[dpdk-dev] rte_eth_tx_queue_setup() failing (error -22) when setting up tx queues on a VMXNET3 port...

["Montorsi, Francesco" <fmontorsi@empirix.com>]

Hi all,
I have a server running VMWare ESXi 5.5.0 and VMWare vCenter 5.5.0. On such server I created a VM with two VMXNET3 NIC cards (one for management, the other one should be used with DPDK to enable fast-RX of packets coming from other VMs / bare-metal NICs).

Inside the VM I have successfully created 2MB hugepages, loaded igb_uio driver and binded the 2nd VMXNET3 NIC to igb_uio driver:

----------------------------------------------------------------------------------------------------------------------
$ ./dpdk_nic_bind.py --status

Network devices using DPDK-compatible driver
============================================
0000:0b:00.0 'VMXNET3 Ethernet Controller' drv=igb_uio unused=vmxnet3

Network devices using kernel driver
===================================
0000:03:00.0 'VMXNET3 Ethernet Controller' if=eth0 drv=vmxnet3 unused=igb_uio *Active*

Other network devices
=====================
<none>
----------------------------------------------------------------------------------------------------------------------

However when I start my DPDK-application I get the following error during TX queue initialization:

ERR rte_eth_tx_queue_setup: err=-22, port=0: Unknown error -22

This is the code that I'm using:

              ...
               rte_eth_dev_info_get(m_portid, m_dev_info);


	// proceed with configuration

	struct rte_eth_conf port_conf;
	memset(&port_conf, 0, sizeof(port_conf));

	port_conf.rxmode.mq_mode = ETH_MQ_RX_RSS;
		/** The multi-queue packet distribution mode to be used, e.g. RSS.; this is important to use multiple RX queues per port ID */
	port_conf.rxmode.max_rx_pkt_len = ETHER_MAX_LEN;
	port_conf.rxmode.hw_strip_crc   = 1; /**< enable CRC stripping by hardware */
	port_conf.rxmode.jumbo_frame    = 1; /**< Jumbo Frame Support enabled */
	//port_conf.rxmode.enable_lro     = 1; /**< Enable LRO */		// NOT SUPPORTED ON TESTED HW
	port_conf.rx_adv_conf.rss_conf.rss_hf = ETH_RSS_IP;
	port_conf.txmode.mq_mode = ETH_MQ_TX_NONE;

	m_num_queues = MIN(64, m_dev_info->max_rx_queues);
	m_num_queues = MIN(128, m_num_queues);
	ret = rte_eth_dev_configure(m_portid, m_num_queues, 1 /* number of tx queues */, &port_conf);
	if (ret < 0)
	{
		HMLogError("HwEmulDPDKPort::init() rte_eth_dev_configure: err=%d, port=%u: %s", ret, m_portid, rte_strerror(ret));
		return false;
	}

	// init one TX queue: even if we never ever TX packets, at least 1 queue is needed!
--->	ret = rte_eth_tx_queue_setup(m_portid, 0 /* queue ID */, 64 /* num descriptors */, rte_eth_dev_socket_id(m_portid), NULL);
	if (ret < 0)
	{
		// retry with just 1 descriptor

--->		ret = rte_eth_tx_queue_setup(m_portid, 0 /* queue ID */, 1 /* num descriptors */, rte_eth_dev_socket_id(m_portid), NULL);
		if (ret < 0)
		{
			HMLogError("HwEmulDPDKPort::init() rte_eth_tx_queue_setup: err=%d, port=%u: %s", ret, m_portid, rte_strerror(ret));
			return false;
		}
	}


Basically since I want to only receive packets (no TX) I'm not really interested in TX queues / num of TX descriptors... However I have troubles decrypting this -22 error code... any hint?


Thanks a lot,

Francesco Montorsi