public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Jakub Kicinski <kuba@kernel•org>
To: davem@davemloft•net
Cc: netdev@vger•kernel.org, edumazet@google•com, pabeni@redhat•com,
	andrew+netdev@lunn•ch, horms@kernel•org, donald.hunter@gmail•com,
	shuah@kernel•org, kory.maincent@bootlin•com,
	maxime.chevallier@bootlin•com, sdf@fomichev•me,
	ecree.xilinx@gmail•com, gal@nvidia•com, jdamato@fastly•com,
	andrew@lunn•ch, Jakub Kicinski <kuba@kernel•org>
Subject: [PATCH net-next v3 05/11] ethtool: rss: support setting hfunc via Netlink
Date: Tue, 15 Jul 2025 17:03:25 -0700	[thread overview]
Message-ID: <20250716000331.1378807-6-kuba@kernel.org> (raw)
In-Reply-To: <20250716000331.1378807-1-kuba@kernel.org>

Support setting RSS hash function / algo via ethtool Netlink.
Like IOCTL we don't validate that the function is within the
range known to the kernel. The drivers do a pretty good job
validating the inputs, and the IDs are technically "dynamically
queried" rather than part of uAPI.

Only change should be that in Netlink we don't support user
explicitly passing ETH_RSS_HASH_NO_CHANGE (0), if no change
is requested the attribute should be absent.

The ETH_RSS_HASH_NO_CHANGE is retained in driver-facing
API for consistency (not that I see a strong reason for it).

Reviewed-by: Gal Pressman <gal@nvidia•com>
Signed-off-by: Jakub Kicinski <kuba@kernel•org>
---
 Documentation/netlink/specs/ethtool.yaml     |  1 +
 Documentation/networking/ethtool-netlink.rst |  1 +
 net/ethtool/rss.c                            | 12 +++++++++++-
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 1eca88a508a0..0d02d8342e4c 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -2654,6 +2654,7 @@ c-version-name: ethtool-genl-version
           attributes:
             - header
             - context
+            - hfunc
             - indir
     -
       name: rss-ntf
diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 27db7540e60e..f6e4439caa94 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1999,6 +1999,7 @@ RSS_SET
 =====================================  ======  ==============================
   ``ETHTOOL_A_RSS_HEADER``             nested  request header
   ``ETHTOOL_A_RSS_CONTEXT``            u32     context number
+  ``ETHTOOL_A_RSS_HFUNC``              u32     RSS hash func
   ``ETHTOOL_A_RSS_INDIR``              binary  Indir table bytes
 =====================================  ======  ==============================
 
diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index c8db523671de..bc9025cfcf1c 100644
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -475,6 +475,7 @@ void ethtool_rss_notify(struct net_device *dev, u32 rss_context)
 const struct nla_policy ethnl_rss_set_policy[ETHTOOL_A_RSS_START_CONTEXT + 1] = {
 	[ETHTOOL_A_RSS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
 	[ETHTOOL_A_RSS_CONTEXT] = { .type = NLA_U32, },
+	[ETHTOOL_A_RSS_HFUNC] = NLA_POLICY_MIN(NLA_U32, 1),
 	[ETHTOOL_A_RSS_INDIR] = { .type = NLA_BINARY, },
 };
 
@@ -489,6 +490,9 @@ ethnl_rss_set_validate(struct ethnl_req_info *req_info, struct genl_info *info)
 	if (request->rss_context && !ops->create_rxfh_context)
 		bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_CONTEXT];
 
+	if (request->rss_context && !ops->rxfh_per_ctx_key)
+		bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_HFUNC];
+
 	if (bad_attr) {
 		NL_SET_BAD_ATTR(info->extack, bad_attr);
 		return -EOPNOTSUPP;
@@ -588,6 +592,8 @@ rss_set_ctx_update(struct ethtool_rxfh_context *ctx, struct nlattr **tb,
 			ethtool_rxfh_context_indir(ctx)[i] = rxfh->indir[i];
 		ctx->indir_configured = !!nla_len(tb[ETHTOOL_A_RSS_INDIR]);
 	}
+	if (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE)
+		ctx->hfunc = rxfh->hfunc;
 }
 
 static int
@@ -618,7 +624,11 @@ ethnl_rss_set(struct ethnl_req_info *req_info, struct genl_info *info)
 		goto exit_clean_data;
 	indir_mod = !!tb[ETHTOOL_A_RSS_INDIR];
 
-	rxfh.hfunc = ETH_RSS_HASH_NO_CHANGE;
+	rxfh.hfunc = data.hfunc;
+	ethnl_update_u8(&rxfh.hfunc, tb[ETHTOOL_A_RSS_HFUNC], &mod);
+	if (rxfh.hfunc == data.hfunc)
+		rxfh.hfunc = ETH_RSS_HASH_NO_CHANGE;
+
 	rxfh.input_xfrm = RXH_XFRM_NO_CHANGE;
 
 	mutex_lock(&dev->ethtool->rss_lock);
-- 
2.50.1


  parent reply	other threads:[~2025-07-16  0:04 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-16  0:03 [PATCH net-next v3 00/11] ethtool: rss: support RSS_SET via Netlink Jakub Kicinski
2025-07-16  0:03 ` [PATCH net-next v3 01/11] ethtool: rss: initial RSS_SET (indirection table handling) Jakub Kicinski
2025-07-16  7:30   ` Gal Pressman
2025-07-16  0:03 ` [PATCH net-next v3 02/11] selftests: drv-net: rss_api: factor out checking min queue count Jakub Kicinski
2025-07-16  0:03 ` [PATCH net-next v3 03/11] tools: ynl: support packing binary arrays of scalars Jakub Kicinski
2025-07-16  0:03 ` [PATCH net-next v3 04/11] selftests: drv-net: rss_api: test setting indirection table via Netlink Jakub Kicinski
2025-07-16  0:03 ` Jakub Kicinski [this message]
2025-07-16  0:03 ` [PATCH net-next v3 06/11] ethtool: rss: support setting hkey " Jakub Kicinski
2025-07-16  0:03 ` [PATCH net-next v3 07/11] selftests: drv-net: rss_api: test setting hashing key " Jakub Kicinski
2025-07-16  0:03 ` [PATCH net-next v3 08/11] netlink: specs: define input-xfrm enum in the spec Jakub Kicinski
2025-07-16  7:43   ` Gal Pressman
2025-07-16  0:03 ` [PATCH net-next v3 09/11] ethtool: rss: support setting input-xfrm via Netlink Jakub Kicinski
2025-07-16  0:03 ` [PATCH net-next v3 10/11] ethtool: rss: support setting flow hashing fields Jakub Kicinski
2025-07-16  7:28   ` Gal Pressman
2025-07-16  0:03 ` [PATCH net-next v3 11/11] selftests: drv-net: rss_api: test input-xfrm and hash fields Jakub Kicinski
2025-07-17 23:30 ` [PATCH net-next v3 00/11] ethtool: rss: support RSS_SET via Netlink patchwork-bot+netdevbpf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20250716000331.1378807-6-kuba@kernel.org \
    --to=kuba@kernel$(echo .)org \
    --cc=andrew+netdev@lunn$(echo .)ch \
    --cc=andrew@lunn$(echo .)ch \
    --cc=davem@davemloft$(echo .)net \
    --cc=donald.hunter@gmail$(echo .)com \
    --cc=ecree.xilinx@gmail$(echo .)com \
    --cc=edumazet@google$(echo .)com \
    --cc=gal@nvidia$(echo .)com \
    --cc=horms@kernel$(echo .)org \
    --cc=jdamato@fastly$(echo .)com \
    --cc=kory.maincent@bootlin$(echo .)com \
    --cc=maxime.chevallier@bootlin$(echo .)com \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=pabeni@redhat$(echo .)com \
    --cc=sdf@fomichev$(echo .)me \
    --cc=shuah@kernel$(echo .)org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox