diff options
| -rw-r--r-- | hw/qdev-core.h | 52 | ||||
| -rw-r--r-- | hw/qdev.c | 94 |
2 files changed, 122 insertions, 24 deletions
diff --git a/hw/qdev-core.h b/hw/qdev-core.h index cb6b30b82d..3d75ae2e3a 100644 --- a/hw/qdev-core.h +++ b/hw/qdev-core.h @@ -20,11 +20,59 @@ enum { typedef int (*qdev_initfn)(DeviceState *dev); typedef int (*qdev_event)(DeviceState *dev); typedef void (*qdev_resetfn)(DeviceState *dev); +typedef void (*DeviceRealize)(DeviceState *dev, Error **errp); +typedef void (*DeviceUnrealize)(DeviceState *dev, Error **errp); struct VMStateDescription; +/** + * DeviceClass: + * @props: Properties accessing state fields. + * @realize: Callback function invoked when the #DeviceState:realized + * property is changed to %true. The default invokes @init if not %NULL. + * @unrealize: Callback function invoked when the #DeviceState:realized + * property is changed to %false. + * @init: Callback function invoked when the #DeviceState::realized property + * is changed to %true. Deprecated, new types inheriting directly from + * TYPE_DEVICE should use @realize instead, new leaf types should consult + * their respective parent type. + * + * # Realization # + * Devices are constructed in two stages, + * 1) object instantiation via object_initialize() and + * 2) device realization via #DeviceState:realized property. + * The former may not fail (it might assert or exit), the latter may return + * error information to the caller and must be re-entrant. + * Trivial field initializations should go into #TypeInfo.instance_init. + * Operations depending on @props static properties should go into @realize. + * After successful realization, setting static properties will fail. + * + * As an interim step, the #DeviceState:realized property is set by deprecated + * functions qdev_init() and qdev_init_nofail(). + * In the future, devices will propagate this state change to their children + * and along busses they expose. + * The point in time will be deferred to machine creation, so that values + * set in @realize will not be introspectable beforehand. Therefore devices + * must not create children during @realize; they should initialize them via + * object_initialize() in their own #TypeInfo.instance_init and forward the + * realization events appropriately. + * + * The @init callback is considered private to a particular bus implementation + * (immediate abstract child types of TYPE_DEVICE). Derived leaf types set an + * "init" callback on their parent class instead. + * Any type may override the @realize and/or @unrealize callbacks but needs + * to call (and thus save) the parent type's implementation if so desired. + * Usually this means storing the previous value of, e.g., @realized inside + * the type's class structure and overwriting it with a function that first + * invokes the stored callback, then performs any additional steps. + * If a type derived directly from TYPE_DEVICE implements @realize, it does + * not need to implement @init and therefore does not need to store and call + * #DeviceClass' default @realize callback. + */ typedef struct DeviceClass { + /*< private >*/ ObjectClass parent_class; + /*< public >*/ const char *fw_name; const char *desc; @@ -33,12 +81,14 @@ typedef struct DeviceClass { /* callbacks */ void (*reset)(DeviceState *dev); + DeviceRealize realize; + DeviceUnrealize unrealize; /* device state */ const struct VMStateDescription *vmsd; /* Private to qdev / bus. */ - qdev_initfn init; + qdev_initfn init; /* TODO remove, once users are converted to realize */ qdev_event unplug; qdev_event exit; const char *bus_type; @@ -148,37 +148,30 @@ DeviceState *qdev_try_create(BusState *bus, const char *type) Return 0 on success. */ int qdev_init(DeviceState *dev) { - DeviceClass *dc = DEVICE_GET_CLASS(dev); - int rc; + Error *local_err = NULL; assert(!dev->realized); - rc = dc->init(dev); - if (rc < 0) { + object_property_set_bool(OBJECT(dev), true, "realized", &local_err); + if (local_err != NULL) { + error_free(local_err); qdev_free(dev); - return rc; + return -1; } + return 0; +} - if (!OBJECT(dev)->parent) { - static int unattached_count = 0; - gchar *name = g_strdup_printf("device[%d]", unattached_count++); - - object_property_add_child(container_get(qdev_get_machine(), - "/unattached"), - name, OBJECT(dev), NULL); - g_free(name); - } +static void device_realize(DeviceState *dev, Error **err) +{ + DeviceClass *dc = DEVICE_GET_CLASS(dev); - if (qdev_get_vmsd(dev)) { - vmstate_register_with_alias_id(dev, -1, qdev_get_vmsd(dev), dev, - dev->instance_id_alias, - dev->alias_required_for_version); - } - dev->realized = true; - if (dev->hotplugged) { - device_reset(dev); + if (dc->init) { + int rc = dc->init(dev); + if (rc < 0) { + error_setg(err, "Device initialization failed."); + return; + } } - return 0; } void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id, @@ -641,6 +634,55 @@ void qdev_property_add_static(DeviceState *dev, Property *prop, assert_no_error(local_err); } +static bool device_get_realized(Object *obj, Error **err) +{ + DeviceState *dev = DEVICE(obj); + return dev->realized; +} + +static void device_set_realized(Object *obj, bool value, Error **err) +{ + DeviceState *dev = DEVICE(obj); + DeviceClass *dc = DEVICE_GET_CLASS(dev); + Error *local_err = NULL; + + if (value && !dev->realized) { + if (dc->realize) { + dc->realize(dev, &local_err); + } + + if (!obj->parent && local_err == NULL) { + static int unattached_count; + gchar *name = g_strdup_printf("device[%d]", unattached_count++); + + object_property_add_child(container_get(qdev_get_machine(), + "/unattached"), + name, obj, &local_err); + g_free(name); + } + + if (qdev_get_vmsd(dev) && local_err == NULL) { + vmstate_register_with_alias_id(dev, -1, qdev_get_vmsd(dev), dev, + dev->instance_id_alias, + dev->alias_required_for_version); + } + if (dev->hotplugged && local_err == NULL) { + device_reset(dev); + } + } else if (!value && dev->realized) { + if (dc->unrealize) { + dc->unrealize(dev, &local_err); + } + } + + if (local_err != NULL) { + error_propagate(err, local_err); + return; + } + + dev->realized = value; +} + static void device_initfn(Object *obj) { DeviceState *dev = DEVICE(obj); @@ -655,6 +697,9 @@ static void device_initfn(Object *obj) dev->instance_id_alias = -1; dev->realized = false; + object_property_add_bool(obj, "realized", + device_get_realized, device_set_realized, NULL); + class = object_get_class(OBJECT(dev)); do { for (prop = DEVICE_CLASS(class)->props; prop && prop->name; prop++) { @@ -714,7 +759,10 @@ static void device_unparent(Object *obj) static void device_class_init(ObjectClass *class, void *data) { + DeviceClass *dc = DEVICE_CLASS(class); + class->unparent = device_unparent; + dc->realize = device_realize; } void device_reset(DeviceState *dev) |