Function tap_rx_queue_setup

dpdk/drivers/net/tap/rte_eth_tap.c:1546–1633

}

static int
tap_rx_queue_setup(struct rte_eth_dev *dev,
		   uint16_t rx_queue_id,
		   uint16_t nb_rx_desc,
		   unsigned int socket_id,
		   const struct rte_eth_rxconf *rx_conf __rte_unused,
		   struct rte_mempool *mp)
{
	struct pmd_internals *internals = dev->data->dev_private;
	struct pmd_process_private *process_private = dev->process_private;
	struct rx_queue *rxq = &internals->rxq[rx_queue_id];
	struct rte_mbuf **tmp = &rxq->pool;
	long iov_max = sysconf(_SC_IOV_MAX);

	if (iov_max <= 0) {
		TAP_LOG(WARNING,
			"_SC_IOV_MAX is not defined. Using %d as default",
			TAP_IOV_DEFAULT_MAX);
		iov_max = TAP_IOV_DEFAULT_MAX;
	}
	uint16_t nb_desc = RTE_MIN(nb_rx_desc, iov_max - 1);
	struct iovec (*iovecs)[nb_desc + 1];
	int data_off = RTE_PKTMBUF_HEADROOM;
	int ret = 0;
	int fd;
	int i;

	if (rx_queue_id >= dev->data->nb_rx_queues || !mp) {
		TAP_LOG(WARNING,
			"nb_rx_queues %d too small or mempool NULL",
			dev->data->nb_rx_queues);
		return -1;
	}

	rxq->mp = mp;
	rxq->trigger_seen = 1; /* force initial burst */
	rxq->in_port = dev->data->port_id;
	rxq->queue_id = rx_queue_id;
	rxq->nb_rx_desc = nb_desc;
	iovecs = rte_zmalloc_socket(dev->device->name, sizeof(*iovecs), 0,
				    socket_id);
	if (!iovecs) {
		TAP_LOG(WARNING,
			"%s: Couldn't allocate %d RX descriptors",
			dev->device->name, nb_desc);
		return -ENOMEM;
	}
	rxq->iovecs = iovecs;

	dev->data->rx_queues[rx_queue_id] = rxq;
	fd = tap_setup_queue(dev, internals, rx_queue_id, 1);
	if (fd == -1) {
		ret = fd;
		goto error;
	}

	(*rxq->iovecs)[0].iov_len = sizeof(struct tun_pi);
	(*rxq->iovecs)[0].iov_base = &rxq->pi;