From 3203148917d035b09f71986ac2eaa19a352d6d9d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Thu, 14 May 2020 15:15:38 +0200 Subject: hw/nvram/fw_cfg: Add the FW_CFG_DATA_GENERATOR interface MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The FW_CFG_DATA_GENERATOR allows any object to produce blob of data consumable by the fw_cfg device. Reviewed-by: Laszlo Ersek Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Daniel P. Berrangé Message-Id: <20200623172726.21040-3-philmd@redhat.com> --- docs/specs/fw_cfg.txt | 9 ++++++++- hw/nvram/fw_cfg.c | 35 +++++++++++++++++++++++++++++++++++ include/hw/nvram/fw_cfg.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 86 insertions(+), 1 deletion(-) diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index 8f1ebc66fa..bc16daa38a 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -219,7 +219,7 @@ To check the result, read the "control" field: = Externally Provided Items = -As of v2.4, "file" fw_cfg items (i.e., items with selector keys above +Since v2.4, "file" fw_cfg items (i.e., items with selector keys above FW_CFG_FILE_FIRST, and with a corresponding entry in the fw_cfg file directory structure) may be inserted via the QEMU command line, using the following syntax: @@ -230,6 +230,13 @@ Or -fw_cfg [name=],string= +Since v5.1, QEMU allows some objects to generate fw_cfg-specific content, +the content is then associated with a "file" item using the 'gen_id' option +in the command line, using the following syntax: + + -object ,id=,[generator-specific-options] \ + -fw_cfg [name=],gen_id= + See QEMU man page for more documentation. Using item_name with plain ASCII characters only is recommended. diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index 0408a31f8e..694722b212 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -1032,6 +1032,35 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, return NULL; } +void fw_cfg_add_from_generator(FWCfgState *s, const char *filename, + const char *gen_id, Error **errp) +{ + FWCfgDataGeneratorClass *klass; + Error *local_err = NULL; + GByteArray *array; + Object *obj; + gsize size; + + obj = object_resolve_path_component(object_get_objects_root(), gen_id); + if (!obj) { + error_setg(errp, "Cannot find object ID '%s'", gen_id); + return; + } + if (!object_dynamic_cast(obj, TYPE_FW_CFG_DATA_GENERATOR_INTERFACE)) { + error_setg(errp, "Object ID '%s' is not a '%s' subclass", + gen_id, TYPE_FW_CFG_DATA_GENERATOR_INTERFACE); + return; + } + klass = FW_CFG_DATA_GENERATOR_GET_CLASS(obj); + array = klass->get_data(obj, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + size = array->len; + fw_cfg_add_file(s, filename, g_byte_array_free(array, TRUE), size); +} + static void fw_cfg_machine_reset(void *opaque) { MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine()); @@ -1333,12 +1362,18 @@ static const TypeInfo fw_cfg_mem_info = { .class_init = fw_cfg_mem_class_init, }; +static const TypeInfo fw_cfg_data_generator_interface_info = { + .parent = TYPE_INTERFACE, + .name = TYPE_FW_CFG_DATA_GENERATOR_INTERFACE, + .class_size = sizeof(FWCfgDataGeneratorClass), +}; static void fw_cfg_register_types(void) { type_register_static(&fw_cfg_info); type_register_static(&fw_cfg_io_info); type_register_static(&fw_cfg_mem_info); + type_register_static(&fw_cfg_data_generator_interface_info); } type_init(fw_cfg_register_types) diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h index 25d9307018..11feae3177 100644 --- a/include/hw/nvram/fw_cfg.h +++ b/include/hw/nvram/fw_cfg.h @@ -9,11 +9,36 @@ #define TYPE_FW_CFG "fw_cfg" #define TYPE_FW_CFG_IO "fw_cfg_io" #define TYPE_FW_CFG_MEM "fw_cfg_mem" +#define TYPE_FW_CFG_DATA_GENERATOR_INTERFACE "fw_cfg-data-generator" #define FW_CFG(obj) OBJECT_CHECK(FWCfgState, (obj), TYPE_FW_CFG) #define FW_CFG_IO(obj) OBJECT_CHECK(FWCfgIoState, (obj), TYPE_FW_CFG_IO) #define FW_CFG_MEM(obj) OBJECT_CHECK(FWCfgMemState, (obj), TYPE_FW_CFG_MEM) +#define FW_CFG_DATA_GENERATOR_CLASS(class) \ + OBJECT_CLASS_CHECK(FWCfgDataGeneratorClass, (class), \ + TYPE_FW_CFG_DATA_GENERATOR_INTERFACE) +#define FW_CFG_DATA_GENERATOR_GET_CLASS(obj) \ + OBJECT_GET_CLASS(FWCfgDataGeneratorClass, (obj), \ + TYPE_FW_CFG_DATA_GENERATOR_INTERFACE) + +typedef struct FWCfgDataGeneratorClass { + /*< private >*/ + InterfaceClass parent_class; + /*< public >*/ + + /** + * get_data: + * @obj: the object implementing this interface + * @errp: pointer to a NULL-initialized error object + * + * Returns: reference to a byte array containing the data. + * The caller should release the reference when no longer + * required. + */ + GByteArray *(*get_data)(Object *obj, Error **errp); +} FWCfgDataGeneratorClass; + typedef struct fw_cfg_file FWCfgFile; #define FW_CFG_ORDER_OVERRIDE_VGA 70 @@ -263,6 +288,24 @@ void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, void *fw_cfg_modify_file(FWCfgState *s, const char *filename, void *data, size_t len); +/** + * fw_cfg_add_from_generator: + * @s: fw_cfg device being modified + * @filename: name of new fw_cfg file item + * @gen_id: name of object implementing FW_CFG_DATA_GENERATOR interface + * @errp: pointer to a NULL initialized error object + * + * Add a new NAMED fw_cfg item with the content generated from the + * @gen_id object. The data generated by the @gen_id object is copied + * into the data structure of the fw_cfg device. + * The next available (unused) selector key starting at FW_CFG_FILE_FIRST + * will be used; also, a new entry will be added to the file directory + * structure residing at key value FW_CFG_FILE_DIR, containing the item name, + * data size, and assigned selector key value. + */ +void fw_cfg_add_from_generator(FWCfgState *s, const char *filename, + const char *gen_id, Error **errp); + FWCfgState *fw_cfg_init_io_dma(uint32_t iobase, uint32_t dma_iobase, AddressSpace *dma_as); FWCfgState *fw_cfg_init_io(uint32_t iobase); -- cgit v1.2.3