Re: [dpdk-dev] [PATCH v3 01/10] ethdev: add flow shared action API

[Andrey Vesnovaty <andreyv@nvidia.com>]

Hi Ori,

PSB

Thanks,
Andrey

> -----Original Message-----
> From: Ori Kam <orika@nvidia.com>
> Sent: Sunday, October 4, 2020 2:10 PM
> To: Andrey Vesnovaty <andreyv@nvidia.com>; dev@dpdk.org
> Cc: jer@marvell.com; jerinjacobk@gmail.com; NBU-Contact-Thomas Monjalon
> <thomas@monjalon.net>; ferruh.yigit@intel.com;
> stephen@networkplumber.org; bruce.richardson@intel.com; Slava Ovsiienko
> <viacheslavo@nvidia.com>; andrey.vesnovaty@gmail.com; mdr@ashroe.eu;
> nhorman@tuxdriver.com; ajit.khaparde@broadcom.com;
> samik.gupta@broadcom.com; Andrey Vesnovaty <andreyv@mellanox.com>;
> Andrew Rybchenko <arybchenko@solarflare.com>; Ori Kam
> <orika@mellanox.com>
> Subject: RE: [PATCH v3 01/10] ethdev: add flow shared action API
> 
> Hi Andrey,
> 
> You are missing the doc update (rte_flow)

Got it. Will update in release_notes_20.11.rst & testpmd.

> PSB for more comments.
> 
> Best,
> Ori
> 
> > -----Original Message-----
> > From: Andrey Vesnovaty <andreyv@nvidia.com>
> > Sent: Sunday, October 4, 2020 1:06 AM
> > Subject: [PATCH v3 01/10] ethdev: add flow shared action API
> >
> > This commit introduces extension of DPDK flow action API enabling
> > sharing of single rte_flow_action in multiple flows. The API intended for
> > PMDs where multiple HW offloaded flows can reuse the same HW
> > essence/object representing flow action and modification of such an
> > essence/object effects all the rules using it.
> >
> > Motivation and example
> > ===
> > Adding or removing one or more queues to RSS used by multiple flow rules
> > imposes per rule toll for current DPDK flow API; the scenario requires
> > for each flow sharing cloned RSS action:
> > - call `rte_flow_destroy()`
> > - call `rte_flow_create()` with modified RSS action
> >
> > API for sharing action and its in-place update benefits:
> > - reduce the overhead of multiple RSS flow rules reconfiguration
> > - optimize resource utilization by sharing action across of multiple
> >   flows
> >
> > Change description
> > ===
> >
> > Shared action
> > ===
> > In order to represent flow action shared by multiple flows new action
> > type RTE_FLOW_ACTION_TYPE_SHARED is introduced (see `enum
> > rte_flow_action_type`).
> > Actually the introduced API decouples action from any specific flow and
> > enables sharing of single action by its handle across multiple flows.
> >
> > Shared action create/use/destroy
> > ===
> > Shared action may be reused by some or none flow rules at any given
> > moment, i.e. shared action reside outside of the context of any flow.
> > Shared action represent HW resources/objects used for action offloading
> > implementation.
> > API for shared action create (see `rte_flow_shared_action_create()`):
> > - should allocate HW resources and make related initializations required
> >   for shared action implementation.
> > - make necessary preparations to maintain shared access to
> >   the action resources, configuration and state.
> > API for shared action destroy (see `rte_flow_shared_action_destroy()`)
> > should release HW resources and make related cleanups required for shared
> > action implementation.
> >
> > In order to share some flow action reuse the handle of type
> > `struct rte_flow_shared_action` returned by
> > rte_flow_shared_action_create() as a `conf` field of
> > `struct rte_flow_action` (see "example" section).
> >
> > If some shared action not used by any flow rule all resources allocated
> > by the shared action can be released by rte_flow_shared_action_destroy()
> > (see "example" section). The shared action handle passed as argument to
> > destroy API should not be used any further i.e. result of the usage is
> > undefined.
> >
> > Shared action re-configuration
> > ===
> > Shared action behavior defined by its configuration can be updated via
> > rte_flow_shared_action_update() (see "example" section). The shared
> > action update operation modifies HW related resources/objects allocated
> > on the action creation. The number of operations performed by the update
> > operation should not be dependent on number of flows sharing the related
> > action. On return of shared action update API action behavior should be
> > according to updated configuration for all flows sharing the action.
> >
> > Shared action query
> > ===
> > Provide separate API to query shared action sate (see
> 
> I think sate --> state, also it is not clear if we are sharing both configuration and
> state
> or only configuration. For example what will happen if we create counter and
> attached it
> to number of flow? Does it count for all flow so counter = flow1 + flow2?
> Or it is only for configuration which means that one each flow gets different
> counter?
> For counter there is a shared bit in the action so this can be used to determent if
> the state
> should be shared,  but counter doesn't have configuration to share.
> What happens with aging where we have state and configuration?
> 
> I'm O.K with starting just with configuration, but it should be clear.
>

Shared action state considered shared till it's defined differently.
So when shared action queried it's considered query for state.
Configuration of shred action controlled by rte_flow_sahred_action_create()
and rte_flow_shared_action_update() APIs and no supposed to change by
other means. Do you think there is a need to query shared action configuration?
 
> > rte_flow_shared_action_update()). Taking a counter as an example: query
> > returns value aggregating all counter increments across all flow rules
> > sharing the counter.
> >
> > PMD support
> > ===
> > The support of introduced API is pure PMD specific design and
> > responsibility for each action type (see struct rte_flow_ops).
> >
> > testpmd
> > ===
> > In order to utilize introduced API testpmd cli may implement following
> > extension
> > create/update/destroy/query shared action accordingly
> >
> > flow shared_action (port) create {action_id (id)} (action) / end
> > flow shared_action (port) update (id) (action) / end
> > flow shared_action (port) destroy action_id (id) {action_id (id) [...]}
> > flow shared_action (port) query (id)
> >
> > testpmd example
> > ===
> >
> > configure rss to queues 1 & 2
> >
> > > flow shared_action 0 create action_id 100 rss queues 1 2 end / end
> >
> > create flow rule utilizing shared action
> >
> > > flow create 0 ingress \
> >     pattern eth dst is 0c:42:a1:15:fd:ac / ipv6 / tcp / end \
> >   actions shared 100 / end
> >
> > add 2 more queues
> >
> > > flow shared_action 0 modify 100 rss queues 1 2 3 4 end / end
> >
> > example
> > ===
> >
> > struct rte_flow_action actions[2];
> > struct rte_flow_action action;
> > /* skipped: initialize action */
> > struct rte_flow_shared_action *handle = rte_flow_shared_action_create(
> > 					port_id, &action, &error);
> > actions[0].type = RTE_FLOW_ACTION_TYPE_SHARED;
> > actions[0].conf = handle;
> > actions[1].type = RTE_FLOW_ACTION_TYPE_END;
> > /* skipped: init attr0 & pattern0 args */
> > struct rte_flow *flow0 = rte_flow_create(port_id, &attr0, pattern0,
> > 					actions, error);
> > /* create more rules reusing shared action */
> > struct rte_flow *flow1 = rte_flow_create(port_id, &attr1, pattern1,
> > 					actions, error);
> > /* skipped: for flows 2 till N */
> > struct rte_flow *flowN = rte_flow_create(port_id, &attrN, patternN,
> > 					actions, error);
> > /* update shared action */
> > struct rte_flow_action updated_action;
> > /*
> >  * skipped: initialize updated_action according to desired action
> >  * configuration change
> >  */
> > rte_flow_shared_action_update(port_id, handle, &updated_action, error);
> > /*
> >  * from now on all flows 1 till N will act according to configuration of
> >  * updated_action
> >  */
> > /* skipped: destroy all flows 1 till N */
> > rte_flow_shared_action_destroy(port_id, handle, error);
> >
> > Signed-off-by: Andrey Vesnovaty <andreyv@mellanox.com>
> > Signed-off-by: Andrey Vesnovaty <andreyv@nvidia.com>
> > ---
> >  lib/librte_ethdev/rte_ethdev_version.map |   4 +
> >  lib/librte_ethdev/rte_flow.c             |  82 +++++++++++++
> >  lib/librte_ethdev/rte_flow.h             | 148 ++++++++++++++++++++++-
> >  lib/librte_ethdev/rte_flow_driver.h      |  22 ++++
> >  4 files changed, 255 insertions(+), 1 deletion(-)
> >
> > diff --git a/lib/librte_ethdev/rte_ethdev_version.map
> > b/lib/librte_ethdev/rte_ethdev_version.map
> > index fc47f6472e..168bf7fc12 100644
> > --- a/lib/librte_ethdev/rte_ethdev_version.map
> > +++ b/lib/librte_ethdev/rte_ethdev_version.map
> > @@ -225,6 +225,10 @@ EXPERIMENTAL {
> >  	rte_tm_shared_wred_context_delete;
> >  	rte_tm_wred_profile_add;
> >  	rte_tm_wred_profile_delete;
> > +	rte_flow_shared_action_create;
> > +	rte_flow_shared_action_destroy;
> > +	rte_flow_shared_action_update;
> > +	rte_flow_shared_action_query;
> >  };
> >
> >  INTERNAL {
> > diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c
> > index f8fdd68fe9..ba3f01f7c7 100644
> > --- a/lib/librte_ethdev/rte_flow.c
> > +++ b/lib/librte_ethdev/rte_flow.c
> > @@ -174,6 +174,7 @@ static const struct rte_flow_desc_data
> > rte_flow_desc_action[] = {
> >  	MK_FLOW_ACTION(SET_IPV4_DSCP, sizeof(struct
> > rte_flow_action_set_dscp)),
> >  	MK_FLOW_ACTION(SET_IPV6_DSCP, sizeof(struct
> > rte_flow_action_set_dscp)),
> >  	MK_FLOW_ACTION(AGE, sizeof(struct rte_flow_action_age)),
> > +	MK_FLOW_ACTION(SHARED, 0),
> >  };
> >
> >  int
> > @@ -1251,3 +1252,84 @@ rte_flow_get_aged_flows(uint16_t port_id, void
> > **contexts,
> >  				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
> >  				  NULL, rte_strerror(ENOTSUP));
> >  }
> > +
> > +struct rte_flow_shared_action *
> > +rte_flow_shared_action_create(uint16_t port_id,
> > +			      const struct rte_flow_action *action,
> > +			      struct rte_flow_error *error)
> 
> You are missing the property for direction that we agreed in previous version.
> 
> > +{
> > +	struct rte_eth_dev *dev = &rte_eth_devices[port_id];
> > +	struct rte_flow_shared_action *shared_action;
> > +	const struct rte_flow_ops *ops = rte_flow_ops_get(port_id, error);
> > +
> > +	if (unlikely(!ops))
> > +		return NULL;
> > +	if (likely(!!ops->shared_action_create)) {
> > +		shared_action = ops->shared_action_create(dev, action, error);
> > +		if (shared_action == NULL)
> > +			flow_err(port_id, -rte_errno, error);
> > +		return shared_action;
> > +	}
> > +	rte_flow_error_set(error, ENOSYS,
> > RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
> > +			   NULL, rte_strerror(ENOSYS));
> > +	return NULL;
> > +}
> > +
> > +int
> > +rte_flow_shared_action_destroy(uint16_t port_id,
> > +			      struct rte_flow_shared_action *action,
> > +			      struct rte_flow_error *error)
> > +{
> > +	struct rte_eth_dev *dev = &rte_eth_devices[port_id];
> > +	const struct rte_flow_ops *ops = rte_flow_ops_get(port_id, error);
> > +
> > +	if (unlikely(!ops))
> > +		return -rte_errno;
> > +	if (likely(!!ops->shared_action_destroy))
> > +		return flow_err(port_id,
> > +				ops->shared_action_destroy(dev, action,
> > error),
> > +				error);
> > +	return rte_flow_error_set(error, ENOSYS,
> > +				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
> > +				  NULL, rte_strerror(ENOSYS));
> > +}
> > +
> > +int
> > +rte_flow_shared_action_update(uint16_t port_id,
> > +			      struct rte_flow_shared_action *action,
> > +			      const struct rte_flow_action *update,
> > +			      struct rte_flow_error *error)
> > +{
> > +	struct rte_eth_dev *dev = &rte_eth_devices[port_id];
> > +	const struct rte_flow_ops *ops = rte_flow_ops_get(port_id, error);
> > +
> > +	if (unlikely(!ops))
> > +		return -rte_errno;
> > +	if (likely(!!ops->shared_action_update))
> > +		return flow_err(port_id, ops->shared_action_update(dev,
> > action,
> > +				update, error),
> > +			error);
> > +	return rte_flow_error_set(error, ENOSYS,
> > +				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
> > +				  NULL, rte_strerror(ENOSYS));
> > +}
> > +
> > +int
> > +rte_flow_shared_action_query(uint16_t port_id,
> > +			     const struct rte_flow_shared_action *action,
> > +			     void *data,
> > +			     struct rte_flow_error *error)
> > +{
> > +	struct rte_eth_dev *dev = &rte_eth_devices[port_id];
> > +	const struct rte_flow_ops *ops = rte_flow_ops_get(port_id, error);
> > +
> > +	if (unlikely(!ops))
> > +		return -rte_errno;
> > +	if (likely(!!ops->shared_action_query))
> > +		return flow_err(port_id, ops->shared_action_query(dev, action,
> > +				data, error),
> > +			error);
> > +	return rte_flow_error_set(error, ENOSYS,
> > +				  RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
> > +				  NULL, rte_strerror(ENOSYS));
> > +}
> > diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
> > index da8bfa5489..02391316cb 100644
> > --- a/lib/librte_ethdev/rte_flow.h
> > +++ b/lib/librte_ethdev/rte_flow.h
> > @@ -1714,7 +1714,8 @@ enum rte_flow_action_type {
> >  	/**
> >  	 * Enables counters for this flow rule.
> >  	 *
> > -	 * These counters can be retrieved and reset through rte_flow_query(),
> > +	 * These counters can be retrieved and reset through rte_flow_query()
> > or
> > +	 * rte_flow_shared_action_query() if the action provided via handle,
> >  	 * see struct rte_flow_query_count.
> >  	 *
> >  	 * See struct rte_flow_action_count.
> > @@ -2132,6 +2133,14 @@ enum rte_flow_action_type {
> >  	 * see enum RTE_ETH_EVENT_FLOW_AGED
> >  	 */
> >  	RTE_FLOW_ACTION_TYPE_AGE,
> > +
> > +	/**
> > +	 * Describes action shared a cross multiple flow rules.
> > +	 *
> > +	 * Enables multiple rules reference the same action by handle (see
> > +	 * struct rte_flow_shared_action).
> > +	 */
> > +	RTE_FLOW_ACTION_TYPE_SHARED,
> >  };
> >
> >  /**
> > @@ -2693,6 +2702,20 @@ struct rte_flow_action_set_dscp {
> >  	uint8_t dscp;
> >  };
> >
> > +
> > +/**
> > + * RTE_FLOW_ACTION_TYPE_SHARED
> > + *
> > + * Opaque type returned after successfully creating a shared action.
> > + *
> > + * This handle can be used to manage and query the related action:
> > + * - share it a cross multiple flow rules
> > + * - update action configuration
> > + * - query action data
> > + * - destroy action
> > + */
> > +struct rte_flow_shared_action;
> > +
> >  /* Mbuf dynamic field offset for metadata. */
> >  extern int32_t rte_flow_dynf_metadata_offs;
> >
> > @@ -3357,6 +3380,129 @@ int
> >  rte_flow_get_aged_flows(uint16_t port_id, void **contexts,
> >  			uint32_t nb_contexts, struct rte_flow_error *error);
> >
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this API may change without prior notice.
> > + *
> > + * Create shared action for reuse in multiple flow rules.
> > + *
> > + * @param[in] port_id
> > + *    The port identifier of the Ethernet device.
> > + * @param[in] action
> > + *   Action configuration for shared action creation.
> > + * @param[out] error
> > + *   Perform verbose error reporting if not NULL. PMDs initialize this
> > + *   structure in case of error only.
> > + * @return
> > + *   A valid handle in case of success, NULL otherwise and rte_errno is set
> > + *   to one of the error codes defined:
> > + *   - (ENOSYS) if underlying device does not support this functionality.
> > + *   - (EIO) if underlying device is removed.
> > + *   - (EINVAL) if *action* invalid.
> > + *   - (ENOTSUP) if *action* valid but unsupported.
> > + */
> > +__rte_experimental
> > +struct rte_flow_shared_action *
> > +rte_flow_shared_action_create(uint16_t port_id,
> > +			      const struct rte_flow_action *action,
> > +			      struct rte_flow_error *error);
> > +
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this API may change without prior notice.
> > + *
> > + * Destroys the shared action by handle.
> > + *
> > + * @param[in] port_id
> > + *    The port identifier of the Ethernet device.
> > + * @param[in] action
> > + *   Handle for the shared action to be destroyed.
> > + * @param[out] error
> > + *   Perform verbose error reporting if not NULL. PMDs initialize this
> > + *   structure in case of error only.
> > + * @return
> > + *   - (0) if success.
> > + *   - (-ENOSYS) if underlying device does not support this functionality.
> > + *   - (-EIO) if underlying device is removed.
> > + *   - (-ENOENT) if action pointed by *action* handle was not found.
> > + *   - (-ETOOMANYREFS) if action pointed by *action* handle still used by one
> > or
> > + *     more rules
> > + *   rte_errno is also set.
> > + */
> > +__rte_experimental
> > +int
> > +rte_flow_shared_action_destroy(uint16_t port_id,
> > +			      struct rte_flow_shared_action *action,
> > +			      struct rte_flow_error *error);
> > +
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this API may change without prior notice.
> > + *
> > + * Updates inplace the shared action configuration pointed by *action*
> handle
> > + * with the configuration provided as *update* argument.
> > + * The update of the shared action configuration effects all flow rules reusing
> > + * the action via handle.
> > + *
> > + * @param[in] port_id
> > + *    The port identifier of the Ethernet device.
> > + * @param[in] action
> > + *   Handle for the shared action to be updated.
> > + * @param[in] update
> > + *   Action specification used to modify the action pointed by handle.
> > + *   *update* should be of same type with the action pointed by the *action*
> > + *   handle argument, otherwise considered as invalid.
> > + * @param[out] error
> > + *   Perform verbose error reporting if not NULL. PMDs initialize this
> > + *   structure in case of error only.
> > + * @return
> > + *   - (0) if success.
> > + *   - (-ENOSYS) if underlying device does not support this functionality.
> > + *   - (-EIO) if underlying device is removed.
> > + *   - (-EINVAL) if *update* invalid.
> > + *   - (-ENOTSUP) if *update* valid but unsupported.
> > + *   - (-ENOENT) if action pointed by *ctx* was not found.
> > + *   rte_errno is also set.
> > + */
> > +__rte_experimental
> > +int
> > +rte_flow_shared_action_update(uint16_t port_id,
> > +			      struct rte_flow_shared_action *action,
> > +			      const struct rte_flow_action *update,
> > +			      struct rte_flow_error *error);
> > +
> > +/**
> > + * @warning
> > + * @b EXPERIMENTAL: this API may change without prior notice.
> > + *
> > + * Query the shared action by handle.
> > + *
> > + * This function allows retrieving action-specific data such as counters.
> > + * Data is gathered by special action which may be present/referenced in
> > + * more than one flow rule definition.
> > + *
> > + * \see RTE_FLOW_ACTION_TYPE_COUNT
> > + *
> > + * @param port_id
> > + *   Port identifier of Ethernet device.
> > + * @param[in] action
> > + *   Handle for the shared action to query.
> > + * @param[in, out] data
> > + *   Pointer to storage for the associated query data type.
> > + * @param[out] error
> > + *   Perform verbose error reporting if not NULL. PMDs initialize this
> > + *   structure in case of error only.
> > + *
> > + * @return
> > + *   0 on success, a negative errno value otherwise and rte_errno is set.
> > + */
> > +__rte_experimental
> > +int
> > +rte_flow_shared_action_query(uint16_t port_id,
> > +			     const struct rte_flow_shared_action *action,
> > +			     void *data,
> > +			     struct rte_flow_error *error);
> > +
> >  #ifdef __cplusplus
> >  }
> >  #endif
> > diff --git a/lib/librte_ethdev/rte_flow_driver.h
> > b/lib/librte_ethdev/rte_flow_driver.h
> > index 3ee871d3eb..72bfc3b7a7 100644
> > --- a/lib/librte_ethdev/rte_flow_driver.h
> > +++ b/lib/librte_ethdev/rte_flow_driver.h
> > @@ -108,6 +108,28 @@ struct rte_flow_ops {
> >  		 void **context,
> >  		 uint32_t nb_contexts,
> >  		 struct rte_flow_error *err);
> > +	/** See rte_flow_shared_action_create() */
> > +	struct rte_flow_shared_action *(*shared_action_create)
> > +		(struct rte_eth_dev *dev,
> > +		const struct rte_flow_action *action,
> > +		struct rte_flow_error *error);
> > +	/** See rte_flow_shared_action_destroy() */
> > +	int (*shared_action_destroy)
> > +		(struct rte_eth_dev *dev,
> > +		 struct rte_flow_shared_action *shared_action,
> > +		 struct rte_flow_error *error);
> > +	/** See rte_flow_shared_action_update() */
> > +	int (*shared_action_update)
> > +		(struct rte_eth_dev *dev,
> > +		 struct rte_flow_shared_action *shared_action,
> > +		 const struct rte_flow_action *update,
> > +		 struct rte_flow_error *error);
> > +	/** See rte_flow_shared_action_query() */
> > +	int (*shared_action_query)
> > +		(struct rte_eth_dev *dev,
> > +		 const struct rte_flow_shared_action *shared_action,
> > +		 void *data,
> > +		 struct rte_flow_error *error);
> >  };
> >
> >  /**
> > --
> > 2.26.2