[RFC 1/5] ethdev: add port affinity match item

[Jiawei(Jonny) Wang]

Hi,


> > >
> > > 21/12/2022 11:29, Jiawei Wang:
> > > > +	/**
> > > > +	 * Matches on the physical port affinity of the received packet.
> > > > +	 *
> > > > +	 * See struct rte_flow_item_port_affinity.
> > > > +	 */
> > > > +	RTE_FLOW_ITEM_TYPE_PORT_AFFINITY,
> > > >  };
> > >
> > > I'm not sure about the word "affinity".
> > > I think you want to match on a physical port.
> > > It could be a global physical port id or an index in the group of
> > > physical ports connected to a single DPDK port.
> > > In first case, the name of the item could be
> > > RTE_FLOW_ITEM_TYPE_PHY_PORT, in the second case, the name could be
> > > RTE_FLOW_ITEM_TYPE_MHPSDP_PHY_PORT,
> > > "MHPSDP" meaning "Multiple Hardware Ports - Single DPDK Port".
> > > We could replace "PHY" with "HW" as well.
> > >
> >
> > Since DPDK only probe/attach the single port, seems first case does not meet
> this case.
> > Here, 'affinity' stands for the packet association with actual physical port.
> 
> I think it is more than affinity because the packet is effectively received from
> this port.
> And the other concern is that this name does not give any clue that we are
> talking about multiple ports merged in a single one.
> 

RTE_FLOW_ITEM_TYPE_MHPSDP_HW_PORT is better? @Ori Kam WDYT?

> > > Note that we cannot use the new item
> > > RTE_FLOW_ITEM_TYPE_REPRESENTED_PORT
> > > because we are in a case where multiple hardware ports are merged in
> > > a single software represented port.
> > >
> > >
> > > [...]
> > > > +/**
> > > > + * @warning
> > > > + * @b EXPERIMENTAL: this structure may change without prior
> > > > +notice
> > > > + *
> > > > + * RTE_FLOW_ITEM_TYPE_PORT_AFFINITY
> > > > + *
> > > > + * For the multiple hardware ports connect to a single DPDK port
> > > > +(mhpsdp),
> > > > + * use this item to match the hardware port affinity of the packets.
> > > > + */
> > > > +struct rte_flow_item_port_affinity {
> > > > +	uint8_t affinity; /**< port affinity value. */ };
> > >
> > > We need to define how the port numbering is done.
> > > Is it driver-dependent?
> > > Does it start at 0? etc...
> >
> > User can define any value they want; one use case is the packet could
> > be received and sent to same port, then they can set the same 'affinity' value
> in flow and queue configuration.
> 
> No it does not work.
> If ports are numbered 1 and 2, and user thinks it is 0 and 1, the port 2 won't be
> matched at all.
> 

OK, I can update the document the affinity 0 is no affinity in tx side and then match on affinity 0
will result an error.
For above case, user should use 1 and 2 to match.

> > The flow behavior is driver dependent.
> >
> > Thanks.
> 
> 
> 
>