qmp: add qom-list command

This can be used to list properties in the device model.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

qapi-schema.json

@@ -1168,3 +1168,51 @@
 # Since: 0.14.0
 ##
 { 'command': 'migrate_set_speed', 'data': {'value': 'int'} }
+
+##
+# @DevicePropertyInfo:
+#
+# @name: the name of the property
+#
+# @type: the type of the property.  This will typically come in one of four
+#        forms:
+#
+#        1) A primitive type such as 'u8', 'u16', 'bool', 'str', or 'double'.
+#           These types are mapped to the appropriate JSON type.
+#
+#        2) A legacy type in the form 'legacy<subtype>' where subtype is the
+#           legacy qdev typename.  These types are always treated as strings.
+#
+#        3) A child type in the form 'child<subtype>' where subtype is a qdev
+#           device type name.  Child properties create the composition tree.
+#
+#        4) A link type in the form 'link<subtype>' where subtype is a qdev
+#           device type name.  Link properties form the device model graph.
+#
+# Since: 1.1
+#
+# Notes: This type is experimental.  Its syntax may change in future releases.
+##
+{ 'type': 'DevicePropertyInfo',
+  'data': { 'name': 'str', 'type': 'str' } }
+
+##
+# @qom-list:
+#
+# This command will list any properties of a device given a path in the device
+# model.
+#
+# @path: the path within the device model.  See @qom-get for a description of
+#        this parameter.
+#
+# Returns: a list of @DevicePropertyInfo that describe the properties of the
+#          device.
+#
+# Since: 1.1
+#
+# Notes: This command is experimental.  It's syntax may change in future
+#        releases.
+##
+{ 'command': 'qom-list',
+  'data': { 'path': 'str' },
+  'returns': [ 'DevicePropertyInfo' ] }

qmp-commands.hx

@@ -2009,3 +2009,9 @@ EQMP
         .args_type  = "",
         .mhandler.cmd_new = qmp_marshal_input_query_balloon,
     },
+
+    {
+        .name       = "qom-list",
+        .args_type  = "path:s",
+        .mhandler.cmd_new = qmp_marshal_input_qom_list,
+    },

qmp.c

@@ -16,6 +16,7 @@
 #include "qmp-commands.h"
 #include "kvm.h"
 #include "arch_init.h"
+#include "hw/qdev.h"
 
 NameInfo *qmp_query_name(Error **errp)
 {
@@ -154,3 +155,30 @@ void qmp_cont(Error **errp)
 
     vm_start();
 }
+
+DevicePropertyInfoList *qmp_qom_list(const char *path, Error **errp)
+{
+    DeviceState *dev;
+    bool ambiguous = false;
+    DevicePropertyInfoList *props = NULL;
+    DeviceProperty *prop;
+
+    dev = qdev_resolve_path(path, &ambiguous);
+    if (dev == NULL) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, path);
+        return NULL;
+    }
+
+    QTAILQ_FOREACH(prop, &dev->properties, node) {
+        DevicePropertyInfoList *entry = g_malloc0(sizeof(*entry));
+
+        entry->value = g_malloc0(sizeof(DevicePropertyInfo));
+        entry->next = props;
+        props = entry;
+
+        entry->value->name = g_strdup(prop->name);
+        entry->value->type = g_strdup(prop->type);
+    }
+
+    return props;
+}