Re: [dpdk-dev] [PATCH v5] ethdev: add IPv4 and L4 checksum RSS offload types

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Zhang, AlvinX <alvinx.zhang@intel.com>
> Sent: Wednesday, August 18, 2021 10:32 AM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Guo, Junfeng
> <junfeng.guo@intel.com>
> Cc: dev@dpdk.org; Zhang, AlvinX <alvinx.zhang@intel.com>; Ajit Khaparde
> <ajit.khaparde@broadcom.com>; Singh, Aman Deep
> <aman.deep.singh@intel.com>
> Subject: [PATCH v5] ethdev: add IPv4 and L4 checksum RSS offload types
> 
> This patch defines new RSS offload types for IPv4 and
> L4(TCP/UDP/SCTP) checksum, which are required when users want to
> distribute packets based on the IPv4 or L4 checksum field.
> 
> For example "flow create 0 ingress pattern eth / ipv4 / end actions rss types
> ipv4-chksum end queues end / end", this flow causes all matching packets to be
> distributed to queues on basis of IPv4 checksum.
> 
> Signed-off-by: Alvin Zhang <alvinx.zhang@intel.com>
> Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
> Acked-by: Aman Deep Singh <aman.deep.singh@intel.com>
> ---
> 
> v5: Add release note and code commands.
> ---
>  app/test-pmd/cmdline.c                 |  4 ++-
>  app/test-pmd/config.c                  |  2 ++
>  doc/guides/rel_notes/release_21_11.rst | 61
> ++++++++++++++++++++++++++++++++++
>  lib/ethdev/rte_ethdev.h                | 23 +++++++++++++
>  4 files changed, 89 insertions(+), 1 deletion(-)  create mode 100644
> doc/guides/rel_notes/release_21_11.rst
> 
> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c index
> 82253bc..656a311 100644
> --- a/app/test-pmd/cmdline.c
> +++ b/app/test-pmd/cmdline.c
> @@ -2252,6 +2252,8 @@ struct cmd_config_rss {
>  		rss_conf.rss_hf = ETH_RSS_ECPRI;
>  	else if (!strcmp(res->value, "mpls"))
>  		rss_conf.rss_hf = ETH_RSS_MPLS;
> +	else if (!strcmp(res->value, "ipv4-chksum"))
> +		rss_conf.rss_hf = ETH_RSS_IPV4_CHKSUM;
>  	else if (!strcmp(res->value, "none"))
>  		rss_conf.rss_hf = 0;
>  	else if (!strcmp(res->value, "level-default")) { @@ -2323,7 +2325,7 @@
> struct cmd_config_rss {
>  	.help_str = "port config all rss "
>  		"all|default|eth|vlan|ip|tcp|udp|sctp|ether|port|vxlan|geneve|"
> 
> 	"nvgre|vxlan-gpe|l2tpv3|esp|ah|pfcp|ecpri|mpls|none|level-default|"
> -		"level-outer|level-inner|<flowtype_id>",
> +		"level-outer|level-inner|ipv4-chksum|<flowtype_id>",
>  	.tokens = {
>  		(void *)&cmd_config_rss_port,
>  		(void *)&cmd_config_rss_keyword,
> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c index
> 31d8ba1..ece78f2 100644
> --- a/app/test-pmd/config.c
> +++ b/app/test-pmd/config.c
> @@ -140,6 +140,8 @@
>  	{ "gtpu", ETH_RSS_GTPU },
>  	{ "ecpri", ETH_RSS_ECPRI },
>  	{ "mpls", ETH_RSS_MPLS },
> +	{ "ipv4-chksum", ETH_RSS_IPV4_CHKSUM },
> +	{ "l4-chksum", ETH_RSS_L4_CHKSUM },
>  	{ NULL, 0 },
>  };
> 
> diff --git a/doc/guides/rel_notes/release_21_11.rst
> b/doc/guides/rel_notes/release_21_11.rst
> new file mode 100644
> index 0000000..1017550
> --- /dev/null
> +++ b/doc/guides/rel_notes/release_21_11.rst
> @@ -0,0 +1,61 @@
> +.. SPDX-License-Identifier: BSD-3-Clause
> +   Copyright 2021 The DPDK contributors
> +
> +.. include:: <isonum.txt>
> +
> +DPDK Release 21.11
> +==================
> +
> +.. **Read this first.**
> +
> +   The text in the sections below explains how to update the release notes.
> +
> +   Use proper spelling, capitalization and punctuation in all sections.
> +
> +   Variable and config names should be quoted as fixed width text:
> +   ``LIKE_THIS``.
> +
> +   Build the docs and view the output file to ensure the changes are correct::
> +
> +      make doc-guides-html
> +      xdg-open build/doc/html/guides/rel_notes/release_21_11.html
> +
> +
> +New Features
> +------------
> +
> +.. This section should contain new features added in this release.
> +   Sample format:
> +
> +   * **Add a title in the past tense with a full stop.**
> +
> +     Add a short 1-2 sentence description in the past tense.
> +     The description should be enough to allow someone scanning
> +     the release notes to understand the new feature.
> +
> +     If the feature adds a lot of sub-features you can use a bullet list
> +     like this:
> +
> +     * Added feature foo to do something.
> +     * Enhanced feature bar to do something else.
> +
> +     Refer to the previous release notes for examples.
> +
> +     Suggested order in release notes items:
> +     * Core libs (EAL, mempool, ring, mbuf, buses)
> +     * Device abstraction libs and PMDs (ordered alphabetically by vendor
> name)
> +       - ethdev (lib, PMDs)
> +       - cryptodev (lib, PMDs)
> +       - eventdev (lib, PMDs)
> +       - etc
> +     * Other libs
> +     * Apps, Examples, Tools (if significant)
> +
> +     This section is a comment. Do not overwrite or remove it.
> +     Also, make sure to start the actual text at the margin.
> +     =======================================================
> +
> +* **Add new RSS offload types for IPv4/L4 checksum in RSS flow.**
> +
> +     Add macros ETH_RSS_IPV4_CHKSUM and ETH_RSS_L4_CHKSUM, now
> IPv4 and
> +     TCP/UDP/SCTP header checksum field can be used as input set for RSS.
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h index
> d2b27c3..9a59e7b 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -537,6 +537,29 @@ struct rte_eth_rss_conf {
>  #define ETH_RSS_PPPOE		   (1ULL << 31)
>  #define ETH_RSS_ECPRI		   (1ULL << 32)
>  #define ETH_RSS_MPLS		   (1ULL << 33)
> +#define ETH_RSS_IPV4_CHKSUM	   (1ULL << 34)
> +
> +/**
> + * The ETH_RSS_L4_CHKSUM generally refers to a type of checksum field
> +for
> + * any L4 header, such as TCP, UDP and SCTP. It is similar to
> +ETH_RSS_PORT,
> + * it does not specify the type of L4 header.
> + * We use this macro to replace below macro for constricting the use of
> +RSS
> + * offload bits:
> + * ETH_RSS_IPV4_TCP_CHKSUM
> + * ETH_RSS_IPV4_UDP_CHKSUM
> + * ETH_RSS_IPV4_SCTP_CHKSUM
> + * ETH_RSS_IPV6_TCP_CHKSUM
> + * ETH_RSS_IPV6_UDP_CHKSUM
> + * ETH_RSS_IPV6_SCTP_CHKSUM
> + *
> + * Then how to use this macro? We can use it in RSS flow where the
> +pattern
> + * type will specify the L4 header type, for example "flow create 0
> +ingress \
> + * pattern eth / ipv4 / tcp / end actions rss types l4-chksum  end
> +queues end \
> + * / end"
> + * For UDP, the checksum is not required, if the checksum is 0, it will

Do you mean
For UDP , the checksum is optional, if the checksum is not used, it will...?

> +be
> + * treated as a regular checksum with value equal to 0.
> + */

Or maybe just reword to below
For the case that checksum is not used in a UDP header, it take the reserved value 0 as input for the hash function.

> +#define ETH_RSS_L4_CHKSUM	   (1ULL << 35)
> 
>  /*
>   * We use the following macros to combine with above ETH_RSS_* for
> --
> 1.8.3.1