[dpdk-dev] [PATCH v4] net/ice: add flow mark hint support

[Zhang, Qi Z]

> -----Original Message-----
> From: Thomas Monjalon <thomas at monjalon.net>
> Sent: Thursday, November 21, 2019 2:57 AM
> To: Zhang, Qi Z <qi.z.zhang at intel.com>
> Cc: dev at dpdk.org; Ye, Xiaolong <xiaolong.ye at intel.com>; Yigit, Ferruh
> <ferruh.yigit at intel.com>; arybchenko at solarflare.com; orika at mellanox.com
> Subject: Re: [dpdk-dev] [PATCH v4] net/ice: add flow mark hint support
> 
> 19/11/2019 07:14, Qi Zhang:
> > Since not all data paths support flow mark, the driver needs a hint
> > from application to select the correct data path if flow mark is
> > required. The patch introduces a devarg "flow-mark-support" as a
> > workaround solution, since a standard way is still ongoing.
> >
> > Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
> > Acked-by: Qiming Yang <qiming.yang at intel.com>
> > ---
> >
> > v4:
> > - remove debug code, fix typos
> >
> > v3:
> > - add "experimental notification" in ice.rst
> >
> > v2:
> > - fix typos
> 
> Please use --in-reply-to to help tracking all the versions together.
> 
> > +- ``Flow Mark Support`` (default ``0``)
> > +
> > +  This is a hint to the driver to select the data path that supports
> > + flow mark extraction  by default.
> > +  NOTE: This is an experimental devarg, it will be removed when any
> > + of below conditions  is ready.
> > +  1) all data paths support flow mark (currently vPMD does not)
> > +  2) a new offload like RTE_DEV_RX_OFFLOAD_FLOW_MARK be introduced
> as a standard way to hint.
> 
> When the data path is selected?

dev_start

> I suppose such decision should be done when starting the port, after everything
> is configured.
> So you can check if a rte_flow rule was added for mark action.
> Why the user needs to use an explicit option?

A rte_flow with mark can be issued at any time after dev_start when it is need, in that case, we have to reject the flow, this has been complained a lot base on previous feedback by users, since inconsistent behavior (sometimes mark works, some time it does not) is not expected
Also this option is overwhelmed by option 1 if we plan to do a clean fix in driver.







>