On 9/11/2024 7:55 AM, Taehee Yoo wrote:
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The tcp-data-split-thresh option configures the threshold value of
the tcp-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 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, like the tcp-data-split option, If tcp-data-split-thresh is set,
it affects UDP and TCP packets.
The tcp-data-split-thresh has a dependency, that is tcp-data-split
option. This threshold value can be get/set only when tcp-data-split
option is enabled.
Example:
# ethtool -G <interface name> tcp-data-split-thresh <value>
# ethtool -G enp14s0f0np0 tcp-data-split on tcp-data-split-thresh 256
# ethtool -g enp14s0f0np0
Ring parameters for enp14s0f0np0:
Pre-set maximums:
...
Current hardware settings:
...
TCP data split: on
TCP data split thresh: 256
The tcp-data-split is not enabled, the tcp-data-split-thresh will
not be used and can't be configured.
# ethtool -G enp14s0f0np0 tcp-data-split off
# ethtool -g enp14s0f0np0
Ring parameters for enp14s0f0np0:
Pre-set maximums:
...
Current hardware settings:
...
TCP data split: off
TCP data split thresh: n/a
The default/min/max values are not defined in the ethtool so the drivers
should define themself.
The 0 value means that all TCP and UDP packets' header and payload
will be split.
Users should consider the overhead due to this feature.
Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx>
---
v2:
- Patch added.
Documentation/networking/ethtool-netlink.rst | 31 +++++++++++--------
include/linux/ethtool.h | 2 ++
include/uapi/linux/ethtool_netlink.h | 1 +
net/ethtool/netlink.h | 2 +-
net/ethtool/rings.c | 32 +++++++++++++++++---
5 files changed, 51 insertions(+), 17 deletions(-)
<snip>
diff --git a/net/ethtool/rings.c b/net/ethtool/rings.c
index b7865a14fdf8..0b68ea316815 100644
--- a/net/ethtool/rings.c
+++ b/net/ethtool/rings.c
@@ -61,7 +61,8 @@ 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_TCP_DATA_SPLIT_THRESH */
}
static int rings_fill_reply(struct sk_buff *skb,
@@ -108,7 +109,10 @@ 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))) ||
+ (kr->tcp_data_split == ETHTOOL_TCP_DATA_SPLIT_ENABLED &&
+ (nla_put_u32(skb, ETHTOOL_A_RINGS_TCP_DATA_SPLIT_THRESH,
+ kr->tcp_data_split_thresh))))
return -EMSGSIZE;
return 0;
@@ -130,6 +134,7 @@ 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_TCP_DATA_SPLIT_THRESH] = { .type = NLA_U32 },
};
static int
@@ -155,6 +160,14 @@ ethnl_set_rings_validate(struct ethnl_req_info *req_info,
return -EOPNOTSUPP;
}
+ if (tb[ETHTOOL_A_RINGS_TCP_DATA_SPLIT_THRESH] &&
+ !(ops->supported_ring_params & ETHTOOL_RING_USE_TCP_DATA_SPLIT)) {
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ tb[ETHTOOL_A_RINGS_TCP_DATA_SPLIT_THRESH],
+ "setting TDS threshold is not supported");
Small nit.
Here you use "TDS threshold", but based on the TCP data split extack
message, it seems like it should be the following for consistency:
"setting TCP data split threshold 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,
@@ -196,9 +209,9 @@ ethnl_set_rings(struct ethnl_req_info *req_info, struct genl_info *info)
struct kernel_ethtool_ringparam kernel_ringparam = {};
struct ethtool_ringparam ringparam = {};
struct net_device *dev = req_info->dev;
+ bool mod = false, thresh_mod = false;
struct nlattr **tb = info->attrs;
const struct nlattr *err_attr;
- bool mod = false;
int ret;
dev->ethtool_ops->get_ringparam(dev, &ringparam,
@@ -222,9 +235,20 @@ 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);
- if (!mod)
+ ethnl_update_u32(&kernel_ringparam.tcp_data_split_thresh,
+ tb[ETHTOOL_A_RINGS_TCP_DATA_SPLIT_THRESH],
+ &thresh_mod);
+ if (!mod && !thresh_mod)
return 0;
+ if (kernel_ringparam.tcp_data_split == ETHTOOL_TCP_DATA_SPLIT_DISABLED &&
+ thresh_mod) {
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ tb[ETHTOOL_A_RINGS_TCP_DATA_SPLIT_THRESH],
+ "tcp-data-split-thresh can not be updated while tcp-data-split is disabled");
+ return -EINVAL;
I think using the userspace command line argument names makes sense for
this extack message.
