[PATCH v2 1/5] ethdev: support setting and querying RSS algorithm

[Jie Hai]

On 2023/9/9 4:58, Stephen Hemminger wrote:
> On Fri, 8 Sep 2023 17:28:08 +0800
> Jie Hai <haijie1 at huawei.com> wrote:
> 
>> Hi, Stephen Hemminger
>>
>> On 2023/9/6 23:10, Stephen Hemminger wrote:
>>> On Sat, 26 Aug 2023 15:46:03 +0800
>>> Jie Hai <haijie1 at huawei.com> wrote:
>>>    
>>>> Currently, rte_eth_rss_conf supports configuring and querying
>>>> rss hash functions, rss key and it's length, but not rss hash
>>>> algorithm.
>>>>
>>>> The structure ``rte_eth_rss_conf`` is extended by adding a new
>>>> field "func". This represents the RSS algorithms to apply. The
>>>> following API is affected:
>>>> 	- rte_eth_dev_configure
>>>> 	- rte_eth_dev_rss_hash_update
>>>> 	- rte_eth_dev_rss_hash_conf_get
>>>>
>>>> If the value of "func" used for configuration is a gibberish
>>>> value, report the error and return. Do the same for
>>>> rte_eth_dev_rss_hash_update and rte_eth_dev_configure.
>>>>
>>>> To check whether the drivers report the "func" field, it is set
>>>> to default value before querying.
>>>>
>>>> Signed-off-by: Jie Hai <haijie1 at huawei.com>
>>>> Signed-off-by: Dongdong Liu <liudongdong3 at huawei.com>
>>>
>>> This is unannounced API/ABI change.
>> Thanks for pointing that. I'm sorry I didn't pay attention to this before.
>> What should I do with this set of patches?
>> Is it feasible to send annouce now?
> 
> Since this API/ABI breaking release, I am ok taking it. But will need a release
> note. Also you should treat 0 as "no change" case to allow for code that does hash_update
> without setting the value.
> 
The release note 'doc/guides/rel_notes/release_23_11.rst' has been 
updated in this patch. Please check it.

Whether or not to treat 0 as no change depends on the implemetation of 
the driver.

According to the drivers that support algorithm modification through the
flow API, the 0 is regarded as no change.
It is believed that these drivers have the same behavior when updating 
the hash_update with setting algorithm.

For the current drivers that do hash_update without setting the 'func'
value, the implemetation does not involve the modification of the 
algorithm.

In either case, 0 is regarded as "no change".
> 
> .