ethtool: add support for RSS input transformation

Add support for RSS input transformation [1]. Currently, only symmetric-xor
is supported. The user can set the RSS input transformation via:

    # ethtool -X <dev> xfrm symmetric-xor

and sets it off (default) by:

    # ethtool -X <dev> xfrm none

The status of the transformation is reported by a new section at the end
of "ethtool -x":

    # ethtool -x <dev>
      .
      .
      .
      .
      RSS hash function:
          toeplitz: on
          xor: off
          crc32: off
      RSS input transformation:
          symmetric-xor: on

Link: https://lore.kernel.org/netdev/20231213003321.605376-1-ahmed.zaki@intel.com/
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/ethtool.c b/ethtool.c
index 3ac15a7..82919f8 100644
--- a/ethtool.c
+++ b/ethtool.c
@@ -4029,6 +4029,10 @@ static int do_grxfh(struct cmd_context *ctx)
 		       (const char *)hfuncs->data + i * ETH_GSTRING_LEN,
 		       (rss->hfunc & (1 << i)) ? "on" : "off");
 
+	printf("RSS input transformation:\n");
+	printf("    symmetric-xor: %s\n",
+	       (rss->input_xfrm & RXH_XFRM_SYM_XOR) ? "on" : "off");
+
 out:
 	free(hfuncs);
 	free(rss);
@@ -4146,6 +4150,7 @@ static int do_srxfh(struct cmd_context *ctx)
 	u32 arg_num = 0, indir_bytes = 0;
 	u32 req_hfunc = 0;
 	u32 entry_size = sizeof(rss_head.rss_config[0]);
+	u32 req_input_xfrm = 0xff;
 	u32 num_weights = 0;
 	u32 rss_context = 0;
 	int delete = 0;
@@ -4189,6 +4194,15 @@ static int do_srxfh(struct cmd_context *ctx)
 			if (!req_hfunc_name)
 				exit_bad_args();
 			++arg_num;
+		} else if (!strcmp(ctx->argp[arg_num], "xfrm")) {
+			++arg_num;
+			if (!strcmp(ctx->argp[arg_num], "symmetric-xor"))
+				req_input_xfrm = RXH_XFRM_SYM_XOR;
+			else if (!strcmp(ctx->argp[arg_num], "none"))
+				req_input_xfrm = 0;
+			else
+				exit_bad_args();
+			++arg_num;
 		} else if (!strcmp(ctx->argp[arg_num], "context")) {
 			++arg_num;
 			if(!strcmp(ctx->argp[arg_num], "new"))
@@ -4333,6 +4347,7 @@ static int do_srxfh(struct cmd_context *ctx)
 	rss->cmd = ETHTOOL_SRSSH;
 	rss->rss_context = rss_context;
 	rss->hfunc = req_hfunc;
+	rss->input_xfrm = req_input_xfrm;
 	if (delete) {
 		rss->indir_size = rss->key_size = 0;
 	} else {
@@ -5887,6 +5902,7 @@ static const struct option args[] = {
 			  "		[ equal N | weight W0 W1 ... | default ]\n"
 			  "		[ hkey %x:%x:%x:%x:%x:.... ]\n"
 			  "		[ hfunc FUNC ]\n"
+			  "		[ xfrm symmetric-xor|none ]\n"
 			  "		[ delete ]\n"
 	},
 	{