diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index f1070d6dc7..06cadfc492 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -10,6 +10,65 @@ #include "hw/hotplug.h" #include "hw/resettable.h" +/** + * DOC: The QEMU Device API + * + * All modern devices should represented as a derived QOM class of + * TYPE_DEVICE. The device API introduces the additional methods of + * @realize and @unrealize to represent additional stages in a device + * objects life cycle. + * + * Realization + * ----------- + * + * Devices are constructed in two stages: + * + * 1) object instantiation via object_initialize() and + * 2) device realization via the #DeviceState.realized property + * + * The former may not fail (and must not abort or exit, since it is called + * during device introspection already), and 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 can also be + * set with qdev_realize(). 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. + * + * Any type may override the @realize and/or @unrealize callbacks but needs + * to call the parent type's implementation if keeping their functionality + * is desired. Refer to QOM documentation for further discussion and examples. + * + * .. note:: + * Since TYPE_DEVICE doesn't implement @realize and @unrealize, types + * derived directly from it need not call their parent's @realize and + * @unrealize. For other types consult the documentation and + * implementation of the respective parent types. + * + * Hiding a device + * --------------- + * + * To hide a device, a DeviceListener function hide_device() needs to + * be registered. It can be used to defer adding a device and + * therefore hide it from the guest. The handler registering to this + * DeviceListener can save the QOpts passed to it for re-using it + * later. It must return if it wants the device to be hidden or + * visible. When the handler function decides the device shall be + * visible it will be added with qdev_device_add() and realized as any + * other device. Otherwise qdev_device_add() will return early without + * adding the device. The guest will not see a "hidden" device until + * it was marked visible and qdev_device_add called again. + * + */ + enum { DEV_NVECTORS_UNSPECIFIED = -1, }; @@ -38,7 +97,7 @@ typedef void (*BusRealize)(BusState *bus, Error **errp); typedef void (*BusUnrealize)(BusState *bus); /** - * DeviceClass: + * struct DeviceClass - The base class for all devices. * @props: Properties accessing state fields. * @realize: Callback function invoked when the #DeviceState:realized * property is changed to %true. @@ -47,72 +106,37 @@ typedef void (*BusUnrealize)(BusState *bus); * @hotpluggable: indicates if #DeviceClass is hotpluggable, available * as readonly "hotpluggable" property of #DeviceState instance * - * # 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 (and must not abort or exit, since it is called - * during device introspection already), and 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 can also be - * set with qdev_realize(). - * 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. - * - * Any type may override the @realize and/or @unrealize callbacks but needs - * to call the parent type's implementation if keeping their functionality - * is desired. Refer to QOM documentation for further discussion and examples. - * - * - * - * Since TYPE_DEVICE doesn't implement @realize and @unrealize, types - * derived directly from it need not call their parent's @realize and - * @unrealize. - * For other types consult the documentation and implementation of the - * respective parent types. - * - * - * - * # Hiding a device # - * To hide a device, a DeviceListener function hide_device() needs to - * be registered. - * It can be used to defer adding a device and therefore hide it from - * the guest. The handler registering to this DeviceListener can save - * the QOpts passed to it for re-using it later. It must return if it - * wants the device to be hidden or visible. When the handler function - * decides the device shall be visible it will be added with - * qdev_device_add() and realized as any other device. Otherwise - * qdev_device_add() will return early without adding the device. The - * guest will not see a "hidden" device until it was marked visible - * and qdev_device_add called again. - * */ struct DeviceClass { - /*< private >*/ + /* private: */ ObjectClass parent_class; - /*< public >*/ + /* public: */ + + /** + * @categories: device categories device belongs to + */ DECLARE_BITMAP(categories, DEVICE_CATEGORY_MAX); + /** + * @fw_name: name used to identify device to firmware interfaces + */ const char *fw_name; + /** + * @desc: human readable description of device + */ const char *desc; - /* - * The underscore at the end ensures a compile-time error if someone - * assigns to dc->props instead of using device_class_set_props. + /** + * @props_: properties associated with device, should only be + * assigned by using device_class_set_props(). The underscore + * ensures a compile-time error if someone attempts to assign + * dc->props directly. */ Property *props_; - /* - * Can this device be instantiated with -device / device_add? + /** + * @user_creatable: Can user instantiate with -device / device_add? + * * All devices should support instantiation with device_add, and * this flag should not exist. But we're not there, yet. Some * devices fail to instantiate with cryptic error messages. @@ -120,25 +144,35 @@ struct DeviceClass { * behavior would be cruel; clearing this flag will protect them. * It should never be cleared without a comment explaining why it * is cleared. + * * TODO remove once we're there */ bool user_creatable; bool hotpluggable; /* callbacks */ - /* - * Reset method here is deprecated and replaced by methods in the - * resettable class interface to implement a multi-phase reset. + /** + * @reset: deprecated device reset method pointer + * + * Modern code should use the ResettableClass interface to + * implement a multi-phase reset. + * * TODO: remove once every reset callback is unused */ DeviceReset reset; DeviceRealize realize; DeviceUnrealize unrealize; - /* device state */ + /** + * @vmsd: device state serialisation description for + * migration/save/restore + */ const VMStateDescription *vmsd; - /* Private to qdev / bus. */ + /** + * @bus_type: bus type + * private: to qdev / bus. + */ const char *bus_type; }; @@ -167,37 +201,96 @@ typedef struct { bool engaged_in_io; } MemReentrancyGuard; + +typedef QLIST_HEAD(, NamedGPIOList) NamedGPIOListHead; +typedef QLIST_HEAD(, NamedClockList) NamedClockListHead; +typedef QLIST_HEAD(, BusState) BusStateHead; + /** - * DeviceState: - * @reset: ResettableState for the device; handled by Resettable interface. + * struct DeviceState - common device state, accessed with qdev helpers * * This structure should not be accessed directly. We declare it here * so that it can be embedded in individual device state structures. */ struct DeviceState { - /*< private >*/ + /* private: */ Object parent_obj; - /*< public >*/ + /* public: */ + /** + * @id: global device id + */ char *id; + /** + * @canonical_path: canonical path of realized device in the QOM tree + */ char *canonical_path; + /** + * @realized: has device been realized? + */ bool realized; + /** + * @pending_deleted_event: track pending deletion events during unplug + */ bool pending_deleted_event; + /** + * @pending_deleted_expires_ms: optional timeout for deletion events + */ int64_t pending_deleted_expires_ms; + /** + * @opts: QDict of options for the device + */ QDict *opts; + /** + * @hotplugged: was device added after PHASE_MACHINE_READY? + */ int hotplugged; + /** + * @allow_unplug_during_migration: can device be unplugged during migration + */ bool allow_unplug_during_migration; + /** + * @parent_bus: bus this device belongs to + */ BusState *parent_bus; - QLIST_HEAD(, NamedGPIOList) gpios; - QLIST_HEAD(, NamedClockList) clocks; - QLIST_HEAD(, BusState) child_bus; + /** + * @gpios: QLIST of named GPIOs the device provides. + */ + NamedGPIOListHead gpios; + /** + * @clocks: QLIST of named clocks the device provides. + */ + NamedClockListHead clocks; + /** + * @child_bus: QLIST of child buses + */ + BusStateHead child_bus; + /** + * @num_child_bus: number of @child_bus entries + */ int num_child_bus; + /** + * @instance_id_alias: device alias for handling legacy migration setups + */ int instance_id_alias; + /** + * @alias_required_for_version: indicates @instance_id_alias is + * needed for migration + */ int alias_required_for_version; + /** + * @reset: ResettableState for the device; handled by Resettable interface. + */ ResettableState reset; + /** + * @unplug_blockers: list of reasons to block unplugging of device + */ GSList *unplug_blockers; - - /* Is the device currently in mmio/pio/dma? Used to prevent re-entrancy */ + /** + * @mem_reentrancy_guard: Is the device currently in mmio/pio/dma? + * + * Used to prevent re-entrancy confusing things. + */ MemReentrancyGuard mem_reentrancy_guard; }; @@ -264,13 +357,24 @@ typedef struct BusChild { #define QDEV_HOTPLUG_HANDLER_PROPERTY "hotplug-handler" +typedef QTAILQ_HEAD(, BusChild) BusChildHead; +typedef QLIST_ENTRY(BusState) BusStateEntry; + /** - * BusState: + * struct BusState: + * @obj: parent object + * @parent: parent Device + * @name: name of bus * @hotplug_handler: link to a hotplug handler associated with bus. - * @reset: ResettableState for the bus; handled by Resettable interface. + * @max_index: max number of child buses + * @realized: is the bus itself realized? + * @full: is the bus full? + * @num_children: current number of child buses */ struct BusState { + /* private: */ Object obj; + /* public: */ DeviceState *parent; char *name; HotplugHandler *hotplug_handler; @@ -279,18 +383,24 @@ struct BusState { bool full; int num_children; - /* - * children is a RCU QTAILQ, thus readers must use RCU to access it, - * and writers must hold the big qemu lock + /** + * @children: an RCU protected QTAILQ, thus readers must use RCU + * to access it, and writers must hold the big qemu lock + */ + BusChildHead children; + /** + * @sibling: next bus + */ + BusStateEntry sibling; + /** + * @reset: ResettableState for the bus; handled by Resettable interface. */ - - QTAILQ_HEAD(, BusChild) children; - QLIST_ENTRY(BusState) sibling; ResettableState reset; }; /** - * GlobalProperty: + * typedef GlobalProperty - a global property type + * * @used: Set to true if property was used when initializing a device. * @optional: If set to true, GlobalProperty will be skipped without errors * if the property doesn't exist. @@ -324,7 +434,8 @@ compat_props_add(GPtrArray *arr, * This only allocates the memory and initializes the device state * structure, ready for the caller to set properties if they wish. * The device still needs to be realized. - * The returned object has a reference count of 1. + * + * Return: a derived DeviceState object with a reference count of 1. */ DeviceState *qdev_new(const char *name); @@ -334,16 +445,18 @@ DeviceState *qdev_new(const char *name); * * This is like qdev_new(), except it returns %NULL when type @name * does not exist, rather than asserting. + * + * Return: a derived DeviceState object with a reference count of 1 or + * NULL if type @name does not exist. */ DeviceState *qdev_try_new(const char *name); /** - * qdev_is_realized: + * qdev_is_realized() - check if device is realized * @dev: The device to check. * - * May be called outside big qemu lock. - * - * Returns: %true% if the device has been fully constructed, %false% otherwise. + * Context: May be called outside big qemu lock. + * Return: true if the device has been fully constructed, false otherwise. */ static inline bool qdev_is_realized(DeviceState *dev) { @@ -361,11 +474,11 @@ static inline bool qdev_is_realized(DeviceState *dev) * @dev must not be plugged into a bus already. * If @bus, plug @dev into @bus. This takes a reference to @dev. * If @dev has no QOM parent, make one up, taking another reference. - * On success, return true. - * On failure, store an error through @errp and return false. * * If you created @dev using qdev_new(), you probably want to use * qdev_realize_and_unref() instead. + * + * Return: true on success, else false setting @errp with error */ bool qdev_realize(DeviceState *dev, BusState *bus, Error **errp); @@ -392,6 +505,8 @@ bool qdev_realize(DeviceState *dev, BusState *bus, Error **errp); * for the only reference to the child device to be held by the parent * via the child<> property, and so the reference-count-drop done here * would be incorrect. For that use case you want qdev_realize(). + * + * Return: true on success, else false setting @errp with error */ bool qdev_realize_and_unref(DeviceState *dev, BusState *bus, Error **errp); @@ -420,16 +535,16 @@ void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id, HotplugHandler *qdev_get_bus_hotplug_handler(DeviceState *dev); HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev); bool qdev_hotplug_allowed(DeviceState *dev, Error **errp); + /** - * qdev_get_hotplug_handler: Get handler responsible for device wiring - * - * Find HOTPLUG_HANDLER for @dev that provides [pre|un]plug callbacks for it. + * qdev_get_hotplug_handler() - Get handler responsible for device wiring + * @dev: the device we want the HOTPLUG_HANDLER for. * * Note: in case @dev has a parent bus, it will be returned as handler unless * machine handler overrides it. * - * Returns: pointer to object that implements TYPE_HOTPLUG_HANDLER interface - * or NULL if there aren't any. + * Return: pointer to object that implements TYPE_HOTPLUG_HANDLER interface + * or NULL if there aren't any. */ HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev); void qdev_unplug(DeviceState *dev, Error **errp); @@ -459,15 +574,15 @@ void qdev_del_unplug_blocker(DeviceState *dev, Error *reason); * qdev_unplug_blocked: Confirm if a device is blocked from unplug * * @dev: Device to be tested - * @reason: Returns one of the reasons why the device is blocked, - * if any + * @errp: The reasons why the device is blocked, if any * - * Returns: true if device is blocked from unplug, false otherwise + * Returns: true (also setting @errp) if device is blocked from unplug, + * false otherwise */ bool qdev_unplug_blocked(DeviceState *dev, Error **errp); /** - * GpioPolarity: Polarity of a GPIO line + * typedef GpioPolarity - Polarity of a GPIO line * * GPIO lines use either positive (active-high) logic, * or negative (active-low) logic. @@ -499,6 +614,8 @@ typedef enum { * connect another device's output GPIO line to this input. * * For named input GPIO lines, use qdev_get_gpio_in_named(). + * + * Return: qemu_irq corresponding to anonymous input GPIO line */ qemu_irq qdev_get_gpio_in(DeviceState *dev, int n); @@ -516,6 +633,8 @@ qemu_irq qdev_get_gpio_in(DeviceState *dev, int n); * array); this function will assert() if passed an invalid name or index. * * For anonymous input GPIO lines, use qdev_get_gpio_in(). + * + * Return: qemu_irq corresponding to named input GPIO line */ qemu_irq qdev_get_gpio_in_named(DeviceState *dev, const char *name, int n); @@ -523,7 +642,7 @@ qemu_irq qdev_get_gpio_in_named(DeviceState *dev, const char *name, int n); * qdev_connect_gpio_out: Connect one of a device's anonymous output GPIO lines * @dev: Device whose GPIO to connect * @n: Number of the anonymous output GPIO line (which must be in range) - * @input_pin: qemu_irq to connect the output line to + * @pin: qemu_irq to connect the output line to * * This function connects an anonymous output GPIO line on a device * up to an arbitrary qemu_irq, so that when the device asserts that @@ -594,6 +713,8 @@ void qdev_connect_gpio_out_named(DeviceState *dev, const char *name, int n, * * You probably don't need to use this function -- it is used only * by the platform-bus subsystem. + * + * Return: qemu_irq associated with GPIO or NULL if un-wired. */ qemu_irq qdev_get_gpio_out_connector(DeviceState *dev, const char *name, int n); @@ -604,14 +725,17 @@ qemu_irq qdev_get_gpio_out_connector(DeviceState *dev, const char *name, int n); * @name: Name of the output GPIO array * @n: Number of the GPIO line in the array * - * This function is provided only for use by the qtest testing framework - * and is not suitable for use in non-testing parts of QEMU. + * .. note:: + * This function is provided only for use by the qtest testing framework + * and is not suitable for use in non-testing parts of QEMU. * * This function breaks an existing connection of an outbound GPIO * line from @dev, and replaces it with the new qemu_irq @icpt, as if * ``qdev_connect_gpio_out_named(dev, icpt, name, n)`` had been called. * The previously connected qemu_irq is returned, so it can be restored * by a second call to qdev_intercept_gpio_out() if desired. + * + * Return: old disconnected qemu_irq if one existed */ qemu_irq qdev_intercept_gpio_out(DeviceState *dev, qemu_irq icpt, const char *name, int n); @@ -683,9 +807,7 @@ void qdev_init_gpio_out_named(DeviceState *dev, qemu_irq *pins, const char *name, int n); /** - * qdev_init_gpio_in_named_with_opaque: create an array of input GPIO lines - * for the specified device - * + * qdev_init_gpio_in_named_with_opaque() - create an array of input GPIO lines * @dev: Device to create input GPIOs for * @handler: Function to call when GPIO line value is set * @opaque: Opaque data pointer to pass to @handler @@ -698,8 +820,11 @@ void qdev_init_gpio_in_named_with_opaque(DeviceState *dev, const char *name, int n); /** - * qdev_init_gpio_in_named: create an array of input GPIO lines - * for the specified device + * qdev_init_gpio_in_named() - create an array of input GPIO lines + * @dev: device to add array to + * @handler: a &typedef qemu_irq_handler function to call when GPIO is set + * @name: Name of the GPIO input (must be unique for this device) + * @n: Number of GPIO lines in this input set * * Like qdev_init_gpio_in_named_with_opaque(), but the opaque pointer * passed to the handler is @dev (which is the most commonly desired behaviour). @@ -762,14 +887,17 @@ int qdev_walk_children(DeviceState *dev, void *opaque); /** - * device_cold_reset: + * device_cold_reset() - perform a recursive cold reset on a device + * @dev: device to reset. + * * Reset device @dev and perform a recursive processing using the resettable * interface. It triggers a RESET_TYPE_COLD. */ void device_cold_reset(DeviceState *dev); /** - * bus_cold_reset: + * bus_cold_reset() - perform a recursive cold reset on a bus + * @bus: bus to reset * * Reset bus @bus and perform a recursive processing using the resettable * interface. It triggers a RESET_TYPE_COLD. @@ -777,14 +905,18 @@ void device_cold_reset(DeviceState *dev); void bus_cold_reset(BusState *bus); /** - * device_is_in_reset: - * Return true if the device @dev is currently being reset. + * device_is_in_reset() - check device reset state + * @dev: device to check + * + * Return: true if the device @dev is currently being reset. */ bool device_is_in_reset(DeviceState *dev); /** - * bus_is_in_reset: - * Return true if the bus @bus is currently being reset. + * bus_is_in_reset() - check bus reset state + * @bus: bus to check + * + * Return: true if the bus @bus is currently being reset. */ bool bus_is_in_reset(BusState *bus); @@ -797,7 +929,14 @@ char *qdev_get_own_fw_dev_path_from_handler(BusState *bus, DeviceState *dev); void device_class_set_props(DeviceClass *dc, Property *props); /** - * device_class_set_parent_reset: + * device_class_set_parent_reset() - legacy set device reset handlers + * @dc: device class + * @dev_reset: function pointer to reset handler + * @parent_reset: function pointer to parents reset handler + * + * Modern code should use the ResettableClass interface to + * implement a multi-phase reset instead. + * * TODO: remove the function when DeviceClass's reset method * is not used anymore. */ @@ -871,14 +1010,15 @@ void device_listener_register(DeviceListener *listener); void device_listener_unregister(DeviceListener *listener); /** - * @qdev_should_hide_device: + * qdev_should_hide_device() - check if device should be hidden + * * @opts: options QDict * @from_json: true if @opts entries are typed, false for all strings * @errp: pointer to error object * - * Check if a device should be added. - * When a device is added via qdev_device_add() this will be called, - * and return if the device should be added now or not. + * When a device is added via qdev_device_add() this will be called. + * + * Return: if the device should be added now or not. */ bool qdev_should_hide_device(const QDict *opts, bool from_json, Error **errp);