[PATCH] ethdev: add calculate hash function

[fengchengwen]

Hi,

On 2023/10/10 19:05, Ferruh Yigit wrote:
> On 9/26/2023 12:37 PM, Ori Kam wrote:
>> rte_flow supports insert by index table[1].
>>
>> Using the above table, the application can create rules
>> that are based on hash.
>> For example application can create the following logic in order
>> to create load balancing:
>> 1. Create insert by index table with 2 rules, that hashes based on dmac
>> 2. Insert to index 0 a rule that sends the traffic to port A.
>> 3. Insert to index 1 a rule that sends the traffic to port B.
>>
>> Let's also assume that before this table, there is a 5 tuple
>> match table that jumps to the above table.
>>
>> So each packet that matches one of the 5 tuple rules is RSSed
>> to port A or B, based on dmac hash.
>>
>> The issue arises when there is a miss on the 5 tuple table,
>> which resulted due to the packet being the first packet of this flow, or
>> fragmented packet or any other reason.
>> In this case, the application must calculate what would be the
>> hash calculated by the HW so it can send the packet to the correct
>> port.
>>
>> This new API allows applications to calculate the hash value of a given
>> packet for a given table.
>>
>> [1] - http://patches.dpdk.org/project/dpdk/patch/20230208030624.78465-2-akozyrev@nvidia.com/
>>
>> Signed-off-by: Ori Kam <orika at nvidia.com>
>> ---
>>  app/test-pmd/cmdline_flow.c  | 86 +++++++++++++++++++++++++++++++++++-
>>  app/test-pmd/config.c        | 54 ++++++++++++++++++++++
>>  app/test-pmd/testpmd.h       |  2 +
>>  lib/ethdev/rte_flow.c        | 21 +++++++++
>>  lib/ethdev/rte_flow.h        | 32 ++++++++++++++
>>  lib/ethdev/rte_flow_driver.h |  5 +++
>>  lib/ethdev/version.map       |  1 +
>>  7 files changed, 200 insertions(+), 1 deletion(-)
>>
> 
> This is a new rte_flow API but unfortunately there isn't any
> review/comment, at least it is experimental API. If there is no
> objection/discussion in next few days, I will merge the feature.
> 
> Probably it will be another rte flow feature that only NVIDIA knows and
> uses. While mentioned from using, is the driver update for the feature

The hns3 driver support subset of rte_flow, we found the rte_flow feature is very flexible.
And its implementation varies according to vendors.

Can the rte_flow be standardized ?

> planned for this release?
> 
> 
> Meanwhile, can you please update the documentation, `rte_flow.rst` and
> `testpmd_funcs.rst`?
> Also can you please rebase on top of latest next-net, this patch
> conflicts with merged group set miss action feature.
> 
> .
>