Re: [PATCH v8 05/12] net/nfp: add flower PF setup logic

[Ferruh Yigit <ferruh.yigit@xilinx.com>]

On 9/9/2022 3:36 AM, Chaoyong He wrote:
>> On 9/8/2022 9:44 AM, Chaoyong He wrote:
>>> Adds the vNIC initialization logic for the flower PF vNIC. The flower
>>> firmware exposes this vNIC for the purposes of fallback traffic in the
>>> switchdev use-case.
>>>
>>> Adds minimal dev_ops for this PF device. Because the device is being
>>> exposed externally to DPDK it should also be configured using DPDK
>>> helpers like rte_eth_configure(). For these helpers to work the flower
>>> logic needs to implements a minimal set of dev_ops.
>>>
>>> Signed-off-by: Chaoyong He <chaoyong.he@corigine.com>
>>> Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>

<...>

>>> +static int
>>> +nfp_flower_init_pf_vnic(struct nfp_net_hw *hw) {
>>> +	int ret;
>>> +	uint16_t i;
>>> +	uint16_t n_txq;
>>> +	uint16_t n_rxq;
>>> +	uint16_t port_id;
>>> +	unsigned int numa_node;
>>> +	struct rte_mempool *mp;
>>> +	struct nfp_pf_dev *pf_dev;
>>> +	struct rte_eth_dev *eth_dev;
>>> +	struct nfp_app_fw_flower *app_fw_flower;
>>> +
>>> +	static const struct rte_eth_conf port_conf = {
>>> +		.rxmode = {
>>> +			.mq_mode  = RTE_ETH_MQ_RX_RSS,
>>> +			.offloads = RTE_ETH_RX_OFFLOAD_CHECKSUM,
>>> +		},
>>> +		.txmode = {
>>> +			.mq_mode = RTE_ETH_MQ_TX_NONE,
>>> +		},
>>> +	};
>>> +
>>> +	/* Set up some pointers here for ease of use */
>>> +	pf_dev = hw->pf_dev;
>>> +	app_fw_flower = NFP_PRIV_TO_APP_FW_FLOWER(pf_dev-
>>> app_fw_priv);
>>> +
>>> +	/*
>>> +	 * Perform the "common" part of setting up a flower vNIC.
>>> +	 * Mostly reading configuration from hardware.
>>> +	 */
>>> +	ret = nfp_flower_init_vnic_common(hw, "pf_vnic");
>>> +	if (ret != 0)
>>> +		goto done;
>>> +
>>> +	hw->eth_dev = rte_eth_dev_allocate("nfp_pf_vnic");
>>> +	if (hw->eth_dev == NULL) {
>>> +		ret = -ENOMEM;
>>> +		goto done;
>>> +	}
>>> +
>>> +	/* Grab the pointer to the newly created rte_eth_dev here */
>>> +	eth_dev = hw->eth_dev;
>>> +
>>> +	numa_node = rte_socket_id();
>>> +
>>> +	/* Fill in some of the eth_dev fields */
>>> +	eth_dev->device = &pf_dev->pci_dev->device;
>>> +	eth_dev->data->dev_private = hw;
>>> +
>>> +	/* Create a mbuf pool for the PF */
>>> +	app_fw_flower->pf_pktmbuf_pool = nfp_flower_pf_mp_create();
>>> +	if (app_fw_flower->pf_pktmbuf_pool == NULL) {
>>> +		ret = -ENOMEM;
>>> +		goto port_release;
>>> +	}
>>> +
>>> +	mp = app_fw_flower->pf_pktmbuf_pool;
>>> +
>>> +	/* Add Rx/Tx functions */
>>> +	eth_dev->dev_ops = &nfp_flower_pf_vnic_ops;
>>> +
>>> +	/* PF vNIC gets a random MAC */
>>> +	eth_dev->data->mac_addrs = rte_zmalloc("mac_addr",
>> RTE_ETHER_ADDR_LEN, 0);
>>> +	if (eth_dev->data->mac_addrs == NULL) {
>>> +		ret = -ENOMEM;
>>> +		goto mempool_cleanup;
>>> +	}
>>> +
>>> +	rte_eth_random_addr(eth_dev->data->mac_addrs->addr_bytes);
>>> +	rte_eth_dev_probing_finish(eth_dev);
>>> +
>>> +	/* Configure the PF device now */
>>> +	n_rxq = hw->max_rx_queues;
>>> +	n_txq = hw->max_tx_queues;
>>> +	port_id = hw->eth_dev->data->port_id;
>>> +
>>> +	ret = rte_eth_dev_configure(port_id, n_rxq, n_txq, &port_conf);
>>
>> Still not sure about PMD calling 'rte_eth_dev_configure()', can you please
>> give more details on what specific configuration is expected with that call?
> 
> The main configuration we need is the number of rx/tx queue.
> So we should use the internal api `eth_dev_rx/tx_queue_config` to instead?
> 

nb_rx_q/nb_tx_q are parameters provided by user (via 
rte_eth_dev_configure()), won't is wrong for PMD to set a value on its own?

Why nb_rx_q/nb_tx_q are required in the probe() stage? Probe stage is 
not to configure the device.