Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 1976 insertions, 0 deletions

diff --git a/include/qom/object.h b/include/qom/object.h
new file mode 100644
index 000000000..fae096f51
--- /dev/null
+++ b/include/qom/object.h
@@ -0,0 +1,1976 @@
+/*
+ * QEMU Object Model
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_OBJECT_H
+#define QEMU_OBJECT_H
+
+#include "qapi/qapi-builtin-types.h"
+#include "qemu/module.h"
+#include "qom/object.h"
+
+struct TypeImpl;
+typedef struct TypeImpl *Type;
+
+typedef struct TypeInfo TypeInfo;
+
+typedef struct InterfaceClass InterfaceClass;
+typedef struct InterfaceInfo InterfaceInfo;
+
+#define TYPE_OBJECT "object"
+
+typedef struct ObjectProperty ObjectProperty;
+
+/**
+ * typedef ObjectPropertyAccessor:
+ * @obj: the object that owns the property
+ * @v: the visitor that contains the property data
+ * @name: the name of the property
+ * @opaque: the object property opaque
+ * @errp: a pointer to an Error that is filled if getting/setting fails.
+ *
+ * Called when trying to get/set a property.
+ */
+typedef void (ObjectPropertyAccessor)(Object *obj,
+                                      Visitor *v,
+                                      const char *name,
+                                      void *opaque,
+                                      Error **errp);
+
+/**
+ * typedef ObjectPropertyResolve:
+ * @obj: the object that owns the property
+ * @opaque: the opaque registered with the property
+ * @part: the name of the property
+ *
+ * Resolves the #Object corresponding to property @part.
+ *
+ * The returned object can also be used as a starting point
+ * to resolve a relative path starting with "@part".
+ *
+ * Returns: If @path is the path that led to @obj, the function
+ * returns the #Object corresponding to "@path/@part".
+ * If "@path/@part" is not a valid object path, it returns #NULL.
+ */
+typedef Object *(ObjectPropertyResolve)(Object *obj,
+                                        void *opaque,
+                                        const char *part);
+
+/**
+ * typedef ObjectPropertyRelease:
+ * @obj: the object that owns the property
+ * @name: the name of the property
+ * @opaque: the opaque registered with the property
+ *
+ * Called when a property is removed from a object.
+ */
+typedef void (ObjectPropertyRelease)(Object *obj,
+                                     const char *name,
+                                     void *opaque);
+
+/**
+ * typedef ObjectPropertyInit:
+ * @obj: the object that owns the property
+ * @prop: the property to set
+ *
+ * Called when a property is initialized.
+ */
+typedef void (ObjectPropertyInit)(Object *obj, ObjectProperty *prop);
+
+struct ObjectProperty
+{
+    char *name;
+    char *type;
+    char *description;
+    ObjectPropertyAccessor *get;
+    ObjectPropertyAccessor *set;
+    ObjectPropertyResolve *resolve;
+    ObjectPropertyRelease *release;
+    ObjectPropertyInit *init;
+    void *opaque;
+    QObject *defval;
+};
+
+/**
+ * typedef ObjectUnparent:
+ * @obj: the object that is being removed from the composition tree
+ *
+ * Called when an object is being removed from the QOM composition tree.
+ * The function should remove any backlinks from children objects to @obj.
+ */
+typedef void (ObjectUnparent)(Object *obj);
+
+/**
+ * typedef ObjectFree:
+ * @obj: the object being freed
+ *
+ * Called when an object's last reference is removed.
+ */
+typedef void (ObjectFree)(void *obj);
+
+#define OBJECT_CLASS_CAST_CACHE 4
+
+/**
+ * struct ObjectClass:
+ *
+ * The base for all classes.  The only thing that #ObjectClass contains is an
+ * integer type handle.
+ */
+struct ObjectClass
+{
+    /* private: */
+    Type type;
+    GSList *interfaces;
+
+    const char *object_cast_cache[OBJECT_CLASS_CAST_CACHE];
+    const char *class_cast_cache[OBJECT_CLASS_CAST_CACHE];
+
+    ObjectUnparent *unparent;
+
+    GHashTable *properties;
+};
+
+/**
+ * struct Object:
+ *
+ * The base for all objects.  The first member of this object is a pointer to
+ * a #ObjectClass.  Since C guarantees that the first member of a structure
+ * always begins at byte 0 of that structure, as long as any sub-object places
+ * its parent as the first member, we can cast directly to a #Object.
+ *
+ * As a result, #Object contains a reference to the objects type as its
+ * first member.  This allows identification of the real type of the object at
+ * run time.
+ */
+struct Object
+{
+    /* private: */
+    ObjectClass *class;
+    ObjectFree *free;
+    GHashTable *properties;
+    uint32_t ref;
+    Object *parent;
+};
+
+/**
+ * DECLARE_INSTANCE_CHECKER:
+ * @InstanceType: instance struct name
+ * @OBJ_NAME: the object name in uppercase with underscore separators
+ * @TYPENAME: type name
+ *
+ * Direct usage of this macro should be avoided, and the complete
+ * OBJECT_DECLARE_TYPE macro is recommended instead.
+ *
+ * This macro will provide the instance type cast functions for a
+ * QOM type.
+ */
+#define DECLARE_INSTANCE_CHECKER(InstanceType, OBJ_NAME, TYPENAME) \
+    static inline G_GNUC_UNUSED InstanceType * \
+    OBJ_NAME(const void *obj) \
+    { return OBJECT_CHECK(InstanceType, obj, TYPENAME); }
+
+/**
+ * DECLARE_CLASS_CHECKERS:
+ * @ClassType: class struct name
+ * @OBJ_NAME: the object name in uppercase with underscore separators
+ * @TYPENAME: type name
+ *
+ * Direct usage of this macro should be avoided, and the complete
+ * OBJECT_DECLARE_TYPE macro is recommended instead.
+ *
+ * This macro will provide the class type cast functions for a
+ * QOM type.
+ */
+#define DECLARE_CLASS_CHECKERS(ClassType, OBJ_NAME, TYPENAME) \
+    static inline G_GNUC_UNUSED ClassType * \
+    OBJ_NAME##_GET_CLASS(const void *obj) \
+    { return OBJECT_GET_CLASS(ClassType, obj, TYPENAME); } \
+    \
+    static inline G_GNUC_UNUSED ClassType * \
+    OBJ_NAME##_CLASS(const void *klass) \
+    { return OBJECT_CLASS_CHECK(ClassType, klass, TYPENAME); }
+
+/**
+ * DECLARE_OBJ_CHECKERS:
+ * @InstanceType: instance struct name
+ * @ClassType: class struct name
+ * @OBJ_NAME: the object name in uppercase with underscore separators
+ * @TYPENAME: type name
+ *
+ * Direct usage of this macro should be avoided, and the complete
+ * OBJECT_DECLARE_TYPE macro is recommended instead.
+ *
+ * This macro will provide the three standard type cast functions for a
+ * QOM type.
+ */
+#define DECLARE_OBJ_CHECKERS(InstanceType, ClassType, OBJ_NAME, TYPENAME) \
+    DECLARE_INSTANCE_CHECKER(InstanceType, OBJ_NAME, TYPENAME) \
+    \
+    DECLARE_CLASS_CHECKERS(ClassType, OBJ_NAME, TYPENAME)
+
+/**
+ * OBJECT_DECLARE_TYPE:
+ * @InstanceType: instance struct name
+ * @ClassType: class struct name
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ *
+ * This macro is typically used in a header file, and will:
+ *
+ *   - create the typedefs for the object and class structs
+ *   - register the type for use with g_autoptr
+ *   - provide three standard type cast functions
+ *
+ * The object struct and class struct need to be declared manually.
+ */
+#define OBJECT_DECLARE_TYPE(InstanceType, ClassType, MODULE_OBJ_NAME) \
+    typedef struct InstanceType InstanceType; \
+    typedef struct ClassType ClassType; \
+    \
+    G_DEFINE_AUTOPTR_CLEANUP_FUNC(InstanceType, object_unref) \
+    \
+    DECLARE_OBJ_CHECKERS(InstanceType, ClassType, \
+                         MODULE_OBJ_NAME, TYPE_##MODULE_OBJ_NAME)
+
+/**
+ * OBJECT_DECLARE_SIMPLE_TYPE:
+ * @InstanceType: instance struct name
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ *
+ * This does the same as OBJECT_DECLARE_TYPE(), but with no class struct
+ * declared.
+ *
+ * This macro should be used unless the class struct needs to have
+ * virtual methods declared.
+ */
+#define OBJECT_DECLARE_SIMPLE_TYPE(InstanceType, MODULE_OBJ_NAME) \
+    typedef struct InstanceType InstanceType; \
+    \
+    G_DEFINE_AUTOPTR_CLEANUP_FUNC(InstanceType, object_unref) \
+    \
+    DECLARE_INSTANCE_CHECKER(InstanceType, MODULE_OBJ_NAME, TYPE_##MODULE_OBJ_NAME)
+
+
+/**
+ * OBJECT_DEFINE_TYPE_EXTENDED:
+ * @ModuleObjName: the object name with initial caps
+ * @module_obj_name: the object name in lowercase with underscore separators
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
+ *                          separators
+ * @ABSTRACT: boolean flag to indicate whether the object can be instantiated
+ * @...: list of initializers for "InterfaceInfo" to declare implemented interfaces
+ *
+ * This macro is typically used in a source file, and will:
+ *
+ *   - declare prototypes for _finalize, _class_init and _init methods
+ *   - declare the TypeInfo struct instance
+ *   - provide the constructor to register the type
+ *
+ * After using this macro, implementations of the _finalize, _class_init,
+ * and _init methods need to be written. Any of these can be zero-line
+ * no-op impls if no special logic is required for a given type.
+ *
+ * This macro should rarely be used, instead one of the more specialized
+ * macros is usually a better choice.
+ */
+#define OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
+                                    MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
+                                    ABSTRACT, ...) \
+    static void \
+    module_obj_name##_finalize(Object *obj); \
+    static void \
+    module_obj_name##_class_init(ObjectClass *oc, void *data); \
+    static void \
+    module_obj_name##_init(Object *obj); \
+    \
+    static const TypeInfo module_obj_name##_info = { \
+        .parent = TYPE_##PARENT_MODULE_OBJ_NAME, \
+        .name = TYPE_##MODULE_OBJ_NAME, \
+        .instance_size = sizeof(ModuleObjName), \
+        .instance_align = __alignof__(ModuleObjName), \
+        .instance_init = module_obj_name##_init, \
+        .instance_finalize = module_obj_name##_finalize, \
+        .class_size = sizeof(ModuleObjName##Class), \
+        .class_init = module_obj_name##_class_init, \
+        .abstract = ABSTRACT, \
+        .interfaces = (InterfaceInfo[]) { __VA_ARGS__ } , \
+    }; \
+    \
+    static void \
+    module_obj_name##_register_types(void) \
+    { \
+        type_register_static(&module_obj_name##_info); \
+    } \
+    type_init(module_obj_name##_register_types);
+
+/**
+ * OBJECT_DEFINE_TYPE:
+ * @ModuleObjName: the object name with initial caps
+ * @module_obj_name: the object name in lowercase with underscore separators
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
+ *                          separators
+ *
+ * This is a specialization of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable
+ * for the common case of a non-abstract type, without any interfaces.
+ */
+#define OBJECT_DEFINE_TYPE(ModuleObjName, module_obj_name, MODULE_OBJ_NAME, \
+                           PARENT_MODULE_OBJ_NAME) \
+    OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
+                                MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
+                                false, { NULL })
+
+/**
+ * OBJECT_DEFINE_TYPE_WITH_INTERFACES:
+ * @ModuleObjName: the object name with initial caps
+ * @module_obj_name: the object name in lowercase with underscore separators
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
+ *                          separators
+ * @...: list of initializers for "InterfaceInfo" to declare implemented interfaces
+ *
+ * This is a specialization of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable
+ * for the common case of a non-abstract type, with one or more implemented
+ * interfaces.
+ *
+ * Note when passing the list of interfaces, be sure to include the final
+ * NULL entry, e.g.  { TYPE_USER_CREATABLE }, { NULL }
+ */
+#define OBJECT_DEFINE_TYPE_WITH_INTERFACES(ModuleObjName, module_obj_name, \
+                                           MODULE_OBJ_NAME, \
+                                           PARENT_MODULE_OBJ_NAME, ...) \
+    OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
+                                MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
+                                false, __VA_ARGS__)
+
+/**
+ * OBJECT_DEFINE_ABSTRACT_TYPE:
+ * @ModuleObjName: the object name with initial caps
+ * @module_obj_name: the object name in lowercase with underscore separators
+ * @MODULE_OBJ_NAME: the object name in uppercase with underscore separators
+ * @PARENT_MODULE_OBJ_NAME: the parent object name in uppercase with underscore
+ *                          separators
+ *
+ * This is a specialization of OBJECT_DEFINE_TYPE_EXTENDED, which is suitable
+ * for defining an abstract type, without any interfaces.
+ */
+#define OBJECT_DEFINE_ABSTRACT_TYPE(ModuleObjName, module_obj_name, \
+                                    MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME) \
+    OBJECT_DEFINE_TYPE_EXTENDED(ModuleObjName, module_obj_name, \
+                                MODULE_OBJ_NAME, PARENT_MODULE_OBJ_NAME, \
+                                true, { NULL })
+
+/**
+ * struct TypeInfo:
+ * @name: The name of the type.
+ * @parent: The name of the parent type.
+ * @instance_size: The size of the object (derivative of #Object).  If
+ *   @instance_size is 0, then the size of the object will be the size of the
+ *   parent object.
+ * @instance_align: The required alignment of the object.  If @instance_align
+ *   is 0, then normal malloc alignment is sufficient; if non-zero, then we
+ *   must use qemu_memalign for allocation.
+ * @instance_init: This function is called to initialize an object.  The parent
+ *   class will have already been initialized so the type is only responsible
+ *   for initializing its own members.
+ * @instance_post_init: This function is called to finish initialization of
+ *   an object, after all @instance_init functions were called.
+ * @instance_finalize: This function is called during object destruction.  This
+ *   is called before the parent @instance_finalize function has been called.
+ *   An object should only free the members that are unique to its type in this
+ *   function.
+ * @abstract: If this field is true, then the class is considered abstract and
+ *   cannot be directly instantiated.
+ * @class_size: The size of the class object (derivative of #ObjectClass)
+ *   for this object.  If @class_size is 0, then the size of the class will be
+ *   assumed to be the size of the parent class.  This allows a type to avoid
+ *   implementing an explicit class type if they are not adding additional
+ *   virtual functions.
+ * @class_init: This function is called after all parent class initialization
+ *   has occurred to allow a class to set its default virtual method pointers.
+ *   This is also the function to use to override virtual methods from a parent
+ *   class.
+ * @class_base_init: This function is called for all base classes after all
+ *   parent class initialization has occurred, but before the class itself
+ *   is initialized.  This is the function to use to undo the effects of
+ *   memcpy from the parent class to the descendants.
+ * @class_data: Data to pass to the @class_init,
+ *   @class_base_init. This can be useful when building dynamic
+ *   classes.
+ * @interfaces: The list of interfaces associated with this type.  This
+ *   should point to a static array that's terminated with a zero filled
+ *   element.
+ */
+struct TypeInfo
+{
+    const char *name;
+    const char *parent;
+
+    size_t instance_size;
+    size_t instance_align;
+    void (*instance_init)(Object *obj);
+    void (*instance_post_init)(Object *obj);
+    void (*instance_finalize)(Object *obj);
+
+    bool abstract;
+    size_t class_size;
+
+    void (*class_init)(ObjectClass *klass, void *data);
+    void (*class_base_init)(ObjectClass *klass, void *data);
+    void *class_data;
+
+    InterfaceInfo *interfaces;
+};
+
+/**
+ * OBJECT:
+ * @obj: A derivative of #Object
+ *
+ * Converts an object to a #Object.  Since all objects are #Objects,
+ * this function will always succeed.
+ */
+#define OBJECT(obj) \
+    ((Object *)(obj))
+
+/**
+ * OBJECT_CLASS:
+ * @class: A derivative of #ObjectClass.
+ *
+ * Converts a class to an #ObjectClass.  Since all objects are #Objects,
+ * this function will always succeed.
+ */
+#define OBJECT_CLASS(class) \
+    ((ObjectClass *)(class))
+
+/**
+ * OBJECT_CHECK:
+ * @type: The C type to use for the return value.
+ * @obj: A derivative of @type to cast.
+ * @name: The QOM typename of @type
+ *
+ * A type safe version of @object_dynamic_cast_assert.  Typically each class
+ * will define a macro based on this type to perform type safe dynamic_casts to
+ * this object type.
+ *
+ * If an invalid object is passed to this function, a run time assert will be
+ * generated.
+ */
+#define OBJECT_CHECK(type, obj, name) \
+    ((type *)object_dynamic_cast_assert(OBJECT(obj), (name), \
+                                        __FILE__, __LINE__, __func__))
+
+/**
+ * OBJECT_CLASS_CHECK:
+ * @class_type: The C type to use for the return value.
+ * @class: A derivative class of @class_type to cast.
+ * @name: the QOM typename of @class_type.
+ *
+ * A type safe version of @object_class_dynamic_cast_assert.  This macro is
+ * typically wrapped by each type to perform type safe casts of a class to a
+ * specific class type.
+ */
+#define OBJECT_CLASS_CHECK(class_type, class, name) \
+    ((class_type *)object_class_dynamic_cast_assert(OBJECT_CLASS(class), (name), \
+                                               __FILE__, __LINE__, __func__))
+
+/**
+ * OBJECT_GET_CLASS:
+ * @class: The C type to use for the return value.
+ * @obj: The object to obtain the class for.
+ * @name: The QOM typename of @obj.
+ *
+ * This function will return a specific class for a given object.  Its generally
+ * used by each type to provide a type safe macro to get a specific class type
+ * from an object.
+ */
+#define OBJECT_GET_CLASS(class, obj, name) \
+    OBJECT_CLASS_CHECK(class, object_get_class(OBJECT(obj)), name)
+
+/**
+ * struct InterfaceInfo:
+ * @type: The name of the interface.
+ *
+ * The information associated with an interface.
+ */
+struct InterfaceInfo {
+    const char *type;
+};
+
+/**
+ * struct InterfaceClass:
+ * @parent_class: the base class
+ *
+ * The class for all interfaces.  Subclasses of this class should only add
+ * virtual methods.
+ */
+struct InterfaceClass
+{
+    ObjectClass parent_class;
+    /* private: */
+    ObjectClass *concrete_class;
+    Type interface_type;
+};
+
+#define TYPE_INTERFACE "interface"
+
+/**
+ * INTERFACE_CLASS:
+ * @klass: class to cast from
+ * Returns: An #InterfaceClass or raise an error if cast is invalid
+ */
+#define INTERFACE_CLASS(klass) \
+    OBJECT_CLASS_CHECK(InterfaceClass, klass, TYPE_INTERFACE)
+
+/**
+ * INTERFACE_CHECK:
+ * @interface: the type to return
+ * @obj: the object to convert to an interface
+ * @name: the interface type name
+ *
+ * Returns: @obj casted to @interface if cast is valid, otherwise raise error.
+ */
+#define INTERFACE_CHECK(interface, obj, name) \
+    ((interface *)object_dynamic_cast_assert(OBJECT((obj)), (name), \
+                                             __FILE__, __LINE__, __func__))
+
+/**
+ * object_new_with_class:
+ * @klass: The class to instantiate.
+ *
+ * This function will initialize a new object using heap allocated memory.
+ * The returned object has a reference count of 1, and will be freed when
+ * the last reference is dropped.
+ *
+ * Returns: The newly allocated and instantiated object.
+ */
+Object *object_new_with_class(ObjectClass *klass);
+
+/**
+ * object_new:
+ * @typename: The name of the type of the object to instantiate.
+ *
+ * This function will initialize a new object using heap allocated memory.
+ * The returned object has a reference count of 1, and will be freed when
+ * the last reference is dropped.
+ *
+ * Returns: The newly allocated and instantiated object.
+ */
+Object *object_new(const char *typename);
+
+/**
+ * object_new_with_props:
+ * @typename:  The name of the type of the object to instantiate.
+ * @parent: the parent object
+ * @id: The unique ID of the object
+ * @errp: pointer to error object
+ * @...: list of property names and values
+ *
+ * This function will initialize a new object using heap allocated memory.
+ * The returned object has a reference count of 1, and will be freed when
+ * the last reference is dropped.
+ *
+ * The @id parameter will be used when registering the object as a
+ * child of @parent in the composition tree.
+ *
+ * The variadic parameters are a list of pairs of (propname, propvalue)
+ * strings. The propname of %NULL indicates the end of the property
+ * list. If the object implements the user creatable interface, the
+ * object will be marked complete once all the properties have been
+ * processed.
+ *
+ * .. code-block:: c
+ *    :caption: Creating an object with properties
+ *
+ *      Error *err = NULL;
+ *      Object *obj;
+ *
+ *      obj = object_new_with_props(TYPE_MEMORY_BACKEND_FILE,
+ *                                  object_get_objects_root(),
+ *                                  "hostmem0",
+ *                                  &err,
+ *                                  "share", "yes",
+ *                                  "mem-path", "/dev/shm/somefile",
+ *                                  "prealloc", "yes",
+ *                                  "size", "1048576",
+ *                                  NULL);
+ *
+ *      if (!obj) {
+ *        error_reportf_err(err, "Cannot create memory backend: ");
+ *      }
+ *
+ * The returned object will have one stable reference maintained
+ * for as long as it is present in the object hierarchy.
+ *
+ * Returns: The newly allocated, instantiated & initialized object.
+ */
+Object *object_new_with_props(const char *typename,
+                              Object *parent,
+                              const char *id,
+                              Error **errp,
+                              ...) QEMU_SENTINEL;
+
+/**
+ * object_new_with_propv:
+ * @typename:  The name of the type of the object to instantiate.
+ * @parent: the parent object
+ * @id: The unique ID of the object
+ * @errp: pointer to error object
+ * @vargs: list of property names and values
+ *
+ * See object_new_with_props() for documentation.
+ */
+Object *object_new_with_propv(const char *typename,
+                              Object *parent,
+                              const char *id,
+                              Error **errp,
+                              va_list vargs);
+
+bool object_apply_global_props(Object *obj, const GPtrArray *props,
+                               Error **errp);
+void object_set_machine_compat_props(GPtrArray *compat_props);
+void object_set_accelerator_compat_props(GPtrArray *compat_props);
+void object_register_sugar_prop(const char *driver, const char *prop,
+                                const char *value, bool optional);
+void object_apply_compat_props(Object *obj);
+
+/**
+ * object_set_props:
+ * @obj: the object instance to set properties on
+ * @errp: pointer to error object
+ * @...: list of property names and values
+ *
+ * This function will set a list of properties on an existing object
+ * instance.
+ *
+ * The variadic parameters are a list of pairs of (propname, propvalue)
+ * strings. The propname of %NULL indicates the end of the property
+ * list.
+ *
+ * .. code-block:: c
+ *    :caption: Update an object's properties
+ *
+ *      Error *err = NULL;
+ *      Object *obj = ...get / create object...;
+ *
+ *      if (!object_set_props(obj,
+ *                            &err,
+ *                            "share", "yes",
+ *                            "mem-path", "/dev/shm/somefile",
+ *                            "prealloc", "yes",
+ *                            "size", "1048576",
+ *                            NULL)) {
+ *        error_reportf_err(err, "Cannot set properties: ");
+ *      }
+ *
+ * The returned object will have one stable reference maintained
+ * for as long as it is present in the object hierarchy.
+ *
+ * Returns: %true on success, %false on error.
+ */
+bool object_set_props(Object *obj, Error **errp, ...) QEMU_SENTINEL;
+
+/**
+ * object_set_propv:
+ * @obj: the object instance to set properties on
+ * @errp: pointer to error object
+ * @vargs: list of property names and values
+ *
+ * See object_set_props() for documentation.
+ *
+ * Returns: %true on success, %false on error.
+ */
+bool object_set_propv(Object *obj, Error **errp, va_list vargs);
+
+/**
+ * object_initialize:
+ * @obj: A pointer to the memory to be used for the object.
+ * @size: The maximum size available at @obj for the object.
+ * @typename: The name of the type of the object to instantiate.
+ *
+ * This function will initialize an object.  The memory for the object should
+ * have already been allocated.  The returned object has a reference count of 1,
+ * and will be finalized when the last reference is dropped.
+ */
+void object_initialize(void *obj, size_t size, const char *typename);
+
+/**
+ * object_initialize_child_with_props:
+ * @parentobj: The parent object to add a property to
+ * @propname: The name of the property
+ * @childobj: A pointer to the memory to be used for the object.
+ * @size: The maximum size available at @childobj for the object.
+ * @type: The name of the type of the object to instantiate.
+ * @errp: If an error occurs, a pointer to an area to store the error
+ * @...: list of property names and values
+ *
+ * This function will initialize an object. The memory for the object should
+ * have already been allocated. The object will then be added as child property
+ * to a parent with object_property_add_child() function. The returned object
+ * has a reference count of 1 (for the "child<...>" property from the parent),
+ * so the object will be finalized automatically when the parent gets removed.
+ *
+ * The variadic parameters are a list of pairs of (propname, propvalue)
+ * strings. The propname of %NULL indicates the end of the property list.
+ * If the object implements the user creatable interface, the object will
+ * be marked complete once all the properties have been processed.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_initialize_child_with_props(Object *parentobj,
+                             const char *propname,
+                             void *childobj, size_t size, const char *type,
+                             Error **errp, ...) QEMU_SENTINEL;
+
+/**
+ * object_initialize_child_with_propsv:
+ * @parentobj: The parent object to add a property to
+ * @propname: The name of the property
+ * @childobj: A pointer to the memory to be used for the object.
+ * @size: The maximum size available at @childobj for the object.
+ * @type: The name of the type of the object to instantiate.
+ * @errp: If an error occurs, a pointer to an area to store the error
+ * @vargs: list of property names and values
+ *
+ * See object_initialize_child() for documentation.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_initialize_child_with_propsv(Object *parentobj,
+                              const char *propname,
+                              void *childobj, size_t size, const char *type,
+                              Error **errp, va_list vargs);
+
+/**
+ * object_initialize_child:
+ * @parent: The parent object to add a property to
+ * @propname: The name of the property
+ * @child: A precisely typed pointer to the memory to be used for the
+ * object.
+ * @type: The name of the type of the object to instantiate.
+ *
+ * This is like::
+ *
+ *   object_initialize_child_with_props(parent, propname,
+ *                                      child, sizeof(*child), type,
+ *                                      &error_abort, NULL)
+ */
+#define object_initialize_child(parent, propname, child, type)          \
+    object_initialize_child_internal((parent), (propname),              \
+                                     (child), sizeof(*(child)), (type))
+void object_initialize_child_internal(Object *parent, const char *propname,
+                                      void *child, size_t size,
+                                      const char *type);
+
+/**
+ * object_dynamic_cast:
+ * @obj: The object to cast.
+ * @typename: The @typename to cast to.
+ *
+ * This function will determine if @obj is-a @typename.  @obj can refer to an
+ * object or an interface associated with an object.
+ *
+ * Returns: This function returns @obj on success or #NULL on failure.
+ */
+Object *object_dynamic_cast(Object *obj, const char *typename);
+
+/**
+ * object_dynamic_cast_assert:
+ * @obj: The object to cast.
+ * @typename: The @typename to cast to.
+ * @file: Source code file where function was called
+ * @line: Source code line where function was called
+ * @func: Name of function where this function was called
+ *
+ * See object_dynamic_cast() for a description of the parameters of this
+ * function.  The only difference in behavior is that this function asserts
+ * instead of returning #NULL on failure if QOM cast debugging is enabled.
+ * This function is not meant to be called directly, but only through
+ * the wrapper macro OBJECT_CHECK.
+ */
+Object *object_dynamic_cast_assert(Object *obj, const char *typename,
+                                   const char *file, int line, const char *func);
+
+/**
+ * object_get_class:
+ * @obj: A derivative of #Object
+ *
+ * Returns: The #ObjectClass of the type associated with @obj.
+ */
+ObjectClass *object_get_class(Object *obj);
+
+/**
+ * object_get_typename:
+ * @obj: A derivative of #Object.
+ *
+ * Returns: The QOM typename of @obj.
+ */
+const char *object_get_typename(const Object *obj);
+
+/**
+ * type_register_static:
+ * @info: The #TypeInfo of the new type.
+ *
+ * @info and all of the strings it points to should exist for the life time
+ * that the type is registered.
+ *
+ * Returns: the new #Type.
+ */
+Type type_register_static(const TypeInfo *info);
+
+/**
+ * type_register:
+ * @info: The #TypeInfo of the new type
+ *
+ * Unlike type_register_static(), this call does not require @info or its
+ * string members to continue to exist after the call returns.
+ *
+ * Returns: the new #Type.
+ */
+Type type_register(const TypeInfo *info);
+
+/**
+ * type_register_static_array:
+ * @infos: The array of the new type #TypeInfo structures.
+ * @nr_infos: number of entries in @infos
+ *
+ * @infos and all of the strings it points to should exist for the life time
+ * that the type is registered.
+ */
+void type_register_static_array(const TypeInfo *infos, int nr_infos);
+
+/**
+ * DEFINE_TYPES:
+ * @type_array: The array containing #TypeInfo structures to register
+ *
+ * @type_array should be static constant that exists for the life time
+ * that the type is registered.
+ */
+#define DEFINE_TYPES(type_array)                                            \
+static void do_qemu_init_ ## type_array(void)                               \
+{                                                                           \
+    type_register_static_array(type_array, ARRAY_SIZE(type_array));         \
+}                                                                           \
+type_init(do_qemu_init_ ## type_array)
+
+/**
+ * type_print_class_properties:
+ * @type: a QOM class name
+ *
+ * Print the object's class properties to stdout or the monitor.
+ * Return whether an object was found.
+ */
+bool type_print_class_properties(const char *type);
+
+/**
+ * object_set_properties_from_keyval:
+ * @obj: a QOM object
+ * @qdict: a dictionary with the properties to be set
+ * @from_json: true if leaf values of @qdict are typed, false if they
+ * are strings
+ * @errp: pointer to error object
+ *
+ * For each key in the dictionary, parse the value string if needed,
+ * then set the corresponding property in @obj.
+ */
+void object_set_properties_from_keyval(Object *obj, const QDict *qdict,
+                                       bool from_json, Error **errp);
+
+/**
+ * object_class_dynamic_cast_assert:
+ * @klass: The #ObjectClass to attempt to cast.
+ * @typename: The QOM typename of the class to cast to.
+ * @file: Source code file where function was called
+ * @line: Source code line where function was called
+ * @func: Name of function where this function was called
+ *
+ * See object_class_dynamic_cast() for a description of the parameters
+ * of this function.  The only difference in behavior is that this function
+ * asserts instead of returning #NULL on failure if QOM cast debugging is
+ * enabled.  This function is not meant to be called directly, but only through
+ * the wrapper macro OBJECT_CLASS_CHECK.
+ */
+ObjectClass *object_class_dynamic_cast_assert(ObjectClass *klass,
+                                              const char *typename,
+                                              const char *file, int line,
+                                              const char *func);
+
+/**
+ * object_class_dynamic_cast:
+ * @klass: The #ObjectClass to attempt to cast.
+ * @typename: The QOM typename of the class to cast to.
+ *
+ * Returns: If @typename is a class, this function returns @klass if
+ * @typename is a subtype of @klass, else returns #NULL.
+ *
+ * If @typename is an interface, this function returns the interface
+ * definition for @klass if @klass implements it unambiguously; #NULL
+ * is returned if @klass does not implement the interface or if multiple
+ * classes or interfaces on the hierarchy leading to @klass implement
+ * it.  (FIXME: perhaps this can be detected at type definition time?)
+ */
+ObjectClass *object_class_dynamic_cast(ObjectClass *klass,
+                                       const char *typename);
+
+/**
+ * object_class_get_parent:
+ * @klass: The class to obtain the parent for.
+ *
+ * Returns: The parent for @klass or %NULL if none.
+ */
+ObjectClass *object_class_get_parent(ObjectClass *klass);
+
+/**
+ * object_class_get_name:
+ * @klass: The class to obtain the QOM typename for.
+ *
+ * Returns: The QOM typename for @klass.
+ */
+const char *object_class_get_name(ObjectClass *klass);
+
+/**
+ * object_class_is_abstract:
+ * @klass: The class to obtain the abstractness for.
+ *
+ * Returns: %true if @klass is abstract, %false otherwise.
+ */
+bool object_class_is_abstract(ObjectClass *klass);
+
+/**
+ * object_class_by_name:
+ * @typename: The QOM typename to obtain the class for.
+ *
+ * Returns: The class for @typename or %NULL if not found.
+ */
+ObjectClass *object_class_by_name(const char *typename);
+
+/**
+ * module_object_class_by_name:
+ * @typename: The QOM typename to obtain the class for.
+ *
+ * For objects which might be provided by a module.  Behaves like
+ * object_class_by_name, but additionally tries to load the module
+ * needed in case the class is not available.
+ *
+ * Returns: The class for @typename or %NULL if not found.
+ */
+ObjectClass *module_object_class_by_name(const char *typename);
+
+void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
+                          const char *implements_type, bool include_abstract,
+                          void *opaque);
+
+/**
+ * object_class_get_list:
+ * @implements_type: The type to filter for, including its derivatives.
+ * @include_abstract: Whether to include abstract classes.
+ *
+ * Returns: A singly-linked list of the classes in reverse hashtable order.
+ */
+GSList *object_class_get_list(const char *implements_type,
+                              bool include_abstract);
+
+/**
+ * object_class_get_list_sorted:
+ * @implements_type: The type to filter for, including its derivatives.
+ * @include_abstract: Whether to include abstract classes.
+ *
+ * Returns: A singly-linked list of the classes in alphabetical
+ * case-insensitive order.
+ */
+GSList *object_class_get_list_sorted(const char *implements_type,
+                              bool include_abstract);
+
+/**
+ * object_ref:
+ * @obj: the object
+ *
+ * Increase the reference count of a object.  A object cannot be freed as long
+ * as its reference count is greater than zero.
+ * Returns: @obj
+ */
+Object *object_ref(void *obj);
+
+/**
+ * object_unref:
+ * @obj: the object
+ *
+ * Decrease the reference count of a object.  A object cannot be freed as long
+ * as its reference count is greater than zero.
+ */
+void object_unref(void *obj);
+
+/**
+ * object_property_try_add:
+ * @obj: the object to add a property to
+ * @name: the name of the property.  This can contain any character except for
+ *  a forward slash.  In general, you should use hyphens '-' instead of
+ *  underscores '_' when naming properties.
+ * @type: the type name of the property.  This namespace is pretty loosely
+ *   defined.  Sub namespaces are constructed by using a prefix and then
+ *   to angle brackets.  For instance, the type 'virtio-net-pci' in the
+ *   'link' namespace would be 'link<virtio-net-pci>'.
+ * @get: The getter to be called to read a property.  If this is NULL, then
+ *   the property cannot be read.
+ * @set: the setter to be called to write a property.  If this is NULL,
+ *   then the property cannot be written.
+ * @release: called when the property is removed from the object.  This is
+ *   meant to allow a property to free its opaque upon object
+ *   destruction.  This may be NULL.
+ * @opaque: an opaque pointer to pass to the callbacks for the property
+ * @errp: pointer to error object
+ *
+ * Returns: The #ObjectProperty; this can be used to set the @resolve
+ * callback for child and link properties.
+ */
+ObjectProperty *object_property_try_add(Object *obj, const char *name,
+                                        const char *type,
+                                        ObjectPropertyAccessor *get,
+                                        ObjectPropertyAccessor *set,
+                                        ObjectPropertyRelease *release,
+                                        void *opaque, Error **errp);
+
+/**
+ * object_property_add:
+ * Same as object_property_try_add() with @errp hardcoded to
+ * &error_abort.
+ *
+ * @obj: the object to add a property to
+ * @name: the name of the property.  This can contain any character except for
+ *  a forward slash.  In general, you should use hyphens '-' instead of
+ *  underscores '_' when naming properties.
+ * @type: the type name of the property.  This namespace is pretty loosely
+ *   defined.  Sub namespaces are constructed by using a prefix and then
+ *   to angle brackets.  For instance, the type 'virtio-net-pci' in the
+ *   'link' namespace would be 'link<virtio-net-pci>'.
+ * @get: The getter to be called to read a property.  If this is NULL, then
+ *   the property cannot be read.
+ * @set: the setter to be called to write a property.  If this is NULL,
+ *   then the property cannot be written.
+ * @release: called when the property is removed from the object.  This is
+ *   meant to allow a property to free its opaque upon object
+ *   destruction.  This may be NULL.
+ * @opaque: an opaque pointer to pass to the callbacks for the property
+ */
+ObjectProperty *object_property_add(Object *obj, const char *name,
+                                    const char *type,
+                                    ObjectPropertyAccessor *get,
+                                    ObjectPropertyAccessor *set,
+                                    ObjectPropertyRelease *release,
+                                    void *opaque);
+
+void object_property_del(Object *obj, const char *name);
+
+ObjectProperty *object_class_property_add(ObjectClass *klass, const char *name,
+                                          const char *type,
+                                          ObjectPropertyAccessor *get,
+                                          ObjectPropertyAccessor *set,
+                                          ObjectPropertyRelease *release,
+                                          void *opaque);
+
+/**
+ * object_property_set_default_bool:
+ * @prop: the property to set
+ * @value: the value to be written to the property
+ *
+ * Set the property default value.
+ */
+void object_property_set_default_bool(ObjectProperty *prop, bool value);
+
+/**
+ * object_property_set_default_str:
+ * @prop: the property to set
+ * @value: the value to be written to the property
+ *
+ * Set the property default value.
+ */
+void object_property_set_default_str(ObjectProperty *prop, const char *value);
+
+/**
+ * object_property_set_default_int:
+ * @prop: the property to set
+ * @value: the value to be written to the property
+ *
+ * Set the property default value.
+ */
+void object_property_set_default_int(ObjectProperty *prop, int64_t value);
+
+/**
+ * object_property_set_default_uint:
+ * @prop: the property to set
+ * @value: the value to be written to the property
+ *
+ * Set the property default value.
+ */
+void object_property_set_default_uint(ObjectProperty *prop, uint64_t value);
+
+/**
+ * object_property_find:
+ * @obj: the object
+ * @name: the name of the property
+ *
+ * Look up a property for an object.
+ *
+ * Return its #ObjectProperty if found, or NULL.
+ */
+ObjectProperty *object_property_find(Object *obj, const char *name);
+
+/**
+ * object_property_find_err:
+ * @obj: the object
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Look up a property for an object.
+ *
+ * Return its #ObjectProperty if found, or NULL.
+ */
+ObjectProperty *object_property_find_err(Object *obj,
+                                         const char *name,
+                                         Error **errp);
+
+/**
+ * object_class_property_find:
+ * @klass: the object class
+ * @name: the name of the property
+ *
+ * Look up a property for an object class.
+ *
+ * Return its #ObjectProperty if found, or NULL.
+ */
+ObjectProperty *object_class_property_find(ObjectClass *klass,
+                                           const char *name);
+
+/**
+ * object_class_property_find_err:
+ * @klass: the object class
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Look up a property for an object class.
+ *
+ * Return its #ObjectProperty if found, or NULL.
+ */
+ObjectProperty *object_class_property_find_err(ObjectClass *klass,
+                                               const char *name,
+                                               Error **errp);
+
+typedef struct ObjectPropertyIterator {
+    ObjectClass *nextclass;
+    GHashTableIter iter;
+} ObjectPropertyIterator;
+
+/**
+ * object_property_iter_init:
+ * @iter: the iterator instance
+ * @obj: the object
+ *
+ * Initializes an iterator for traversing all properties
+ * registered against an object instance, its class and all parent classes.
+ *
+ * It is forbidden to modify the property list while iterating,
+ * whether removing or adding properties.
+ *
+ * Typical usage pattern would be
+ *
+ * .. code-block:: c
+ *    :caption: Using object property iterators
+ *
+ *      ObjectProperty *prop;
+ *      ObjectPropertyIterator iter;
+ *
+ *      object_property_iter_init(&iter, obj);
+ *      while ((prop = object_property_iter_next(&iter))) {
+ *        ... do something with prop ...
+ *      }
+ */
+void object_property_iter_init(ObjectPropertyIterator *iter,
+                               Object *obj);
+
+/**
+ * object_class_property_iter_init:
+ * @iter: the iterator instance
+ * @klass: the class
+ *
+ * Initializes an iterator for traversing all properties
+ * registered against an object class and all parent classes.
+ *
+ * It is forbidden to modify the property list while iterating,
+ * whether removing or adding properties.
+ *
+ * This can be used on abstract classes as it does not create a temporary
+ * instance.
+ */
+void object_class_property_iter_init(ObjectPropertyIterator *iter,
+                                     ObjectClass *klass);
+
+/**
+ * object_property_iter_next:
+ * @iter: the iterator instance
+ *
+ * Return the next available property. If no further properties
+ * are available, a %NULL value will be returned and the @iter
+ * pointer should not be used again after this point without
+ * re-initializing it.
+ *
+ * Returns: the next property, or %NULL when all properties
+ * have been traversed.
+ */
+ObjectProperty *object_property_iter_next(ObjectPropertyIterator *iter);
+
+void object_unparent(Object *obj);
+
+/**
+ * object_property_get:
+ * @obj: the object
+ * @name: the name of the property
+ * @v: the visitor that will receive the property value.  This should be an
+ *   Output visitor and the data will be written with @name as the name.
+ * @errp: returns an error if this function fails
+ *
+ * Reads a property from a object.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_property_get(Object *obj, const char *name, Visitor *v,
+                         Error **errp);
+
+/**
+ * object_property_set_str:
+ * @obj: the object
+ * @name: the name of the property
+ * @value: the value to be written to the property
+ * @errp: returns an error if this function fails
+ *
+ * Writes a string value to a property.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_property_set_str(Object *obj, const char *name,
+                             const char *value, Error **errp);
+
+/**
+ * object_property_get_str:
+ * @obj: the object
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Returns: the value of the property, converted to a C string, or NULL if
+ * an error occurs (including when the property value is not a string).
+ * The caller should free the string.
+ */
+char *object_property_get_str(Object *obj, const char *name,
+                              Error **errp);
+
+/**
+ * object_property_set_link:
+ * @obj: the object
+ * @name: the name of the property
+ * @value: the value to be written to the property
+ * @errp: returns an error if this function fails
+ *
+ * Writes an object's canonical path to a property.
+ *
+ * If the link property was created with
+ * %OBJ_PROP_LINK_STRONG bit, the old target object is
+ * unreferenced, and a reference is added to the new target object.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_property_set_link(Object *obj, const char *name,
+                              Object *value, Error **errp);
+
+/**
+ * object_property_get_link:
+ * @obj: the object
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Returns: the value of the property, resolved from a path to an Object,
+ * or NULL if an error occurs (including when the property value is not a
+ * string or not a valid object path).
+ */
+Object *object_property_get_link(Object *obj, const char *name,
+                                 Error **errp);
+
+/**
+ * object_property_set_bool:
+ * @obj: the object
+ * @name: the name of the property
+ * @value: the value to be written to the property
+ * @errp: returns an error if this function fails
+ *
+ * Writes a bool value to a property.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_property_set_bool(Object *obj, const char *name,
+                              bool value, Error **errp);
+
+/**
+ * object_property_get_bool:
+ * @obj: the object
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Returns: the value of the property, converted to a boolean, or false if
+ * an error occurs (including when the property value is not a bool).
+ */
+bool object_property_get_bool(Object *obj, const char *name,
+                              Error **errp);
+
+/**
+ * object_property_set_int:
+ * @obj: the object
+ * @name: the name of the property
+ * @value: the value to be written to the property
+ * @errp: returns an error if this function fails
+ *
+ * Writes an integer value to a property.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_property_set_int(Object *obj, const char *name,
+                             int64_t value, Error **errp);
+
+/**
+ * object_property_get_int:
+ * @obj: the object
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Returns: the value of the property, converted to an integer, or -1 if
+ * an error occurs (including when the property value is not an integer).
+ */
+int64_t object_property_get_int(Object *obj, const char *name,
+                                Error **errp);
+
+/**
+ * object_property_set_uint:
+ * @obj: the object
+ * @name: the name of the property
+ * @value: the value to be written to the property
+ * @errp: returns an error if this function fails
+ *
+ * Writes an unsigned integer value to a property.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_property_set_uint(Object *obj, const char *name,
+                              uint64_t value, Error **errp);
+
+/**
+ * object_property_get_uint:
+ * @obj: the object
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Returns: the value of the property, converted to an unsigned integer, or 0
+ * an error occurs (including when the property value is not an integer).
+ */
+uint64_t object_property_get_uint(Object *obj, const char *name,
+                                  Error **errp);
+
+/**
+ * object_property_get_enum:
+ * @obj: the object
+ * @name: the name of the property
+ * @typename: the name of the enum data type
+ * @errp: returns an error if this function fails
+ *
+ * Returns: the value of the property, converted to an integer (which
+ * can't be negative), or -1 on error (including when the property
+ * value is not an enum).
+ */
+int object_property_get_enum(Object *obj, const char *name,
+                             const char *typename, Error **errp);
+
+/**
+ * object_property_set:
+ * @obj: the object
+ * @name: the name of the property
+ * @v: the visitor that will be used to write the property value.  This should
+ *   be an Input visitor and the data will be first read with @name as the
+ *   name and then written as the property value.
+ * @errp: returns an error if this function fails
+ *
+ * Writes a property to a object.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_property_set(Object *obj, const char *name, Visitor *v,
+                         Error **errp);
+
+/**
+ * object_property_parse:
+ * @obj: the object
+ * @name: the name of the property
+ * @string: the string that will be used to parse the property value.
+ * @errp: returns an error if this function fails
+ *
+ * Parses a string and writes the result into a property of an object.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool object_property_parse(Object *obj, const char *name,
+                           const char *string, Error **errp);
+
+/**
+ * object_property_print:
+ * @obj: the object
+ * @name: the name of the property
+ * @human: if true, print for human consumption
+ * @errp: returns an error if this function fails
+ *
+ * Returns a string representation of the value of the property.  The
+ * caller shall free the string.
+ */
+char *object_property_print(Object *obj, const char *name, bool human,
+                            Error **errp);
+
+/**
+ * object_property_get_type:
+ * @obj: the object
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Returns:  The type name of the property.
+ */
+const char *object_property_get_type(Object *obj, const char *name,
+                                     Error **errp);
+
+/**
+ * object_get_root:
+ *
+ * Returns: the root object of the composition tree
+ */
+Object *object_get_root(void);
+
+
+/**
+ * object_get_objects_root:
+ *
+ * Get the container object that holds user created
+ * object instances. This is the object at path
+ * "/objects"
+ *
+ * Returns: the user object container
+ */
+Object *object_get_objects_root(void);
+
+/**
+ * object_get_internal_root:
+ *
+ * Get the container object that holds internally used object
+ * instances.  Any object which is put into this container must not be
+ * user visible, and it will not be exposed in the QOM tree.
+ *
+ * Returns: the internal object container
+ */
+Object *object_get_internal_root(void);
+
+/**
+ * object_get_canonical_path_component:
+ * @obj: the object
+ *
+ * Returns: The final component in the object's canonical path.  The canonical
+ * path is the path within the composition tree starting from the root.
+ * %NULL if the object doesn't have a parent (and thus a canonical path).
+ */
+const char *object_get_canonical_path_component(const Object *obj);
+
+/**
+ * object_get_canonical_path:
+ * @obj: the object
+ *
+ * Returns: The canonical path for a object, newly allocated.  This is
+ * the path within the composition tree starting from the root.  Use
+ * g_free() to free it.
+ */
+char *object_get_canonical_path(const Object *obj);
+
+/**
+ * object_resolve_path:
+ * @path: the path to resolve
+ * @ambiguous: returns true if the path resolution failed because of an
+ *   ambiguous match
+ *
+ * There are two types of supported paths--absolute paths and partial paths.
+ * 
+ * Absolute paths are derived from the root object and can follow child<> or
+ * link<> properties.  Since they can follow link<> properties, they can be
+ * arbitrarily long.  Absolute paths look like absolute filenames and are
+ * prefixed with a leading slash.
+ * 
+ * Partial paths look like relative filenames.  They do not begin with a
+ * prefix.  The matching rules for partial paths are subtle but designed to make
+ * specifying objects easy.  At each level of the composition tree, the partial
+ * path is matched as an absolute path.  The first match is not returned.  At
+ * least two matches are searched for.  A successful result is only returned if
+ * only one match is found.  If more than one match is found, a flag is
+ * returned to indicate that the match was ambiguous.
+ *
+ * Returns: The matched object or NULL on path lookup failure.
+ */
+Object *object_resolve_path(const char *path, bool *ambiguous);
+
+/**
+ * object_resolve_path_type:
+ * @path: the path to resolve
+ * @typename: the type to look for.
+ * @ambiguous: returns true if the path resolution failed because of an
+ *   ambiguous match
+ *
+ * This is similar to object_resolve_path.  However, when looking for a
+ * partial path only matches that implement the given type are considered.
+ * This restricts the search and avoids spuriously flagging matches as
+ * ambiguous.
+ *
+ * For both partial and absolute paths, the return value goes through
+ * a dynamic cast to @typename.  This is important if either the link,
+ * or the typename itself are of interface types.
+ *
+ * Returns: The matched object or NULL on path lookup failure.
+ */
+Object *object_resolve_path_type(const char *path, const char *typename,
+                                 bool *ambiguous);
+
+/**
+ * object_resolve_path_at:
+ * @parent: the object in which to resolve the path
+ * @path: the path to resolve
+ *
+ * This is like object_resolve_path(), except paths not starting with
+ * a slash are relative to @parent.
+ *
+ * Returns: The resolved object or NULL on path lookup failure.
+ */
+Object *object_resolve_path_at(Object *parent, const char *path);
+
+/**
+ * object_resolve_path_component:
+ * @parent: the object in which to resolve the path
+ * @part: the component to resolve.
+ *
+ * This is similar to object_resolve_path with an absolute path, but it
+ * only resolves one element (@part) and takes the others from @parent.
+ *
+ * Returns: The resolved object or NULL on path lookup failure.
+ */
+Object *object_resolve_path_component(Object *parent, const char *part);
+
+/**
+ * object_property_try_add_child:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @child: the child object
+ * @errp: pointer to error object
+ *
+ * Child properties form the composition tree.  All objects need to be a child
+ * of another object.  Objects can only be a child of one object.
+ *
+ * There is no way for a child to determine what its parent is.  It is not
+ * a bidirectional relationship.  This is by design.
+ *
+ * The value of a child property as a C string will be the child object's
+ * canonical path. It can be retrieved using object_property_get_str().
+ * The child object itself can be retrieved using object_property_get_link().
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_try_add_child(Object *obj, const char *name,
+                                              Object *child, Error **errp);
+
+/**
+ * object_property_add_child:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @child: the child object
+ *
+ * Same as object_property_try_add_child() with @errp hardcoded to
+ * &error_abort
+ */
+ObjectProperty *object_property_add_child(Object *obj, const char *name,
+                                          Object *child);
+
+typedef enum {
+    /* Unref the link pointer when the property is deleted */
+    OBJ_PROP_LINK_STRONG = 0x1,
+
+    /* private */
+    OBJ_PROP_LINK_DIRECT = 0x2,
+    OBJ_PROP_LINK_CLASS = 0x4,
+} ObjectPropertyLinkFlags;
+
+/**
+ * object_property_allow_set_link:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @child: the child object
+ * @errp: pointer to error object
+ *
+ * The default implementation of the object_property_add_link() check()
+ * callback function.  It allows the link property to be set and never returns
+ * an error.
+ */
+void object_property_allow_set_link(const Object *obj, const char *name,
+                                    Object *child, Error **errp);
+
+/**
+ * object_property_add_link:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @type: the qobj type of the link
+ * @targetp: a pointer to where the link object reference is stored
+ * @check: callback to veto setting or NULL if the property is read-only
+ * @flags: additional options for the link
+ *
+ * Links establish relationships between objects.  Links are unidirectional
+ * although two links can be combined to form a bidirectional relationship
+ * between objects.
+ *
+ * Links form the graph in the object model.
+ *
+ * The @check() callback is invoked when
+ * object_property_set_link() is called and can raise an error to prevent the
+ * link being set.  If @check is NULL, the property is read-only
+ * and cannot be set.
+ *
+ * Ownership of the pointer that @child points to is transferred to the
+ * link property.  The reference count for *@child is
+ * managed by the property from after the function returns till the
+ * property is deleted with object_property_del().  If the
+ * @flags %OBJ_PROP_LINK_STRONG bit is set,
+ * the reference count is decremented when the property is deleted or
+ * modified.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_link(Object *obj, const char *name,
+                              const char *type, Object **targetp,
+                              void (*check)(const Object *obj, const char *name,
+                                            Object *val, Error **errp),
+                              ObjectPropertyLinkFlags flags);
+
+ObjectProperty *object_class_property_add_link(ObjectClass *oc,
+                              const char *name,
+                              const char *type, ptrdiff_t offset,
+                              void (*check)(const Object *obj, const char *name,
+                                            Object *val, Error **errp),
+                              ObjectPropertyLinkFlags flags);
+
+/**
+ * object_property_add_str:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @get: the getter or NULL if the property is write-only.  This function must
+ *   return a string to be freed by g_free().
+ * @set: the setter or NULL if the property is read-only
+ *
+ * Add a string property using getters/setters.  This function will add a
+ * property of type 'string'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_str(Object *obj, const char *name,
+                             char *(*get)(Object *, Error **),
+                             void (*set)(Object *, const char *, Error **));
+
+ObjectProperty *object_class_property_add_str(ObjectClass *klass,
+                                   const char *name,
+                                   char *(*get)(Object *, Error **),
+                                   void (*set)(Object *, const char *,
+                                               Error **));
+
+/**
+ * object_property_add_bool:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @get: the getter or NULL if the property is write-only.
+ * @set: the setter or NULL if the property is read-only
+ *
+ * Add a bool property using getters/setters.  This function will add a
+ * property of type 'bool'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_bool(Object *obj, const char *name,
+                              bool (*get)(Object *, Error **),
+                              void (*set)(Object *, bool, Error **));
+
+ObjectProperty *object_class_property_add_bool(ObjectClass *klass,
+                                    const char *name,
+                                    bool (*get)(Object *, Error **),
+                                    void (*set)(Object *, bool, Error **));
+
+/**
+ * object_property_add_enum:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @typename: the name of the enum data type
+ * @lookup: enum value namelookup table
+ * @get: the getter or %NULL if the property is write-only.
+ * @set: the setter or %NULL if the property is read-only
+ *
+ * Add an enum property using getters/setters.  This function will add a
+ * property of type '@typename'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_enum(Object *obj, const char *name,
+                              const char *typename,
+                              const QEnumLookup *lookup,
+                              int (*get)(Object *, Error **),
+                              void (*set)(Object *, int, Error **));
+
+ObjectProperty *object_class_property_add_enum(ObjectClass *klass,
+                                    const char *name,
+                                    const char *typename,
+                                    const QEnumLookup *lookup,
+                                    int (*get)(Object *, Error **),
+                                    void (*set)(Object *, int, Error **));
+
+/**
+ * object_property_add_tm:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @get: the getter or NULL if the property is write-only.
+ *
+ * Add a read-only struct tm valued property using a getter function.
+ * This function will add a property of type 'struct tm'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_tm(Object *obj, const char *name,
+                            void (*get)(Object *, struct tm *, Error **));
+
+ObjectProperty *object_class_property_add_tm(ObjectClass *klass,
+                            const char *name,
+                            void (*get)(Object *, struct tm *, Error **));
+
+typedef enum {
+    /* Automatically add a getter to the property */
+    OBJ_PROP_FLAG_READ = 1 << 0,
+    /* Automatically add a setter to the property */
+    OBJ_PROP_FLAG_WRITE = 1 << 1,
+    /* Automatically add a getter and a setter to the property */
+    OBJ_PROP_FLAG_READWRITE = (OBJ_PROP_FLAG_READ | OBJ_PROP_FLAG_WRITE),
+} ObjectPropertyFlags;
+
+/**
+ * object_property_add_uint8_ptr:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @v: pointer to value
+ * @flags: bitwise-or'd ObjectPropertyFlags
+ *
+ * Add an integer property in memory.  This function will add a
+ * property of type 'uint8'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_uint8_ptr(Object *obj, const char *name,
+                                              const uint8_t *v,
+                                              ObjectPropertyFlags flags);
+
+ObjectProperty *object_class_property_add_uint8_ptr(ObjectClass *klass,
+                                         const char *name,
+                                         const uint8_t *v,
+                                         ObjectPropertyFlags flags);
+
+/**
+ * object_property_add_uint16_ptr:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @v: pointer to value
+ * @flags: bitwise-or'd ObjectPropertyFlags
+ *
+ * Add an integer property in memory.  This function will add a
+ * property of type 'uint16'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_uint16_ptr(Object *obj, const char *name,
+                                    const uint16_t *v,
+                                    ObjectPropertyFlags flags);
+
+ObjectProperty *object_class_property_add_uint16_ptr(ObjectClass *klass,
+                                          const char *name,
+                                          const uint16_t *v,
+                                          ObjectPropertyFlags flags);
+
+/**
+ * object_property_add_uint32_ptr:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @v: pointer to value
+ * @flags: bitwise-or'd ObjectPropertyFlags
+ *
+ * Add an integer property in memory.  This function will add a
+ * property of type 'uint32'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_uint32_ptr(Object *obj, const char *name,
+                                    const uint32_t *v,
+                                    ObjectPropertyFlags flags);
+
+ObjectProperty *object_class_property_add_uint32_ptr(ObjectClass *klass,
+                                          const char *name,
+                                          const uint32_t *v,
+                                          ObjectPropertyFlags flags);
+
+/**
+ * object_property_add_uint64_ptr:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @v: pointer to value
+ * @flags: bitwise-or'd ObjectPropertyFlags
+ *
+ * Add an integer property in memory.  This function will add a
+ * property of type 'uint64'.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_uint64_ptr(Object *obj, const char *name,
+                                    const uint64_t *v,
+                                    ObjectPropertyFlags flags);
+
+ObjectProperty *object_class_property_add_uint64_ptr(ObjectClass *klass,
+                                          const char *name,
+                                          const uint64_t *v,
+                                          ObjectPropertyFlags flags);
+
+/**
+ * object_property_add_alias:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @target_obj: the object to forward property access to
+ * @target_name: the name of the property on the forwarded object
+ *
+ * Add an alias for a property on an object.  This function will add a property
+ * of the same type as the forwarded property.
+ *
+ * The caller must ensure that @target_obj stays alive as long as
+ * this property exists.  In the case of a child object or an alias on the same
+ * object this will be the case.  For aliases to other objects the caller is
+ * responsible for taking a reference.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_alias(Object *obj, const char *name,
+                               Object *target_obj, const char *target_name);
+
+/**
+ * object_property_add_const_link:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @target: the object to be referred by the link
+ *
+ * Add an unmodifiable link for a property on an object.  This function will
+ * add a property of type link<TYPE> where TYPE is the type of @target.
+ *
+ * The caller must ensure that @target stays alive as long as
+ * this property exists.  In the case @target is a child of @obj,
+ * this will be the case.  Otherwise, the caller is responsible for
+ * taking a reference.
+ *
+ * Returns: The newly added property on success, or %NULL on failure.
+ */
+ObjectProperty *object_property_add_const_link(Object *obj, const char *name,
+                                               Object *target);
+
+/**
+ * object_property_set_description:
+ * @obj: the object owning the property
+ * @name: the name of the property
+ * @description: the description of the property on the object
+ *
+ * Set an object property's description.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+void object_property_set_description(Object *obj, const char *name,
+                                     const char *description);
+void object_class_property_set_description(ObjectClass *klass, const char *name,
+                                           const char *description);
+
+/**
+ * object_child_foreach:
+ * @obj: the object whose children will be navigated
+ * @fn: the iterator function to be called
+ * @opaque: an opaque value that will be passed to the iterator
+ *
+ * Call @fn passing each child of @obj and @opaque to it, until @fn returns
+ * non-zero.
+ *
+ * It is forbidden to add or remove children from @obj from the @fn
+ * callback.
+ *
+ * Returns: The last value returned by @fn, or 0 if there is no child.
+ */
+int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
+                         void *opaque);
+
+/**
+ * object_child_foreach_recursive:
+ * @obj: the object whose children will be navigated
+ * @fn: the iterator function to be called
+ * @opaque: an opaque value that will be passed to the iterator
+ *
+ * Call @fn passing each child of @obj and @opaque to it, until @fn returns
+ * non-zero. Calls recursively, all child nodes of @obj will also be passed
+ * all the way down to the leaf nodes of the tree. Depth first ordering.
+ *
+ * It is forbidden to add or remove children from @obj (or its
+ * child nodes) from the @fn callback.
+ *
+ * Returns: The last value returned by @fn, or 0 if there is no child.
+ */
+int object_child_foreach_recursive(Object *obj,
+                                   int (*fn)(Object *child, void *opaque),
+                                   void *opaque);
+/**
+ * container_get:
+ * @root: root of the #path, e.g., object_get_root()
+ * @path: path to the container
+ *
+ * Return a container object whose path is @path.  Create more containers
+ * along the path if necessary.
+ *
+ * Returns: the container object.
+ */
+Object *container_get(Object *root, const char *path);
+
+/**
+ * object_type_get_instance_size:
+ * @typename: Name of the Type whose instance_size is required
+ *
+ * Returns the instance_size of the given @typename.
+ */
+size_t object_type_get_instance_size(const char *typename);
+
+/**
+ * object_property_help:
+ * @name: the name of the property
+ * @type: the type of the property
+ * @defval: the default value
+ * @description: description of the property
+ *
+ * Returns: a user-friendly formatted string describing the property
+ * for help purposes.
+ */
+char *object_property_help(const char *name, const char *type,
+                           QObject *defval, const char *description);
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(Object, object_unref)
+
+#endif