[v2] net/i40e: fix forward outer IPv6 VXLAN packets

  Testpmd forwards packets in checksum mode that it need to calculate
the checksum of each layer's protocol. Then it will fill flags and
header length into mbuf.

In process_outer_cksums, HW calculates the outer checksum if
tx_offloads contains outer UDP checksum otherwise SW calculates
the outer checksum.

When tx_offloads contains outer UDP checksum or outer IPv4 checksum,
mbuf will be filled with correct header length.

This patch added outer UDP checksum in tx_offload_capa and
I40E_TX_OFFLOAD_MASK, when we set csum hw outer-udp on that the
engine can forward outer IPv6 VXLAN packets.

Fixes: 7497d3e2f777 ("net/i40e: convert to new Tx offloads API")
Cc: stable@dpdk.org

Signed-off-by: Jie Wang <jie1x.wang@intel.com>
---
 drivers/net/i40e/i40e_ethdev.c | 1 +
 drivers/net/i40e/i40e_rxtx.c   | 1 +
 2 files changed, 2 insertions(+)
  

> -----Original Message-----
> From: Wang, Jie1X <jie1x.wang@intel.com>
> Sent: Friday, November 5, 2021 11:37 AM
> To: dev@dpdk.org
> Cc: Zhang, Yuying <yuying.zhang@intel.com>; Li, Xiaoyun
> <xiaoyun.li@intel.com>; Yang, SteveX <stevex.yang@intel.com>; Xing, Beilei
> <beilei.xing@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>; Wang, Jie1X
> <jie1x.wang@intel.com>; stable@dpdk.org
> Subject: [PATCH v2] net/i40e: fix forward outer IPv6 VXLAN packets
> 
> Testpmd forwards packets in checksum mode that it need to calculate the
> checksum of each layer's protocol. Then it will fill flags and header length into
> mbuf.
> 
> In process_outer_cksums, HW calculates the outer checksum if tx_offloads
> contains outer UDP checksum otherwise SW calculates the outer checksum.
> 
> When tx_offloads contains outer UDP checksum or outer IPv4 checksum,
> mbuf will be filled with correct header length.
> 
> This patch added outer UDP checksum in tx_offload_capa and
> I40E_TX_OFFLOAD_MASK, when we set csum hw outer-udp on that the
> engine can forward outer IPv6 VXLAN packets.
> 
> Fixes: 7497d3e2f777 ("net/i40e: convert to new Tx offloads API")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Jie Wang <jie1x.wang@intel.com>
Acked-by: Beilei Xing <beilei.xing@intel.com>
  

On 11/5/2021 3:48 AM, Xing, Beilei wrote:
> 
> 
>> -----Original Message-----
>> From: Wang, Jie1X <jie1x.wang@intel.com>
>> Sent: Friday, November 5, 2021 11:37 AM
>> To: dev@dpdk.org
>> Cc: Zhang, Yuying <yuying.zhang@intel.com>; Li, Xiaoyun
>> <xiaoyun.li@intel.com>; Yang, SteveX <stevex.yang@intel.com>; Xing, Beilei
>> <beilei.xing@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>; Wang, Jie1X
>> <jie1x.wang@intel.com>; stable@dpdk.org
>> Subject: [PATCH v2] net/i40e: fix forward outer IPv6 VXLAN packets
>>
>> Testpmd forwards packets in checksum mode that it need to calculate the
>> checksum of each layer's protocol. Then it will fill flags and header length into
>> mbuf.
>>
>> In process_outer_cksums, HW calculates the outer checksum if tx_offloads
>> contains outer UDP checksum otherwise SW calculates the outer checksum.
>>
>> When tx_offloads contains outer UDP checksum or outer IPv4 checksum,
>> mbuf will be filled with correct header length.
>>
>> This patch added outer UDP checksum in tx_offload_capa and
>> I40E_TX_OFFLOAD_MASK, when we set csum hw outer-udp on that the
>> engine can forward outer IPv6 VXLAN packets.
>>
>> Fixes: 7497d3e2f777 ("net/i40e: convert to new Tx offloads API")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Jie Wang <jie1x.wang@intel.com>
> Acked-by: Beilei Xing <beilei.xing@intel.com>
> 

For record,
This patch has been merged to next-net-intel, and pulled to next-net from there.
  

Hello Bruce, John,

On Fri, Nov 5, 2021 at 4:39 AM Jie Wang <jie1x.wang@intel.com> wrote:
>
> Testpmd forwards packets in checksum mode that it need to calculate
> the checksum of each layer's protocol. Then it will fill flags and
> header length into mbuf.
>
> In process_outer_cksums, HW calculates the outer checksum if
> tx_offloads contains outer UDP checksum otherwise SW calculates
> the outer checksum.
>
> When tx_offloads contains outer UDP checksum or outer IPv4 checksum,
> mbuf will be filled with correct header length.
>
> This patch added outer UDP checksum in tx_offload_capa and
> I40E_TX_OFFLOAD_MASK, when we set csum hw outer-udp on that the
> engine can forward outer IPv6 VXLAN packets.
>
> Fixes: 7497d3e2f777 ("net/i40e: convert to new Tx offloads API")
> Cc: stable@dpdk.org
>
> Signed-off-by: Jie Wang <jie1x.wang@intel.com>

- There is a bz opened by a OVS user trying to offload geneve checksum.
https://bugs.dpdk.org/show_bug.cgi?id=1406

Reading the X7xx datasheet, parsing i40e_parse_tunneling_params() and
looking at the packets reported by the user, I understand that outer
udp checksum is actually *not* supported by net/i40e.
And so the change from this mail thread should be reverted as the
driver falsely claims support for this feature.


- I found some bits about X722 (5535087e6c56 ("i40e/base: add outer
UDP checksum for X722")) supporting this feature, but I did not find a
definition in the datasheet.
Besides, this I40E_TXD_CTX_QW0_L4T_CS_MASK is not used in the net/i40e tx path.


We need Intel to clear state what is supported or not, and send fixes
accordingly.

Thanks.