diff options
| author | Ahmed Zaki <ahmed.zaki@intel.com> | 2023-12-12 17:33:16 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-12-13 22:07:16 -0800 |
| commit | 13e59344fb9d3c9d3acd138ae320b5b67b658694 (patch) | |
| tree | 3f7a839e6f1077c04088aa3cdafa18e659357821 /include/uapi/linux/ethtool.h | |
| parent | dcd8dbf9e734eb334113ea43186c1c26e9f497bb (diff) | |
net: ethtool: add support for symmetric-xor RSS hash
Symmetric RSS hash functions are beneficial in applications that monitor
both Tx and Rx packets of the same flow (IDS, software firewalls, ..etc).
Getting all traffic of the same flow on the same RX queue results in
higher CPU cache efficiency.
A NIC that supports "symmetric-xor" can achieve this RSS hash symmetry
by XORing the source and destination fields and pass the values to the
RSS hash algorithm.
The user may request RSS hash symmetry for a specific algorithm, via:
# ethtool -X eth0 hfunc <hash_alg> symmetric-xor
or turn symmetry off (asymmetric) by:
# ethtool -X eth0 hfunc <hash_alg>
The specific fields for each flow type should then be specified as usual
via:
# ethtool -N|-U eth0 rx-flow-hash <flow_type> s|d|f|n
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Link: https://lore.kernel.org/r/20231213003321.605376-4-ahmed.zaki@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/uapi/linux/ethtool.h')
| -rw-r--r-- | include/uapi/linux/ethtool.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h index f7fba0dc87e5..0787d561ace0 100644 --- a/include/uapi/linux/ethtool.h +++ b/include/uapi/linux/ethtool.h @@ -1266,6 +1266,8 @@ struct ethtool_rxfh_indir { * hardware hash key. * @hfunc: Defines the current RSS hash function used by HW (or to be set to). * Valid values are one of the %ETH_RSS_HASH_*. + * @input_xfrm: Defines how the input data is transformed. Valid values are one + * of %RXH_XFRM_*. * @rsvd8: Reserved for future use; see the note on reserved space. * @rsvd32: Reserved for future use; see the note on reserved space. * @rss_config: RX ring/queue index for each hash value i.e., indirection table @@ -1285,7 +1287,8 @@ struct ethtool_rxfh { __u32 indir_size; __u32 key_size; __u8 hfunc; - __u8 rsvd8[3]; + __u8 input_xfrm; + __u8 rsvd8[2]; __u32 rsvd32; __u32 rss_config[]; }; @@ -1992,6 +1995,14 @@ static inline int ethtool_validate_duplex(__u8 duplex) #define WOL_MODE_COUNT 8 +/* RSS hash function data + * XOR the corresponding source and destination fields of each specified + * protocol. Both copies of the XOR'ed fields are fed into the RSS and RXHASH + * calculation. Note that this XORing reduces the input set entropy and could + * be exploited to reduce the RSS queue spread. + */ +#define RXH_XFRM_SYM_XOR (1 << 0) + /* L2-L4 network traffic flow types */ #define TCP_V4_FLOW 0x01 /* hash or spec (tcp_ip4_spec) */ #define UDP_V4_FLOW 0x02 /* hash or spec (udp_ip4_spec) */ |