On 11/27/2023 3:43 PM, Ferruh Yigit wrote:
> On 11/27/2023 1:12 PM, lihuisong (C) wrote:
>>
>> 在 2023/11/27 20:19, Ferruh Yigit 写道:
>>> On 11/25/2023 1:47 AM, Huisong Li wrote:
>>>> Add hash algorithm feature introduced by 23.11 and fix some RSS features
>>>> description.
>>>>
>>>> Fixes: 34ff088cc241 ("ethdev: set and query RSS hash algorithm")
>>>>
>>>> Signed-off-by: Huisong Li <lihuis...@huawei.com>
>>>> Acked-by: Chengwen Feng <fengcheng...@huawei.com>
>>>> ---
>>>> doc/guides/nics/features.rst | 26 ++++++++++++++++++++++----
>>>> 1 file changed, 22 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/doc/guides/nics/features.rst b/doc/guides/nics/features.rst
>>>> index 1a1dc16c1e..0d38c5c525 100644
>>>> --- a/doc/guides/nics/features.rst
>>>> +++ b/doc/guides/nics/features.rst
>>>> @@ -277,10 +277,12 @@ RSS hash
>>>> Supports RSS hashing on RX.
>>>> * **[uses] user config**: ``dev_conf.rxmode.mq_mode`` =
>>>> ``RTE_ETH_MQ_RX_RSS_FLAG``.
>>>> -* **[uses] user config**: ``dev_conf.rx_adv_conf.rss_conf``.
>>>> +* **[uses] user config**: ``rss_conf.rss_hf``.
>>>>
>>> Feature title is "RSS hash", it can be two things,
>>> 1. "Receive Side Scaling" support
>>> 2. Provide RSS hash to application
>>>
>>> When this document first prepared RSS hash value was always provided to
>>> the application when RSS enabled.
>>> So intention with this feature was "Receive Side Scaling" support, hence
>>> 'RTE_ETH_MQ_RX_RSS_FLAG' added.
>>>
>>> Later providing RSS has to the application separated as optimization,
>>> 'RTE_ETH_RX_OFFLOAD_RSS_HASH' & 'RTE_MBUF_F_RX_RSS_HASH' added for this
>>> support.
>> What should I do for above two comments？
>> To tell application how to use it?
>>
>
> Just tried to give some context.
>
>
>>>
>>> As the intention of this feature is "Receive Side Scaling" support, we
>>> shouldn't reduce configuration struct to 'rss_conf.rss_hf'.
>>>
>>> Instead perhaps can expand to:
>>> 'rte_eth_conf.rx_adv_conf.rss_conf', 'rte_eth_rss_conf'
>>
>> I just pick their common part.😁
>>
>> ok, will fix it.
>>
>>>
>>>
>>>> * **[uses] rte_eth_rxconf,rte_eth_rxmode**:
>>>> ``offloads:RTE_ETH_RX_OFFLOAD_RSS_HASH``.
>>>> * **[provides] rte_eth_dev_info**: ``flow_type_rss_offloads``.
>>>> * **[provides] mbuf**: ``mbuf.ol_flags:RTE_MBUF_F_RX_RSS_HASH``,
>>>> ``mbuf.rss``.
>>>> +* **[related] API**: ``rte_eth_dev_configure``,
>>>> ``rte_eth_dev_rss_hash_update``
>>>> + ``rte_eth_dev_rss_hash_conf_get()``.
>>>>
>>> ack
>>>
>>>> .. _nic_features_inner_rss:
>>>> @@ -288,7 +290,7 @@ Supports RSS hashing on RX.
>>>> Inner RSS
>>>> ---------
>>>> -Supports RX RSS hashing on Inner headers.
>>>> +Supports RX RSS hashing on Inner headers by rte_flow API.
>>>>
>>> This should be clarified with details below, not sure if it required to
>>> limit description to rte_flow.
>> But this block like rte_flow_action_rss is from rte_flow.
>> And ethdev ops doesn't support inner RSS.
>> So I think it is ok.
>>
>
> Yes it is supported by rte_flow, and '[uses]' information should already
> clarify it.
>
>
>>>
>>>
>>> And I guess similar confusion exist with the providing hash to user.
>>> Need to check if rte_flow implementation puts hash to mbuf along with
>>> doing the RSS, or if it checks 'RTE_ETH_RX_OFFLOAD_RSS_HASH' offload,
>>> and update below items accordingly.
>> Do we need to tell user how to use it here?
>> I feel this document is a little simple and main to list interface for
>> user.
>> In addition, it is better that the more detail about RSS should be
>> presented in rte_flow features.
>>
>
> No, I am not suggesting to add more detail.
>
> My concern is 'RTE_ETH_RX_OFFLOAD_RSS_HASH' information may not be
> correct, ethdev APIs checks offload flags, but does rte_flow
> implementation check it?
>
> My suggestion is double check that piece of information and fix it if
> required.
>
Thinking twice, ethdev API or rte_flow or different ways to configure
RSS, but datapath that puts hash value to mbuf is same.
So same 'RTE_ETH_RX_OFFLOAD_RSS_HASH' check is used for both method, and
it is OK to have it documented.
>
>>>
>>>
>>>> * **[uses] rte_flow_action_rss**: ``level``.
>>>> * **[uses] rte_eth_rxconf,rte_eth_rxmode**:
>>>> ``offloads:RTE_ETH_RX_OFFLOAD_RSS_HASH``.
>>>> @@ -303,9 +305,25 @@ RSS key update
>>>> Supports configuration of Receive Side Scaling (RSS) hash
>>>> computation. Updating
>>>> Receive Side Scaling (RSS) hash key.
>>>> -* **[implements] eth_dev_ops**: ``rss_hash_update``,
>>>> ``rss_hash_conf_get``.
>>>> +* **[implements] eth_dev_ops**: ``dev_configure``,
>>>> ``rss_hash_update``, ``rss_hash_conf_get``.
>>>> +* **[uses] user config**: ``rss_conf.rss_key``,
>>>> ``rss_conf.rss_key_len``
>>>> * **[provides] rte_eth_dev_info**: ``hash_key_size``.
>>>> -* **[related] API**: ``rte_eth_dev_rss_hash_update()``,
>>>> +* **[related] API**: ``rte_eth_dev_configure``,
>>>> ``rte_eth_dev_rss_hash_update()``,
>>>> + ``rte_eth_dev_rss_hash_conf_get()``.
>>>> +
>>> ack
>>>
>>> There is an inconsistency in the documentation but I think it is good to
>>> use '()' when documenting API, like: 'rte_eth_dev_configure()'
>> +1 will fix it.
>>>
>>>
>>>> +
>>>> +.. _nic_features_rss_hash_algo_update:
>>>> +
>>>> +RSS hash algorithm update
>>>> +-------------------------
>>>> +
>>>> +Supports configuration of Receive Side Scaling (RSS) hash algorithm.
>>>> Updating
>>>> +RSS hash algorithm.
>>>> +
>>>> +* **[implements] eth_dev_ops**: ``dev_configure``,
>>>> ``rss_hash_update``, ``rss_hash_conf_get``.
>>>> +* **[uses] user config**: ``rss_conf.algorithm``
>>>> +* **[provides] rte_eth_dev_info**: ``rss_algo_capa``.
>>>> +* **[related] API**: ``rte_eth_dev_configure``,
>>>> ``rte_eth_dev_rss_hash_update()``,
>>>> ``rte_eth_dev_rss_hash_conf_get()``.
>>>>
>>>
>>> This document describes features listed in the 'default.ini', so we
>>> shouldn't have above.
>>>
>>> And I don't think RSS hash algorithm update is a big enough feature to
>>> list in the feature list, perhaps it can be embedded in the RSS support
>>> block, what do you think?
>> Yes it is not a bit feature.
>> so put it to RSS hash, right?
>>
>
> Yes please.
>
