From: Rajasekhar Pulluru <pullururajasekhar@gmail.com>
Sent: Tuesday, March 7, 2023 12:52 PM
To: dev@dpdk.org
Subject: ixgbe rxq interrupt not working

Hi Team,

Bringing-up dpdk-22.07 on an intel machine with 8 ports, 4 of them driven by igb and the rest of the 4 ports driven by ixgbe.
[Honnappa]  Do you have packets crossing between the 2 drivers?


I am following the below sequence to initialize these ports:

dev_conf.intr_conf.lsc = 1; //Enable link state change interrupt
dev_conf.intr_conf.rxq = 1; //Enable RX Queue Interrupt
dev_conf.rxmode.mq_mode = RTE_ETH_MQ_RX_NONE;
dev_conf.rxmode.offloads = 0;
dev_conf.txmode.mq_mode = RTE_ETH_MQ_TX_NONE;
dev_conf.txmode.offloads = 0;

rte_eth_dev_configure
rte_eth_rx_queue_setup
rte_eth_tx_queue_setup
rte_eth_dev_start
data = port_id << CHAR_BIT | queue_id;
rte_eth_dev_rx_intr_ctl_q(port_id, queue_id, RTE_EPOLL_PER_THREAD, RTE_INTR_EVENT_ADD, (void *)((uintptr_t)data));
rte_eth_dev_rx_intr_enable(port_id, queue_id);

And then main loop repeats the below:

rte_epoll_wait(RTE_EPOLL_PER_THREAD, event, 1, timeout /* 200micro-sec */); /* ignore return value */
rte_eth_dev_rx_intr_disable(port_id, queue_id);
rte_eth_rx_burst(port_id, queue_id, pkts, num_pkts);
rte_eth_dev_rx_intr_enable(port_id, queue_id);

The code is same for all the ports, igb ports are able to come-up and rx packets, where-as the ixgbe ports are not able to rx packets at all.
cat /proc/interrupts dumps vfio-msix counters for ixgbe as 0, where-as it's non-zero for igb.
If I don't use/enable rxq interrupt for ixgbe (and remove epoll wait, interrupt enable/disable from while loop) and simply poll for rte_eth_rx_burst in a loop, ixgbe ports are able to rx packets.

What could be wrong here? Appreciate any help.

I would also like to know if there's an asynchronous rxq interrupt notification to the application instead of rte_epoll_wait (and sleep).

Thanks & Regards,
Rajasekhar