Re: [dpdk-dev] [PATCH v2 1/4] ethdev: add Rx offload outer UDP checksum definition

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

-----Original Message-----
> Date: Wed, 3 Oct 2018 10:34:52 +0300
> From: Andrew Rybchenko <arybchenko@solarflare.com>
> To: Jerin Jacob <jerin.jacob@caviumnetworks.com>, Wenzhuo Lu
>  <wenzhuo.lu@intel.com>, Jingjing Wu <jingjing.wu@intel.com>, Bernard
>  Iremonger <bernard.iremonger@intel.com>, John McNamara
>  <john.mcnamara@intel.com>, Marko Kovacevic <marko.kovacevic@intel.com>,
>  Thomas Monjalon <thomas@monjalon.net>, Ferruh Yigit
>  <ferruh.yigit@intel.com>, Olivier Matz <olivier.matz@6wind.com>
> CC: dev@dpdk.org, shahafs@mellanox.com, "Ananyev, Konstantin"
>  <konstantin.ananyev@intel.com>
> Subject: Re: [dpdk-dev] [PATCH v2 1/4] ethdev: add Rx offload outer UDP
>  checksum definition
> User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
>  Thunderbird/60.0
> 
> 
> On 10/2/18 10:24 PM, Jerin Jacob wrote:
> 
> Introduced DEV_RX_OFFLOAD_OUTER_UDP_CKSUM Rx offload flag and
> PKT_RX_EL4_CKSUM_BAD mbuf ol_flags to detect outer UDP checksum
> failure.
> 
> - To use hardware Rx outer UDP checksum offload, the user needs to
> configure DEV_RX_OFFLOAD_OUTER_UDP_CKSUM offload flags in slowpath.
> 
> - Driver updates the PKT_RX_EL4_CKSUM_BAD mbuf ol_flag on checksum failure
> similar to the outer L3 PKT_RX_EIP_CKSUM_BAD flag.
> 
> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com><mailto:jerin.jacob@caviumnetworks.com>
> 
> 1. I'm not sure that it is OK that mbuf and ethdev changes go in one patch.
>    It seems typically mbuf changes go separately and mbuf changes should
>    be applied to main dpdk repo.


I don't have strong opinion on this. If there are no other objection, I
will split the patch further as mbuf and ethdev as you pointed out.

> 
> 2. I'd like to see thought why single bit is used for outer L2 checksum when
>    2 bits (UNKNOWN, BAD, GOOD, NONE) are used for PKT_RX_L4_CKSUM.
>    May be it is OK, but it would be useful to state explicitly why it is decided
>    to go this way.

I am following the scheme similar to OUTER IP checksum where we have only
one bit filed(PKT_RX_EIP_CKSUM_BAD). I will mention in the git commit.


> 
> 3. PKT_RX_L4_CKSUM_MASK description says nothing if it is inner or outer.
>    May be it is not directly related to changeset, but I think it would be really
>    useful to clarify it.

I will update the comment.

> 
> 
> Plus one nit below.
> 
> 
> 
> ---
> 
> v2:
> - Removed DEV_RX_OFFLOAD_OUTER_TCP_CKSUM and DEV_RX_OFFLOAD_OUTER_SCTP_CKSUM
> as there is no realworld use case for it.
> See: http://patches.dpdk.org/patch/44692/
> 
> This patch series is depended on http://patches.dpdk.org/patch/45840/
> 
> --
> app/test-pmd/config.c          | 9 +++++++++
> doc/guides/nics/features.rst   | 3 +++
> lib/librte_ethdev/rte_ethdev.c | 1 +
> lib/librte_ethdev/rte_ethdev.h | 1 +
> lib/librte_mbuf/rte_mbuf.c     | 2 ++
> lib/librte_mbuf/rte_mbuf.h     | 3 +++
> 6 files changed, 19 insertions(+)
> 
> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
> index 1adc9b94b..d53c527e5 100644
> --- a/app/test-pmd/config.c
> +++ b/app/test-pmd/config.c
> @@ -594,6 +594,15 @@ port_offload_cap_display(portid_t port_id)
>                        printf("off\n");
>        }
> 
> +       if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_OUTER_UDP_CKSUM) {
> +               printf("RX Outer UDP checksum:               ");
> +               if (ports[port_id].dev_conf.rxmode.offloads &
> +                   DEV_RX_OFFLOAD_OUTER_UDP_CKSUM)
> +                       printf("on\n");
> +               else
> +                       printf("off\n");
> +       }
> +
>        if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_TCP_LRO) {
>                printf("Large receive offload:         ");
>                if (ports[port_id].dev_conf.rxmode.offloads &
> diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
> index d42489b6d..2c2959e0b 100644
> --- a/doc/guides/nics/features.rst
> +++ b/doc/guides/nics/features.rst
> @@ -639,6 +639,9 @@ Inner L4 checksum
> 
> Supports inner packet L4 checksum.
> 
> +* **[uses]     rte_eth_rxconf,rte_eth_rxmode**: ``offloads:DEV_RX_OFFLOAD_OUTER_UDP_CKSUM``.
> +* **[provides] mbuf**: ``mbuf.ol_flags:PKT_RX_EL4_CKSUM_BAD``.
> +* **[provides] rte_eth_dev_info**: ``rx_offload_capa,rx_queue_offload_capa:DEV_RX_OFFLOAD_OUTER_UDP_CKSUM``,
> 
> 
> One more empty line should be added here to have two empty lines between features.

OK.

Thanks for the review.

> 
> Andrew.