 
 -> { "execute": "blockdev-change-medium",
-             "arguments": { "device": "isa-fd0",
+             "arguments": { "id": "floppyA",
                             "filename": "/srv/images/ro.img",
                             "format": "raw",
                             "read-only-mode": "read-only" } }

hmp.c

@@ -1422,8 +1422,9 @@ void hmp_change(Monitor *mon, const QDict *qdict)
             }
         }
 
-        qmp_blockdev_change_medium(device, target, !!arg, arg,
-                                   !!read_only, read_only_mode, &err);
+        qmp_blockdev_change_medium(true, device, false, NULL, target,
+                                   !!arg, arg, !!read_only, read_only_mode,
+                                   &err);
         if (err &&
             error_get_class(err) == ERROR_CLASS_DEVICE_ENCRYPTED) {
             error_free(err);

qapi/block-core.json

@@ -2470,7 +2470,10 @@
 # combines blockdev-open-tray, x-blockdev-remove-medium,
 # x-blockdev-insert-medium and blockdev-close-tray).
 #
-# @device:          block device name
+# @device:          #optional Block device name (deprecated, use @id instead)
+#
+# @id:              #optional The name or QOM path of the guest device
+#                   (since: 2.8)
 #
 # @filename:        filename of the new image to be loaded
 #
@@ -2483,7 +2486,8 @@
 # Since: 2.5
 ##
 { 'command': 'blockdev-change-medium',
-  'data': { 'device': 'str',
+  'data': { '*device': 'str',
+            '*id': 'str',
             'filename': 'str',
             '*format': 'str',
             '*read-only-mode': 'BlockdevChangeReadOnlyMode' } }

qmp.c

@@ -436,8 +436,8 @@ void qmp_change(const char *device, const char *target,
     if (strcmp(device, "vnc") == 0) {
         qmp_change_vnc(target, has_arg, arg, errp);
     } else {
-        qmp_blockdev_change_medium(device, target, has_arg, arg, false, 0,
-                                   errp);
+        qmp_blockdev_change_medium(true, device, false, NULL, target,
+                                   has_arg, arg, false, 0, errp);
     }
 }
 

ui/cocoa.m

@@ -1119,8 +1119,10 @@ QemuCocoaView *cocoaView;
         }
 
         Error *err = NULL;
-        qmp_blockdev_change_medium([drive cStringUsingEncoding:
+        qmp_blockdev_change_medium(true,
+                                   [drive cStringUsingEncoding:
                                           NSASCIIStringEncoding],
+                                   false, NULL,
                                    [file cStringUsingEncoding:
                                          NSASCIIStringEncoding],
                                    true, "raw",