RE: [PATCH v2 2/4] ethdev: add get restore flags driver callback

[Dariusz Sosnowski <dsosnowski@nvidia.com>]

> -----Original Message-----
> From: Konstantin Ananyev <konstantin.ananyev@huawei.com>
> Sent: Friday, October 11, 2024 14:54
> To: Dariusz Sosnowski <dsosnowski@nvidia.com>; NBU-Contact-Thomas
> Monjalon (EXTERNAL) <thomas@monjalon.net>; Ferruh Yigit
> <ferruh.yigit@amd.com>; Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
> Cc: dev@dpdk.org
> Subject: RE: [PATCH v2 2/4] ethdev: add get restore flags driver callback
> 
> External email: Use caution opening links or attachments
> 
> 
> > Before this patch, ethdev layer assumed that all drivers require that
> > it has to forcefully restore:
> >
> > - MAC addresses
> > - promiscuous mode setting
> > - all multicast mode setting
> >
> > upon rte_eth_dev_start().
> >
> > This patch introduces a new callback to eth_dev_ops -
> > get_restore_flags().
> > Drivers implementing this callback can explicitly enable/disable
> > certain parts of config restore procedure.
> >
> > In order to minimize the changes to all the drivers and preserve the
> > current behavior, it is assumed that if this callback is not defined,
> > all configuration should be restored.
> >
> > Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
> 
> LGTM, just few nits/suggestions, pls see below.
> Series-Acked-by: Konstantin Ananyev <konstantin.ananyev@huawei.com>
> 
> > ---
> >  lib/ethdev/ethdev_driver.c | 11 +++++++  lib/ethdev/ethdev_driver.h |
> > 64 ++++++++++++++++++++++++++++++++++++++
> >  lib/ethdev/version.map     |  1 +
> >  3 files changed, 76 insertions(+)
> >
> > diff --git a/lib/ethdev/ethdev_driver.c b/lib/ethdev/ethdev_driver.c
> > index c335a25a82..f78f9fb5c1 100644
> > --- a/lib/ethdev/ethdev_driver.c
> > +++ b/lib/ethdev/ethdev_driver.c
> > @@ -958,3 +958,14 @@ rte_eth_switch_domain_free(uint16_t domain_id)
> >
> >       return 0;
> >  }
> > +
> > +void
> > +rte_eth_get_restore_flags(struct rte_eth_dev *dev,
> > +                       enum rte_eth_dev_operation op,
> > +                       uint32_t *flags)
> 
> I would go with uint64_t for flags (to avoid limitations in future).

+1

> Also, If it is void anyway, might be just return flags?
> i.e:
> uint64_t  +rte_eth_get_restore_flags(struct rte_eth_dev *dev, enum
> rte_eth_dev_operation op);

+1

> 
> Another thing - do we need to do update docs?
> PMD or PG sections, release notes?

IIRC new additions and internal changes in ethdev are not advertised in release notes.
@Ferruh Yigit: Should these changes be documented/announced somewhere?

> 
> > +{
> > +     if (dev->dev_ops->get_restore_flags != NULL)
> > +             dev->dev_ops->get_restore_flags(dev, op, flags);
> > +     else
> > +             *flags = RTE_ETH_RESTORE_ALL; }
> > diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
> > index ae00ead865..8ac5328521 100644
> > --- a/lib/ethdev/ethdev_driver.h
> > +++ b/lib/ethdev/ethdev_driver.h
> > @@ -1235,6 +1235,47 @@ typedef int (*eth_count_aggr_ports_t)(struct
> > rte_eth_dev *dev);  typedef int (*eth_map_aggr_tx_affinity_t)(struct
> rte_eth_dev *dev, uint16_t tx_queue_id,
> >                                         uint8_t affinity);
> >
> > +/**
> > + * @internal
> > + * Defines types of operations which can be executed by the application.
> > + */
> > +enum rte_eth_dev_operation {
> > +     RTE_ETH_START,
> > +};
> > +
> > +/**@{@name Restore flags
> > + * Flags returned by get_restore_flags() callback.
> > + * They indicate to ethdev layer which configuration is required to be restored.
> > + */
> > +/** If set, ethdev layer will forcefully restore default and any
> > +other added MAC addresses. */ #define RTE_ETH_RESTORE_MAC_ADDR
> > +RTE_BIT32(0)
> > +/** If set, ethdev layer will forcefully restore current promiscuous
> > +mode setting. */ #define RTE_ETH_RESTORE_PROMISC  RTE_BIT32(1)
> > +/** If set, ethdev layer will forcefully restore current all
> > +multicast mode setting. */ #define RTE_ETH_RESTORE_ALLMULTI
> > +RTE_BIT32(2) /**@}*/
> > +
> > +/** All configuration which can be restored by ethdev layer. */
> > +#define RTE_ETH_RESTORE_ALL (RTE_ETH_RESTORE_MAC_ADDR | \
> > +                          RTE_ETH_RESTORE_PROMISC | \
> > +                          RTE_ETH_RESTORE_ALLMULTI)
> > +
> > +/**
> > + * @internal
> > + * Fetch from the driver what kind of configuration must be restored
> > +by ethdev layer,
> > + * after certain operations are performed by the application (such as
> rte_eth_dev_start()).
> > + *
> > + * @param dev
> > + *   Port (ethdev) handle.
> > + * @param op
> > + *   Type of operation executed by the application.
> > + * @param flags
> > + *   Flags indicating what configuration must be restored by ethdev layer.
> > + */
> > +typedef void (*eth_get_restore_flags_t)(struct rte_eth_dev *dev,
> > +                                     enum rte_eth_dev_operation op,
> > +                                     uint32_t *flags);
> > +
> >  /**
> >   * @internal A structure containing the functions exported by an Ethernet
> driver.
> >   */
> > @@ -1474,6 +1515,9 @@ struct eth_dev_ops {
> >       eth_count_aggr_ports_t count_aggr_ports;
> >       /** Map a Tx queue with an aggregated port of the DPDK port */
> >       eth_map_aggr_tx_affinity_t map_aggr_tx_affinity;
> > +
> > +     /** Get configuration which ethdev should restore */
> > +     eth_get_restore_flags_t get_restore_flags;
> >  };
> >
> >  /**
> > @@ -2131,6 +2175,26 @@ struct rte_eth_fdir_conf {
> >       struct rte_eth_fdir_flex_conf flex_conf;  };
> >
> > +/**
> > + * @internal
> > + * Fetch from the driver what kind of configuration must be restored
> > +by ethdev layer,
> > + * using get_restore_flags() callback.
> > + *
> > + * If callback is not defined, it is assumed that all supported configuration must
> be restored.
> > + *
> > + * @param dev
> > + *   Port (ethdev) handle.
> > + * @param op
> > + *   Type of operation executed by the application.
> > + * @param flags
> > + *   Flags indicating what configuration must be restored by ethdev layer.
> > + */
> > +__rte_internal
> 
> For new function we probably need 'rte_experimental'...
> But from other side - it is internal.
> Not sure what are rules here for such case.
> 
> > +void
> > +rte_eth_get_restore_flags(struct rte_eth_dev *dev,
> > +                       enum rte_eth_dev_operation op,
> > +                       uint32_t *flags);
> > +
> >  #ifdef __cplusplus
> >  }
> >  #endif
> > diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map index
> > 1669055ca5..fa0469e602 100644
> > --- a/lib/ethdev/version.map
> > +++ b/lib/ethdev/version.map
> > @@ -358,4 +358,5 @@ INTERNAL {
> >       rte_eth_switch_domain_alloc;
> >       rte_eth_switch_domain_free;
> >       rte_flow_fp_default_ops;
> > +     rte_eth_get_restore_flags;
> >  };
> > --
> > 2.39.5