From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Subject: Re: [PATCH 1/2] doc: clarify L3 Tx checksum prerequisite
Date: Fri, 5 Oct 2018 07:06:15 +0000
Message-ID: <20181005070605.GA6990@jerin>
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Cc: John McNamara <john.mcnamara@intel.com>, Marko Kovacevic
 <marko.kovacevic@intel.com>, "dev@dpdk.org" <dev@dpdk.org>,
 "thomas@monjalon.net" <thomas@monjalon.net>, "ferruh.yigit@intel.com"
 <ferruh.yigit@intel.com>, "olivier.matz@6wind.com" <olivier.matz@6wind.com>,
 "stable@dpdk.org" <stable@dpdk.org>
To: Andrew Rybchenko <arybchenko@solarflare.com>
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-----Original Message-----
> Date: Fri, 5 Oct 2018 09:44:43 +0300
> From: Andrew Rybchenko <arybchenko@solarflare.com>
> To: Jerin Jacob <jerin.jacob@caviumnetworks.com>, John McNamara
>  <john.mcnamara@intel.com>, Marko Kovacevic <marko.kovacevic@intel.com>
> CC: dev@dpdk.org, thomas@monjalon.net, ferruh.yigit@intel.com,
>  olivier.matz@6wind.com, stable@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 1/2] doc: clarify L3 Tx checksum prerequis=
ite
> User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
>  Thunderbird/60.0
>=20
> External Email
>=20
> On 10/5/18 7:46 AM, Jerin Jacob wrote:
>=20
> Based on PKT_TX_IP_CKSUM definition the user needs
> to fill l2_len and l3_len mbuf fields before issuing
> HW Tx checksum request.
>=20
> Fixes: dad1ec72a377 ("doc: document NIC features")
> Cc: stable@dpdk.org<mailto:stable@dpdk.org>
>=20
> Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com><mailto:jerin.=
jacob@caviumnetworks.com>
>=20
> Acked-by: Andrew Rybchenko <arybchenko@solarflare.com><mailto:arybchenko@=
solarflare.com>
>=20
> plus one question below
>=20
>=20
> ---
>=20
> See PKT_TX_IP_CKSUM at
> https://git.dpdk.org/dpdk/tree/lib/librte_mbuf/rte_mbuf.h#n283
>=20
> ---
> doc/guides/nics/features.rst | 1 +
> 1 file changed, 1 insertion(+)
>=20
> diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
> index b085bda86..e726a6bb8 100644
> --- a/doc/guides/nics/features.rst
> +++ b/doc/guides/nics/features.rst
> @@ -562,6 +562,7 @@ Supports L3 checksum offload.
> * **[uses]     rte_eth_txconf,rte_eth_txmode**: ``offloads:DEV_TX_OFFLOAD=
_IPV4_CKSUM``.
> * **[uses]     mbuf**: ``mbuf.ol_flags:PKT_TX_IP_CKSUM``,
>   ``mbuf.ol_flags:PKT_TX_IPV4`` | ``PKT_TX_IPV6``.
>=20
> Shouldn't PKT_TX_IPV6 be removed above since L3 checksum offload is not a=
pplicable for IPv6?

I think, some HW(What I am aware of) need to provide following[1] info in T=
x
descriptors for checksum. IPV6 may be used by the HW in case, packet is
tunneled to see where inner start etc(thought it has outer_l3_len)(not stri=
ctly from outer checksum
perspective)

[1]
- IPV4
- IPV4 with csum
- IPV6


>=20
>=20
>=20
> +* **[uses]     mbuf**: ``mbuf.l2_len``, ``mbuf.l3_len``.
> * **[provides] mbuf**: ``mbuf.ol_flags:PKT_RX_IP_CKSUM_UNKNOWN`` |
>   ``PKT_RX_IP_CKSUM_BAD`` | ``PKT_RX_IP_CKSUM_GOOD`` |
>   ``PKT_RX_IP_CKSUM_NONE``.
>=20
>=20