[PATCH] net/i40e: fix symmetric toeplitz hashing for SCTP

[Anurag Mandal]

When symmetric toeplitz is configured for SCTP, packets belonging
to the same SCTP session are getting distributed to multiple queues
due to improper hash computation.

Removed SCTP Verification Tag from hash computation of symmetric toeplitz
as it changes for same SCTP session.

Tested the following with the fix & enabling symmetric toeplitz for SCTP:-
1. Packets belonging to the same SCTP session getting into the same queue.
2. Packets belonging to the different SCTP sessions getting distributed
to multiple queues.

Fixes: 0e4ae6c7e864 ("net/i40e: fix symmetric toeplitz hashing for SCTP")
Cc: stable at dpdk.org

Signed-off-by: Anurag Mandal <anurag.mandal at intel.com>
---
 .mailmap                           |  1 +
 drivers/net/intel/i40e/i40e_hash.c | 16 ++++++++++++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/.mailmap b/.mailmap
index 0b043cb0c0..1f1265fe20 100644
--- a/.mailmap
+++ b/.mailmap
@@ -136,6 +136,7 @@ Anthony Harivel <aharivel at redhat.com>
 Antonio Fischetti <antonio.fischetti at intel.com>
 Anup Prabhu <aprabhu at marvell.com>
 Anupam Kapoor <anupam.kapoor at gmail.com>
+Anurag Mandal <anurag.mandal at intel.com>
 Apeksha Gupta <apeksha.gupta at nxp.com>
 Archana Muniganti <marchana at marvell.com> <muniganti.archana at caviumnetworks.com>
 Archit Pandey <architpandeynitk at gmail.com>
diff --git a/drivers/net/intel/i40e/i40e_hash.c b/drivers/net/intel/i40e/i40e_hash.c
index 02e1457d80..661215d777 100644
--- a/drivers/net/intel/i40e/i40e_hash.c
+++ b/drivers/net/intel/i40e/i40e_hash.c
@@ -561,7 +561,7 @@ i40e_hash_get_pattern_pctypes(const struct rte_eth_dev *dev,
 }
 
 static uint64_t
-i40e_hash_get_inset(uint64_t rss_types)
+i40e_hash_get_inset(uint64_t rss_types, bool symmetric_enable)
 {
 	uint64_t mask, inset = 0;
 	int i;
@@ -608,6 +608,17 @@ i40e_hash_get_inset(uint64_t rss_types)
 				 I40E_INSET_IPV4_SRC | I40E_INSET_IPV6_SRC);
 	}
 
+	/* SCTP Verification Tag is not required in hash computation for SYMMETRIC_TOEPLITZ */
+	if (symmetric_enable) {
+		mask = rss_types & RTE_ETH_RSS_NONFRAG_IPV4_SCTP;
+		if (mask == RTE_ETH_RSS_NONFRAG_IPV4_SCTP)
+			inset &= ~I40E_INSET_SCTP_VT;
+
+		mask = rss_types & RTE_ETH_RSS_NONFRAG_IPV6_SCTP;
+		if (mask == RTE_ETH_RSS_NONFRAG_IPV6_SCTP)
+			inset &= ~I40E_INSET_SCTP_VT;
+        }
+
 	return inset;
 }
 
@@ -1113,6 +1124,7 @@ i40e_hash_parse_pattern_act(const struct rte_eth_dev *dev,
 					  RTE_FLOW_ERROR_TYPE_ACTION_CONF,
 					  NULL,
 					  "RSS Queues not supported when pattern specified");
+	rss_conf->symmetric_enable = false;  /* by default, symmetric is disabled */
 
 	switch (rss_act->func) {
 	case RTE_ETH_HASH_FUNCTION_SYMMETRIC_TOEPLITZ:
@@ -1140,7 +1152,7 @@ i40e_hash_parse_pattern_act(const struct rte_eth_dev *dev,
 
 	rss_conf->conf.func = rss_act->func;
 	rss_conf->conf.types = rss_act->types;
-	rss_conf->inset = i40e_hash_get_inset(rss_act->types);
+	rss_conf->inset = i40e_hash_get_inset(rss_act->types, rss_conf->symmetric_enable);
 
 	return i40e_hash_get_pattern_pctypes(dev, pattern, rss_act,
 					     rss_conf, error);
-- 
2.39.1