Re: [dpdk-dev] [PATCH v4 4/6] ethdev: add mark flow item to flow item types

[Shahaf Shuler <shahafs@mellanox.com>]

Thursday, April 19, 2018 4:04 PM, Adrien Mazarguil:
>
> Subject: Re: [dpdk-dev] [PATCH v4 4/6] ethdev: add mark flow item to flow
> item types
> 
> On Wed, Apr 18, 2018 at 10:04:21PM +0100, Declan Doherty wrote:
> > Introduces a new action type RTE_FLOW_ITEM_TYPE_MARK which enables
> > flow patterns to specify arbitrary integer values to match aginst
> 
> Typo on "aginst".
> 
> > which are set by the RTE_FLOW_ACTION_TYPE_MARK action in a
> previously
> > matched flow from a higher prioriry group.
> 
> prioriry => priority, however this last addition is unnecessary, it could be any
> prior flow rule that happens to use PASSTHRU.
> 
> >
> > Signed-off-by: Declan Doherty <declan.doherty@intel.com>
> > ---
> >  doc/guides/prog_guide/rte_flow.rst | 28
> ++++++++++++++++++++++++++++
> >  lib/librte_ether/rte_flow.h        | 24 ++++++++++++++++++++++++
> >  2 files changed, 52 insertions(+)
> >
> > diff --git a/doc/guides/prog_guide/rte_flow.rst
> > b/doc/guides/prog_guide/rte_flow.rst
> > index 325010544..6f23ad909 100644
> > --- a/doc/guides/prog_guide/rte_flow.rst
> > +++ b/doc/guides/prog_guide/rte_flow.rst
> > @@ -598,6 +598,34 @@ associated with a port_id should be retrieved by
> other means.
> >     | ``mask`` | ``index`` | zeroed to match any port index |
> >     +----------+-----------+--------------------------------+
> >
> > +Item: ``MARK``
> > +^^^^^^^^^^^^^^
> > +
> > +Matches packets coming from a previously matched flow in a higher
> > +priority group
> 
> See above re "higher priority group".
> 
> > +with an arbitrary integer value which was set using the ``MARK``
> > +action in the previously matched rule.
> > +

Why we have to bind It with the MARK? It is HW limitation or design consideration? 

My understanding is you want flow action of setting metadata to be used later as a matching item for the flows on other group.
It doesn't have to, but can be, bounded with the specific mark the application wants to receive.