[dpdk-dev] RSS Reta redirection not working on 82599 NIC(Niantic)

[Kamraan Nasim <knasim@sidebandnetworks.com>]

Hello,

Following from a previous thread, I took up Bruce Richardson's advice to
modify the RSS redirection table(RETA) to exclude entries pointing to a
specific queue:

For e.g, this is the RETA table before any modifications are done:
*Default *Reta table:
0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1
2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0
1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2 0 1 2
0 1 2 0 1 2 0 1 2 0 0 0 0 0

I have initialized 3 queues on this NIC(82599-Niantic) and as can be seen,
NIC will forward traffic to queue's 1 & 2.

Now the reta table is modified so that everything goes to queue 0

*Modified* Reta table:
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0

However despite this, RSS is loadbalancing packets on queues 1 & 2.

The following is a snippet of my code:
          /*
         * Rewrite the RETA(Redirection Table) for RSS
         * We want all traffic to be RX'd on queue 0
         * and only filtered traffic to be mapped to specific
         * queues, with one per filter for us to report
         * statistics
         */

        struct rte_eth_rss_reta port_reta_conf;
        memset(&port_reta_conf,0,sizeof(struct rte_eth_rss_reta));
        port_reta_conf.mask_lo = 0xffffffffffffffff;
        port_reta_conf.mask_hi = 0xfffffffffffffff;
        int reta_ret = 0;
        for (int rc = 0; rc < ETH_RSS_RETA_NUM_ENTRIES; rc++) {
                port_reta_conf.reta[rc] = 0x00;
            }
        reta_ret = rte_eth_dev_rss_reta_update(port, &port_reta_conf);

        printf("Reta return code: %d\n", reta_ret);


I have tried to restart the port, start/stop, linkup/linkdown but the
effect is the same: Reta table shows that it has all been zero'd out
however packets are still send to all configured queues. I am using DPDK
v1.7.0

Have others come across something similar? Any clues would be much
appreciated :)

--Kam