Re: ethdev new offloading API switch in PMDs

From: Ferruh Yigit <ferruh.yigit@intel.com>
To: "Shahaf Shuler" <shahafs@mellanox.com>,
	"Gaetan Rivet" <gaetan.rivet@6wind.com>,
	"Qi Zhang" <qi.z.zhang@intel.com>,
	"Xiao Wang" <xiao.w.wang@intel.com>,
	"Beilei Xing" <beilei.xing@intel.com>,
	"Wenzhuo Lu" <wenzhuo.lu@intel.com>,
	"Konstantin Ananyev" <konstantin.ananyev@intel.com>,
	"Adrien Mazarguil" <adrien.mazarguil@6wind.com>,
	"Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>,
	"Yongseok Koh" <yskoh@mellanox.com>,
	"Santosh Shukla" <santosh.shukla@caviumnetworks.com>,
	"Jerin Jacob" <jerin.jacob@caviumnetworks.com>,
	"Rasesh Mody" <rasesh.mody@cavium.com>,
	"Harish Patil" <harish.patil@cavium.com>,
	"Shahed Shaikh" <shahed.shaikh@cavium.com>,
	"Andrew Rybchenko" <arybchenko@solarflare.com>,
	"Pascal Mazon" <pascal.mazon@6wind.com>,
	"Maciej Czekaj" <maciej.czekaj@caviumnetworks.com>,
	"Maxime Coquelin" <maxime.coquelin@redhat.com>,
	"Tiwei Bie" <tiwei.bie@intel.com>,
	"Yong Wang" <yongwang@vmware.com>
Cc: Thomas Monjalon <thomas@monjalon.net>, dpdk-dev <dev@dpdk.org>,
	Ravi Kumar <ravi1.kumar@amd.com>,
	Ajit Khaparde <ajit.khaparde@broadcom.com>,
	Somnath Kotur <somnath.kotur@broadcom.com>,
	Marcin Wojtas <mw@semihalf.com>,
	Michal Krawczyk <mk@semihalf.com>,
	Guy Tzalik <gtzalik@amazon.com>,
	Evgeny Schemeilin <evgenys@amazon.com>,
	Bruce Richardson <bruce.richardson@intel.com>
Subject: Re: ethdev new offloading API switch in PMDs
Date: Wed, 2 May 2018 14:27:33 +0100	[thread overview]
Message-ID: <b62f28c8-1c9d-9ab0-ff29-63d9d76b048b@intel.com> (raw)
In-Reply-To: <DB7PR05MB4426D7B9EEEC7E6DB7B3DA56C3800@DB7PR05MB4426.eurprd05.prod.outlook.com>

On 5/2/2018 1:52 PM, Shahaf Shuler wrote:
> Wednesday, May 2, 2018 11:47 AM, Ferruh Yigit:
>> Subject: Re: [dpdk-dev] ethdev new offloading API switch in PMDs
>>
>> On 5/2/2018 6:34 AM, Shahaf Shuler wrote:
>>> Tuesday, May 1, 2018 5:01 PM, Ferruh Yigit:
>>>> Subject: ethdev new offloading API switch in PMDs
>>>>
>>>> Hi,
>>>>
>>>> Following PMDs still has .txq_flags in use, after basic grep, no
>>>> in-dept investigation done.
>>>>
>>>> With PMDs switch to new API, that flag no longer should be needed.
>>>>
>>>> Old applications still use it but ethdev converts them to the
>>>> offloads, so that PMDs can only concern about offloads.
>>>>
>>>
>>> Full removal of txq_flags can be done only after we will mitigate the
>> "queue offloads must match port offload" constrain.
>>
>> Why? What is the relation of the flag and constrain?
> 
> The PMD has to know if to verify port offloads and queue offload correlation. 
> It is done by looking on the ETH_TXQ_FLAGS_IGNORE flag.

Perhaps I am missing something but why done looking ETH_TXQ_FLAGS_IGNORE flag?

ETH_TXQ_FLAGS_IGNORE flag means application is using new API and "offloads"
variable is valid instead of "txq_flags"

ethdev uses this information to convert "txq_flags" to "offloads", for PMD
"offloads" are always valid.

PMD can check [rt]xmode->offloads (port offloads) and [rt]xq->offloads (queue
offloads) to verify between port and queue offloads. What is missing in this check?

> 
> When we mitigate the constraion/deprecate the old API we can remove this. 
> 
>> Independent from constrain all PMDs switch to new API which doesn't use
>> txq_flags anymore, what blocks removing it from PMDs?
>>
>>>
>>>> Can maintainer of following PMDs please check their offloading API
>>>> implementation:
>>>>
>>>> axgbe
>>>> bnxt
>>>> e1000
>>>> ena
>>>> failsafe
>>>> fm10k
>>>> i40e
>>>> ixgbe
>>>> mlx4
>>>> mlx5
>>>> octeontx
>>>> qede
>>>> sfc
>>>> tap
>>>> thunderx
>>>> virtio
>>>> vmxnet3
> 