qmp: introduce device-list-properties command

This can be used in conjunction with qom-list-types to determine the supported
set of devices and their parameters.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

qapi-schema.json

@@ -1724,6 +1724,34 @@
   'data': { '*implements': 'str', '*abstract': 'bool' },
   'returns': [ 'ObjectTypeInfo' ] }
 
+##
+# @DevicePropertyInfo:
+#
+# Information about device properties.
+#
+# @name: the name of the property
+# @type: the typename of the property
+#
+# Since: 1.2
+##
+{ 'type': 'DevicePropertyInfo',
+  'data': { 'name': 'str', 'type': 'str' } }
+
+##
+# @device-list-properties:
+#
+# List properties associated with a device.
+#
+# @typename: the type name of a device
+#
+# Returns: a list of DevicePropertyInfo describing a devices properties
+#
+# Since: 1.2
+##
+{ 'command': 'device-list-properties',
+  'data': { 'typename': 'str'},
+  'returns': [ 'DevicePropertyInfo' ] }
+
 ##
 # @migrate
 #

qmp-commands.hx

@@ -2217,3 +2217,10 @@ EQMP
         .args_type  = "implements:s?,abstract:b?",
         .mhandler.cmd_new = qmp_marshal_input_qom_list_types,
     },
+
+    {
+        .name       = "device-list-properties",
+        .args_type  = "typename:s",
+        .mhandler.cmd_new = qmp_marshal_input_device_list_properties,
+    },
+

qmp.c

@@ -417,3 +417,53 @@ ObjectTypeInfoList *qmp_qom_list_types(bool has_implements,
 
     return ret;
 }
+
+DevicePropertyInfoList *qmp_device_list_properties(const char *typename,
+                                                   Error **errp)
+{
+    ObjectClass *klass;
+    Property *prop;
+    DevicePropertyInfoList *prop_list = NULL;
+
+    klass = object_class_by_name(typename);
+    if (klass == NULL) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, typename);
+        return NULL;
+    }
+
+    klass = object_class_dynamic_cast(klass, TYPE_DEVICE);
+    if (klass == NULL) {
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE,
+                  "name", TYPE_DEVICE);
+        return NULL;
+    }
+
+    do {
+        for (prop = DEVICE_CLASS(klass)->props; prop && prop->name; prop++) {
+            DevicePropertyInfoList *entry;
+            DevicePropertyInfo *info;
+
+            /*
+             * TODO Properties without a parser are just for dirty hacks.
+             * qdev_prop_ptr is the only such PropertyInfo.  It's marked
+             * for removal.  This conditional should be removed along with
+             * it.
+             */
+            if (!prop->info->set) {
+                continue;           /* no way to set it, don't show */
+            }
+
+            info = g_malloc0(sizeof(*info));
+            info->name = g_strdup(prop->name);
+            info->type = g_strdup(prop->info->legacy_name ?: prop->info->name);
+
+            entry = g_malloc0(sizeof(*entry));
+            entry->value = info;
+            entry->next = prop_list;
+            prop_list = entry;
+        }
+        klass = object_class_get_parent(klass);
+    } while (klass != object_class_by_name(TYPE_DEVICE));
+
+    return prop_list;
+}