Re: [dpdk-dev] [PATCH v4 7/7] ethdev: hide eth dev related structures

[Thomas Monjalon <thomas@monjalon.net>]

04/10/2021 15:56, Konstantin Ananyev:
> Move rte_eth_dev, rte_eth_dev_data, rte_eth_rxtx_callback and related
> data into private header (ethdev_driver.h).
[...]
> +/**
> + * @internal
> + * Structure used to hold information about the callbacks to be called for a
> + * queue on RX and TX.
> + */
> +struct rte_eth_rxtx_callback {
> +	struct rte_eth_rxtx_callback *next;
> +	union{
> +		rte_rx_callback_fn rx;
> +		rte_tx_callback_fn tx;
> +	} fn;
> +	void *param;
> +};
> +
> +/**
> + * @internal
> + * The generic data structure associated with each ethernet device.
> + *
> + * Pointers to burst-oriented packet receive and transmit functions are
> + * located at the beginning of the structure, along with the pointer to
> + * where all the data elements for the particular device are stored in shared
> + * memory. This split allows the function pointer and driver data to be per-
> + * process, while the actual configuration data for the device is shared.
> + */
> +struct rte_eth_dev {
> +	eth_rx_burst_t rx_pkt_burst; /**< Pointer to PMD receive function. */
> +	eth_tx_burst_t tx_pkt_burst; /**< Pointer to PMD transmit function. */
> +	eth_tx_prep_t tx_pkt_prepare;
> +	/**< Pointer to PMD transmit prepare function. */
> +	eth_rx_queue_count_t rx_queue_count;
> +	/**< Get the number of used RX descriptors. */
> +	eth_rx_descriptor_status_t rx_descriptor_status;
> +	/**< Check the status of a Rx descriptor. */
> +	eth_tx_descriptor_status_t tx_descriptor_status;
> +	/**< Check the status of a Tx descriptor. */

Why not using the new struct rte_eth_fp_ops?

> +
> +	/**
> +	 * Next two fields are per-device data but *data is shared between
> +	 * primary and secondary processes and *process_private is per-process
> +	 * private. The second one is managed by PMDs if necessary.
> +	 */
> +	struct rte_eth_dev_data *data;  /**< Pointer to device data. */

We should mention that "data" is shared between processes.

> +	void *process_private; /**< Pointer to per-process device data. */
> +	const struct eth_dev_ops *dev_ops; /**< Functions exported by PMD */
> +	struct rte_device *device; /**< Backing device */
> +	struct rte_intr_handle *intr_handle; /**< Device interrupt handle */
> +	/** User application callbacks for NIC interrupts */
> +	struct rte_eth_dev_cb_list link_intr_cbs;
> +	/**
> +	 * User-supplied functions called from rx_burst to post-process
> +	 * received packets before passing them to the user
> +	 */
> +	struct rte_eth_rxtx_callback *post_rx_burst_cbs[RTE_MAX_QUEUES_PER_PORT];
> +	/**
> +	 * User-supplied functions called from tx_burst to pre-process
> +	 * received packets before passing them to the driver for transmission.
> +	 */
> +	struct rte_eth_rxtx_callback *pre_tx_burst_cbs[RTE_MAX_QUEUES_PER_PORT];
> +	enum rte_eth_dev_state state; /**< Flag indicating the port state */
> +	void *security_ctx; /**< Context for security ops */
> +
> +	uint64_t reserved_64s[4]; /**< Reserved for future fields */
> +	void *reserved_ptrs[4];   /**< Reserved for future fields */
> +} __rte_cache_aligned;
> +
> +struct rte_eth_dev_sriov;
> +struct rte_eth_dev_owner;
> +
> +/**
> + * @internal
> + * The data part, with no function pointers, associated with each ethernet
> + * device. This structure is safe to place in shared memory to be common
> + * among different processes in a multi-process configuration.
> + */
> +struct rte_eth_dev_data {
> +	char name[RTE_ETH_NAME_MAX_LEN]; /**< Unique identifier name */
> +
> +	void **rx_queues; /**< Array of pointers to RX queues. */
> +	void **tx_queues; /**< Array of pointers to TX queues. */
> +	uint16_t nb_rx_queues; /**< Number of RX queues. */
> +	uint16_t nb_tx_queues; /**< Number of TX queues. */
> +
> +	struct rte_eth_dev_sriov sriov;    /**< SRIOV data */
> +
> +	void *dev_private;
> +			/**< PMD-specific private data.
> +			 *   @see rte_eth_dev_release_port()
> +			 */
> +
> +	struct rte_eth_link dev_link;   /**< Link-level information & status. */
> +	struct rte_eth_conf dev_conf;   /**< Configuration applied to device. */
> +	uint16_t mtu;                   /**< Maximum Transmission Unit. */
> +	uint32_t min_rx_buf_size;
> +			/**< Common RX buffer size handled by all queues. */
> +
> +	uint64_t rx_mbuf_alloc_failed; /**< RX ring mbuf allocation failures. */
> +	struct rte_ether_addr *mac_addrs;
> +			/**< Device Ethernet link address.
> +			 *   @see rte_eth_dev_release_port()
> +			 */
> +	uint64_t mac_pool_sel[ETH_NUM_RECEIVE_MAC_ADDR];
> +			/**< Bitmap associating MAC addresses to pools. */
> +	struct rte_ether_addr *hash_mac_addrs;
> +			/**< Device Ethernet MAC addresses of hash filtering.
> +			 *   @see rte_eth_dev_release_port()
> +			 */
> +	uint16_t port_id;           /**< Device [external] port identifier. */
> +
> +	__extension__
> +	uint8_t promiscuous   : 1,
> +		/**< RX promiscuous mode ON(1) / OFF(0). */
> +		scattered_rx : 1,
> +		/**< RX of scattered packets is ON(1) / OFF(0) */
> +		all_multicast : 1,
> +		/**< RX all multicast mode ON(1) / OFF(0). */
> +		dev_started : 1,
> +		/**< Device state: STARTED(1) / STOPPED(0). */
> +		lro         : 1,
> +		/**< RX LRO is ON(1) / OFF(0) */
> +		dev_configured : 1;
> +		/**< Indicates whether the device is configured.
> +		 *   CONFIGURED(1) / NOT CONFIGURED(0).
> +		 */
> +	uint8_t rx_queue_state[RTE_MAX_QUEUES_PER_PORT];
> +		/**< Queues state: HAIRPIN(2) / STARTED(1) / STOPPED(0). */
> +	uint8_t tx_queue_state[RTE_MAX_QUEUES_PER_PORT];
> +		/**< Queues state: HAIRPIN(2) / STARTED(1) / STOPPED(0). */
> +	uint32_t dev_flags;             /**< Capabilities. */
> +	int numa_node;                  /**< NUMA node connection. */
> +	struct rte_vlan_filter_conf vlan_filter_conf;
> +			/**< VLAN filter configuration. */
> +	struct rte_eth_dev_owner owner; /**< The port owner. */
> +	uint16_t representor_id;
> +			/**< Switch-specific identifier.
> +			 *   Valid if RTE_ETH_DEV_REPRESENTOR in dev_flags.
> +			 */
> +
> +	pthread_mutex_t flow_ops_mutex; /**< rte_flow ops mutex. */
> +	uint64_t reserved_64s[4]; /**< Reserved for future fields */
> +	void *reserved_ptrs[4];   /**< Reserved for future fields */
> +} __rte_cache_aligned;
> +
> +/**
> + * @internal
> + * The pool of *rte_eth_dev* structures. The size of the pool
> + * is configured at compile-time in the <rte_ethdev.c> file.
> + */
> +extern struct rte_eth_dev rte_eth_devices[];

Later we should add a function to configure the size of this array dynamically
in the early DPDK init stage.