[dpdk-dev] [EXT] Re: [PATCH v7 1/3] ethdev: add level support for RSS offload types

[Ferruh Yigit]

On 9/1/2020 3:27 PM, Kiran Kumar Kokkilagadda wrote:
> 
> 
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit at intel.com>
>> Sent: Tuesday, September 1, 2020 7:08 PM
>> To: Kiran Kumar Kokkilagadda <kirankumark at marvell.com>; Thomas Monjalon
>> <thomas at monjalon.net>; Andrew Rybchenko <arybchenko at solarflare.com>
>> Cc: dev at dpdk.org; Jerin Jacob Kollanukkaran <jerinj at marvell.com>;
>> orika at mellanox.com; xuanziyang2 at huawei.com;
>> cloud.wangxiaoyun at huawei.com; zhouguoyang at huawei.com;
>> rosen.xu at intel.com; beilei.xing at intel.com; jia.guo at intel.com; Rasesh Mody
>> <rmody at marvell.com>; Shahed Shaikh <shshaikh at marvell.com>; Nithin Kumar
>> Dabilpuram <ndabilpuram at marvell.com>; qiming.yang at intel.com;
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>> Subject: [EXT] Re: [dpdk-dev][PATCH v7 1/3] ethdev: add level support for RSS
>> offload types
>>
>> External Email
>>
>> ----------------------------------------------------------------------
>> On 9/1/2020 4:27 AM, kirankumark at marvell.com wrote:
>>> From: Kiran Kumar K <kirankumark at marvell.com>
>>>
>>> This patch reserves 2 bits as input selection to select Inner and
>>> outer encapsulation level for RSS computation. It is combined with
>>> existing
>>> ETH_RSS_* to choose Inner or outer layers.
>>> This functionality already exists in rte_flow through level parameter
>>> in RSS action configuration rte_flow_action_rss.
>>>
>>> Signed-off-by: Kiran Kumar K <kirankumark at marvell.com>
>>> ---
>>> V7 Changes:
>>> * Re-worked to keep it in sync with rte_flow_action_rss and support
>>> upto
>>> 3 levels.
>>> * Addressed testpmd review comments.
>>>
>>>    lib/librte_ethdev/rte_ethdev.h | 27 +++++++++++++++++++++++++++
>>>    1 file changed, 27 insertions(+)
>>>
>>> diff --git a/lib/librte_ethdev/rte_ethdev.h
>>> b/lib/librte_ethdev/rte_ethdev.h index 70295d7ab..13e49bbd7 100644
>>> --- a/lib/librte_ethdev/rte_ethdev.h
>>> +++ b/lib/librte_ethdev/rte_ethdev.h
>>> @@ -552,6 +552,33 @@ struct rte_eth_rss_conf {
>>>    #define RTE_ETH_RSS_L3_PRE64	   (1ULL << 53)
>>>    #define RTE_ETH_RSS_L3_PRE96	   (1ULL << 52)
>>>
>>> +/*
>>> + * We use the following macros to combine with the above layers to
>>> +choose
>>> + * inner and outer layers or both for RSS computation.
>>> + * bit 50 and 51 are reserved for this.
>>> + */
>>> +
>>> +/** level 0, requests the default behavior. Depending on the packet
>>> + * type, it can mean outermost, innermost, anything in between or even no
>> RSS.
>>> + * It basically stands for the innermost encapsulation level RSS
>>> + * can be performed on according to PMD and device capabilities.
>>> + */
>>> +#define ETH_RSS_LEVEL_0         (0ULL << 50)
>>
>> I can see from history how this is involved, but the 'ETH_RSS_LEVEL_0' naming is
>> not really clear what it is, the naming in v6 is more clear.
>>
>> What about following one:
>> 0 -> LEVEL_PMD_DEFAULT
>> 1 -> LEVEL_OUTER
>> 2 -> LEVEL_INNER
>> 3 -> LEVEL_INNER_OUTER
>>
>> This doesn't exactly match to rte_flow one, but closer than v6 one. This ends
>> with max level 2. And defines a way to say both inner and outer.
> 
> This one looks good to me. If everyone is ok with the proposed changes, I will send V8.
> 

Let's wait for more comments before v8.

>>
>>> +
>>> +/** level 1,  requests RSS to be performed on the outermost packet
>>> + * encapsulation level.
>>> + */
>>> +#define ETH_RSS_LEVEL_1         (1ULL << 50)
>>> +
>>> +/** level 2,  requests RSS to be performed on the
>>> + * specified inner packet encapsulation level, from outermost to
>>> + * innermost (lower to higher values).
>>> + */
>>> +#define ETH_RSS_LEVEL_2	        (2ULL << 50)
>>
>> I can see you are trying to copy rte_flow usage, but this doesn't really makes
>> sense here. Where the value of the level is defined in this case? If not defined
>> how the PMD knows which level to use?
>>
>>> +#define ETH_RSS_LEVEL_MASK	(3ULL << 50)
>>> +
>>> +#define ETH_RSS_LEVEL(rss_hf) ((rss_hf & ETH_RSS_LEVEL_MASK) >> 50)
>>> +
>>>    /**
>>>     * For input set change of hash filter, if SRC_ONLY and DST_ONLY of
>>>     * the same level are used simultaneously, it is the same case as
>>> --
>>> 2.25.1
>>>
>