net: ethtool: add support for configuring hds-thresh

The hds-thresh option configures the threshold value of
the header-data-split.
If a received packet size is larger than this threshold value, a packet
will be split into header and payload.
The header indicates TCP and UDP header, but it depends on driver spec.
The bnxt_en driver supports HDS(Header-Data-Split) configuration at
FW level, affecting TCP and UDP too.
So, If hds-thresh is set, it affects UDP and TCP packets.

Example:
   # ethtool -G <interface name> hds-thresh <value>

   # ethtool -G enp14s0f0np0 tcp-data-split on hds-thresh 256
   # ethtool -g enp14s0f0np0
   Ring parameters for enp14s0f0np0:
   Pre-set maximums:
   ...
   HDS thresh:  1023
   Current hardware settings:
   ...
   TCP data split:         on
   HDS thresh:  256

The default/min/max values are not defined in the ethtool so the drivers
should define themself.
The 0 value means that all TCP/UDP packets' header and payload
will be split.

Tested-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://patch.msgid.link/20250114142852.3364986-3-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 60f85fbf41561c3332bf9e63b919a1ec014921bf..66be040130481900a6d26c160212e9f519e2885a 100644 (file)
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -332,6 +332,12 @@ attribute-sets:
       -
         name: tx-push-buf-len-max
         type: u32
+      -
+        name: hds-thresh
+        type: u32
+      -
+        name: hds-thresh-max
+        type: u32
 
   -
     name: mm-stat
@@ -1777,6 +1783,8 @@ operations:
             - rx-push
             - tx-push-buf-len
             - tx-push-buf-len-max
+            - hds-thresh
+            - hds-thresh-max
       dump: *ring-get-op
     -
       name: rings-set

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index da846f1d998ecbe227f5bf6029dffbae4e6e4844..f70c0249860cd5f2555bf163e4e7f3ed6e7aea0a 100644 (file)
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -899,6 +899,10 @@ Kernel response contents:
   ``ETHTOOL_A_RINGS_RX_PUSH``               u8      flag of RX Push mode
   ``ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN``       u32     size of TX push buffer
   ``ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN_MAX``   u32     max size of TX push buffer
+  ``ETHTOOL_A_RINGS_HDS_THRESH``            u32     threshold of
+                                                    header / data split
+  ``ETHTOOL_A_RINGS_HDS_THRESH_MAX``        u32     max threshold of
+                                                    header / data split
   =======================================   ======  ===========================
 
 ``ETHTOOL_A_RINGS_TCP_DATA_SPLIT`` indicates whether the device is usable with
@@ -941,10 +945,12 @@ Request contents:
   ``ETHTOOL_A_RINGS_RX_JUMBO``          u32     size of RX jumbo ring
   ``ETHTOOL_A_RINGS_TX``                u32     size of TX ring
   ``ETHTOOL_A_RINGS_RX_BUF_LEN``        u32     size of buffers on the ring
+  ``ETHTOOL_A_RINGS_TCP_DATA_SPLIT``    u8      TCP header / data split
   ``ETHTOOL_A_RINGS_CQE_SIZE``          u32     Size of TX/RX CQE
   ``ETHTOOL_A_RINGS_TX_PUSH``           u8      flag of TX Push mode
   ``ETHTOOL_A_RINGS_RX_PUSH``           u8      flag of RX Push mode
   ``ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN``   u32     size of TX push buffer
+  ``ETHTOOL_A_RINGS_HDS_THRESH``        u32     threshold of header / data split
   ====================================  ======  ===========================
 
 Kernel checks that requested ring sizes do not exceed limits reported by
@@ -961,6 +967,10 @@ A bigger CQE can have more receive buffer pointers, and in turn the NIC can
 transfer a bigger frame from wire. Based on the NIC hardware, the overall
 completion queue size can be adjusted in the driver if CQE size is modified.
 
+``ETHTOOL_A_RINGS_HDS_THRESH`` specifies the threshold value of
+header / data split feature. If a received packet size is larger than this
+threshold value, header and data will be split.
+
 CHANNELS_GET
 ============
 

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index d79bd201c1c89e73431d070bd5c9aebe123f7886..e4136b0df89236de03174c8d1197bb2f076b20dd 100644 (file)
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -78,6 +78,9 @@ enum {
  * @cqe_size: Size of TX/RX completion queue event
  * @tx_push_buf_len: Size of TX push buffer
  * @tx_push_buf_max_len: Maximum allowed size of TX push buffer
+ * @hds_thresh: Packet size threshold for header data split (HDS)
+ * @hds_thresh_max: Maximum supported setting for @hds_threshold
+ *
  */
 struct kernel_ethtool_ringparam {
        u32     rx_buf_len;
@@ -87,6 +90,8 @@ struct kernel_ethtool_ringparam {
        u32     cqe_size;
        u32     tx_push_buf_len;
        u32     tx_push_buf_max_len;
+       u32     hds_thresh;
+       u32     hds_thresh_max;
 };
 
 /**
@@ -97,6 +102,7 @@ struct kernel_ethtool_ringparam {
  * @ETHTOOL_RING_USE_RX_PUSH: capture for setting rx_push
  * @ETHTOOL_RING_USE_TX_PUSH_BUF_LEN: capture for setting tx_push_buf_len
  * @ETHTOOL_RING_USE_TCP_DATA_SPLIT: capture for setting tcp_data_split
+ * @ETHTOOL_RING_USE_HDS_THRS: capture for setting header-data-split-thresh
  */
 enum ethtool_supported_ring_param {
        ETHTOOL_RING_USE_RX_BUF_LEN             = BIT(0),
@@ -105,6 +111,7 @@ enum ethtool_supported_ring_param {
        ETHTOOL_RING_USE_RX_PUSH                = BIT(3),
        ETHTOOL_RING_USE_TX_PUSH_BUF_LEN        = BIT(4),
        ETHTOOL_RING_USE_TCP_DATA_SPLIT         = BIT(5),
+       ETHTOOL_RING_USE_HDS_THRS               = BIT(6),
 };
 
 #define __ETH_RSS_HASH_BIT(bit)        ((u32)1 << (bit))
@@ -1157,6 +1164,7 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
  * @rss_ctx:           XArray of custom RSS contexts
  * @rss_lock:          Protects entries in @rss_ctx.  May be taken from
  *                     within RTNL.
+ * @hds_thresh:                HDS Threshold value.
  * @hds_config:                HDS value from userspace.
  * @wol_enabled:       Wake-on-LAN is enabled
  * @module_fw_flash_in_progress: Module firmware flashing is in progress.
@@ -1164,6 +1172,7 @@ int ethtool_virtdev_set_link_ksettings(struct net_device *dev,
 struct ethtool_netdev_state {
        struct xarray           rss_ctx;
        struct mutex            rss_lock;
+       u32                     hds_thresh;
        u8                      hds_config;
        unsigned                wol_enabled:1;
        unsigned                module_fw_flash_in_progress:1;

diff --git a/include/uapi/linux/ethtool_netlink_generated.h b/include/uapi/linux/ethtool_netlink_generated.h
index 43993a2d68e56d9c3e71fc26005c7cbcf8248e9e..2e17ff348f89e304d5888cf381b428afcf4f6f1a 100644 (file)
--- a/include/uapi/linux/ethtool_netlink_generated.h
+++ b/include/uapi/linux/ethtool_netlink_generated.h
@@ -155,6 +155,8 @@ enum {
        ETHTOOL_A_RINGS_RX_PUSH,
        ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN,
        ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN_MAX,
+       ETHTOOL_A_RINGS_HDS_THRESH,
+       ETHTOOL_A_RINGS_HDS_THRESH_MAX,
 
        __ETHTOOL_A_RINGS_CNT,
        ETHTOOL_A_RINGS_MAX = (__ETHTOOL_A_RINGS_CNT - 1)

diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index 1ce0a3de14304956dd9fc7e176c0bc30247ba158..ff69ca0715dea61c4ac3513d37d9b7e1f12136f3 100644 (file)
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -456,7 +456,7 @@ extern const struct nla_policy ethnl_features_set_policy[ETHTOOL_A_FEATURES_WANT
 extern const struct nla_policy ethnl_privflags_get_policy[ETHTOOL_A_PRIVFLAGS_HEADER + 1];
 extern const struct nla_policy ethnl_privflags_set_policy[ETHTOOL_A_PRIVFLAGS_FLAGS + 1];
 extern const struct nla_policy ethnl_rings_get_policy[ETHTOOL_A_RINGS_HEADER + 1];
-extern const struct nla_policy ethnl_rings_set_policy[ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN_MAX + 1];
+extern const struct nla_policy ethnl_rings_set_policy[ETHTOOL_A_RINGS_HDS_THRESH_MAX + 1];
 extern const struct nla_policy ethnl_channels_get_policy[ETHTOOL_A_CHANNELS_HEADER + 1];
 extern const struct nla_policy ethnl_channels_set_policy[ETHTOOL_A_CHANNELS_COMBINED_COUNT + 1];
 extern const struct nla_policy ethnl_coalesce_get_policy[ETHTOOL_A_COALESCE_HEADER + 1];

diff --git a/net/ethtool/rings.c b/net/ethtool/rings.c
index b2a2586b241f67c14d93c48843a3cbce59c73260..a381913a19f0b83bd3bbd5c10f9654ff8a1b4924 100644 (file)
--- a/net/ethtool/rings.c
+++ b/net/ethtool/rings.c
@@ -61,7 +61,9 @@ static int rings_reply_size(const struct ethnl_req_info *req_base,
               nla_total_size(sizeof(u8))  +    /* _RINGS_TX_PUSH */
               nla_total_size(sizeof(u8))) +    /* _RINGS_RX_PUSH */
               nla_total_size(sizeof(u32)) +    /* _RINGS_TX_PUSH_BUF_LEN */
-              nla_total_size(sizeof(u32));     /* _RINGS_TX_PUSH_BUF_LEN_MAX */
+              nla_total_size(sizeof(u32)) +    /* _RINGS_TX_PUSH_BUF_LEN_MAX */
+              nla_total_size(sizeof(u32)) +    /* _RINGS_HDS_THRESH */
+              nla_total_size(sizeof(u32));     /* _RINGS_HDS_THRESH_MAX*/
 }
 
 static int rings_fill_reply(struct sk_buff *skb,
@@ -108,7 +110,12 @@ static int rings_fill_reply(struct sk_buff *skb,
             (nla_put_u32(skb, ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN_MAX,
                          kr->tx_push_buf_max_len) ||
              nla_put_u32(skb, ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN,
-                         kr->tx_push_buf_len))))
+                         kr->tx_push_buf_len))) ||
+           ((supported_ring_params & ETHTOOL_RING_USE_HDS_THRS) &&
+            (nla_put_u32(skb, ETHTOOL_A_RINGS_HDS_THRESH,
+                         kr->hds_thresh) ||
+             nla_put_u32(skb, ETHTOOL_A_RINGS_HDS_THRESH_MAX,
+                         kr->hds_thresh_max))))
                return -EMSGSIZE;
 
        return 0;
@@ -130,6 +137,7 @@ const struct nla_policy ethnl_rings_set_policy[] = {
        [ETHTOOL_A_RINGS_TX_PUSH]               = NLA_POLICY_MAX(NLA_U8, 1),
        [ETHTOOL_A_RINGS_RX_PUSH]               = NLA_POLICY_MAX(NLA_U8, 1),
        [ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN]       = { .type = NLA_U32 },
+       [ETHTOOL_A_RINGS_HDS_THRESH]            = { .type = NLA_U32 },
 };
 
 static int
@@ -155,6 +163,14 @@ ethnl_set_rings_validate(struct ethnl_req_info *req_info,
                return -EOPNOTSUPP;
        }
 
+       if (tb[ETHTOOL_A_RINGS_HDS_THRESH] &&
+           !(ops->supported_ring_params & ETHTOOL_RING_USE_HDS_THRS)) {
+               NL_SET_ERR_MSG_ATTR(info->extack,
+                                   tb[ETHTOOL_A_RINGS_HDS_THRESH],
+                                   "setting hds-thresh is not supported");
+               return -EOPNOTSUPP;
+       }
+
        if (tb[ETHTOOL_A_RINGS_CQE_SIZE] &&
            !(ops->supported_ring_params & ETHTOOL_RING_USE_CQE_SIZE)) {
                NL_SET_ERR_MSG_ATTR(info->extack,
@@ -223,6 +239,8 @@ ethnl_set_rings(struct ethnl_req_info *req_info, struct genl_info *info)
                        tb[ETHTOOL_A_RINGS_RX_PUSH], &mod);
        ethnl_update_u32(&kernel_ringparam.tx_push_buf_len,
                         tb[ETHTOOL_A_RINGS_TX_PUSH_BUF_LEN], &mod);
+       ethnl_update_u32(&kernel_ringparam.hds_thresh,
+                        tb[ETHTOOL_A_RINGS_HDS_THRESH], &mod);
        if (!mod)
                return 0;
 
@@ -243,6 +261,8 @@ ethnl_set_rings(struct ethnl_req_info *req_info, struct genl_info *info)
                err_attr = tb[ETHTOOL_A_RINGS_RX_JUMBO];
        else if (ringparam.tx_pending > ringparam.tx_max_pending)
                err_attr = tb[ETHTOOL_A_RINGS_TX];
+       else if (kernel_ringparam.hds_thresh > kernel_ringparam.hds_thresh_max)
+               err_attr = tb[ETHTOOL_A_RINGS_HDS_THRESH];
        else
                err_attr = NULL;
        if (err_attr) {
@@ -261,8 +281,10 @@ ethnl_set_rings(struct ethnl_req_info *req_info, struct genl_info *info)
 
        ret = dev->ethtool_ops->set_ringparam(dev, &ringparam,
                                              &kernel_ringparam, info->extack);
-       if (!ret)
+       if (!ret) {
                dev->ethtool->hds_config = kernel_ringparam.tcp_data_split;
+               dev->ethtool->hds_thresh = kernel_ringparam.hds_thresh;
+       }
 
        return ret < 0 ? ret : 1;
 }