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From: Stephen Hemminger <stephen@networkplumber.org>
To: Olivier Matz <olivier.matz@6wind.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [RFC 00/16] enhance checksum offload API
Date: Wed, 21 Jan 2015 17:01:49 -0800	[thread overview]
Message-ID: <20150121170149.157da6ed@urahara> (raw)
In-Reply-To: <1421883395-27235-1-git-send-email-olivier.matz@6wind.com>

On Thu, 22 Jan 2015 00:36:19 +0100
Olivier Matz <olivier.matz@6wind.com> wrote:

> The goal of this series is to clarify and simplify the mbuf offload API.
> Several issues are solved:
> 
> - simplify the definitions of PKT_TX_IP_CKSUM and PKT_TX_IPV4, each
>   flag has now only one meaning. No impact on the code.
> 
> - add a feature flag for OUTER_IP_CHECKSUM (from Jijiang's patches)
> 
> - remove the PKT_TX_UDP_TUNNEL_PKT flag: it is useless from an API point
>   of view. It was added because i40e need this info for some reason. We
>   have 3 solutions:
> 
>   - remove the flag and adapt the driver to the API (the choice I made
>     for this series).
> 
>   - remove the flag and stop advertising OUTER_IP_CHECKSUM in i40e
> 
>   - keep this flag, penalizing performance of drivers that do not
>     require the flag. It would also mean that drivers won't support
>     outer IP checksum for all tunnel types, but only for the tunnel
>     types having a flag.
> 
> - a side effect of this API clarification is that there is only one
>   way for doing one operation. If the hardware has several ways to
>   do the same operation, a choice has to be made in the driver.
> 
> The patch adds new tunnel types to testpmd csum forward engine.
> Note: the i40e patches should be carefully checked by i40e experts.
> 
> [1] http://dpdk.org/ml/archives/dev/2015-January/011127.html

If you are doing this could you invert the meaning of the checksum
flags? Right now the flags are fine for Intel hardware but are useless
for devices that have less checksum support.

It would work better if instead of two states:
  * Checksum known bad    =>  PKT_RX_L4_CKSUM_BAD == 1
  * Checksum (maybe) good =>  PKT_RX_L4_CKSUM_BAD == 0
The bit was changed to only flag good checksum:
  * Checksum known good	    => PKT_RX_L4_CKSUM_GOOD == 1
  * Checksum status unknown => PKT_RX_L4_CKSUM_GOOD == 0

That way code code fallback to software checksum if hardware was incapable
of handling the packet. It does mean packets with bad checksums get checked
twice, but thats ok.

  parent reply	other threads:[~2015-01-22  1:01 UTC|newest]

Thread overview: 109+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-21 23:36 Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 01/16] mbuf: remove PKT_TX_IPV4_CSUM Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 02/16] mbuf: enhance the API documentation of offload flags Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 03/16] i40e: call i40e_txd_enable_checksum only for offloaded packets Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 04/16] i40e: remove the use of PKT_TX_UDP_TUNNEL_PKT flag Olivier Matz
2015-01-23  8:06   ` Liu, Jijiang
2015-01-23  8:47     ` Zhang, Helin
2015-01-23  9:06       ` Olivier MATZ
2015-01-21 23:36 ` [dpdk-dev] [RFC 05/16] mbuf: remove " Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 06/16] ethdev: add outer IP offload capability flag Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 07/16] i40e: advertise outer IPv4 checksum capability Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 08/16] testpmd: replace tx_checksum command by csum Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 09/16] testpmd: move csum_show in a function Olivier Matz
2015-01-23 11:03   ` Liu, Jijiang
2015-01-23 17:53     ` Olivier MATZ
2015-01-21 23:36 ` [dpdk-dev] [RFC 10/16] testpmd: add csum parse_tunnel command Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 11/16] testpmd: rename vxlan in outer_ip in csum commands Olivier Matz
2015-01-23 11:21   ` Liu, Jijiang
2015-01-23 17:49     ` Olivier MATZ
2015-01-21 23:36 ` [dpdk-dev] [RFC 12/16] testpmd: introduce parse_ipv* in csum fwd engine Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 13/16] testpmd: use a structure to store offload info " Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 14/16] testpmd: introduce parse_vxlan " Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 15/16] testpmd: support gre tunnels " Olivier Matz
2015-01-21 23:36 ` [dpdk-dev] [RFC 16/16] testpmd: support ipip tunnel in csum forward engine Olivier Matz
2015-01-21 23:41 ` [dpdk-dev] [RFC 00/16] enhance checksum offload API Olivier MATZ
2015-01-22 10:00   ` Thomas Monjalon
2015-01-22  1:01 ` Stephen Hemminger [this message]
2015-01-23  9:52   ` Olivier MATZ
2015-01-23  7:54 ` Liu, Jijiang
2015-01-30 13:15 ` [dpdk-dev] [PATCH 00/20] enhance tx " Olivier Matz
2015-01-30 13:15   ` [dpdk-dev] [PATCH 01/20] mbuf: remove PKT_TX_IPV4_CSUM Olivier Matz
2015-01-30 13:15   ` [dpdk-dev] [PATCH 02/20] mbuf: enhance the API documentation of offload flags Olivier Matz
2015-01-30 13:15   ` [dpdk-dev] [PATCH 03/20] i40e: call i40e_txd_enable_checksum only for offloaded packets Olivier Matz
2015-01-30 13:15   ` [dpdk-dev] [PATCH 04/20] i40e: remove the use of PKT_TX_UDP_TUNNEL_PKT flag Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 05/20] mbuf: remove " Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 06/20] testpmd: replace tx_checksum command by csum Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 07/20] testpmd: move csum_show in a function Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 08/20] testpmd: add csum parse_tunnel command Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 09/20] testpmd: rename vxlan in outer_ip in csum commands Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 10/20] testpmd: introduce parse_ipv* in csum fwd engine Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 11/20] testpmd: use a structure to store offload info " Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 12/20] testpmd: introduce parse_vxlan " Olivier Matz
2015-02-02  1:49     ` Liu, Jijiang
2015-01-30 13:16   ` [dpdk-dev] [PATCH 13/20] testpmd: support gre tunnels " Olivier Matz
2015-02-02  3:04     ` Liu, Jijiang
2015-01-30 13:16   ` [dpdk-dev] [PATCH 14/20] testpmd: support ipip tunnel in csum forward engine Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 15/20] ethdev: add outer IP offload capability flag Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 16/20] i40e: advertise outer IPv4 checksum capability Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 17/20] testpmd: add a warning if outer ip cksum requested but not supported Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 18/20] testpmd: fix TSO when using outer checksum offloads Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 19/20] i40e: fix offloading of outer checksum for ip in ip tunnels Olivier Matz
2015-01-30 13:16   ` [dpdk-dev] [PATCH 20/20] i40e: add debug logs for tx context descriptors Olivier Matz
2015-02-04  9:25   ` [dpdk-dev] [PATCH v2 00/20] enhance tx checksum offload API Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 01/20] mbuf: remove PKT_TX_IPV4_CSUM Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 02/20] mbuf: enhance the API documentation of offload flags Olivier Matz
2015-02-10  5:38       ` Zhang, Helin
2015-02-10 16:54         ` Olivier MATZ
2015-02-11  7:15         ` Liu, Jijiang
2015-02-11 15:15           ` Olivier MATZ
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 03/20] i40e: call i40e_txd_enable_checksum only for offloaded packets Olivier Matz
2015-02-10  6:03       ` Zhang, Helin
2015-02-10 17:06         ` Olivier MATZ
2015-02-11  5:32           ` Zhang, Helin
2015-02-11 17:13             ` Olivier MATZ
2015-02-13  2:25               ` Zhang, Helin
2015-02-13  8:41                 ` Olivier MATZ
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 04/20] i40e: remove the use of PKT_TX_UDP_TUNNEL_PKT flag Olivier Matz
2015-02-10  6:40       ` Zhang, Helin
2015-02-10 17:08         ` Olivier MATZ
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 05/20] mbuf: remove " Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 06/20] testpmd: replace tx_checksum command by csum Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 07/20] testpmd: move csum_show in a function Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 08/20] testpmd: add csum parse_tunnel command Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 09/20] testpmd: rename vxlan in outer_ip in csum commands Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 10/20] testpmd: introduce parse_ipv* in csum fwd engine Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 11/20] testpmd: use a structure to store offload info " Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 12/20] testpmd: introduce parse_vxlan " Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 13/20] testpmd: support gre tunnels " Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 14/20] testpmd: support ipip tunnel in csum forward engine Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 15/20] ethdev: add outer IP offload capability flag Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 16/20] i40e: advertise outer IPv4 checksum capability Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 17/20] testpmd: add a warning if outer ip cksum requested but not supported Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 18/20] testpmd: fix TSO when using outer checksum offloads Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 19/20] i40e: fix offloading of outer checksum for ip in ip tunnels Olivier Matz
2015-02-04  9:25     ` [dpdk-dev] [PATCH v2 20/20] i40e: add debug logs for tx context descriptors Olivier Matz
2015-02-09  1:10     ` [dpdk-dev] [PATCH v2 00/20] enhance tx checksum offload API Liu, Jijiang
2015-02-13  9:22     ` [dpdk-dev] [PATCH v3 " Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 01/20] mbuf: remove PKT_TX_IPV4_CSUM Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 02/20] mbuf: enhance the API documentation of offload flags Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 03/20] i40e: call i40e_txd_enable_checksum only for offloaded packets Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 04/20] i40e: remove the use of PKT_TX_UDP_TUNNEL_PKT flag Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 05/20] mbuf: remove " Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 06/20] testpmd: replace tx_checksum command by csum Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 07/20] testpmd: move csum_show in a function Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 08/20] testpmd: add csum parse_tunnel command Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 09/20] testpmd: rename vxlan in outer_ip in csum commands Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 10/20] testpmd: introduce parse_ipv* in csum fwd engine Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 11/20] testpmd: use a structure to store offload info " Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 12/20] testpmd: introduce parse_vxlan " Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 13/20] testpmd: support gre tunnels " Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 14/20] testpmd: support ipip tunnel in csum forward engine Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 15/20] ethdev: add outer IP offload capability flag Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 16/20] i40e: advertise outer IPv4 checksum capability Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 17/20] testpmd: add a warning if outer ip cksum requested but not supported Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 18/20] testpmd: fix TSO when using outer checksum offloads Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 19/20] i40e: fix offloading of outer checksum for ip in ip tunnels Olivier Matz
2015-02-13  9:22       ` [dpdk-dev] [PATCH v3 20/20] i40e: add debug logs for tx context descriptors Olivier Matz
2015-02-15  6:22       ` [dpdk-dev] [PATCH v3 00/20] enhance tx checksum offload API Liu, Jijiang
2015-02-16 18:23         ` Thomas Monjalon

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