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

Andrey Vesnovaty andreyv at nvidia.com
Sun Oct 4 00:06:10 CEST 2020


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
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 at mellanox.com>
Signed-off-by: Andrey Vesnovaty <andreyv at 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)
+{
+	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



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