RE: [dpdk-dev] [RFC PATCH] ethdev: support priority based flow control

[Ori Kam <orika@nvidia.com>]

Hi Jerin,

Sorry for my late response,

> -----Original Message-----
> From: Jerin Jacob <jerinjacobk@gmail.com>
> Sent: Wednesday, November 17, 2021 11:49 AM
> To: Jerin Jacob <jerinj@marvell.com>
> Subject: Re: [dpdk-dev] [RFC PATCH] ethdev: support priority based flow control
> 
> On Tue, Oct 5, 2021 at 6:32 PM <jerinj@marvell.com> wrote:
> >
> > From: Jerin Jacob <jerinj@marvell.com>
> >
> > rte_eth_dev_priority_flow_ctrl_set() based API is not generic as it
> > can not support other than VLAN priority mapping to PFC traffic class.
> >
> > Introducing RTE_FLOW_ACTION_TYPE_PFC_SET_TC rte_flow action to
> > set the traffic class as per 802.1Qbb specification. This will enable,
> > Traffic class(8bit) to be selected based on any packet field like DSCP.
> >
> > Also, making it as rte_flow action will enable fine control on
> > traffic class selection to a specific queue or VF etc.
> >
> > Signed-off-by: Jerin Jacob <jerinj@marvell.com>
> 
> Ping. If there are no comments on RFC, Planning to send v1 for 22.02.

All the set type of functions are going to be deprecated.
you should use RTE_FLOW_ACTION_TYPE_MODIFY_FIELD.

What is the item that you are matching on when using rte_flow? Is it part of the tci in the vlan item?


> 
> > ---
> >
> > Planning to submit the testpmd and cnxk ethdev driver changes after receiving
> > the feedback on this.
> >
> >
> >  doc/guides/prog_guide/rte_flow.rst | 24 ++++++++++++++++++++++++
> >  lib/ethdev/rte_flow.c              |  1 +
> >  lib/ethdev/rte_flow.h              | 27 +++++++++++++++++++++++++++
> >  3 files changed, 52 insertions(+)
> >
> > diff --git a/doc/guides/prog_guide/rte_flow.rst b/doc/guides/prog_guide/rte_flow.rst
> > index 2b42d5ec8c..e59f8a2902 100644
> > --- a/doc/guides/prog_guide/rte_flow.rst
> > +++ b/doc/guides/prog_guide/rte_flow.rst
> > @@ -2999,6 +2999,30 @@ which is set in the packet meta-data (i.e. struct ``rte_mbuf::sched::color``)
> >     | ``meter_color`` | Packet color |
> >     +-----------------+--------------+
> >
> > +Action: ``PFC_SET_TC``
> > +^^^^^^^^^^^^^^^^^^^^^^
> > +
> > +Set traffic class as per PFC (802.1Qbb) specification.
> > +
> > +This action must be used with any of the following action.
> > +
> > +- ``RTE_FLOW_ACTION_TYPE_QUEUE``
> > +- ``RTE_FLOW_ACTION_TYPE_RSS``
> > +- ``RTE_FLOW_ACTION_TYPE_PF``
> > +- ``RTE_FLOW_ACTION_TYPE_VF``
> > +- ``RTE_FLOW_ACTION_TYPE_PHY_PORT``
> > +- ``RTE_FLOW_ACTION_TYPE_PORT_ID``
> > +

Why? All the above actions are terminating actions so if I want ot match on the value
it doesn't make sense to have it only on the last rule.

> > +.. _table_rte_flow_action_pfc_set_tc:
> > +
> > +.. table:: PFC_SET_PRIORITY
> > +
> > +   +-----------------+-------------------------------------+
> > +   | Field           | Value                               |
> > +   +=================+=====================================+
> > +   | ``tc``          | Traffic class as per PFC (802.1Qbb) |
> > +   +-----------------+-------------------------------------+
> > +
> >  Negative types
> >  ~~~~~~~~~~~~~~
> >
> > diff --git a/lib/ethdev/rte_flow.c b/lib/ethdev/rte_flow.c
> > index 8cb7a069c8..75c661159e 100644
> > --- a/lib/ethdev/rte_flow.c
> > +++ b/lib/ethdev/rte_flow.c
> > @@ -189,6 +189,7 @@ static const struct rte_flow_desc_data rte_flow_desc_action[] = {
> >          */
> >         MK_FLOW_ACTION(INDIRECT, 0),
> >         MK_FLOW_ACTION(CONNTRACK, sizeof(struct rte_flow_action_conntrack)),
> > +       MK_FLOW_ACTION(PFC_SET_TC, sizeof(struct rte_flow_action_pfc_set_tc)),
> >  };
> >
> >  int
> > diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
> > index 7b1ed7f110..5298418e9e 100644
> > --- a/lib/ethdev/rte_flow.h
> > +++ b/lib/ethdev/rte_flow.h
> > @@ -2409,6 +2409,13 @@ enum rte_flow_action_type {
> >          * See struct rte_flow_action_meter_color.
> >          */
> >         RTE_FLOW_ACTION_TYPE_METER_COLOR,
> > +
> > +       /**
> > +        * Set traffic class as per PFC (802.1Qbb) specification.
> > +        *
> > +        * See struct rte_flow_action_pfc_set_tc.
> > +        */
> > +       RTE_FLOW_ACTION_TYPE_PFC_SET_TC,
> >  };
> >
> >  /**
> > @@ -3168,6 +3175,26 @@ struct rte_flow_action_meter_color {
> >         enum rte_color color; /**< Packet color. */
> >  };
> >
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this structure may change without prior notice
> > + *
> > + * RTE_FLOW_ACTION_TYPE_PFC_SET_TC
> > + *
> > + * Set traffic class as per PFC (802.1Qbb) specification.
> > + *
> > + * This action must be used any of the following action.
> > + * - RTE_FLOW_ACTION_TYPE_QUEUE,
> > + * - RTE_FLOW_ACTION_TYPE_RSS,
> > + * - RTE_FLOW_ACTION_TYPE_PF,
> > + * - RTE_FLOW_ACTION_TYPE_VF,
> > + * - RTE_FLOW_ACTION_TYPE_PHY_PORT,
> > + * - RTE_FLOW_ACTION_TYPE_PORT_ID
> > + */

What does it mean?  I must use it only on rules that have one of the above actions?

> > +struct rte_flow_action_pfc_set_tc {
> > +       uint8_t tc; /**< Traffic class as per PFC (802.1Qbb) specification */
> > +};
> > +
> >  /**
> >   * Field IDs for MODIFY_FIELD action.
> >   */
> > --
> > 2.33.0
> >

Best,
Ori