ethtool: rss: support setting input-xfrm via Netlink

Support configuring symmetric hashing via Netlink.
We have the flow field config prepared as part of SET handling,
so scan it for conflicts instead of querying the driver again.

Reviewed-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20250716000331.1378807-10-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index d0a9c4120a1941c9334456d62b10c85f24b6af82..41f26d58f2f9408255b6b28d46eac0a8df6db7a9 100644 (file)
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -2678,6 +2678,7 @@ operations:
             - hfunc
             - indir
             - hkey
+            - input-xfrm
     -
       name: rss-ntf
       doc: |

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 1830354495aee6e3e6596903ed433a87efab09f2..2214d2ce346ab1bcae36bdb9b8b95e0a82d58a72 100644 (file)
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -2002,6 +2002,7 @@ Request contents:
   ``ETHTOOL_A_RSS_HFUNC``              u32     RSS hash func
   ``ETHTOOL_A_RSS_INDIR``              binary  Indir table bytes
   ``ETHTOOL_A_RSS_HKEY``               binary  Hash key bytes
+  ``ETHTOOL_A_RSS_INPUT_XFRM``         u32     RSS input data transformation
 =====================================  ======  ==============================
 
 ``ETHTOOL_A_RSS_INDIR`` is the minimal RSS table the user expects. Kernel and
@@ -2012,9 +2013,6 @@ device needs at least 8 entries - the real table in use will end up being
 of 2, so tables which size is not a power of 2 will likely be rejected.
 Using table of size 0 will reset the indirection table to the default.
 
-Note that, at present, only a subset of RSS configuration can be accomplished
-over Netlink.
-
 PLCA_GET_CFG
 ============
 

diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 459cf25e763eb12af695aff43fb55d7dbc355b68..4dcb4194f3ce19eadae24f2cf3756d9a262da6ba 100644 (file)
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -806,6 +806,21 @@ out_free:
        return rc;
 }
 
+/* Check if fields configured for flow hash are symmetric - if src is included
+ * so is dst and vice versa.
+ */
+int ethtool_rxfh_config_is_sym(u64 rxfh)
+{
+       bool sym;
+
+       sym = rxfh == (rxfh & (RXH_IP_SRC | RXH_IP_DST |
+                              RXH_L4_B_0_1 | RXH_L4_B_2_3));
+       sym &= !!(rxfh & RXH_IP_SRC)   == !!(rxfh & RXH_IP_DST);
+       sym &= !!(rxfh & RXH_L4_B_0_1) == !!(rxfh & RXH_L4_B_2_3);
+
+       return sym;
+}
+
 int ethtool_check_ops(const struct ethtool_ops *ops)
 {
        if (WARN_ON(ops->set_coalesce && !ops->supported_coalesce_params))

diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index c41db1595621e135a3025b564c96afcdb49f5bd8..b2718afe38b56deb65cce6734287c6e0526e7683 100644 (file)
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -44,6 +44,7 @@ int ethtool_check_max_channel(struct net_device *dev,
                              struct ethtool_channels channels,
                              struct genl_info *info);
 int ethtool_check_rss_ctx_busy(struct net_device *dev, u32 rss_context);
+int ethtool_rxfh_config_is_sym(u64 rxfh);
 
 void ethtool_ringparam_get_cfg(struct net_device *dev,
                               struct ethtool_ringparam *param,

diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 830623678cb3bdb54536c07b0a3b13dcb628192d..2dfeaaa099fb3a6981bd6480e7dab3a2718092af 100644 (file)
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -1027,9 +1027,7 @@ static int ethtool_check_xfrm_rxfh(u32 input_xfrm, u64 rxfh)
         */
        if ((input_xfrm != RXH_XFRM_NO_CHANGE &&
             input_xfrm & (RXH_XFRM_SYM_XOR | RXH_XFRM_SYM_OR_XOR)) &&
-           ((rxfh & ~(RXH_IP_SRC | RXH_IP_DST | RXH_L4_B_0_1 | RXH_L4_B_2_3)) ||
-            (!!(rxfh & RXH_IP_SRC) ^ !!(rxfh & RXH_IP_DST)) ||
-            (!!(rxfh & RXH_L4_B_0_1) ^ !!(rxfh & RXH_L4_B_2_3))))
+           !ethtool_rxfh_config_is_sym(rxfh))
                return -EINVAL;
 
        return 0;

diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index 55260830639f97dffd413b6aede923244d366e3d..79de013da28804c55c22ad6f2a2f1d22b4530578 100644 (file)
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -478,6 +478,8 @@ const struct nla_policy ethnl_rss_set_policy[ETHTOOL_A_RSS_START_CONTEXT + 1] =
        [ETHTOOL_A_RSS_HFUNC] = NLA_POLICY_MIN(NLA_U32, 1),
        [ETHTOOL_A_RSS_INDIR] = { .type = NLA_BINARY, },
        [ETHTOOL_A_RSS_HKEY] = NLA_POLICY_MIN(NLA_BINARY, 1),
+       [ETHTOOL_A_RSS_INPUT_XFRM] =
+               NLA_POLICY_MAX(NLA_U32, RXH_XFRM_SYM_OR_XOR),
 };
 
 static int
@@ -487,6 +489,7 @@ ethnl_rss_set_validate(struct ethnl_req_info *req_info, struct genl_info *info)
        struct rss_req_info *request = RSS_REQINFO(req_info);
        struct nlattr **tb = info->attrs;
        struct nlattr *bad_attr = NULL;
+       u32 input_xfrm;
 
        if (request->rss_context && !ops->create_rxfh_context)
                bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_CONTEXT];
@@ -494,8 +497,13 @@ ethnl_rss_set_validate(struct ethnl_req_info *req_info, struct genl_info *info)
        if (request->rss_context && !ops->rxfh_per_ctx_key) {
                bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_HFUNC];
                bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_HKEY];
+               bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_INPUT_XFRM];
        }
 
+       input_xfrm = nla_get_u32_default(tb[ETHTOOL_A_RSS_INPUT_XFRM], 0);
+       if (input_xfrm & ~ops->supported_input_xfrm)
+               bad_attr = bad_attr ?: tb[ETHTOOL_A_RSS_INPUT_XFRM];
+
        if (bad_attr) {
                NL_SET_BAD_ATTR(info->extack, bad_attr);
                return -EOPNOTSUPP;
@@ -609,6 +617,33 @@ rss_set_prep_hkey(struct net_device *dev, struct genl_info *info,
        return 0;
 }
 
+static int
+rss_check_rxfh_fields_sym(struct net_device *dev, struct genl_info *info,
+                         struct rss_reply_data *data, bool xfrm_sym)
+{
+       struct nlattr **tb = info->attrs;
+       int i;
+
+       if (!xfrm_sym)
+               return 0;
+       if (!data->has_flow_hash) {
+               NL_SET_ERR_MSG_ATTR(info->extack, tb[ETHTOOL_A_RSS_INPUT_XFRM],
+                                   "hash field config not reported");
+               return -EINVAL;
+       }
+
+       for (i = 1; i < __ETHTOOL_A_FLOW_CNT; i++)
+               if (data->flow_hash[i] >= 0 &&
+                   !ethtool_rxfh_config_is_sym(data->flow_hash[i])) {
+                       NL_SET_ERR_MSG_ATTR(info->extack,
+                                           tb[ETHTOOL_A_RSS_INPUT_XFRM],
+                                           "hash field config is not symmetric");
+                       return -EINVAL;
+               }
+
+       return 0;
+}
+
 static void
 rss_set_ctx_update(struct ethtool_rxfh_context *ctx, struct nlattr **tb,
                   struct rss_reply_data *data, struct ethtool_rxfh_param *rxfh)
@@ -627,16 +662,18 @@ rss_set_ctx_update(struct ethtool_rxfh_context *ctx, struct nlattr **tb,
        }
        if (rxfh->hfunc != ETH_RSS_HASH_NO_CHANGE)
                ctx->hfunc = rxfh->hfunc;
+       if (rxfh->input_xfrm != RXH_XFRM_NO_CHANGE)
+               ctx->input_xfrm = rxfh->input_xfrm;
 }
 
 static int
 ethnl_rss_set(struct ethnl_req_info *req_info, struct genl_info *info)
 {
+       bool indir_reset = false, indir_mod, xfrm_sym = false;
        struct rss_req_info *request = RSS_REQINFO(req_info);
        struct ethtool_rxfh_context *ctx = NULL;
        struct net_device *dev = req_info->dev;
        struct ethtool_rxfh_param rxfh = {};
-       bool indir_reset = false, indir_mod;
        struct nlattr **tb = info->attrs;
        struct rss_reply_data data = {};
        const struct ethtool_ops *ops;
@@ -666,7 +703,20 @@ ethnl_rss_set(struct ethnl_req_info *req_info, struct genl_info *info)
        if (ret)
                goto exit_free_indir;
 
-       rxfh.input_xfrm = RXH_XFRM_NO_CHANGE;
+       rxfh.input_xfrm = data.input_xfrm;
+       ethnl_update_u8(&rxfh.input_xfrm, tb[ETHTOOL_A_RSS_INPUT_XFRM], &mod);
+       /* For drivers which don't support input_xfrm it will be set to 0xff
+        * in the RSS context info. In all other case input_xfrm != 0 means
+        * symmetric hashing is requested.
+        */
+       if (!request->rss_context || ops->rxfh_per_ctx_key)
+               xfrm_sym = !!rxfh.input_xfrm;
+       if (rxfh.input_xfrm == data.input_xfrm)
+               rxfh.input_xfrm = RXH_XFRM_NO_CHANGE;
+
+       ret = rss_check_rxfh_fields_sym(dev, info, &data, xfrm_sym);
+       if (ret)
+               goto exit_clean_data;
 
        mutex_lock(&dev->ethtool->rss_lock);
        if (request->rss_context) {