[dpdk-dev] ethdev new offloading API switch in PMDs

[Shahaf Shuler]

Wednesday, May 2, 2018 4:28 PM, Ferruh Yigit:
> Subject: Re: [dpdk-dev] ethdev new offloading API switch in PMDs
> 
> 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?

Old application will not set this flag. It will also not set any txmode.offload, as this is a new API. The Tx offload stage comes only after on the tx_queue_setup.
So for such old application we cannot compare the Tx Queue offload to the Tx port offloads, as the later one are 0. 

> 
> >
> > 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
> >