> -----Original Message-----
> From: Nitin Saxena <nsax...@marvell.com>
> Sent: Wednesday, June 4, 2025 3:43 PM
> To: Jerin Jacob <jer...@marvell.com>; Kiran Kumar Kokkilagadda
> <kirankum...@marvell.com>; Nithin Kumar Dabilpuram
> <ndabilpu...@marvell.com>; Zhirun Yan <yanzhirun_...@163.com>; Robin
> Jarry <rja...@redhat.com>; Christophe Fontaine <cfont...@redhat.com>
> Cc: dev@dpdk.org; Nitin Saxena <nsaxen...@gmail.com>
> Subject: [PATCH v10 4/7] graph: add feature enable/disable APIs
>
> This patch also adds feature arc fast path APIs as well along with
> documentation
>
> Signed-off-by: Nitin Saxena <nsax...@marvell.com>
> ---
> doc/guides/prog_guide/graph_lib.rst | 180 ++++++
> lib/graph/graph_feature_arc.c | 701 ++++++++++++++++++++++-
> lib/graph/meson.build | 2 +-
> lib/graph/rte_graph_feature_arc.h | 134 ++++-
> lib/graph/rte_graph_feature_arc_worker.h | 305 +++++++++-
> 5 files changed, 1314 insertions(+), 8 deletions(-)
>
> diff --git a/doc/guides/prog_guide/graph_lib.rst
> b/doc/guides/prog_guide/graph_lib.rst
> index c9ac9e7ae0..fef384d836 100644
> --- a/doc/guides/prog_guide/graph_lib.rst
> +++ b/doc/guides/prog_guide/graph_lib.rst
> @@ -609,6 +609,8 @@ provides application to overload default node path by
> providing hook
> points(like netfilter) to insert out-of-tree or another protocol nodes in
> packet path.
>
> +.. _Control_Data_Plane_Synchronization:
> +
> Control/Data plane synchronization
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Feature arc does not stop worker cores for any runtime control plane updates.
> @@ -839,6 +841,11 @@ which might have allocated during feature enable.
> notifier_cb() is called, at runtime, for every enable/disable of ``[feature,
> index]`` from control thread.
>
> +If RCU is provided to enable/disable APIs, notifier_cb() is called after
> +``rte_rcu_qsbr_synchronize()``. Application also needs to call
> +``rte_rcu_qsbr_quiescent()`` in worker thread (preferably after every
> +``rte_graph_walk()`` iteration)
> +
> override_index_cb()
> ....................
> A feature arc is :ref:`registered<Feature_Arc_Registration>` to operate on
> @@ -869,3 +876,176 @@ sub-system. If not called, feature arc has no impact
> on application.
> ``rte_graph_feature_arc_init()`` API should be called before
> ``rte_graph_create()``. If not called, feature arc is a ``NOP`` to
> application.
> +
> +Runtime feature enable/disable
> +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> +A feature can be enabled or disabled at runtime from control thread using
> +``rte_graph_feature_enable()`` and ``rte_graph_feature_disable()`` APIs
> +respectively.
> +
> +.. code-block:: c
> +
> + struct rte_rcu_qsbr *rcu_qsbr = app_get_rcu_qsbr();
> + rte_graph_feature_arc_t _arc;
> + uint16_t app_cookie;
> +
> + if (rte_graph_feature_arc_lookup_by_name("Arc1", &_arc) < 0) {
> + RTE_LOG(ERR, GRAPH, "Arc1 not found\n");
> + return -ENOENT;
> + }
> + app_cookie = 100; /* Specific to ['Feature-1`, `port-0`]*/
> +
> + /* Enable feature */
> + rte_graph_feature_enable(_arc, 0 /* port-0 */,
> + "Feature-1" /* Name of the node feature */,
> + app_cookie, rcu_qsbr);
> +
> + /* Disable feature */
> + rte_graph_feature_disable(_arc, 0 /* port-0 */,
> + "Feature-1" /* Name of the node feature*/,
> + rcu_qsbr);
> +
> +.. note::
> +
> + RCU argument is optional argument to enable/disable APIs. See
> + :ref:`control/data plane
> + synchronization<Control_Data_Plane_Synchronization>` and
> + :ref:`notifier_cb<Feature_Notifier_Cb>` for more details on when RCU is
> + needed.
> +
> +Fast path traversal rules
> +^^^^^^^^^^^^^^^^^^^^^^^^^
> +``Start node``
> +**************
> +If feature arc is :ref:`initialized<Feature_Arc_Initialization>`,
> +``start_node_feature_process_fn()`` will be called by ``rte_graph_walk()``
> +instead of node's original ``process()``. This function should allow packets
> to
> +enter arc path whenever any feature is enabled at runtime
> +
> +.. code-block:: c
> +
> + static int nodeA_init(const struct rte_graph *graph, struct rte_node
> *node)
> + {
> + rte_graph_feature_arc_t _arc;
> +
> + if (rte_graph_feature_arc_lookup_by_name("Arc1", &_arc) < 0) {
> + RTE_LOG(ERR, GRAPH, "Arc1 not found\n");
> + return -ENOENT;
> + }
> +
> + /* Save arc in node context */
> + node->ctx = _arc;
> + return 0;
> + }
> +
> + int nodeA_process_inline(struct rte_graph *graph, struct rte_node *node,
> + void **objs, uint16_t nb_objs,
> + struct rte_graph_feature_arc *arc,
> + const int do_arc_processing)
> + {
> + for(uint16_t i = 0; i < nb_objs; i++) {
> + struct rte_mbuf *mbuf = objs[i];
> + rte_edge_t edge_to_child = 0; /* By default to Node-B */
> +
> + if (do_arc_processing) {
> + struct rte_graph_feature_arc_mbuf_dynfields *dyn =
> + rte_graph_feature_arc_mbuf_dynfields_get(mbuf, arc-
> >mbuf_dyn_offset);
> +
> + if (rte_graph_feature_data_first_feature_get(mbuf,
> mbuf->port,
> +
> &dyn->feature_data,
> + &edge_to_child)
> < 0) {
> +
> + /* Some feature is enabled, edge_to_child is overloaded*/
> + }
> + }
> + /* enqueue as usual */
> + rte_node_enqueue_x1(graph, node, mbuf, edge_to_child);
> + }
> + }
> +
> + int nodeA_feature_process_fn(struct rte_graph *graph, struct rte_node
> *node,
> + void **objs, uint16_t nb_objs)
> + {
> + struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(node-
> >ctx);
> +
> + if (unlikely(rte_graph_feature_arc_has_any_feature(arc)))
> + return nodeA_process_inline(graph, node, objs, nb_objs, arc, 1
> /* do
> arc processing */);
> + else
> + return nodeA_process_inline(graph, node, objs, nb_objs, NULL, 0
> /*
> skip arc processing */);
> + }
> +
> +``Feature nodes``
> +*****************
> +Following code-snippet explains fast path traversal rule for ``Feature-1``
> +:ref:`feature node<Feature_Nodes>` shown in :ref:`figure<Figure_Arc_2>`.
> +
> +.. code-block:: c
> +
> + static int Feature1_node_init(const struct rte_graph *graph, struct
> rte_node *node)
> + {
> + rte_graph_feature_arc_t _arc;
> +
> + if (rte_graph_feature_arc_lookup_by_name("Arc1", &_arc) < 0) {
> + RTE_LOG(ERR, GRAPH, "Arc1 not found\n");
> + return -ENOENT;
> + }
> +
> + /* Save arc in node context */
> + node->ctx = _arc;
> + return 0;
> + }
> +
> + int feature1_process_inline(struct rte_graph *graph, struct rte_node
> *node,
> + void **objs, uint16_t nb_objs,
> + struct rte_graph_feature_arc *arc)
> + {
> + for(uint16_t i = 0; i < nb_objs; i++) {
> + struct rte_mbuf *mbuf = objs[i];
> + rte_edge_t edge_to_child = 0; /* By default to Node-B */
> +
> + struct rte_graph_feature_arc_mbuf_dynfields *dyn =
> + rte_graph_feature_arc_mbuf_dynfields_get(mbuf, arc-
> >mbuf_dyn_offset);
> +
> + /* Get feature app cookie for mbuf */
> + uint16_t app_cookie = rte_graph_feature_data_app_cookie_get(mbuf,
> &dyn->feature_data);
> +
> + if (feature_local_lookup(app_cookie) {
> +
> + /* Packets is relevant to this feature. Move packet from arc
> path */
> + edge_to_child = X;
> +
> + } else {
> +
> + /* Packet not relevant to this feature. Send this packet to
> + * next enabled feature
> + */
> + rte_graph_feature_data_next_feature_get(mbuf, &dyn-
> >feature_data,
> + &edge_to_child);
> + }
> +
> + /* enqueue as usual */
> + rte_node_enqueue_x1(graph, node, mbuf, edge_to_child);
> + }
> + }
> +
> + int feature1_process_fn(struct rte_graph *graph, struct rte_node *node,
> + void **objs, uint16_t nb_objs)
> + {
> + struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(node-
> >ctx);
> +
> + return feature1_process_inline(graph, node, objs, nb_objs, arc);
> + }
> +
> +``End feature node``
> +********************
> +An end feature node is a feature node through which packets exits feature arc
> +path. It should not use any feature arc fast path APIs.
> +
> +Feature arc destroy
> +^^^^^^^^^^^^^^^^^^^
> +``rte_graph_feature_arc_destroy()`` can be used to free a arc object.
> +
> +Feature arc cleanup
> +^^^^^^^^^^^^^^^^^^^
> +``rte_graph_feature_arc_cleanup()`` can be used to free all resources
> +associated with feature arc module.
> diff --git a/lib/graph/graph_feature_arc.c b/lib/graph/graph_feature_arc.c
> index b28f0ec321..9cad82947a 100644
> --- a/lib/graph/graph_feature_arc.c
> +++ b/lib/graph/graph_feature_arc.c
> @@ -19,6 +19,9 @@
>
> #define graph_uint_cast(f) ((unsigned int)f)
>
> +#define fdata_fix_get(arc, feat, index) \
> + RTE_GRAPH_FEATURE_TO_FEATURE_DATA(arc, feat,
> index)
> +
> #define feat_dbg graph_dbg
>
> #define FEAT_COND_ERR(cond, ...) \
> @@ -61,6 +64,139 @@ static STAILQ_HEAD(, rte_graph_feature_arc_register)
> feature_arc_list =
> static STAILQ_HEAD(, rte_graph_feature_register) feature_list =
>
> STAILQ_HEAD_INITIALIZER(feature_list);
>
> + /*
> + * feature data index is not fixed for given [feature, index], although it
> can
> + * be, which is calculated as follows (fdata_fix_get())
> + *
> + * fdata = (arc->max_features * feature ) + index;
> + *
> + * But feature data index should not be fixed for any index. i.e
> + * on any index, feature data can be placed. A slow path array is
> + * maintained and within a feature range [start, end] it is checked where
> + * feature_data_index is already placed.
> + *
> + * If is_release == false. feature_data_index is searched in a feature
> range.
> + * If found, index is returned. If not found, then reserve and return.
> + *
> + * If is_release == true, then feature_data_index is released for further
> + * usage
> + */
> +static rte_graph_feature_data_t
> +fdata_dyn_reserve_or_rel(struct rte_graph_feature_arc *arc,
> rte_graph_feature_t f,
> + uint32_t index, bool is_release,
> + bool fdata_provided, rte_graph_feature_data_t fd)
> +{
> + rte_graph_feature_data_t start, end, fdata;
> + rte_graph_feature_t next_feat;
> +
> + if (fdata_provided)
> + fdata = fd;
> + else
> + fdata = fdata_fix_get(arc, f, index);
> +
> + next_feat = f + 1;
> + /* Find in a given feature range, feature data is stored or not */
> + for (start = fdata_fix_get(arc, f, 0),
> + end = fdata_fix_get(arc, next_feat, 0);
> + start < end;
> + start++) {
> + if (arc->feature_data_by_index[start] == fdata) {
> + if (is_release)
> + arc->feature_data_by_index[start] =
> RTE_GRAPH_FEATURE_DATA_INVALID;
> +
> + return start;
> + }
> + }
> +
> + if (is_release)
> + return RTE_GRAPH_FEATURE_DATA_INVALID;
> +
> + /* If not found, then reserve valid one */
> + for (start = fdata_fix_get(arc, f, 0),
> + end = fdata_fix_get(arc, next_feat, 0);
> + start < end;
> + start++) {
> + if (arc->feature_data_by_index[start] ==
> RTE_GRAPH_FEATURE_DATA_INVALID) {
> + arc->feature_data_by_index[start] = fdata;
> + return start;
> + }
> + }
> +
> + /* This should not happen */
> + if (!fdata_provided)
> + RTE_VERIFY(0);
> +
Why panic? Return error.
> + return RTE_GRAPH_FEATURE_DATA_INVALID;
> +}
> +
> +static rte_graph_feature_data_t
> +fdata_reserve(struct rte_graph_feature_arc *arc,
> + rte_graph_feature_t feature,
> + uint32_t index)
> +{
> + return fdata_dyn_reserve_or_rel(arc, feature + 1, index, false, false,
> 0);
> +}
> +
> +static rte_graph_feature_data_t
> +fdata_release(struct rte_graph_feature_arc *arc,
> + rte_graph_feature_t feature,
> + uint32_t index)
> +{
> + return fdata_dyn_reserve_or_rel(arc, feature + 1, index, true, false,
> 0);
> +}
> +
> +static rte_graph_feature_data_t
> +first_fdata_reserve(struct rte_graph_feature_arc *arc,
> + uint32_t index)
> +{
> + return fdata_dyn_reserve_or_rel(arc, 0, index, false, false, 0);
> +}
> +
> +static rte_graph_feature_data_t
> +first_fdata_release(struct rte_graph_feature_arc *arc,
> + uint32_t index)
> +{
> + return fdata_dyn_reserve_or_rel(arc, 0, index, true, false, 0);
> +}
> +
> +static rte_graph_feature_data_t
> +extra_fdata_reserve(struct rte_graph_feature_arc *arc,
> + rte_graph_feature_t feature,
> + uint32_t index)
> +{
> + rte_graph_feature_data_t fdata, fdata2;
> + rte_graph_feature_t f;
> +
> + f = arc->num_added_features + NUM_EXTRA_FEATURE_DATA - 1;
> +
> + fdata = fdata_dyn_reserve_or_rel(arc, f, index,
> + false, true, fdata_fix_get(arc,
> feature +
> 1, index));
> +
> + /* we do not have enough space in as
> + * extra fdata accommodates indexes for all features
> + * Needed (feature * index) space but has only (index) number of
> space.
> + * So dynamic allocation can fail. When fail use static allocation
> + */
> + if (fdata == RTE_GRAPH_FEATURE_DATA_INVALID) {
> + fdata = fdata_fix_get(arc, feature + 1, index);
> + fdata2 = fdata_fix_get(arc, f, index);
> + arc->feature_data_by_index[fdata2] = fdata;
> + }
> + return fdata;
> +}
> +
> +static rte_graph_feature_data_t
> +extra_fdata_release(struct rte_graph_feature_arc *arc,
> + rte_graph_feature_t feature,
> + uint32_t index)
> +{
> + rte_graph_feature_t f;
> +
> + f = arc->num_added_features + NUM_EXTRA_FEATURE_DATA - 1;
> + return fdata_dyn_reserve_or_rel(arc, f, index,
> + true, true, fdata_fix_get(arc, feature +
> 1, index));
> +}
> +
> /* feature registration validate */
> static int
> feature_registration_validate(struct rte_graph_feature_register *feat_entry,
> @@ -341,7 +477,10 @@ graph_first_feature_data_ptr_get(struct
> rte_graph_feature_arc *arc,
> static int
> feature_arc_data_reset(struct rte_graph_feature_arc *arc)
> {
> + rte_graph_feature_data_t first_fdata;
> + struct rte_graph_feature_data *fdata;
> rte_graph_feature_data_t *f = NULL;
> + rte_graph_feature_t iter;
> uint16_t index;
>
> arc->runtime_enabled_features = 0;
> @@ -351,6 +490,15 @@ feature_arc_data_reset(struct
> rte_graph_feature_arc *arc)
> *f = RTE_GRAPH_FEATURE_DATA_INVALID;
> }
>
> + for (iter = 0; iter < arc->max_features + NUM_EXTRA_FEATURE_DATA;
> iter++) {
> + first_fdata = fdata_fix_get(arc, iter, 0);
> + for (index = 0; index < arc->max_indexes; index++) {
> + fdata = rte_graph_feature_data_get(arc, first_fdata +
> index);
> + fdata->next_feature_data =
> RTE_GRAPH_FEATURE_DATA_INVALID;
> + fdata->app_cookie = UINT16_MAX;
> + fdata->next_edge = RTE_EDGE_ID_INVALID;
> + }
> + }
> return 0;
> }
>
> @@ -479,6 +627,102 @@ get_existing_edge(const char *arc_name,
> rte_node_t parent_node,
> return -1;
> }
>
> +
> +/* prepare feature arc after addition of all features */
> +static int
> +prepare_feature_arc_before_first_enable(struct rte_graph_feature_arc *arc)
> +{
> + struct rte_graph_feature_node_list *lfinfo = NULL;
> + struct rte_graph_feature_node_list *finfo = NULL;
> + char name[2 * RTE_GRAPH_FEATURE_ARC_NAMELEN];
> + uint32_t findex = 0, iter;
> + uint16_t num_fdata;
> + rte_edge_t edge;
> + size_t sz = 0;
> +
> + STAILQ_FOREACH(lfinfo, &arc->all_features, next_feature) {
> + lfinfo->finfo_index = findex;
> + findex++;
> + }
> + if (!findex) {
> + graph_err("No feature added to arc: %s", arc-
> >feature_arc_name);
> + return -1;
> + }
> + arc->num_added_features = findex;
> + num_fdata = arc->num_added_features +
> NUM_EXTRA_FEATURE_DATA;
> +
> + sz = num_fdata * arc->max_indexes *
> sizeof(rte_graph_feature_data_t);
> +
> + snprintf(name, sizeof(name), "%s-fdata", arc->feature_arc_name);
> +
> + arc->feature_data_by_index = rte_malloc(name, sz, 0);
> + if (!arc->feature_data_by_index) {
> + graph_err("fdata/index rte_malloc failed for %s", name);
> + return -1;
> + }
> +
> + for (iter = 0; iter < (num_fdata * arc->max_indexes); iter++)
> + arc->feature_data_by_index[iter] =
> RTE_GRAPH_FEATURE_DATA_INVALID;
> +
> + /* Grab finfo corresponding to end_feature */
> + nodeinfo_lkup_by_index(arc, arc->num_added_features - 1, &lfinfo,
> 0);
> +
> + /* lfinfo should be the info corresponding to end_feature
> + * Add edge from all features to end feature node to have exception
> path
> + * in fast path from all feature nodes to end feature node during
> enable/disable
> + */
> + if (lfinfo->feature_node_id != arc->end_feature.feature_node_id) {
> + graph_err("end_feature node mismatch [found-%s: exp-%s]",
> + rte_node_id_to_name(lfinfo->feature_node_id),
> + rte_node_id_to_name(arc-
> >end_feature.feature_node_id));
> + goto free_fdata_by_index;
> + }
> +
> + STAILQ_FOREACH(finfo, &arc->all_features, next_feature) {
> + if (get_existing_edge(arc->feature_arc_name, arc-
> >start_node->id,
> + finfo->feature_node_id, &edge)) {
> + graph_err("No edge found from %s to %s",
> + rte_node_id_to_name(arc->start_node->id),
> + rte_node_id_to_name(finfo-
> >feature_node_id));
> + goto free_fdata_by_index;
> + }
> + finfo->edge_to_this_feature = edge;
> +
> + if (finfo == lfinfo)
> + continue;
> +
> + if (get_existing_edge(arc->feature_arc_name, finfo-
> >feature_node_id,
> + lfinfo->feature_node_id, &edge)) {
> + graph_err("No edge found from %s to %s",
> + rte_node_id_to_name(finfo-
> >feature_node_id),
> + rte_node_id_to_name(lfinfo-
> >feature_node_id));
> + goto free_fdata_by_index;
> + }
> + finfo->edge_to_last_feature = edge;
> + }
> + /**
> + * Enable end_feature in control bitmask
> + * (arc->feature_bit_mask_by_index) but not in fast path bitmask
> + * arc->fp_feature_enable_bitmask. This is due to:
> + * 1. Application may not explicitly enabling end_feature node
> + * 2. However it should be enabled internally so that when a feature is
> + * disabled (say on an interface), next_edge of data should be
> + * updated to end_feature node hence packet can exit arc.
> + * 3. We do not want to set bit for end_feature in fast path bitmask as
> + * it will void the purpose of fast path APIs
> + * rte_graph_feature_arc_is_any_feature_enabled(). Since enabling
> + * end_feature would make these APIs to always return "true"
> + */
> + for (iter = 0; iter < arc->max_indexes; iter++)
> + arc->feature_bit_mask_by_index[iter] |= (1 << lfinfo-
> >finfo_index);
> +
> + return 0;
> +
> +free_fdata_by_index:
> + rte_free(arc->feature_data_by_index);
> + return -1;
> +}
> +
> /* feature arc sanity */
> static int
> feature_arc_sanity(rte_graph_feature_arc_t _arc)
> @@ -588,6 +832,229 @@
> feature_arc_main_init(rte_graph_feature_arc_main_t **pfl, uint32_t
> max_feature_a
> return 0;
> }
>
> +static int
> +feature_enable_disable_validate(rte_graph_feature_arc_t _arc, uint32_t
> index,
> + const char *feature_name,
> + int is_enable_disable, bool emit_logs)
> +{
> + struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> + struct rte_graph_feature_node_list *finfo = NULL;
> + uint32_t slot, last_end_feature;
> +
> + if (!arc)
> + return -EINVAL;
> +
> + /* validate _arc */
> + if (arc->feature_arc_main != __rte_graph_feature_arc_main) {
> + FEAT_COND_ERR(emit_logs, "invalid feature arc: 0x%x", _arc);
> + return -EINVAL;
> + }
> +
> + /* validate index */
> + if (index >= arc->max_indexes) {
> + FEAT_COND_ERR(emit_logs, "%s: Invalid provided index: %u
> >= %u configured",
> + arc->feature_arc_name, index, arc->max_indexes);
> + return -1;
> + }
> +
> + /* validate feature_name is already added or not */
> + if (nodeinfo_lkup_by_name(arc, feature_name, &finfo, &slot)) {
> + FEAT_COND_ERR(emit_logs, "%s: No feature %s added",
> + arc->feature_arc_name, feature_name);
> + return -EINVAL;
> + }
> +
> + if (!finfo) {
> + FEAT_COND_ERR(emit_logs, "%s: No feature: %s found to
> enable/disable",
> + arc->feature_arc_name, feature_name);
> + return -EINVAL;
> + }
> +
> + /* slot should be in valid range */
> + if (slot >= arc->num_added_features) {
> + FEAT_COND_ERR(emit_logs, "%s/%s: Invalid free slot
> %u(max=%u) for feature",
> + arc->feature_arc_name, feature_name, slot, arc-
> >num_added_features);
> + return -EINVAL;
> + }
> +
> + /* slot should be in range of 0 - 63 */
> + if (slot > (GRAPH_FEATURE_MAX_NUM_PER_ARC - 1)) {
> + FEAT_COND_ERR(emit_logs, "%s/%s: Invalid slot: %u", arc-
> >feature_arc_name,
> + feature_name, slot);
> + return -EINVAL;
> + }
> +
> + last_end_feature = rte_fls_u64(arc-
> >feature_bit_mask_by_index[index]);
> + if (!last_end_feature) {
> + FEAT_COND_ERR(emit_logs, "%s: End feature not enabled",
> arc->feature_arc_name);
> + return -EINVAL;
> + }
> +
> + /* if enabled feature is not end feature node and already enabled */
> + if (is_enable_disable &&
> + (arc->feature_bit_mask_by_index[index] & RTE_BIT64(slot)) &&
> + (slot != (last_end_feature - 1))) {
> + FEAT_COND_ERR(emit_logs, "%s: %s already enabled on
> index: %u",
> + arc->feature_arc_name, feature_name, index);
> + return -1;
> + }
> +
> + if (!is_enable_disable && !arc->runtime_enabled_features) {
> + FEAT_COND_ERR(emit_logs, "%s: No feature enabled to
> disable",
> + arc->feature_arc_name);
> + return -1;
> + }
> +
> + if (!is_enable_disable && !(arc->feature_bit_mask_by_index[index] &
> RTE_BIT64(slot))) {
> + FEAT_COND_ERR(emit_logs, "%s: %s not enabled in bitmask
> for index: %u",
> + arc->feature_arc_name, feature_name, index);
> + return -1;
> + }
> +
> + /* If no feature has been enabled, avoid extra sanity checks */
> + if (!arc->runtime_enabled_features)
> + return 0;
> +
> + if (finfo->finfo_index != slot) {
> + FEAT_COND_ERR(emit_logs,
> + "%s/%s: lookup slot mismatch for finfo idx: %u and
> lookup slot: %u",
> + arc->feature_arc_name, feature_name, finfo-
> >finfo_index, slot);
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +static int
> +refill_fastpath_data(struct rte_graph_feature_arc *arc, uint32_t feature_bit,
> + uint16_t index /* array index */, int is_enable_disable)
> +{
> + struct rte_graph_feature_data *gfd = NULL, *prev_gfd = NULL, *fdptr =
> NULL;
> + struct rte_graph_feature_node_list *finfo = NULL, *prev_finfo = NULL;
> + RTE_ATOMIC(rte_graph_feature_data_t) * first_fdata = NULL;
> + uint32_t fi = 0, prev_fi = 0, next_fi = 0, cfi = 0;
> + uint64_t bitmask = 0, prev_bitmask, next_bitmask;
> + rte_graph_feature_data_t *__first_fd = NULL;
> + rte_edge_t edge = RTE_EDGE_ID_INVALID;
> + rte_graph_feature_data_t fdata, _fd;
> + bool update_first_feature = false;
> +
> + if (is_enable_disable)
> + bitmask = RTE_BIT64(feature_bit);
> +
> + /* set bit from (feature_bit + 1) to 64th bit */
> + next_bitmask = UINT64_MAX << (feature_bit + 1);
> +
> + /* set bits from 0 to (feature_bit - 1) */
> + prev_bitmask = ((UINT64_MAX & ~next_bitmask) &
> ~(RTE_BIT64(feature_bit)));
> +
> + next_bitmask &= arc->feature_bit_mask_by_index[index];
> + prev_bitmask &= arc->feature_bit_mask_by_index[index];
> +
> + /* Set next bit set in next_bitmask */
> + if (rte_bsf64_safe(next_bitmask, &next_fi))
> + bitmask |= RTE_BIT64(next_fi);
> +
> + /* Set prev bit set in prev_bitmask*/
> + prev_fi = rte_fls_u64(prev_bitmask);
> + if (prev_fi)
> + bitmask |= RTE_BIT64(prev_fi - 1);
> +
> + /* for each feature set for index, set fast path data */
> + prev_gfd = NULL;
> + while (rte_bsf64_safe(bitmask, &fi)) {
> + _fd = fdata_reserve(arc, fi, index);
> + gfd = rte_graph_feature_data_get(arc, _fd);
> +
> + RTE_VERIFY(!nodeinfo_lkup_by_index(arc, fi, &finfo, 1));
> +
> + /* Reset next edge to point to last feature node so that packet
> + * can exit from arc
> + */
> + rte_atomic_store_explicit(&gfd->next_edge,
> + finfo->edge_to_last_feature,
> + rte_memory_order_relaxed);
> +
> + /* If previous feature_index was valid in last loop */
> + if (prev_gfd != NULL) {
> + /*
> + * Get edge of previous feature node connecting
> + * to this feature node
> + */
> + RTE_VERIFY(!nodeinfo_lkup_by_index(arc, prev_fi,
> &prev_finfo, 1));
> +
> + if (!get_existing_edge(arc->feature_arc_name,
> + prev_finfo->feature_node_id,
> + finfo->feature_node_id, &edge)) {
> + feat_dbg("\t[%s/index:%2u,cookie:%u]: (%u-
> >%u)%s[%u] = %s",
> + arc->feature_arc_name, index,
> + gfd->app_cookie, prev_fi, fi,
> + rte_node_id_to_name(prev_finfo-
> >feature_node_id),
> + edge, rte_node_id_to_name(finfo-
> >feature_node_id));
> +
> + rte_atomic_store_explicit(&prev_gfd-
> >next_edge,
> + edge,
> +
> rte_memory_order_relaxed);
> +
> + rte_atomic_store_explicit(&prev_gfd-
> >next_feature_data, _fd,
> +
> rte_memory_order_relaxed);
> + } else {
> + /* Should not fail */
> + RTE_VERIFY(0);
> + }
> + }
> + /* On first feature
> + * 1. Update fdata with next_edge from start_node to feature
> node
> + * 2. Update first enabled feature in its index array
> + */
> + if (rte_bsf64_safe(arc->feature_bit_mask_by_index[index],
> &cfi)) {
> + update_first_feature = (cfi == fi) ? true : false;
> +
> + if (update_first_feature) {
> + feat_dbg("\t[%s/index:%2u,cookie:%u]: (-
> >%u)%s[%u]=%s",
> + arc->feature_arc_name, index,
> + gfd->app_cookie, fi,
> + arc->start_node->name, finfo-
> >edge_to_this_feature,
> + rte_node_id_to_name(finfo-
> >feature_node_id));
> +
> + /* Reserve feature data @0th index for first
> feature */
> + fdata = first_fdata_reserve(arc, index);
> + fdptr = rte_graph_feature_data_get(arc,
> fdata);
> +
> + /* add next edge into feature data
> + * First set feature data then first feature
> memory
> + */
> + rte_atomic_store_explicit(&fdptr->next_edge,
> + finfo-
> >edge_to_this_feature,
> +
> rte_memory_order_relaxed);
> +
> + rte_atomic_store_explicit(&fdptr-
> >next_feature_data,
> + _fd,
> +
> rte_memory_order_relaxed);
> +
> + __first_fd =
> graph_first_feature_data_ptr_get(arc, index);
> + first_fdata =
> (RTE_ATOMIC(rte_graph_feature_data_t) *)__first_fd;
> +
> + /* Save reserved feature data @fp_index */
> + rte_atomic_store_explicit(first_fdata, fdata,
> +
> rte_memory_order_relaxed);
> + }
> + }
> + prev_fi = fi;
> + prev_gfd = gfd;
> + /* Clear current feature index */
> + bitmask &= ~RTE_BIT64(fi);
> + }
> + /* If all features are disabled on index, except end feature
> + * then release 0th index
> + */
> + if (!is_enable_disable &&
> + (rte_popcount64(arc->feature_bit_mask_by_index[index]) == 1))
> + first_fdata_release(arc, index);
> +
> + return 0;
> +}
> +
> /* feature arc initialization, public API */
> RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_graph_feature_arc_init, 25.07);
> int
> @@ -1130,6 +1597,197 @@
> rte_graph_feature_lookup(rte_graph_feature_arc_t _arc, const char
> *feature_name,
> return -1;
> }
>
> +RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_graph_feature_enable, 25.07);
> +int
> +rte_graph_feature_enable(rte_graph_feature_arc_t _arc, uint32_t index,
> + const char *feature_name, uint16_t app_cookie,
> + struct rte_rcu_qsbr *qsbr)
> +{
> + struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> + struct rte_graph_feature_node_list *finfo = NULL;
> + struct rte_graph_feature_data *gfd = NULL;
> + uint64_t bitmask;
> + uint32_t slot;
> +
> + if (!arc) {
> + graph_err("Invalid feature arc: 0x%x", _arc);
> + return -1;
> + }
> +
> + feat_dbg("%s: Enabling feature: %s for index: %u",
> + arc->feature_arc_name, feature_name, index);
> +
> + if ((!arc->runtime_enabled_features &&
> + (prepare_feature_arc_before_first_enable(arc) < 0)))
> + return -1;
> +
> + if (feature_enable_disable_validate(_arc, index, feature_name, 1 /*
> enable */, true))
> + return -1;
> +
> + /** This should not fail as validate() has passed */
> + if (nodeinfo_lkup_by_name(arc, feature_name, &finfo, &slot))
> + RTE_VERIFY(0);
> +
> + gfd = rte_graph_feature_data_get(arc, fdata_reserve(arc, slot, index));
> +
> + /* Set current app_cookie */
> + rte_atomic_store_explicit(&gfd->app_cookie, app_cookie,
> rte_memory_order_relaxed);
> +
> + /* Set bitmask in control path bitmask */
> + rte_bit_relaxed_set64(graph_uint_cast(slot), &arc-
> >feature_bit_mask_by_index[index]);
> +
> + refill_fastpath_data(arc, slot, index, 1 /* enable */);
> +
> + /* On very first feature enable instance */
> + if (!finfo->ref_count) {
> + /* If first time feature getting enabled
> + */
> + bitmask = rte_atomic_load_explicit(&arc-
> >fp_feature_enable_bitmask,
> +
> rte_memory_order_relaxed);
> +
> + bitmask |= RTE_BIT64(slot);
> +
> + rte_atomic_store_explicit(&arc->fp_feature_enable_bitmask,
> + bitmask,
> rte_memory_order_relaxed);
> + }
> +
> + /* Slow path updates */
> + arc->runtime_enabled_features++;
> +
> + /* Increase feature node info reference count */
> + finfo->ref_count++;
> +
> + /* Release extra fdata, if reserved before */
> + extra_fdata_release(arc, slot, index);
> +
> + if (qsbr)
> + rte_rcu_qsbr_synchronize(qsbr, RTE_QSBR_THRID_INVALID);
> +
> + if (finfo->notifier_cb)
> + finfo->notifier_cb(arc->feature_arc_name, finfo-
> >feature_name,
> + finfo->feature_node_id, index,
> + true /* enable */, gfd->app_cookie);
> +
> + return 0;
> +}
> +
> +RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_graph_feature_disable, 25.07);
> +int
> +rte_graph_feature_disable(rte_graph_feature_arc_t _arc, uint32_t index,
> const char *feature_name,
> + struct rte_rcu_qsbr *qsbr)
> +{
> + struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> + struct rte_graph_feature_data *gfd = NULL, *extra_gfd = NULL;
> + struct rte_graph_feature_node_list *finfo = NULL;
> + rte_graph_feature_data_t extra_fdata;
> + uint32_t slot, last_end_feature;
> + uint64_t bitmask;
> +
> + if (!arc) {
> + graph_err("Invalid feature arc: 0x%x", _arc);
> + return -1;
> + }
> + feat_dbg("%s: Disable feature: %s for index: %u",
> + arc->feature_arc_name, feature_name, index);
> +
> + if (feature_enable_disable_validate(_arc, index, feature_name, 0,
> true))
> + return -1;
> +
> + if (nodeinfo_lkup_by_name(arc, feature_name, &finfo, &slot))
> + return -1;
> +
> + last_end_feature = rte_fls_u64(arc-
> >feature_bit_mask_by_index[index]);
> + if (last_end_feature != arc->num_added_features) {
> + graph_err("%s/%s: No end feature enabled",
> + arc->feature_arc_name, feature_name);
> + return -1;
> + }
> +
> + /* If feature is not last feature, unset in control plane bitmask */
> + last_end_feature = arc->num_added_features - 1;
> + if (slot != last_end_feature)
> + rte_bit_relaxed_clear64(graph_uint_cast(slot),
> + &arc-
> >feature_bit_mask_by_index[index]);
> +
> + /* we have allocated one extra feature data space. Get extra feature
> data
> + * No need to reserve instead use fixed extra data for an index
> + */
> + extra_fdata = extra_fdata_reserve(arc, slot, index);
> + extra_gfd = rte_graph_feature_data_get(arc, extra_fdata);
> +
> + gfd = rte_graph_feature_data_get(arc, fdata_reserve(arc, slot, index));
> +
> + /*
> + * Packets may have reached to feature node which is getting disabled.
> + * We want to steer those packets to last feature node so that they can
> + * exit arc
> + * - First, reset next_edge of extra feature data to point to
> last_feature_node
> + * - Secondly, reset next_feature_data of current feature getting
> disabled to extra
> + * feature data
> + */
> + rte_atomic_store_explicit(&extra_gfd->next_edge, finfo-
> >edge_to_last_feature,
> + rte_memory_order_relaxed);
> + rte_atomic_store_explicit(&extra_gfd->next_feature_data,
> RTE_GRAPH_FEATURE_DATA_INVALID,
> + rte_memory_order_relaxed);
> + rte_atomic_store_explicit(&gfd->next_feature_data, extra_fdata,
> + rte_memory_order_relaxed);
> + rte_atomic_store_explicit(&gfd->next_edge, finfo-
> >edge_to_last_feature,
> + rte_memory_order_relaxed);
> +
> + /* Now we can unwire fast path*/
> + refill_fastpath_data(arc, slot, index, 0 /* disable */);
> +
> + finfo->ref_count--;
> +
> + /* When last feature is disabled */
> + if (!finfo->ref_count) {
> + /* If no feature enabled, reset feature in u64 fast path bitmask
> */
> + bitmask = rte_atomic_load_explicit(&arc-
> >fp_feature_enable_bitmask,
> +
> rte_memory_order_relaxed);
> + bitmask &= ~(RTE_BIT64(slot));
> + rte_atomic_store_explicit(&arc->fp_feature_enable_bitmask,
> bitmask,
> + rte_memory_order_relaxed);
> + }
> +
> + if (qsbr)
> + rte_rcu_qsbr_synchronize(qsbr, RTE_QSBR_THRID_INVALID);
> +
> + /* Call notifier cb with valid app_cookie */
> + if (finfo->notifier_cb)
> + finfo->notifier_cb(arc->feature_arc_name, finfo-
> >feature_name,
> + finfo->feature_node_id, index,
> + false /* disable */, gfd->app_cookie);
> +
> + /*
> + * 1. Do not reset gfd for now as feature node might be in execution
> + *
> + * 2. We also don't call fdata_release() as that may return same
> + * feature_data for other index for case like:
> + *
> + * feature_enable(arc, index-0, feature_name, cookie1);
> + * feature_enable(arc, index-1, feature_name, cookie2);
> + *
> + * Second call can return same fdata which we avoided releasing here.
> + * In order to make above case work, application has to mandatory use
> + * RCU mechanism. For now fdata is not released until arc_destroy
> + *
> + * Only exception is
> + * for(i=0; i< 100; i++) {
> + * feature_enable(arc, index-0, feature_name, cookie1);
> + * feature_disable(arc, index-0, feature_name, cookie1);
> + * }
> + * where RCU should be used but this is not valid use-case from
> control plane.
> + * If it is valid use-case then provide RCU argument
> + */
> +
> + /* Reset app_cookie later after calling notifier_cb */
> + rte_atomic_store_explicit(&gfd->app_cookie, UINT16_MAX,
> rte_memory_order_relaxed);
> +
> + arc->runtime_enabled_features--;
> +
> + return 0;
> +}
> +
> RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_graph_feature_arc_destroy,
> 25.07);
> int
> rte_graph_feature_arc_destroy(rte_graph_feature_arc_t _arc)
> @@ -1137,6 +1795,8 @@
> rte_graph_feature_arc_destroy(rte_graph_feature_arc_t _arc)
> struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> rte_graph_feature_arc_main_t *dm = __rte_graph_feature_arc_main;
> struct rte_graph_feature_node_list *node_info = NULL;
> + struct rte_graph_feature_data *fdptr = NULL;
> + rte_graph_feature_data_t fdata;
> int iter;
>
> if (!arc) {
> @@ -1155,11 +1815,28 @@
> rte_graph_feature_arc_destroy(rte_graph_feature_arc_t _arc)
> RTE_BIT64(node_info->finfo_index)))
> continue;
>
> - node_info->notifier_cb(arc-
> >feature_arc_name,
> - node_info->feature_name,
> - node_info-
> >feature_node_id,
> - iter, false /* disable
> */,
> - UINT16_MAX /* invalid
> cookie */);
> + /* fdata_reserve would return already
> allocated
> + * fdata for [finfo_index, iter]
> + */
> + fdata = fdata_reserve(arc, node_info-
> >finfo_index, iter);
> + if (fdata !=
> RTE_GRAPH_FEATURE_DATA_INVALID) {
> + fdptr =
> rte_graph_feature_data_get(arc, fdata);
> + node_info->notifier_cb(arc-
> >feature_arc_name,
> + node_info-
> >feature_name,
> + node_info-
> >feature_node_id,
> + iter, false /*
> disable */,
> + fdptr-
> >app_cookie);
> + } else {
> + node_info->notifier_cb(arc-
> >feature_arc_name,
> + node_info-
> >feature_name,
> + node_info-
> >feature_node_id,
> + iter, false /*
> disable */,
> + UINT16_MAX /*
> invalid cookie */);
> + }
> + /* fdata_release() is not used yet, use it for
> sake
> + * of function unused warnings
> + */
> + fdata = fdata_release(arc, node_info-
> >finfo_index, iter);
> }
> }
> rte_free(node_info);
> @@ -1239,6 +1916,20 @@ rte_graph_feature_arc_lookup_by_name(const
> char *arc_name, rte_graph_feature_arc
> return -1;
> }
>
> +RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_graph_feature_arc_num_enable
> d_features, 25.07);
> +uint32_t
> +rte_graph_feature_arc_num_enabled_features(rte_graph_feature_arc_t
> _arc)
> +{
> + struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> +
> + if (!arc) {
> + graph_err("Invalid feature arc: 0x%x", _arc);
> + return 0;
> + }
> +
> + return arc->runtime_enabled_features;
> +}
> +
>
> RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_graph_feature_arc_num_features,
> 25.07);
> uint32_t
> rte_graph_feature_arc_num_features(rte_graph_feature_arc_t _arc)
> diff --git a/lib/graph/meson.build b/lib/graph/meson.build
> index 6a6d570290..d48d49122d 100644
> --- a/lib/graph/meson.build
> +++ b/lib/graph/meson.build
> @@ -27,4 +27,4 @@ indirect_headers += files(
> 'rte_graph_worker_common.h',
> )
>
> -deps += ['eal', 'pcapng', 'mempool', 'ring']
> +deps += ['eal', 'pcapng', 'mempool', 'ring', 'rcu']
> diff --git a/lib/graph/rte_graph_feature_arc.h
> b/lib/graph/rte_graph_feature_arc.h
> index f25f77df3c..2b90f0111b 100644
> --- a/lib/graph/rte_graph_feature_arc.h
> +++ b/lib/graph/rte_graph_feature_arc.h
> @@ -18,6 +18,7 @@
> #include <rte_compat.h>
> #include <rte_debug.h>
> #include <rte_graph.h>
> +#include <rte_rcu_qsbr.h>
>
> #ifdef __cplusplus
> extern "C" {
> @@ -87,7 +88,9 @@ extern "C" {
> *
> * A feature arc in a graph is represented via *start_node* and *end_node*.
> * Feature nodes are added between start_node and end_node. Packets enter
> - * feature arc traversal via start_node while they exits from end_node.
> + * feature arc traversal via start_node while they exits from end_node.
> Packets
> + * steering from start_node to feature nodes are controlled in control plane
> + * via rte_graph_feature_enable()/rte_graph_feature_disable().
> *
> * This library facilitates rte graph based applications to implement stack
> * functionalities described above by providing "edge" to the next enabled
> @@ -103,6 +106,8 @@ extern "C" {
> * - Before calling rte_graph_create(), rte_graph_feature_arc_init() API must
> * be called. If rte_graph_feature_arc_init() is not called by application,
> * feature arc library has no affect.
> + * - Features can be enabled/disabled on any index at runtime via
> + * rte_graph_feature_enable()/rte_graph_feature_disable()
> * - Feature arc can be destroyed via rte_graph_feature_arc_destroy()
> *
> * If a given feature likes to control number of indexes (which is higher
> than
> @@ -112,10 +117,64 @@ extern "C" {
> * called and with maximum value returned by any of the feature is used for
> * rte_graph_feature_arc_create()
> *
> + * Before enabling a feature, control plane might allocate certain resources
> + * (like VRF table for IP lookup or IPsec SA for inbound policy etc). A
> + * reference of allocated resource can be passed from control plane to
> + * dataplane via *app_cookie* argument in @ref rte_graph_feature_enable().
> A
> + * corresponding dataplane API @ref
> rte_graph_feature_data_app_cookie_get() can
> + * be used to retrieve same cookie in fast path.
> + *
> + * When a feature is disabled, resources allocated during feature enable can
> be
> + * safely released via registering a callback in
> + * RTE_GRAPH_FEATURE_REGISTER::notifier_cb(). See fast path
> synchronization
> + * section below for more details.
> + *
> + * While *app_cookie* can be known corresponding to current feature node
> via
> + * @ref rte_graph_feature_data_app_cookie_get(), however if current
> feature
> + * node is not consuming packet it might want to send it to next enabled
> + * feature using, it can do if current feature node is a:
> + * - start_node (via @ref rte_graph_feature_data_first_feature_get())
> + * - feature nodes added between start_node and end_node (via @ref
> + * rte_graph_feature_data_next_feature_get())
> + * - end node (must not call any feature arc steering APIs) as from this node
> + * packet exits feature arc
> + *
> + * Above APIs deals with fast path object: feature_data(struct
> + * rte_graph_feature_data), which is unique for every index per feature with
> in
> + * a feature arc. It holds three data fields: next node edge, next enabled
> + * feature data and app_cookie.
> + *
> + * rte_mbuf carries [feature_data] into feature arc specific mbuf dynamic
> + * field
> + *
> + * Fast path synchronization
> + * -------------------------
> + * Any feature enable/disable in control plane does not require stopping of
> + * worker cores. rte_graph_feature_enable()/rte_graph_feature_disable()
> APIs
> + * are almost thread-safe avoiding any RCU usage. Only condition when race
> + * condition could occur is when application is trying to enable/disable
> + * feature very fast for [feature, index] combination. In that case,
> + * application should use rte_graph_feature_enable()/disable() APIs with RCU
> + * argument
> + *
> + * RCU synchronization may also be required when application needs to free
> + * resources (using RTE_GRAPH_FEATURE_REGISTER:notifier_cb()) which it
> may have
> + * allocated during feature enable. Resources can be freed only when no
> worker
> + * core is not acting on it.
> + *
> + * If RCU argument to rte_graph_feature_enable()/disable() is non-NULL:
> + * - rte_rcu_qsbr_synchronize(rte_rcu_qsbr *) to synchronize all worker
> cores
> + * - Calls RTE_GRAPH_FEATURE_REGISTER()->notifier_cb((), if set, and helps
> + * application to safely release resources associated with [feature, index]
> + *
> + * It is application responsibility to pass valid RCU argument to APIs
> + *
> * Constraints
> * -----------
> * - rte_graph_feature_arc_init(), rte_graph_feature_create() and
> * rte_graph_feature_add() must be called before rte_graph_create().
> + * rte_graph_feature_enable()/rte_graph_feature_disable() should be called
> + * after rte_graph_create()
> * - Not more than 63 features can be added to a feature arc. There is no
> * limit to number of feature arcs i.e. number of
> * RTE_GRAPH_FEATURE_ARC_REGISTER()
> @@ -359,6 +418,9 @@ int rte_graph_feature_arc_lookup_by_name(const
> char *arc_name, rte_graph_feature
> * Pointer to struct rte_graph_feature_register
> *
> * <I> Must be called before rte_graph_create() </I>
> + * <I> rte_graph_feature_add() is not allowed after call to
> + * rte_graph_feature_enable() so all features must be added before they can
> be
> + * enabled </I>
> * <I> When called by application, then feature_node_id should be
> appropriately set as
> * freg->feature_node_id = freg->feature_node->id;
> * </I>
> @@ -370,6 +432,63 @@ int rte_graph_feature_arc_lookup_by_name(const
> char *arc_name, rte_graph_feature
> __rte_experimental
> int rte_graph_feature_add(struct rte_graph_feature_register *feat_reg);
>
> +/**
> + * Enable feature within a feature arc
> + *
> + * Must be called after @b rte_graph_create().
> + *
> + * @param _arc
> + * Feature arc object returned by @ref rte_graph_feature_arc_create or
> @ref
> + * rte_graph_feature_arc_lookup_by_name
> + * @param index
> + * Application specific index. Can be corresponding to interface_id/port_id
> etc
> + * @param feature_name
> + * Name of the node which is already added via @ref rte_graph_feature_add
> + * @param app_cookie
> + * Application specific data which is retrieved in fast path
> + * @param qsbr
> + * RCU QSBR object. After enabling feature, API calls
> + * rte_rcu_qsbr_synchronize() followed by call to struct
> + * rte_graph_feature_register::notifier_cb(), if it is set, to notify
> feature
> + * caller This object can be passed NULL as well if no RCU synchronization
> is
> + * required
> + *
> + * @return
> + * 0: Success
> + * <0: Failure
> + */
> +__rte_experimental
> +int rte_graph_feature_enable(rte_graph_feature_arc_t _arc, uint32_t index,
> const
> + char *feature_name, uint16_t app_cookie,
> + struct rte_rcu_qsbr *qsbr);
> +
> +/**
> + * Disable already enabled feature within a feature arc
> + *
> + * Must be called after @b rte_graph_create(). API is *NOT* Thread-safe
> + *
> + * @param _arc
> + * Feature arc object returned by @ref rte_graph_feature_arc_create or
> @ref
> + * rte_graph_feature_arc_lookup_by_name
> + * @param index
> + * Application specific index. Can be corresponding to interface_id/port_id
> etc
> + * @param feature_name
> + * Name of the node which is already added via @ref rte_graph_feature_add
> + * @param qsbr
> + * RCU QSBR object. After disabling feature, API calls
> + * rte_rcu_qsbr_synchronize() followed by call to struct
> + * RTE_GRAPH_FEATURE_ARC_REGISTER::notifier_cb(), if it is set, to notify
> feature
> + * caller. This object can be passed NULL as well if no RCU
> synchronization is
> + * required
> + *
> + * @return
> + * 0: Success
> + * <0: Failure
> + */
> +__rte_experimental
> +int rte_graph_feature_disable(rte_graph_feature_arc_t _arc, uint32_t index,
> + const char *feature_name, struct rte_rcu_qsbr
> *qsbr);
> +
> /**
> * Get rte_graph_feature_t object from feature name
> *
> @@ -425,6 +544,19 @@ int rte_graph_feature_arc_cleanup(void);
> __rte_experimental
> uint32_t rte_graph_feature_arc_num_features(rte_graph_feature_arc_t
> _arc);
>
> +/**
> + * Slow path API to know how many features are currently enabled within a
> + * feature arc across all indexes. If a single feature is enabled on all
> interfaces,
> + * this API would return "number_of_interfaces" as count (but not "1")
> + *
> + * @param _arc
> + * Feature arc object
> + *
> + * @return: Number of enabled features across all indexes
> + */
> +__rte_experimental
> +uint32_t
> rte_graph_feature_arc_num_enabled_features(rte_graph_feature_arc_t _arc);
> +
> /**
> * Slow path API to get feature node name from rte_graph_feature_t object
> *
> diff --git a/lib/graph/rte_graph_feature_arc_worker.h
> b/lib/graph/rte_graph_feature_arc_worker.h
> index b2fc539402..060c4f8c6d 100644
> --- a/lib/graph/rte_graph_feature_arc_worker.h
> +++ b/lib/graph/rte_graph_feature_arc_worker.h
> @@ -159,6 +159,45 @@ struct __rte_cache_aligned rte_graph_feature_arc {
> */
> int mbuf_dyn_offset;
>
> + /** Fast path arc data starts */
> + /*
> + * Arc specific fast path data
> + * It accommodates:
> + *
> + * 1. first enabled feature data for every index
> (rte_graph_feature_data_t or fdata)
> + *
> +--------------------------------------------------------------+ <-
> cache_aligned
> + * | 0th Index | 1st Index | ... | max_index - 1 |
> + * +--------------------------------------------------------------+
> + * | Startfdata0 | Startfdata1 | ... | Startfdata(max_index-1) |
> + * +--------------------------------------------------------------+
> + *
> + * 2. struct rte_graph_feature_data per index per feature
> + * +----------------------------------------+ ^ <- Start (Reserved,
> cache aligned)
> + * | struct rte_graph_feature_data[Index0] | |
> + * +----------------------------------------+ | feature_size
> + * | struct rte_graph_feature_data[Index1] | |
> + * +----------------------------------------+ ^ <- Feature-0
> (cache_aligned)
> + * | struct rte_graph_feature_data[Index0] | |
> + * +----------------------------------------+ | feature_size
> + * | struct rte_graph_feature_data[Index1] | |
> + * +----------------------------------------+ v <- Feature-1 (cache
> aligned)
> + * | struct rte_graph_feature_data[Index0] | ^
> + * +----------------------------------------+ | feature_size
> + * | struct rte_graph_feature_data[Index1] | |
> + * +----------------------------------------+ v
> + * | ... .... |
> + * | ... .... |
> + * | ... .... |
> + * +----------------------------------------+ v <- Feature Index-1
> (cache aligned)
> + * | struct rte_graph_feature_data[Index0] | ^
> + * +----------------------------------------+ | feature_size
> + * | struct rte_graph_feature_data[Index1] | |
> + * +----------------------------------------+ v <- Extra (Reserved,
> cache aligned)
> + * | struct rte_graph_feature_data[Index0] | ^
> + * +----------------------------------------+ | feature_size
> + * | struct rte_graph_feature_data[Index1] | |
> + * +----------------------------------------+ v
> + */
> RTE_MARKER8 fp_arc_data;
> };
>
> @@ -193,13 +232,15 @@ typedef struct rte_feature_arc_main {
> * It holds
> * - edge to reach to next feature node
> * - next_feature_data corresponding to next enabled feature
> + * - app_cookie set by application in rte_graph_feature_enable()
> */
> struct rte_graph_feature_data {
> /** edge from this feature node to next enabled feature node */
> RTE_ATOMIC(rte_edge_t) next_edge;
>
> /**
> - * app_cookie
> + * app_cookie set by application in rte_graph_feature_enable() for
> + * current feature data
> */
> RTE_ATOMIC(uint16_t) app_cookie;
>
> @@ -216,6 +257,18 @@ struct rte_graph_feature_arc_mbuf_dynfields {
> /** Name of dynamic mbuf field offset registered in
> rte_graph_feature_arc_init() */
> #define RTE_GRAPH_FEATURE_ARC_DYNFIELD_NAME
> "__rte_graph_feature_arc_mbuf_dynfield"
>
> +/** log2(sizeof (struct rte_graph_feature_data)) */
> +#define RTE_GRAPH_FEATURE_DATA_SIZE_LOG2 3
> +
> +/** Number of struct rte_graph_feature_data per feature*/
> +#define RTE_GRAPH_FEATURE_DATA_NUM_PER_FEATURE(arc)
> \
> + (arc->feature_size >> RTE_GRAPH_FEATURE_DATA_SIZE_LOG2)
> +
> +/** Get rte_graph_feature_data_t from rte_graph_feature_t */
> +#define RTE_GRAPH_FEATURE_TO_FEATURE_DATA(arc, feature, index)
> \
> + ((rte_graph_feature_data_t)
> \
> + ((RTE_GRAPH_FEATURE_DATA_NUM_PER_FEATURE(arc) *
> (feature)) + (index)))
> +
> /**
> * @internal macro
> */
> @@ -271,6 +324,23 @@ rte_graph_feature_is_valid(rte_graph_feature_t
> feature)
> return (feature != RTE_GRAPH_FEATURE_INVALID);
> }
>
> +/**
> + * API to know if feature data is valid or not
> + *
> + * @param feature_data
> + * rte_graph_feature_data_t
> + *
> + * @return
> + * 1: If feature data is valid
> + * 0: If feature data is invalid
> + */
> +__rte_experimental
> +static __rte_always_inline int
> +rte_graph_feature_data_is_valid(rte_graph_feature_data_t feature_data)
> +{
> + return (feature_data != RTE_GRAPH_FEATURE_DATA_INVALID);
> +}
> +
> /**
> * Get pointer to feature arc object from rte_graph_feature_arc_t
> *
> @@ -297,6 +367,239 @@
> rte_graph_feature_arc_get(rte_graph_feature_arc_t arc)
> NULL : (struct rte_graph_feature_arc *)fa;
> }
>
> +/**
> + * Get rte_graph_feature_t from feature arc object without any checks
> + *
> + * @param arc
> + * feature arc
> + * @param fdata
> + * feature data object
> + *
> + * @return
> + * Pointer to feature data object
> + */
> +__rte_experimental
> +static __rte_always_inline struct rte_graph_feature_data*
> +__rte_graph_feature_data_get(struct rte_graph_feature_arc *arc,
> + rte_graph_feature_data_t fdata)
> +{
> + return ((struct rte_graph_feature_data *) ((uint8_t *)arc + arc-
> >fp_feature_data_offset +
> + (fdata <<
> RTE_GRAPH_FEATURE_DATA_SIZE_LOG2)));
> +}
> +
> +/**
> + * Get next edge from feature data pointer, without any check
> + *
> + * @param fdata
> + * feature data object
> + *
> + * @return
> + * next edge
> + */
> +__rte_experimental
> +static __rte_always_inline rte_edge_t
> +__rte_graph_feature_data_edge_get(struct rte_graph_feature_data *fdata)
> +{
> + return rte_atomic_load_explicit(&fdata->next_edge,
> rte_memory_order_relaxed);
> +}
> +
> +/**
> + * Get app_cookie from feature data pointer, without any check
> + *
> + * @param fdata
> + * feature data object
> + *
> + * @return
> + * app_cookie set by caller in rte_graph_feature_enable() API
> + */
> +__rte_experimental
> +static __rte_always_inline uint16_t
> +__rte_graph_feature_data_app_cookie_get(struct rte_graph_feature_data
> *fdata)
> +{
> + return rte_atomic_load_explicit(&fdata->app_cookie,
> rte_memory_order_relaxed);
> +}
> +
> +/**
> + * Get next_enabled_feature_data from pointer to feature data, without any
> check
> + *
> + * @param fdata
> + * feature data object
> + *
> + * @return
> + * next enabled feature data from this feature data
> + */
> +__rte_experimental
> +static __rte_always_inline rte_graph_feature_data_t
> +__rte_graph_feature_data_next_feature_get(struct rte_graph_feature_data
> *fdata)
> +{
> + return rte_atomic_load_explicit(&fdata->next_feature_data,
> rte_memory_order_relaxed);
> +}
> +
> +/**
> + * Get app_cookie from feature data object with checks
> + *
> + * @param arc
> + * feature arc
> + * @param fdata
> + * feature data object
> + *
> + * @return
> + * app_cookie set by caller in rte_graph_feature_enable() API
> + */
> +__rte_experimental
> +static __rte_always_inline uint16_t
> +rte_graph_feature_data_app_cookie_get(struct rte_graph_feature_arc *arc,
> + rte_graph_feature_data_t fdata)
> +{
> + struct rte_graph_feature_data *fdata_obj =
> __rte_graph_feature_data_get(arc, fdata);
> +
> + return __rte_graph_feature_data_app_cookie_get(fdata_obj);
> +}
> +
> +/**
> + * Get next_enabled_feature_data from current feature data object with
> checks
> + *
> + * @param arc
> + * feature arc
> + * @param fdata
> + * Pointer to feature data object
> + * @param[out] next_edge
> + * next_edge from current feature to next enabled feature
> + *
> + * @return
> + * 1: if next feature enabled on index
> + * 0: if no feature is enabled on index
> + */
> +__rte_experimental
> +static __rte_always_inline int
> +rte_graph_feature_data_next_feature_get(struct rte_graph_feature_arc *arc,
> + rte_graph_feature_data_t *fdata,
> + rte_edge_t *next_edge)
> +{
> + struct rte_graph_feature_data *fdata_obj =
> __rte_graph_feature_data_get(arc, *fdata);
> +
> + *fdata = __rte_graph_feature_data_next_feature_get(fdata_obj);
> + *next_edge = __rte_graph_feature_data_edge_get(fdata_obj);
> +
> + return rte_graph_feature_data_is_valid(*fdata);
> +}
> +
> +/**
> + * Get struct rte_graph_feature_data from rte_graph_feature_dat_t
> + *
> + * @param arc
> + * feature arc
> + * @param fdata
> + * feature data object
> + *
> + * @return
> + * NULL: On Failure
> + * Non-NULL pointer on Success
> + */
> +__rte_experimental
> +static __rte_always_inline struct rte_graph_feature_data*
> +rte_graph_feature_data_get(struct rte_graph_feature_arc *arc,
> + rte_graph_feature_data_t fdata)
> +{
> + if (rte_graph_feature_data_is_valid(fdata))
> + return __rte_graph_feature_data_get(arc, fdata);
> + else
> + return NULL;
> +}
> +
> +/**
> + * Get feature data corresponding to first enabled feature on index
> + * @param arc
> + * feature arc
> + * @param index
> + * Interface index
> + * @param[out] fdata
> + * feature data object
> + * @param[out] edge
> + * rte_edge object
> + *
> + * @return
> + * 1: if any feature enabled on index, return corresponding valid feature
> data
> + * 0: if no feature is enabled on index
> + */
> +__rte_experimental
> +static __rte_always_inline int
> +rte_graph_feature_data_first_feature_get(struct rte_graph_feature_arc *arc,
> + uint32_t index,
> + rte_graph_feature_data_t *fdata,
> + rte_edge_t *edge)
> +{
> + struct rte_graph_feature_data *fdata_obj = NULL;
> + rte_graph_feature_data_t *fd;
> +
> + fd = (rte_graph_feature_data_t *)((uint8_t *)arc + arc-
> >fp_first_feature_offset +
> + (sizeof(rte_graph_feature_data_t) *
> index));
> +
> + if (unlikely(rte_graph_feature_data_is_valid(*fd))) {
> + fdata_obj = __rte_graph_feature_data_get(arc, *fd);
> + *edge = __rte_graph_feature_data_edge_get(fdata_obj);
> + *fdata =
> __rte_graph_feature_data_next_feature_get(fdata_obj);
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * Fast path API to check if any feature enabled on a feature arc
> + * Typically from arc->start_node process function
> + *
> + * @param arc
> + * Feature arc object
> + *
> + * @return
> + * 0: If no feature enabled
> + * Non-Zero: Bitmask of features enabled.
> + *
> + */
> +__rte_experimental
> +static __rte_always_inline uint64_t
> +rte_graph_feature_arc_is_any_feature_enabled(struct rte_graph_feature_arc
> *arc)
> +{
> + if (unlikely(arc == NULL))
> + return 0;
> +
> + return (rte_atomic_load_explicit(&arc->fp_feature_enable_bitmask,
> + rte_memory_order_relaxed));
> +}
> +
> +/**
> + * Prefetch feature arc fast path cache line
> + *
> + * @param arc
> + * RTE_GRAPH feature arc object
> + */
> +__rte_experimental
> +static __rte_always_inline void
> +rte_graph_feature_arc_prefetch(struct rte_graph_feature_arc *arc)
> +{
> + rte_prefetch0((void *)arc->fast_path_variables);
> +}
> +
> +/**
> + * Prefetch feature data related fast path cache line
> + *
> + * @param arc
> + * RTE_GRAPH feature arc object
> + * @param fdata
> + * Pointer to feature data object
> + */
> +__rte_experimental
> +static __rte_always_inline void
> +rte_graph_feature_arc_feature_data_prefetch(struct rte_graph_feature_arc
> *arc,
> + rte_graph_feature_data_t fdata)
> +{
> + if (unlikely(fdata == RTE_GRAPH_FEATURE_DATA_INVALID))
> + return;
> +
Do we need above condition? Do we ever run into this? Avoid un necessary checks
in fast path.
> + rte_prefetch0((void *)__rte_graph_feature_data_get(arc, fdata));
> +}
> +
> #ifdef __cplusplus
> }
> #endif
> --
> 2.43.0
