Question about flow_type_rss_offloads in rte_eth_dev_info

[lihuisong (C)]

Hi, Andrew

"Supported RSS offload flow types" code in testpmd has been reworked in
the following patchset:
http://patchwork.dpdk.org/project/dpdk/list/?series=22657
Series title: fix RSS types display

Please review, thanks.

在 2022/4/22 19:41, Andrew Rybchenko 写道:
> Hi,
>
> On 4/22/22 06:55, lihuisong (C) wrote:
>> Hi, all.
>>
>> The RTE_ETH_FLOW_XXX macros, are used to display supported flow types 
>> for PMD based on the rte_eth_dev_info.flow_type_rss_offloads in the 
>> port_infos_display() of testpmd.
>
> That's true and it is wrong in testpmd. RTE_ETH_RSS_* and
> RTE_ETH_FLOW_* are intentionally disconnected right now.
>
> flow_type_rss_offloads docmentation is a bit misleading saying
> that "the bit offset also means flow type". For example,
> RTE_ETH_RSS_L4_CHKSUM and RTE_ETH_RSS_L3_SRC_ONLY hardly mean
> flow type. I think the documentation must be fixed - it should
> just refer to RTE_ETH_RSS_* defines.
>
> So, returning to testpmd, "Supported RSS offload flow types"
> code should be reworked to avoid RTE_ETH_FLOW_* usage.
> flowtype_to_str() should be kept intact since it is used for
> FDIR commands which operate with flows, not RSS bit-field.
> A new function should be implemented which uses maps
> RTE_ETH_RSS_* bits into string to be printed.
>
>> And PMD assigns RSS offload capability bit, like RTE_ETH_RSS_XXX, to 
>> this field.
>> The usage of RTE_ETH_RSS_XXX macros are described as follows in:
>> /*
>>   * Below macros are defined for RSS offload types, they can be used to
>>   * fill rte_eth_rss_conf.rss_hf or rte_flow_action_rss.types.
>>   */
>> #define RTE_ETH_RSS_IPV4               RTE_BIT64(2)
>>
>> But RTE_ETH_FLOW_MAX is 24, and the number of RTE_ETH_FLOW_XXX micro 
>> far less than
>> the number of RTE_ETH_RSS_XXX. If PMD sets RSS offload capability bit 
>> out range of
>> RTE_ETH_FLOW_XXX, like RTE_ETH_RSS_L3_SRC_ONLY, to this field, 
>> testpmd will display
>> "user defined 63" when run 'show port info 0'. This is a problem that 
>> I have now.
>>
>> On the other hand, rx_adv_conf.rte_eth_rss_conf.rss_hf from App must 
>> be within the
>> rte_eth_dev_info.flow_type_rss_offloads in dev_configure.
>>
>> To sum up, I'm a little confused right now.
>> How should PMD populate the field "flow_type_rss_offloads" in struct 
>> rte_eth_dev_info?
>
> flow_type_rss_offloads should be populated in terms of
> RTE_ETH_RSS_* bits.
>
> Andrew.
> .