[PATCH iwl-net] ice: fix empty PTYPE set for GTP RSS profiles

[Takeru Hayasaka <hayatake396@gmail.com>]

Configuring RSS for GTP flows via ethtool, e.g.

  ethtool -N <if> rx-flow-hash gtpu4 sde

is accepted but has no effect: the hash of GTP-U packets does not
include the TEID, so all traffic between a given SGW/PGW pair lands on
a single Rx queue. The GTP RSS configurations the driver installs by
default at VSI init are affected the same way.

ice_flow_set_rss_seg_info() does not set IPV_OTHER on GTP segments, and
such a segment carries no L4 header bit either. ice_flow_proc_seg_hdrs()
therefore takes the "no L4" branch and ANDs the PTYPE set with
ice_ptypes_ipv4_ofos_no_l4, or ice_ptypes_ipv4_il_no_l4 for the inner
segment. Neither holds a GTP PTYPE, so ANDing with ice_ptypes_gtpu
leaves the set empty: the profile matches no packet at all and the
configured TEID field never enters the hash.

Set IPV_OTHER on GTP segments so that the tunnel-inclusive PTYPE sets
are selected instead, which do contain the GTP PTYPEs.

Verified on E810 (kernel 7.2-rc2, COMMS DDP 1.3.63.0) by reading the RSS
hash from the Rx descriptor: GTP-U traffic varying only the TEID goes
from one constant hash on a single Rx queue to 4096 distinct hashes
across all Rx queues. The same holds for inner IPv6 (gtpu6) and for a
PDU session container extension header (gtpu4e); plain UDP flows are
unaffected.

Signed-off-by: Takeru Hayasaka <hayatake396@gmail.com>
---
 drivers/net/ethernet/intel/ice/ice_flow.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/ice_flow.c b/drivers/net/ethernet/intel/ice/ice_flow.c
index 121552c644cd..2156bf246921 100644
--- a/drivers/net/ethernet/intel/ice/ice_flow.c
+++ b/drivers/net/ethernet/intel/ice/ice_flow.c
@@ -2088,6 +2088,14 @@ ice_flow_set_rss_seg_info(struct ice_flow_seg_info *segs, u8 seg_cnt,
 
 	ICE_FLOW_SET_HDRS(seg, cfg->addl_hdrs);
 
+	/* A GTP segment has no L4 header bit: without IPV_OTHER the "no L4"
+	 * PTYPE sets are picked, and they hold no GTP PTYPE at all.
+	 */
+	if (seg->hdrs & (ICE_FLOW_SEG_HDR_GTPU_IP | ICE_FLOW_SEG_HDR_GTPU_EH |
+			 ICE_FLOW_SEG_HDR_GTPU_UP | ICE_FLOW_SEG_HDR_GTPU_DWN |
+			 ICE_FLOW_SEG_HDR_GTPC | ICE_FLOW_SEG_HDR_GTPC_TEID))
+		seg->hdrs |= ICE_FLOW_SEG_HDR_IPV_OTHER;
+
 	/* set outer most header */
 	if (cfg->hdr_type == ICE_RSS_INNER_HEADERS_W_OUTER_IPV4)
 		segs[ICE_RSS_OUTER_HEADERS].hdrs |= ICE_FLOW_SEG_HDR_IPV4 |

base-commit: 1cd23ca80784223fa2204e16203f754da4e821f8
-- 
2.43.0