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, 180 insertions, 0 deletions

diff --git a/include/qom/object_interfaces.h b/include/qom/object_interfaces.h
new file mode 100644
index 000000000..81541e208
--- /dev/null
+++ b/include/qom/object_interfaces.h
@@ -0,0 +1,180 @@
+#ifndef OBJECT_INTERFACES_H
+#define OBJECT_INTERFACES_H
+
+#include "qom/object.h"
+#include "qapi/qapi-types-qom.h"
+#include "qapi/visitor.h"
+
+#define TYPE_USER_CREATABLE "user-creatable"
+
+typedef struct UserCreatableClass UserCreatableClass;
+DECLARE_CLASS_CHECKERS(UserCreatableClass, USER_CREATABLE,
+                       TYPE_USER_CREATABLE)
+#define USER_CREATABLE(obj) \
+     INTERFACE_CHECK(UserCreatable, (obj), \
+                     TYPE_USER_CREATABLE)
+
+typedef struct UserCreatable UserCreatable;
+
+/**
+ * UserCreatableClass:
+ * @parent_class: the base class
+ * @complete: callback to be called after @obj's properties are set.
+ * @can_be_deleted: callback to be called before an object is removed
+ * to check if @obj can be removed safely.
+ *
+ * Interface is designed to work with -object/object-add/object_add
+ * commands.
+ * Interface is mandatory for objects that are designed to be user
+ * creatable (i.e. -object/object-add/object_add, will accept only
+ * objects that inherit this interface).
+ *
+ * Interface also provides an optional ability to do the second
+ * stage * initialization of the object after its properties were
+ * set.
+ *
+ * For objects created without using -object/object-add/object_add,
+ * @user_creatable_complete() wrapper should be called manually if
+ * object's type implements USER_CREATABLE interface and needs
+ * complete() callback to be called.
+ */
+struct UserCreatableClass {
+    /* <private> */
+    InterfaceClass parent_class;
+
+    /* <public> */
+    void (*complete)(UserCreatable *uc, Error **errp);
+    bool (*can_be_deleted)(UserCreatable *uc);
+};
+
+/**
+ * user_creatable_complete:
+ * @uc: the user-creatable object whose complete() method is called if defined
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Wrapper to call complete() method if one of types it's inherited
+ * from implements USER_CREATABLE interface, otherwise the call does
+ * nothing.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool user_creatable_complete(UserCreatable *uc, Error **errp);
+
+/**
+ * user_creatable_can_be_deleted:
+ * @uc: the object whose can_be_deleted() method is called if implemented
+ *
+ * Wrapper to call can_be_deleted() method if one of types it's inherited
+ * from implements USER_CREATABLE interface.
+ */
+bool user_creatable_can_be_deleted(UserCreatable *uc);
+
+/**
+ * user_creatable_add_type:
+ * @type: the object type name
+ * @id: the unique ID for the object
+ * @qdict: the object properties
+ * @v: the visitor
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Create an instance of the user creatable object @type, placing
+ * it in the object composition tree with name @id, initializing
+ * it with properties from @qdict
+ *
+ * Returns: the newly created object or NULL on error
+ */
+Object *user_creatable_add_type(const char *type, const char *id,
+                                const QDict *qdict,
+                                Visitor *v, Error **errp);
+
+/**
+ * user_creatable_add_qapi:
+ * @options: the object definition
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Create an instance of the user creatable object according to the
+ * options passed in @opts as described in the QAPI schema documentation.
+ */
+void user_creatable_add_qapi(ObjectOptions *options, Error **errp);
+
+/**
+ * user_creatable_parse_str:
+ * @optarg: the object definition string as passed on the command line
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Parses the option for the user creatable object with a keyval parser and
+ * implicit key 'qom-type', converting the result to ObjectOptions.
+ *
+ * If a help option is given, print help instead.
+ *
+ * Returns: ObjectOptions on success, NULL when an error occurred (*errp is set
+ * then) or help was printed (*errp is not set).
+ */
+ObjectOptions *user_creatable_parse_str(const char *optarg, Error **errp);
+
+/**
+ * user_creatable_add_from_str:
+ * @optarg: the object definition string as passed on the command line
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Create an instance of the user creatable object by parsing optarg
+ * with a keyval parser and implicit key 'qom-type', converting the
+ * result to ObjectOptions and calling into qmp_object_add().
+ *
+ * If a help option is given, print help instead.
+ *
+ * Returns: true when an object was successfully created, false when an error
+ * occurred (*errp is set then) or help was printed (*errp is not set).
+ */
+bool user_creatable_add_from_str(const char *optarg, Error **errp);
+
+/**
+ * user_creatable_process_cmdline:
+ * @optarg: the object definition string as passed on the command line
+ *
+ * Create an instance of the user creatable object by parsing optarg
+ * with a keyval parser and implicit key 'qom-type', converting the
+ * result to ObjectOptions and calling into qmp_object_add().
+ *
+ * If a help option is given, print help instead and exit.
+ *
+ * This function is only meant to be called during command line parsing.
+ * It exits the process on failure or after printing help.
+ */
+void user_creatable_process_cmdline(const char *optarg);
+
+/**
+ * user_creatable_print_help:
+ * @type: the QOM type to be added
+ * @opts: options to create
+ *
+ * Prints help if requested in @type or @opts. Note that if @type is neither
+ * "help"/"?" nor a valid user creatable type, no help will be printed
+ * regardless of @opts.
+ *
+ * Returns: true if a help option was found and help was printed, false
+ * otherwise.
+ */
+bool user_creatable_print_help(const char *type, QemuOpts *opts);
+
+/**
+ * user_creatable_del:
+ * @id: the unique ID for the object
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Delete an instance of the user creatable object identified
+ * by @id.
+ *
+ * Returns: %true on success, %false on failure.
+ */
+bool user_creatable_del(const char *id, Error **errp);
+
+/**
+ * user_creatable_cleanup:
+ *
+ * Delete all user-creatable objects and the user-creatable
+ * objects container.
+ */
+void user_creatable_cleanup(void);
+
+#endif