Subject: [PATCH net 2/5] eth: bnxt: populate defaults in the RSS context struct

From: Jakub Kicinski <[email-masked]>
Date: Thu, 25 Jul 2024 15:23:50 -0700

As described in the kdoc for .create_rxfh_context we are responsible
for populating the defaults. The core will not call .get_rxfh
for non-0 context.

The problem can be easily observed since Netlink doesn't currently
use the cache. Using netlink ethtool:

  $ ethtool -x eth0 context 1
  [...]
  RSS hash key:
  13:60:cd:60:14:d3:55:36:86:df:90:f2:96:14:e2:21:05:57:a8:8f:a5:12:5e:54:62:7f:fd:3c:15:7e:76:05:71:42:a2:9a:73:80:09:9c
  RSS hash function:
      toeplitz: on
      xor: off
      crc32: off

But using IOCTL ethtool shows:

  $ ./ethtool-old -x eth0 context 1
  [...]
  RSS hash key:
  00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:00
  RSS hash function:
      Operation not supported

Fixes: 7964e7884643 ("net: ethtool: use the tracking array for get_rxfh on custom RSS contexts")
Signed-off-by: Jakub Kicinski <[email-masked]>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 0425a54eca98..ab8e3f197e7b 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -1921,8 +1921,12 @@ static int bnxt_create_rxfh_context(struct net_device *dev,
 	if (rc)
 		goto out;
 
+	/* Populate defaults in the context */
 	bnxt_set_dflt_rss_indir_tbl(bp, ctx);
+	ctx->hfunc = ETH_RSS_HASH_TOP;
 	memcpy(vnic->rss_hash_key, bp->rss_hash_key, HW_HASH_KEY_SIZE);
+	memcpy(ethtool_rxfh_context_key(ctx),
+	       bp->rss_hash_key, HW_HASH_KEY_SIZE);
 
 	rc = bnxt_hwrm_vnic_alloc(bp, vnic, 0, bp->rx_nr_rings);
 	if (rc) {
-- 
2.45.2