OK, I found my issue. The input to the hash function should include all 4 parameters also in case of symmetic: (SRC_IP^DST_IP , SRC_IP^DST_IP, SRC_PORT^DST_PORT, SRC_PORT^DST_PORT) Shaul. From: Shaul Hamoi (shamoi) Date: Sunday, 31 March 2024 at 14:48 To: sismis@cesnet.cz Cc: Balakrishnan.K1@tatacommunications.com , stephen@networkplumber.org , users@dpdk.org Subject: Re: Symmetric RSS Hashing support in DPDK Hi, I am looking to determine the target queue for a flow in advance I’m using dpdk-rss-flows.py to calculate the Toeplitz hash with I40E key. However, If I use the script as is, I don’t obtain the correct queue because the hash calculation isn’t symmetric. I have attempted to XOR the source and destination IP addresses and source and destination port before performing the calculation but I still don’t get the correct queue. In case you use RTE_ETH_HASH_SYMMETRIC_TOEPLITZ , the I40E key doesn’t change - Right ? How do I find that the NIC does for symmetric hash so I can simulate it ? (src="1.0.0.1", dst="2.0.0.2")/TCP(sport=8819, dport=80) Actual queue - 7 (32 RX queues) Result with XOR: dpdk-rss-flows.py -s 8819 -d 80 -k i40e 32 1.0.0.1 2.0.0.2 SRC_IP SPORT DST_IP DPORT QUEUE 1.0.0.1 8819 2.0.0.2 80 19 Result without (original script): dpdk-rss-flows.py -s 8819 -d 80 -k i40e 32 1.0.0.1 2.0.0.2 SRC_IP SPORT DST_IP DPORT QUEUE 1.0.0.1 8819 2.0.0.2 80 20 Thanks in advance, Shaul. From: "Lukáš Šišmiš" To: Balakrishnan K , Stephen Hemminger Cc: "users@dpdk.org" Subject: Re: Symmetric RSS Hashing support in DPDK Date: Fri, 8 Mar 2024 08:29:32 +0100 [thread overview] Message-ID: <90dc11cf-8c60-4b90-a3fc-43b2351b6c93@cesnet.cz> (raw) In-Reply-To: > Hi all, I've made minimalist example app on how to set symmetric RSS support for X710 that uses RTE_FLOW rules - check it out here: https://github.com/lukashino/i40e-symmetric-rss-rte-flow Lukas On 08. 03. 24 6:53, Balakrishnan K wrote: > Hi Stephen, > Thanks for the response . I will below option and come back if any help required. > > Regards, > Bala > > -----Original Message----- > From: Stephen Hemminger > Sent: Wednesday, March 6, 2024 8:34 PM > To: Balakrishnan K > Cc: users@dpdk.org > Subject: Re: Symmetric RSS Hashing support in DPDK > > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. > > On Wed, 6 Mar 2024 07:28:40 +0000 > Balakrishnan K wrote: > >> Hello, >> Our application needs symmetric hashing to handle the reverse >> traffic on the same core, also to Improve performance by distributing the traffic across core. >> Tried using rss config as below . >> action_rss_tcp.types = ETH_RSS_NONFRAG_IPV4_TCP | ETH_RSS_L3_SRC_ONLY| >> ETH_RSS_L3_DST_ONLY | ETH_RSS_L4_SRC_ONLY | ETH_RSS_L4_DST_ONLY; but could not get desired result. >> Is there any options or API available to enable symmetric RSS hashing . >> We are using dpdk 20.11 and intel NIC X710 10GbE . >> >> Regards, >> Bala > With XL710 there are two choices: > 1. Set RSS hash function to RTE_ETH_HASH_SYMMETRIC_TOEPLITZ in > the rte_eth_rss_conf passed in during configure > 2. Use default (non symmetric TOEPLITZ) but pass in a rss_key that > has duplicated bits in the right place. Like: > > 0x6d5a 0x6d5a 0x6d5a 0x6d5a > 0x6d5a 0x6d5a 0x6d5a 0x6d5a > 0x6d5a 0x6d5a 0x6d5a 0x6d5a > 0x6d5a 0x6d5a 0x6d5a 0x6d5a > 0x6d5a 0x6d5a 0x6d5a 0x6d5a > > https://www.ndsl.kaist.edu/~kyoungsoo/papers/TR-symRSS.pdf