RE: [RFC PATCH 1/3] graph: add feature arc support

[Nitin Saxena <nsaxena@marvell.com>]

Hi Kiran,

See my inline comments. Somehow  I forgot to respond earlier

Thanks,
Nitin

> -----Original Message-----
> From: Kiran Kumar Kokkilagadda <kirankumark@marvell.com>
> Sent: Wednesday, September 11, 2024 10:11 AM
> To: Nitin Saxena <nsaxena@marvell.com>; Jerin Jacob <jerinj@marvell.com>;
> Nithin Kumar Dabilpuram <ndabilpuram@marvell.com>; Zhirun Yan
> <yanzhirun_163@163.com>
> Cc: dev@dpdk.org; Nitin Saxena <nsaxena16@gmail.com>
> Subject: RE: [RFC PATCH 1/3] graph: add feature arc support
> 
> 
> 
> > -----Original Message-----
> > From: Nitin Saxena <nsaxena@marvell.com>
> > Sent: Saturday, September 7, 2024 1:01 PM
> > To: Jerin Jacob <jerinj@marvell.com>; Kiran Kumar Kokkilagadda
> > <kirankumark@marvell.com>; Nithin Kumar Dabilpuram
> > <ndabilpuram@marvell.com>; Zhirun Yan <yanzhirun_163@163.com>
> > Cc: dev@dpdk.org; Nitin Saxena <nsaxena16@gmail.com>
> > Subject: [RFC PATCH 1/3] graph: add feature arc support
> >
> > add feature arc to allow dynamic steering of packets across graph nodes
> > based on protocol features enabled on incoming or outgoing interface
> >
> > Signed-off-by: Nitin Saxena <nsaxena@marvell.com>
> > ---
> >  lib/graph/graph_feature_arc.c            | 959 +++++++++++++++++++++++
> >  lib/graph/meson.build                    |   2 +
> >  lib/graph/rte_graph_feature_arc.h        | 373 +++++++++
> >  lib/graph/rte_graph_feature_arc_worker.h | 548 +++++++++++++
> >  lib/graph/version.map                    |  17 +
> >  5 files changed, 1899 insertions(+)
> >  create mode 100644 lib/graph/graph_feature_arc.c
> >  create mode 100644 lib/graph/rte_graph_feature_arc.h
> >  create mode 100644 lib/graph/rte_graph_feature_arc_worker.h
> >
> > diff --git a/lib/graph/graph_feature_arc.c b/lib/graph/graph_feature_arc.c
> > new file mode 100644
> > index 0000000000..3b05bac137
> > --- /dev/null
> > +++ b/lib/graph/graph_feature_arc.c
> > @@ -0,0 +1,959 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright(C) 2024 Marvell International Ltd.
> > + */
> > +
> > +#include "graph_private.h"
> > +#include <rte_graph_feature_arc_worker.h>
> > +#include <rte_malloc.h>
> > +
> > +#define __RTE_GRAPH_FEATURE_ARC_MAX 32
> > +
> > +#define ARC_PASSIVE_LIST(arc) (arc->active_feature_list ^ 0x1)
> > +
> > +#define rte_graph_uint_cast(x) ((unsigned int)x)
> > +#define feat_dbg graph_err
> > +
> > +rte_graph_feature_arc_main_t *__feature_arc_main;
> > +
> > +/* Make sure fast path cache line is compact */
> > +_Static_assert((offsetof(struct rte_graph_feature_arc,
> slow_path_variables)
> > +		- offsetof(struct rte_graph_feature_arc, fast_path_variables))
> > +	       <= RTE_CACHE_LINE_SIZE);
> > +
> > +
> > +static int
> > +feature_lookup(struct rte_graph_feature_arc *arc, const char *feat_name,
> > +	       struct rte_graph_feature_node_list **ffinfo, uint32_t *slot)
> > +{
> > +	struct rte_graph_feature_node_list *finfo = NULL;
> > +	const char *name;
> > +
> > +	if (!feat_name)
> > +		return -1;
> > +
> > +	if (slot)
> > +		*slot = 0;
> > +
> > +	STAILQ_FOREACH(finfo, &arc->all_features, next_feature) {
> > +		RTE_VERIFY(finfo->feature_arc == arc);
> > +		name = rte_node_id_to_name(finfo->feature_node->id);
> > +		if (!strncmp(name, feat_name, RTE_GRAPH_NAMESIZE)) {
> > +			if (ffinfo)
> > +				*ffinfo = finfo;
> > +			return 0;
> > +		}
> > +		if (slot)
> > +			(*slot)++;
> > +	}
> > +	return -1;
> > +}
> > +
> > +static int
> > +feature_arc_node_info_lookup(struct rte_graph_feature_arc *arc, uint32_t
> > feature_index,
> > +			     struct rte_graph_feature_node_list **ppfinfo)
> > +{
> > +	struct rte_graph_feature_node_list *finfo = NULL;
> > +	uint32_t index = 0;
> > +
> > +	if (!ppfinfo)
> > +		return -1;
> > +
> > +	*ppfinfo = NULL;
> > +	STAILQ_FOREACH(finfo, &arc->all_features, next_feature) {
> > +		if (index == feature_index) {
> > +			if (finfo->node_index == feature_index)
> > +				return -1;
> > +			*ppfinfo = finfo;
> > +		}
> > +		index++;
> > +	}
> > +	if (feature_index && (index >= feature_index))
> > +		return -1;
> > +
> > +	return 0;
> > +}
> > +
> > +static void
> > +prepare_feature_arc(struct rte_graph_feature_arc *arc)
> > +{
> > +	struct rte_graph_feature_node_list *finfo = NULL;
> > +	uint32_t index = 0;
> > +
> > +	STAILQ_FOREACH(finfo, &arc->all_features, next_feature) {
> > +		finfo->node_index = index;
> > +		index++;
> > +	}
> > +}
> > +
> > +static int
> > +feature_arc_lookup(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 = __feature_arc_main;
> > +	uint32_t iter;
> > +
> > +	if (!__feature_arc_main)
> > +		return -1;
> > +
> > +	for (iter = 0; iter < dm->max_feature_arcs; iter++) {
> > +		if (dm->feature_arcs[iter] ==
> > RTE_GRAPH_FEATURE_ARC_INITIALIZER)
> > +			continue;
> > +
> > +		if (arc == (rte_graph_feature_arc_get(dm-
> > >feature_arcs[iter])))
> > +			return 0;
> > +	}
> > +	return -1;
> > +}
> > +
> > +static int
> > +get_existing_edge(const char *arc_name, struct rte_node_register
> > *parent_node,
> > +		  struct rte_node_register *child_node, rte_edge_t *_edge)
> > +{
> > +	char **next_edges = NULL;
> > +	uint32_t count, i;
> > +
> > +	RTE_SET_USED(arc_name);
> > +
> > +	count = rte_node_edge_get(parent_node->id, NULL);
> > +	next_edges = malloc(count);
> > +
> > +	if (!next_edges)
> > +		return -1;
> > +
> > +	count = rte_node_edge_get(parent_node->id, next_edges);
> > +	for (i = 0; i < count; i++) {
> > +		if (strstr(child_node->name, next_edges[i])) {
> > +			feat_dbg("%s: Edge exists [%s[%u]: \"%s\"]",
> > arc_name,
> > +				  parent_node->name, i, child_node->name);
> > +			if (_edge)
> > +				*_edge = (rte_edge_t)i;
> > +
> > +			free(next_edges);
> > +			return 0;
> > +		}
> > +	}
> > +	free(next_edges);
> > +
> > +	return -1;
> > +}
> > +
> > +static int
> > +connect_graph_nodes(struct rte_node_register *parent_node, struct
> > rte_node_register *child_node,
> > +		    rte_edge_t *_edge, char *arc_name)
> > +{
> > +	const char *next_node = NULL;
> > +	rte_edge_t edge;
> > +
> > +	if (!get_existing_edge(arc_name, parent_node, child_node, &edge)) {
> > +		feat_dbg("%s: add_feature: Edge reused [%s[%u]: \"%s\"]",
> > arc_name,
> > +			parent_node->name, edge, child_node->name);
> > +
> > +		if (_edge)
> > +			*_edge = edge;
> > +
> > +		return 0;
> > +	}
> > +
> > +	/* Node to be added */
> > +	next_node = child_node->name;
> > +
> > +	edge = rte_node_edge_update(parent_node->id,
> > RTE_EDGE_ID_INVALID, &next_node, 1);
> > +
> > +	if (edge == RTE_EDGE_ID_INVALID) {
> > +		graph_err("edge invalid");
> > +		return -1;
> > +	}
> > +	edge = rte_node_edge_count(parent_node->id) - 1;
> > +
> > +	feat_dbg("%s: add_feature: edge added [%s[%u]: \"%s\"]", arc_name,
> > parent_node->name, edge,
> > +		child_node->name);
> > +
> > +	if (_edge)
> > +		*_edge = edge;
> > +
> > +	return 0;
> > +}
> > +
> > +static int
> > +feature_arc_init(rte_graph_feature_arc_main_t **pfl, uint32_t
> > max_feature_arcs)
> > +{
> > +	rte_graph_feature_arc_main_t *pm = NULL;
> > +	uint32_t i;
> > +	size_t sz;
> > +
> > +	if (!pfl)
> > +		return -1;
> > +
> > +	sz = sizeof(rte_graph_feature_arc_main_t) +
> > +		(sizeof(pm->feature_arcs[0]) * max_feature_arcs);
> > +
> > +	pm = malloc(sz);
> > +	if (!pm)
> > +		return -1;
> > +
> > +	memset(pm, 0, sz);
> > +
> > +	for (i = 0; i < max_feature_arcs; i++)
> > +		pm->feature_arcs[i] =
> > RTE_GRAPH_FEATURE_ARC_INITIALIZER;
> > +
> > +	pm->max_feature_arcs = max_feature_arcs;
> > +
> > +	*pfl = pm;
> > +
> > +	return 0;
> > +}
> > +
> > +int
> > +rte_graph_feature_arc_init(int max_feature_arcs)
> > +{
> > +	if (!max_feature_arcs)
> > +		return -1;
> > +
> > +	if (__feature_arc_main)
> > +		return -1;
> > +
> > +	return feature_arc_init(&__feature_arc_main, max_feature_arcs);
> > +}
> > +
> > +static void
> > +feature_arc_list_reset(struct rte_graph_feature_arc *arc, uint32_t
> list_index)
> > +{
> > +	rte_graph_feature_data_t *fdata = NULL;
> > +	rte_graph_feature_list_t *list = NULL;
> > +	struct rte_graph_feature *feat = NULL;
> > +	uint32_t i, j;
> > +
> > +	list = arc->feature_list[list_index];
> > +	feat = arc->features[list_index];
> > +
> > +	/*Initialize variables*/
> > +	memset(feat, 0, arc->feature_size);
> > +	memset(list, 0, arc->feature_list_size);
> > +
> > +	/* Initialize feature and feature_data */
> > +	for (i = 0; i < arc->max_features; i++) {
> > +		feat = __rte_graph_feature_get(arc, i, list_index);
> > +		feat->this_feature_index = i;
> > +
> > +		for (j = 0; j < arc->max_indexes; j++) {
> > +			fdata = rte_graph_feature_data_get(arc, feat, j);
> > +			fdata->next_enabled_feature =
> > RTE_GRAPH_FEATURE_INVALID;
> > +			fdata->next_edge = UINT16_MAX;
> > +			fdata->user_data = UINT32_MAX;
> > +		}
> > +	}
> > +
> > +	for (i = 0; i < arc->max_indexes; i++)
> > +		list->first_enabled_feature_by_index[i] =
> > RTE_GRAPH_FEATURE_INVALID;
> > +}
> > +
> > +static int
> > +feature_arc_list_init(struct rte_graph_feature_arc *arc, const char
> > *flist_name,
> > +			  rte_graph_feature_list_t **pplist,
> > +			  struct rte_graph_feature **ppfeature, uint32_t
> > list_index)
> > +{
> > +	char fname[2 * RTE_GRAPH_FEATURE_ARC_NAMELEN];
> > +	size_t list_size, feat_size, fdata_size;
> > +	rte_graph_feature_list_t *list = NULL;
> > +	struct rte_graph_feature *feat = NULL;
> > +
> > +	list_size = sizeof(list->first_enabled_feature_by_index[0]) * arc-
> > >max_indexes;
> > +
> > +	list = rte_malloc(flist_name, list_size, RTE_CACHE_LINE_SIZE);
> > +	if (!list)
> > +		return -ENOMEM;
> > +
> > +	fdata_size = arc->max_indexes * sizeof(rte_graph_feature_data_t);
> > +
> > +	/* Let one feature capture complete cache lines */
> > +	feat_size = RTE_ALIGN_CEIL(sizeof(struct rte_graph_feature) +
> > fdata_size,
> > +				   RTE_CACHE_LINE_SIZE);
> > +
> > +	snprintf(fname, sizeof(fname), "%s-%s", arc->feature_arc_name,
> > "feat");
> > +
> > +	feat = rte_malloc(fname, feat_size * arc->max_features,
> > RTE_CACHE_LINE_SIZE);
> > +	if (!feat) {
> > +		rte_free(list);
> > +		return -ENOMEM;
> > +	}
> > +	arc->feature_size = feat_size;
> > +	arc->feature_data_size = fdata_size;
> > +	arc->feature_list_size = list_size;
> > +
> > +	/* Initialize list */
> > +	list->indexed_by_features = feat;
> > +	*pplist = list;
> > +	*ppfeature = feat;
> > +
> > +	feature_arc_list_reset(arc, list_index);
> > +
> > +	return 0;
> > +}
> > +
> > +static void
> > +feature_arc_list_destroy(rte_graph_feature_list_t *list)
> > +{
> > +	rte_free(list->indexed_by_features);
>  Do you need to free individual rte_graph_feature here, that is allocated in
> arc_list_init?

Nitin> It seems correct to me. feature_arc_list_destroy() frees all memory allocated in feature_arc_list_init(). So feature_arc_list_destroy() is calling rte_free() for every rte_malloc() happened in feature_arc_list_init(). To make it clear, I have refactor the function and has added appropriate comment from v2 patch set onwards

> 
> > +	rte_free(list);
> > +}
> > +
> > +int
> > +rte_graph_feature_arc_create(const char *feature_arc_name, int
> > max_features, int max_indexes,
> > +		       struct rte_node_register *start_node,
> > rte_graph_feature_arc_t *_arc)
> > +{
> > +	char name[2 * RTE_GRAPH_FEATURE_ARC_NAMELEN];
> > +	rte_graph_feature_arc_main_t *dfm = NULL;
> > +	struct rte_graph_feature_arc *arc = NULL;
> > +	struct rte_graph_feature_data *gfd = NULL;
> > +	struct rte_graph_feature *df = NULL;
> > +	uint32_t iter, j, arc_index;
> > +	size_t sz;
> > +
> > +	if (!_arc)
> > +		return -1;
> > +
> > +	if (max_features < 2)
> > +		return -1;
> > +
> > +	if (!start_node)
> > +		return -1;
> > +
> > +	if (!feature_arc_name)
> > +		return -1;
> > +
> > +	if (max_features > RTE_GRAPH_FEATURE_MAX_PER_ARC) {
> > +		graph_err("Invalid max features: %u", max_features);
> > +		return -1;
> > +	}
> > +
> > +	/*
> > +	 * Application hasn't called rte_graph_feature_arc_init(). Initialize
> with
> > +	 * default values
> > +	 */
> > +	if (!__feature_arc_main) {
> > +		if
> > (rte_graph_feature_arc_init((int)__RTE_GRAPH_FEATURE_ARC_MAX) < 0) {
> > +			graph_err("rte_graph_feature_arc_init() failed");
> > +			return -1;
> > +		}
> > +	}
> > +
> > +	dfm = __feature_arc_main;
> > +
> > +	/* threshold check */
> > +	if (dfm->num_feature_arcs > (dfm->max_feature_arcs - 1)) {
> > +		graph_err("max threshold for num_feature_arcs: %d
> > reached",
> > +			  dfm->max_feature_arcs - 1);
> > +		return -1;
> > +	}
> > +	/* Find the free slot for feature arc */
> > +	for (iter = 0; iter < dfm->max_feature_arcs; iter++) {
> > +		if (dfm->feature_arcs[iter] ==
> > RTE_GRAPH_FEATURE_ARC_INITIALIZER)
> > +			break;
> > +	}
> > +	arc_index = iter;
> > +
> > +	if (arc_index >= dfm->max_feature_arcs) {
> > +		graph_err("No free slot found for num_feature_arc");
> > +		return -1;
> > +	}
> > +
> > +	/* This should not happen */
> > +	RTE_VERIFY(dfm->feature_arcs[arc_index] ==
> > RTE_GRAPH_FEATURE_ARC_INITIALIZER);
> > +
> > +	/* size of feature arc + feature_bit_mask_by_index */
> > +	sz = sizeof(*arc) + (sizeof(uint64_t) * max_indexes);
> > +
> > +	arc = rte_malloc(feature_arc_name, sz, RTE_CACHE_LINE_SIZE);
> > +
> > +	if (!arc) {
> > +		graph_err("malloc failed for feature_arc_create()");
> > +		return -1;
> > +	}
> > +
> > +	memset(arc, 0, sz);
> > +
> > +	/* Initialize rte_graph port group fixed variables */
> > +	STAILQ_INIT(&arc->all_features);
> > +	strncpy(arc->feature_arc_name, feature_arc_name,
> > RTE_GRAPH_FEATURE_ARC_NAMELEN - 1);
> > +	arc->feature_arc_main = (void *)dfm;
> > +	arc->start_node = start_node;
> > +	arc->max_features = max_features;
> > +	arc->max_indexes = max_indexes;
> > +
> > +	snprintf(name, sizeof(name), "%s-%s", feature_arc_name, "flist0");
> > +
> > +	if (feature_arc_list_init(arc, name, &arc->feature_list[0], &arc-
> > >features[0], 0) < 0) {
> > +		rte_free(arc);
> > +		graph_err("feature_arc_list_init(0) failed");
> > +		return -1;
> > +	}
> > +	snprintf(name, sizeof(name), "%s-%s", feature_arc_name, "flist1");
> > +
> > +	if (feature_arc_list_init(arc, name, &arc->feature_list[1], &arc-
> > >features[1], 1) < 0) {
> > +		feature_arc_list_destroy(arc->feature_list[0]);
> > +		graph_err("feature_arc_list_init(1) failed");
> > +		return -1;
> > +	}
> > +
> > +	for (iter = 0; iter < arc->max_features; iter++) {
> > +		df = rte_graph_feature_get(arc, iter);
> > +		for (j = 0; j < arc->max_indexes; j++) {
> > +			gfd = rte_graph_feature_data_get(arc, df, j);
> > +			gfd->next_enabled_feature =
> > RTE_GRAPH_FEATURE_INVALID;
> > +		}
> > +	}
> > +	arc->feature_arc_index = arc_index;
> > +	dfm->feature_arcs[arc->feature_arc_index] =
> > (rte_graph_feature_arc_t)arc;
> > +	dfm->num_feature_arcs++;
> > +
> > +	if (_arc)
> > +		*_arc = (rte_graph_feature_arc_t)arc;
> > +
> > +	return 0;
> > +}
> > +
> > +int
> > +rte_graph_feature_add(rte_graph_feature_arc_t _arc, struct
> > rte_node_register *feature_node,
> > +		const char *after_feature, const char *before_feature)
> > +{
> > +	struct rte_graph_feature_node_list *after_finfo = NULL, *before_finfo
> > = NULL;
> > +	struct rte_graph_feature_node_list *temp = NULL, *finfo = NULL;
> > +	struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> > +	uint32_t slot, add_flag;
> > +	rte_edge_t edge = -1;
> > +
> > +	RTE_VERIFY(arc->feature_arc_main == __feature_arc_main);
> > +
> > +	if (feature_arc_lookup(_arc)) {
> > +		graph_err("invalid feature arc: 0x%016" PRIx64,
> > (uint64_t)_arc);
> > +		return -1;
> > +	}
> > +
> > +	if (arc->runtime_enabled_features) {
> > +		graph_err("adding features after enabling any one of them is
> > not supported");
> > +		return -1;
> > +	}
> > +
> > +	if ((after_feature != NULL) && (before_feature != NULL) &&
> > +	    (after_feature == before_feature)) {
> > +		graph_err("after_feature and before_feature are same
> > '%s:%s]", after_feature,
> > +			before_feature);
> > +		return -1;
> > +	}
> > +
> > +	if (!feature_node) {
> > +		graph_err("feature_node: %p invalid", feature_node);
> > +		return -1;
> > +	}
> > +
> > +	arc = rte_graph_feature_arc_get(_arc);
> > +
> > +	if (feature_node->id == RTE_NODE_ID_INVALID) {
> > +		graph_err("Invalid node: %s", feature_node->name);
> > +		return -1;
> > +	}
> > +
> > +	if (!feature_lookup(arc, feature_node->name, &finfo, &slot)) {
> > +		graph_err("%s feature already added", feature_node->name);
> > +		return -1;
> > +	}
> > +
> > +	if (slot >= RTE_GRAPH_FEATURE_MAX_PER_ARC) {
> > +		graph_err("Max slot %u reached for feature addition", slot);
> > +		return -1;
> > +	}
> > +
> > +	if (strstr(feature_node->name, arc->start_node->name)) {
> > +		graph_err("Feature %s cannot point to itself: %s",
> > feature_node->name,
> > +			arc->start_node->name);
> > +		return -1;
> > +	}
> > +
> > +	if (connect_graph_nodes(arc->start_node, feature_node, &edge, arc-
> > >feature_arc_name)) {
> > +		graph_err("unable to connect %s -> %s", arc->start_node-
> > >name, feature_node->name);
> > +		return -1;
> > +	}
> > +
> > +	finfo = malloc(sizeof(*finfo));
> > +	if (!finfo)
> > +		return -1;
> > +
> > +	memset(finfo, 0, sizeof(*finfo));
> > +
> > +	finfo->feature_arc = (void *)arc;
> > +	finfo->feature_node = feature_node;
> > +	finfo->edge_to_this_feature = edge;
> > +
> > +	/* Check for before and after constraints */
> > +	if (before_feature) {
> > +		/* before_feature sanity */
> > +		if (feature_lookup(arc, before_feature, &before_finfo, NULL))
> > +			SET_ERR_JMP(EINVAL, finfo_free,
> > +				     "Invalid before feature name: %s",
> > before_feature);
> > +
> > +		if (!before_finfo)
> > +			SET_ERR_JMP(EINVAL, finfo_free,
> > +				     "before_feature %s does not exist",
> > before_feature);
> > +
> > +		/*
> > +		 * Starting from 0 to before_feature, continue connecting
> > edges
> > +		 */
> > +		add_flag = 1;
> > +		STAILQ_FOREACH(temp, &arc->all_features, next_feature) {
> > +			/*
> > +			 * As soon as we see before_feature. stop adding
> > edges
> > +			 */
> > +			if (!strncmp(temp->feature_node->name,
> > before_feature,
> > +				     RTE_GRAPH_NAMESIZE))
> > +				if (!connect_graph_nodes(finfo-
> > >feature_node, temp->feature_node,
> > +							 &edge, arc-
> > >feature_arc_name))
> > +					add_flag = 0;
> > +
> > +			if (add_flag)
> > +				connect_graph_nodes(temp->feature_node,
> > finfo->feature_node, NULL,
> > +						    arc->feature_arc_name);
> > +		}
> > +	}
> > +
> > +	if (after_feature) {
> > +		if (feature_lookup(arc, after_feature, &after_finfo, NULL))
> > +			SET_ERR_JMP(EINVAL, finfo_free,
> > +				     "Invalid after feature_name %s",
> > after_feature);
> > +
> > +		if (!after_finfo)
> > +			SET_ERR_JMP(EINVAL, finfo_free,
> > +				     "after_feature %s does not exist",
> > after_feature);
> > +
> > +		/* Starting from after_feature to end continue connecting
> > edges */
> > +		add_flag = 0;
> > +		STAILQ_FOREACH(temp, &arc->all_features, next_feature) {
> > +			/* We have already seen after_feature now */
> > +			if (add_flag)
> > +				/* Add all features as next node to current
> > feature*/
> > +				connect_graph_nodes(finfo->feature_node,
> > temp->feature_node, NULL,
> > +						    arc->feature_arc_name);
> > +
> > +			/* as soon as we see after_feature. start adding edges
> > +			 * from next iteration
> > +			 */
> > +			if (!strncmp(temp->feature_node->name,
> > after_feature, RTE_GRAPH_NAMESIZE))
> > +				/* connect after_feature to this feature */
> > +				if (!connect_graph_nodes(temp-
> > >feature_node, finfo->feature_node,
> > +							 &edge, arc-
> > >feature_arc_name))
> > +					add_flag = 1;
> > +		}
> > +
> > +		/* add feature next to after_feature */
> > +		STAILQ_INSERT_AFTER(&arc->all_features, after_finfo, finfo,
> > next_feature);
> > +	} else {
> > +		if (before_finfo) {
> > +			after_finfo = NULL;
> > +			STAILQ_FOREACH(temp, &arc->all_features,
> > next_feature) {
> > +				if (before_finfo == temp) {
> > +					if (after_finfo)
> > +						STAILQ_INSERT_AFTER(&arc-
> > >all_features, after_finfo,
> > +								    finfo,
> > next_feature);
> > +					else
> > +						STAILQ_INSERT_HEAD(&arc-
> > >all_features, finfo,
> > +
> > next_feature);
> > +
> > +					return 0;
> > +				}
> > +				after_finfo = temp;
> > +			}
> > +		} else {
> > +			STAILQ_INSERT_TAIL(&arc->all_features, finfo,
> > next_feature);
> > +		}
> > +	}
> > +
> > +	return 0;
> > +
> > +finfo_free:
> > +	free(finfo);
> > +
> > +	return -1;
> > +}
> > +
> > +int
> > +rte_graph_feature_lookup(rte_graph_feature_arc_t _arc, const char
> > *feature_name,
> > +			 rte_graph_feature_t *feat)
> > +{
> > +	struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> > +	struct rte_graph_feature_node_list *finfo = NULL;
> > +	uint32_t slot;
> > +
> > +	if (!feature_lookup(arc, feature_name, &finfo, &slot)) {
> > +		*feat = (rte_graph_feature_t) slot;
> > +		return 0;
> > +	}
> > +
> > +	return -1;
> > +}
> > +
> > +int
> > +rte_graph_feature_validate(rte_graph_feature_arc_t _arc, uint32_t index,
> > const char *feature_name,
> > +			   int is_enable_disable)
> > +{
> > +	struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> > +	struct rte_graph_feature_node_list *finfo = NULL;
> > +	struct rte_graph_feature *gf = NULL;
> > +	uint32_t slot;
> > +
> > +	/* validate _arc */
> > +	if (arc->feature_arc_main != __feature_arc_main) {
> > +		graph_err("invalid feature arc: 0x%016" PRIx64,
> > (uint64_t)_arc);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* validate index */
> > +	if (index >= arc->max_indexes) {
> > +		graph_err("%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 (feature_lookup(arc, feature_name, &finfo, &slot)) {
> > +		graph_err("%s: No feature %s added", arc-
> > >feature_arc_name, feature_name);
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (!finfo) {
> > +		graph_err("%s: No feature: %s found", arc-
> > >feature_arc_name, feature_name);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* slot should be in valid range */
> > +	if (slot >= arc->max_features) {
> > +		graph_err("%s/%s: Invalid free slot %u(max=%u) for feature",
> > arc->feature_arc_name,
> > +			feature_name, slot, arc->max_features);
> > +		return -EINVAL;
> > +	}
> > +
> > +	/* slot should be in range of 0 - 63 */
> > +	if (slot > (RTE_GRAPH_FEATURE_MAX_PER_ARC - 1)) {
> > +		graph_err("%s/%s: Invalid slot: %u", arc->feature_arc_name,
> > +			  feature_name, slot);
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (finfo->node_index != slot) {
> > +		graph_err("%s/%s: feature lookup slot mismatch with finfo
> > index: %u and lookup slot: %u",
> > +			  arc->feature_arc_name, feature_name, finfo-
> > >node_index, slot);
> > +		return -1;
> > +	}
> > +
> > +	/* Get feature from active list */
> > +	gf = __rte_graph_feature_get(arc, slot, ARC_PASSIVE_LIST(arc));
> > +	if (gf->this_feature_index != slot) {
> > +		graph_err("%s: %s received feature_index: %u does not
> match
> > with saved feature_index: %u",
> > +			  arc->feature_arc_name, feature_name, slot, gf-
> > >this_feature_index);
> > +		return -1;
> > +	}
> > +
> > +	if (is_enable_disable && (arc->feature_bit_mask_by_index[index] &
> > +				  RTE_BIT64(slot))) {
> > +		graph_err("%s: %s already enabled on index: %u",
> > +			  arc->feature_arc_name, feature_name, index);
> > +		return -1;
> > +	}
> > +
> > +	if (!is_enable_disable && !arc->runtime_enabled_features) {
> > +		graph_err("%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))) {
> > +		graph_err("%s: %s not enabled in bitmask for index: %u",
> > +			  arc->feature_arc_name, feature_name, index);
> > +		return -1;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static void
> > +copy_fastpath_user_data(struct rte_graph_feature_arc *arc, uint16_t
> > dest_list_index,
> > +			uint16_t src_list_index)
> > +{
> > +	rte_graph_feature_data_t *sgfd = NULL, *dgfd = NULL;
> > +	struct rte_graph_feature *sgf = NULL, *dgf = NULL;
> > +	uint32_t i, j;
> > +
> > +	for (i = 0; i < arc->max_features; i++) {
> > +		sgf = __rte_graph_feature_get(arc, i, src_list_index);
> > +		dgf = __rte_graph_feature_get(arc, i, dest_list_index);
> > +		for (j = 0; j < arc->max_indexes; j++) {
> > +			sgfd = rte_graph_feature_data_get(arc, sgf, j);
> > +			dgfd = rte_graph_feature_data_get(arc, dgf, j);
> > +			dgfd->user_data = sgfd->user_data;
> > +		}
> > +	}
> > +}
> > +
> > +static void
> > +refill_feature_fastpath_data(struct rte_graph_feature_arc *arc, uint16_t
> > list_index)
> > +{
> > +	struct rte_graph_feature_node_list *finfo = NULL, *prev_finfo = NULL;
> > +	struct rte_graph_feature_data *gfd = NULL, *prev_gfd = NULL;
> > +	struct rte_graph_feature *gf = NULL, *prev_gf = NULL;
> > +	rte_graph_feature_list_t *flist = NULL;
> > +	uint32_t fi, di, prev_fi;
> > +	uint64_t bitmask;
> > +	rte_edge_t edge;
> > +
> > +	flist = arc->feature_list[list_index];
> > +
> > +	for (di = 0; di < arc->max_indexes; di++) {
> > +		bitmask = arc->feature_bit_mask_by_index[di];
> > +		prev_fi = RTE_GRAPH_FEATURE_INVALID;
> > +		/* for each feature set for index, set fast path data */
> > +		while (rte_bsf64_safe(bitmask, &fi)) {
> > +			gf = __rte_graph_feature_get(arc, fi, list_index);
> > +			gfd = rte_graph_feature_data_get(arc, gf, di);
> > +			feature_arc_node_info_lookup(arc, fi, &finfo);
> > +
> > +			/* If previous feature_index was valid in last loop */
> > +			if (prev_fi != RTE_GRAPH_FEATURE_INVALID) {
> > +				prev_gf = __rte_graph_feature_get(arc,
> > prev_fi, list_index);
> > +				prev_gfd = rte_graph_feature_data_get(arc,
> > prev_gf, di);
> > +				/*
> > +				 * Get edge of previous feature node
> > connecting to this feature node
> > +				 */
> > +				feature_arc_node_info_lookup(arc, prev_fi,
> > &prev_finfo);
> > +				if (!get_existing_edge(arc->feature_arc_name,
> > +						      prev_finfo->feature_node,
> > +						      finfo->feature_node,
> > &edge)) {
> > +					feat_dbg("[%s/%s(%2u)/idx:%2u]:
> > %s[%u] = %s",
> > +						 arc->feature_arc_name,
> > +						 prev_finfo->feature_node-
> > >name, prev_fi, di,
> > +						 prev_finfo->feature_node-
> > >name,
> > +						 edge, finfo->feature_node-
> > >name);
> > +					/* Copy feature index for next
> > iteration*/
> > +					gfd->next_edge = edge;
> > +					prev_fi = fi;
> > +					/*
> > +					 * Fill current feature as next enabled
> > +					 * feature to previous one
> > +					 */
> > +					prev_gfd->next_enabled_feature = fi;
> > +				} else {
> > +					/* Should not fail */
> > +					RTE_VERIFY(0);
> > +				}
> > +			}
> > +			/* On first feature edge of the node to be added */
> > +			if (fi == rte_bsf64(arc-
> > >feature_bit_mask_by_index[di])) {
> > +				if (!get_existing_edge(arc->feature_arc_name,
> > arc->start_node,
> > +						      finfo->feature_node,
> > +						      &edge)) {
> > +					feat_dbg("[%s/%s/%2u/idx:%2u]: 1st
> > feat %s[%u] = %s",
> > +						 arc->feature_arc_name,
> > +						 arc->start_node->name, fi, di,
> > +						 arc->start_node->name,
> > edge,
> > +						 finfo->feature_node->name);
> > +					/* Copy feature index for next
> > iteration*/
> > +					gfd->next_edge = edge;
> > +					prev_fi = fi;
> > +					/* Set first feature set array for
> > index*/
> > +					flist-
> > >first_enabled_feature_by_index[di] = fi;
> > +				} else {
> > +					/* Should not fail */
> > +					RTE_VERIFY(0);
> > +				}
> > +			}
> > +			/* Clear current feature index */
> > +			bitmask &= ~RTE_BIT64(fi);
> > +		}
> > +	}
> > +}
> > +
> > +int
> > +rte_graph_feature_enable(rte_graph_feature_arc_t _arc, uint32_t index,
> > const
> > +			 char *feature_name, int32_t user_data)
> > +{
> > +	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;
> > +	rte_graph_feature_rt_list_t passive_list;
> > +	struct rte_graph_feature *gf = NULL;
> > +	uint64_t fp_bitmask;
> > +	uint32_t slot;
> > +
> > +	if (rte_graph_feature_validate(_arc, index, feature_name, 1))
> > +		return -1;
> > +
> > +	/** This should not fail as validate() has passed */
> > +	if (feature_lookup(arc, feature_name, &finfo, &slot))
> > +		RTE_VERIFY(0);
> > +
> > +	if (!arc->runtime_enabled_features)
> > +		prepare_feature_arc(arc);
> > +
> > +	passive_list = ARC_PASSIVE_LIST(arc);
> > +
> > +	gf = __rte_graph_feature_get(arc, slot, passive_list);
> > +	gfd = rte_graph_feature_data_get(arc, gf, index);
> > +
> > +	feat_dbg("%s/%s: Enabling feature on list: %u for index: %u at feature
> > slot %u",
> > +		 arc->feature_arc_name, feature_name, passive_list, index,
> > slot);
> > +
> > +	/* Reset feature list */
> > +	feature_arc_list_reset(arc, passive_list);
> > +
> > +	/* Copy user-data */
> > +	copy_fastpath_user_data(arc, passive_list, arc->active_feature_list);
> > +
> > +	/* Set current user-data */
> > +	gfd->user_data = user_data;
> > +
> > +	/* Set bitmask in control path bitmask */
> > +	rte_bit_relaxed_set64(rte_graph_uint_cast(slot), &arc-
> > >feature_bit_mask_by_index[index]);
> > +	refill_feature_fastpath_data(arc, passive_list);
> > +
> > +	/* Set fast path enable bitmask */
> > +	fp_bitmask = __atomic_load_n(&arc-
> > >feature_enable_bitmask[passive_list], __ATOMIC_RELAXED);
> > +	fp_bitmask |= RTE_BIT64(slot);
> > +	__atomic_store(&arc->feature_enable_bitmask[passive_list],
> > &fp_bitmask, __ATOMIC_RELAXED);
> > +
> > +	/* Slow path updates */
> > +	arc->runtime_enabled_features++;
> > +
> > +	/* Increase feature node info reference count */
> > +	finfo->ref_count++;
> > +
> > +	/* Store release semantics for active_list update */
> > +	__atomic_store(&arc->active_feature_list, &passive_list,
> > __ATOMIC_RELEASE);
> > +
> > +	return 0;
> > +}
> > +
> > +int
> > +rte_graph_feature_disable(rte_graph_feature_arc_t _arc, uint32_t index,
> > const char *feature_name)
> > +{
> > +	struct rte_graph_feature_arc *arc = rte_graph_feature_arc_get(_arc);
> > +	struct rte_graph_feature_data *gfd = NULL;
> > +	struct rte_graph_feature_node_list *finfo = NULL;
> > +	rte_graph_feature_rt_list_t passive_list;
> > +	struct rte_graph_feature *gf = NULL;
> > +	uint32_t slot;
> > +
> > +	if (rte_graph_feature_validate(_arc, index, feature_name, 0))
> > +		return -1;
> > +
> > +	if (feature_lookup(arc, feature_name, &finfo, &slot))
> > +		return -1;
> > +
> > +	passive_list = ARC_PASSIVE_LIST(arc);
> > +
> > +	gf = __rte_graph_feature_get(arc, slot, passive_list);
> > +	gfd = rte_graph_feature_data_get(arc, gf, index);
> > +
> > +	feat_dbg("%s/%s: Disabling feature for index: %u at feature slot %u",
> > arc->feature_arc_name,
> > +		feature_name, index, slot);
> > +
> > +	rte_bit_relaxed_clear64(rte_graph_uint_cast(slot), &arc-
> > >feature_bit_mask_by_index[index]);
> > +
> > +	/* Set fast path enable bitmask */
> > +	arc->feature_enable_bitmask[passive_list] &= ~(RTE_BIT64(slot));
> > +
> > +	/* Reset feature list */
> > +	feature_arc_list_reset(arc, passive_list);
> > +
> > +	/* Copy user-data */
> > +	copy_fastpath_user_data(arc, passive_list, arc->active_feature_list);
> > +
> > +	/* Reset current user-data */
> > +	gfd->user_data = ~0;
> > +
> > +	refill_feature_fastpath_data(arc, passive_list);
> > +
> > +	finfo->ref_count--;
> > +	arc->runtime_enabled_features--;
> > +
> > +	/* Store release semantics for active_list update */
> > +	__atomic_store(&arc->active_feature_list, &passive_list,
> > __ATOMIC_RELEASE);
> > +
> > +	return 0;
> > +}
> > +
> > +int
> > +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 = __feature_arc_main;
> > +	struct rte_graph_feature_node_list *node_info = NULL;
> > +
> > +	while (!STAILQ_EMPTY(&arc->all_features)) {
> > +		node_info = STAILQ_FIRST(&arc->all_features);
> > +		STAILQ_REMOVE_HEAD(&arc->all_features, next_feature);
> > +		free(node_info);
> > +	}
> > +	feature_arc_list_destroy(arc->feature_list[0]);
> > +	feature_arc_list_destroy(arc->feature_list[1]);
> > +	rte_free(arc->features[0]);
> > +	rte_free(arc->features[1]);
> > +
> > +	dm->feature_arcs[arc->feature_arc_index] =
> > RTE_GRAPH_FEATURE_ARC_INITIALIZER;
> > +
> > +	rte_free(arc);
> > +	return 0;
> > +}
> > +
> > +int
> > +rte_graph_feature_arc_cleanup(void)
> > +{
> > +	rte_graph_feature_arc_main_t *dm = __feature_arc_main;
> > +	uint32_t iter;
> > +
> > +	if (!__feature_arc_main)
> > +		return -1;
> > +
> > +	for (iter = 0; iter < dm->max_feature_arcs; iter++) {
> > +		if (dm->feature_arcs[iter] ==
> > RTE_GRAPH_FEATURE_ARC_INITIALIZER)
> > +			continue;
> > +
> > +		rte_graph_feature_arc_destroy((rte_graph_feature_arc_t)dm-
> > >feature_arcs[iter]);
> > +	}
> > +	free(dm);
> > +
> > +	__feature_arc_main = NULL;
> > +
> > +	return 0;
> > +}
> > +
> > +int
> > +rte_graph_feature_arc_lookup_by_name(const char *arc_name,
> > rte_graph_feature_arc_t *_arc)
> > +{
> > +	rte_graph_feature_arc_main_t *dm = __feature_arc_main;
> > +	struct rte_graph_feature_arc *arc = NULL;
> > +	uint32_t iter;
> > +
> > +	if (!__feature_arc_main)
> > +		return -1;
> > +
> > +	for (iter = 0; iter < dm->max_feature_arcs; iter++) {
> > +		if (dm->feature_arcs[iter] ==
> > RTE_GRAPH_FEATURE_ARC_INITIALIZER)
> > +			continue;
> > +
> > +		arc = rte_graph_feature_arc_get(dm->feature_arcs[iter]);
> > +
> > +		if (strstr(arc_name, arc->feature_arc_name)) {
> > +			if (_arc)
> > +				*_arc = (rte_graph_feature_arc_t)arc;
> > +			return 0;
> > +		}
> > +	}
> > +
> > +	return -1;
> > +}
> > +
> > +int
> > +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);
> > +
> > +	return arc->runtime_enabled_features;
> > +}
> > +
> > +
> > diff --git a/lib/graph/meson.build b/lib/graph/meson.build
> > index 0cb15442ab..d916176fb7 100644
> > --- a/lib/graph/meson.build
> > +++ b/lib/graph/meson.build
> > @@ -14,11 +14,13 @@ sources = files(
> >          'graph_debug.c',
> >          'graph_stats.c',
> >          'graph_populate.c',
> > +        'graph_feature_arc.c',
> >          'graph_pcap.c',
> >          'rte_graph_worker.c',
> >          'rte_graph_model_mcore_dispatch.c',
> >  )
> >  headers = files('rte_graph.h', 'rte_graph_worker.h')
> > +headers += files('rte_graph_feature_arc.h',
> 'rte_graph_feature_arc_worker.h')
> >  indirect_headers += files(
> >          'rte_graph_model_mcore_dispatch.h',
> >          'rte_graph_model_rtc.h',
> > diff --git a/lib/graph/rte_graph_feature_arc.h
> > b/lib/graph/rte_graph_feature_arc.h
> > new file mode 100644
> > index 0000000000..e3bf4eb73d
> > --- /dev/null
> > +++ b/lib/graph/rte_graph_feature_arc.h
> > @@ -0,0 +1,373 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright(C) 2024 Marvell International Ltd.
> > + */
> > +
> > +#ifndef _RTE_GRAPH_FEATURE_ARC_H_
> > +#define _RTE_GRAPH_FEATURE_ARC_H_
> > +
> > +#include <assert.h>
> > +#include <errno.h>
> > +#include <signal.h>
> > +#include <stddef.h>
> > +#include <stdint.h>
> > +#include <stdio.h>
> > +#include <stdlib.h>
> > +#include <string.h>
> > +
> > +#include <rte_common.h>
> > +#include <rte_compat.h>
> > +#include <rte_debug.h>
> > +#include <rte_graph.h>
> > +#include <rte_graph_worker.h>
> > +
> > +#ifdef __cplusplus
> > +extern "C" {
> > +#endif
> > +
> > +/**
> > + * @file
> > + *
> > + * rte_graph_feature_arc.h
> > + *
> > + * Define APIs and structures/variables with respect to feature arc
> > + *
> > + * - Feature arc(s)
> > + * - Feature(s)
> > + *
> > + * A feature arc represents an ordered list of features/protocol-nodes at a
> > + * given networking layer. Feature arc provides a high level abstraction to
> > + * connect various *rte_graph* nodes, designated as *feature nodes*, and
> > + * allowing steering of packets across these feature nodes fast path
> > processing
> > + * in a generic manner. In a typical network stack, often a protocol or
> feature
> > + * must be first enabled on a given interface, before any packet is steered
> > + * towards it for feature processing. For eg: incoming IPv4 packets are sent
> to
> > + * routing sub-system only after a valid IPv4 address is assigned to the
> > + * received interface. In other words, often packets needs to be steered
> across
> > + * features not based on the packet content but based on whether a
> feature is
> > + * enable or disable on a given incoming/outgoing interface. Feature arc
> > + * provides mechanism to enable/disable feature(s) on each interface at
> > runtime
> > + * and allow seamless packet steering across runtime enabled feature
> nodes
> > in
> > + * fast path.
> > + *
> > + * Feature arc also provides a way to steer packets from standard nodes to
> > + * custom/user-defined *feature nodes* without any change in standard
> > node's
> > + * fast path functions
> > + *
> > + * On a given interface multiple feature(s) might be enabled in a particular
> > + * feature arc. For instance, both "ipv4-output" and "IPsec policy output"
> > + * features may be enabled on "eth0" interface in "L3-output" feature arc.
> > + * Similarly, "ipv6-output" and "ipsec-output" may be enabled on "eth1"
> > + * interface in same "L3-output" feature arc.
> > + *
> > + * When multiple features are present in a given feature arc, its imperative
> > + * to allow each feature processing in a particular sequential order. For
> > + * instance, in "L3-input" feature arc it may be required to run "IPsec
> > + * input" feature first, for packet decryption, before "ip-lookup".  So a
> > + * sequential order must be maintained among features present in a
> feature
> > arc.
> > + *
> > + * Features are enabled/disabled multiple times at runtime to some or all
> > + * available interfaces present in the system. Features can be
> > enabled/disabled
> > + * even after @b rte_graph_create() is called. Enable/disabling features on
> > one
> > + * interface is independent of other interface.
> > + *
> > + * A given feature might consume packet (if it's configured to consume) or
> > may
> > + * forward it to next enabled feature. For instance, "IPsec input" feature
> may
> > + * consume/drop all packets with "Protect" policy action while all packets
> with
> > + * policy action as "Bypass" may be forwarded to next enabled feature
> (with
> > in
> > + * same feature arc)
> > + *
> > + * This library facilitates rte graph based applications to steer packets in
> > + * fast path to different feature nodes with-in a feature arc and support all
> > + * functionalities described above
> > + *
> > + * In order to use feature-arc APIs, applications needs to do following in
> > + * control path:
> > + * - Initialize feature arc library via rte_graph_feature_arc_init()
> > + * - Create feature arc via rte_graph_feature_arc_create()
> > + * - *Before calling rte_graph_create()*, features must be added to feature-
> > arc
> > + *   via rte_graph_feature_add(). rte_graph_feature_add() allows adding
> > + *   features in a sequential order with "runs_after" and "runs_before"
> > + *   constraints.
> > + * - Post rte_graph_create(), features can be enabled/disabled at runtime
> on
> > + *   any interface via
> rte_graph_feature_enable()/rte_graph_feature_disable()
> > + * - Feature arc can be destroyed via rte_graph_feature_arc_destroy()
> > + *
> > + * In fast path, APIs are provided to steer packets towards feature path
> from
> > + * - start_node (provided as an argument to
> rte_graph_feature_arc_create())
> > + * - feature nodes (which are added via rte_graph_feature_add())
> > + *
> > + * For typical steering of packets across feature nodes, application required
> > + * to know "rte_edges" which are saved in feature data object. Feature
> data
> > + * object is unique for every interface per feature with in a feature arc.
> > + *
> > + * When steering packets from start_node to feature node:
> > + * - rte_graph_feature_arc_first_feature_get() provides first enabled
> feature.
> > + * - Next rte_edge from start_node to first enabled feature can be obtained
> > via
> > + *   rte_graph_feature_arc_feature_set()
> > + *
> > + * rte_mbuf can carry [current feature, index] from start_node of an arc to
> > other
> > + * feature nodes
> > + *
> > + * In feature node, application can get 32-bit user_data
> > + * via_rte_graph_feature_user_data_get() which is provided in
> > + * rte_graph_feature_enable(). User data can hold feature specific cookie
> like
> > + * IPsec policy database index (if more than one are supported)
> > + *
> > + * If feature node is not consuming packet, next enabled feature and next
> > + * rte_edge can be obtained via rte_graph_feature_arc_next_feature_get()
> > + *
> > + * It is application responsibility to ensure that at-least *last feature*(or
> sink
> > + * feature) must be enabled from where packet can exit feature-arc path, if
> > + * *NO* intermediate feature is consuming the packet and it has reached
> till
> > + * the end of feature arc path
> > + *
> > + * Synchronization among cores
> > + * ---------------------------
> > + * Subsequent calls to rte_graph_feature_enable() is allowed while worker
> > cores
> > + * are processing in rte_graph_walk() loop. However, for
> > + * rte_graph_feature_disable() application must use RCU based
> > synchronization
> > + */
> > +
> > +/**< Initializer value for rte_graph_feature_arc_t */
> > +#define RTE_GRAPH_FEATURE_ARC_INITIALIZER
> > ((rte_graph_feature_arc_t)UINT64_MAX)
> > +
> > +/** Max number of features supported in a given feature arc */
> > +#define RTE_GRAPH_FEATURE_MAX_PER_ARC 64
> > +
> > +/** Length of feature arc name */
> > +#define RTE_GRAPH_FEATURE_ARC_NAMELEN RTE_NODE_NAMESIZE
> > +
> > +/** @internal */
> > +#define rte_graph_feature_cast(x) ((rte_graph_feature_t)x)
> > +
> > +/**< Initializer value for rte_graph_feature_arc_t */
> > +#define RTE_GRAPH_FEATURE_INVALID
> > rte_graph_feature_cast(UINT8_MAX)
> > +
> > +/** rte_graph feature arc object */
> > +typedef uint64_t rte_graph_feature_arc_t;
> > +
> > +/** rte_graph feature object */
> > +typedef uint8_t rte_graph_feature_t;
> > +
> > +/** runtime active feature list index with in feature arc*/
> > +typedef uint8_t rte_graph_feature_rt_list_t;
> > +
> > +/** per feature arc monotonically increasing counter to synchronize fast
> path
> > APIs */
> > +typedef uint16_t rte_graph_feature_counter_t;
> > +
> > +/**
> > + * Initialize feature arc subsystem
> > + *
> > + * @param max_feature_arcs
> > + *   Maximum number of feature arcs required to be supported
> > + *
> > + * @return
> > + *  0: Success
> > + * <0: Failure
> > + */
> > +__rte_experimental
> > +int rte_graph_feature_arc_init(int max_feature_arcs);
> > +
> > +/**
> > + * Create a feature arc
> > + *
> > + * @param feature_arc_name
> > + *   Feature arc name with max length of @ref
> > RTE_GRAPH_FEATURE_ARC_NAMELEN
> > + * @param max_features
> > + *   Maximum number of features to be supported in this feature arc
> > + * @param max_indexes
> > + *   Maximum number of interfaces/ports/indexes to be supported
> > + * @param start_node
> > + *   Base node where this feature arc's features are checked in fast path
> > + * @param[out] _arc
> > + *  Feature arc object
> > + *
> > + * @return
> > + *  0: Success
> > + * <0: Failure
> > + */
> > +__rte_experimental
> > +int rte_graph_feature_arc_create(const char *feature_arc_name, int
> > max_features, int max_indexes,
> > +				 struct rte_node_register *start_node,
> > +				 rte_graph_feature_arc_t *_arc);
> > +
> > +/**
> > + * Get feature arc object with name
> > + *
> > + * @param arc_name
> > + *   Feature arc name provided to successful @ref
> > rte_graph_feature_arc_create
> > + * @param[out] _arc
> > + *   Feature arc object returned
> > + *
> > + * @return
> > + *  0: Success
> > + * <0: Failure.
> > + */
> > +__rte_experimental
> > +int rte_graph_feature_arc_lookup_by_name(const char *arc_name,
> > rte_graph_feature_arc_t *_arc);
> > +
> > +/**
> > + * Add a feature to already created feature arc. For instance
> > + *
> > + * 1. Add first feature node: "ipv4-input" to input arc
> > + *    rte_graph_feature_add(ipv4_input_arc, "ipv4-input", NULL, NULL);
> > + *
> > + * 2. Add "ipsec-input" feature node after "ipv4-input" node
> > + *    rte_graph_feature_add(ipv4_input_arc, "ipsec-input", "ipv4-input",
> > NULL);
> > + *
> > + * 3. Add "ipv4-pre-classify-input" node before "ipv4-input" node
> > + *    rte_graph_feature_add(ipv4_input_arc, "ipv4-pre-classify-input"",
> NULL,
> > "ipv4-input");
> > + *
> > + * 4. Add "acl-classify-input" node after ipv4-input but before ipsec-input
> > + *    rte_graph_feature_add(ipv4_input_arc, "acl-classify-input", "ipv4-
> input",
> > "ipsec-input");
> > + *
> > + * @param _arc
> > + *   Feature arc handle returned from @ref rte_graph_feature_arc_create()
> > + * @param feature_node
> > + *   Graph node representing feature. On success, feature_node is
> next_node
> > of
> > + *   feature_arc->start_node
> > + * @param runs_after
> > + *   Add this feature_node after already added "runs_after". Creates
> > + *   start_node -> runs_after -> this_feature sequence
> > + * @param runs_before
> > + *  Add this feature_node before already added "runs_before". Creates
> > + *  start_node -> this_feature -> runs_before sequence
> > + *
> > + * <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>
> > + *
> > + * @return
> > + *  0: Success
> > + * <0: Failure
> > + */
> > +__rte_experimental
> > +int rte_graph_feature_add(rte_graph_feature_arc_t _arc, struct
> > rte_node_register *feature_node,
> > +		    const char *runs_after, const char *runs_before);
> > +
> > +/**
> > + * 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 user_data
> > + *   Application specific data which is retrieved in fast path
> > + *
> > + * @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,
> > +			     int32_t user_data);
> > +
> > +/**
> > + * Validate whether subsequent enable/disable feature would succeed or
> not.
> > + * API is 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 is_enable_disable
> > + *   If 1, validate whether subsequent @ref rte_graph_feature_enable
> would
> > pass or not
> > + *   If 0, validate whether subsequent @ref rte_graph_feature_disable
> would
> > pass or not
> > + *
> > + * @return
> > + *  0: Subsequent enable/disable API would pass
> > + * <0: Subsequent enable/disable API would not pass
> > + */
> > +__rte_experimental
> > +int rte_graph_feature_validate(rte_graph_feature_arc_t _arc, uint32_t
> index,
> > +			       const char *feature_name, int is_enable_disable);
> > +
> > +/**
> > + * 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
> > + *
> > + * @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);
> > +
> > +/**
> > + * Get rte_graph_feature_t object from feature name
> > + *
> > + * @param arc
> > + *   Feature arc object returned by @ref rte_graph_feature_arc_create or
> > @ref
> > + *   rte_graph_feature_arc_lookup_by_name
> > + * @param feature_name
> > + *   Feature name provided to @ref rte_graph_feature_add
> > + * @param[out] feature
> > + *   Feature object
> > + *
> > + * @return
> > + *  0: Success
> > + * <0: Failure
> > + */
> > +__rte_experimental
> > +int rte_graph_feature_lookup(rte_graph_feature_arc_t _arc, const char
> > *feature_name,
> > +			     rte_graph_feature_t *feature);
> > +
> > +/**
> > + * Delete feature_arc object
> > + *
> > + * @param _arc
> > + *   Feature arc object returned by @ref rte_graph_feature_arc_create or
> > @ref
> > + *   rte_graph_feature_arc_lookup_by_name
> > + *
> > + * @return
> > + *  0: Success
> > + * <0: Failure
> > + */
> > +__rte_experimental
> > +int rte_graph_feature_arc_destroy(rte_graph_feature_arc_t _arc);
> > +
> > +/**
> > + * Cleanup all feature arcs
> > + *
> > + * @return
> > + *  0: Success
> > + * <0: Failure
> > + */
> > +__rte_experimental
> > +int rte_graph_feature_arc_cleanup(void);
> > +
> > +/**
> > + * Slow path API to know how many features are currently enabled within a
> > featur-arc
> > + *
> > + * @param _arc
> > + *  Feature arc object
> > + *
> > + * @return: Number of enabled features
> > + */
> > +__rte_experimental
> > +int
> rte_graph_feature_arc_num_enabled_features(rte_graph_feature_arc_t
> > _arc);
> > +#ifdef __cplusplus
> > +}
> > +#endif
> > +
> > +#endif
> > diff --git a/lib/graph/rte_graph_feature_arc_worker.h
> > b/lib/graph/rte_graph_feature_arc_worker.h
> > new file mode 100644
> > index 0000000000..6019d74853
> > --- /dev/null
> > +++ b/lib/graph/rte_graph_feature_arc_worker.h
> > @@ -0,0 +1,548 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright(C) 2024 Marvell International Ltd.
> > + */
> > +
> > +#ifndef _RTE_GRAPH_FEATURE_ARC_WORKER_H_
> > +#define _RTE_GRAPH_FEATURE_ARC_WORKER_H_
> > +
> > +#include <stddef.h>
> > +#include <rte_graph_feature_arc.h>
> > +#include <rte_bitops.h>
> > +
> > +/**
> > + * @file
> > + *
> > + * rte_graph_feature_arc_worker.h
> > + *
> > + * Defines fast path structure
> > + */
> > +
> > +#ifdef __cplusplus
> > +extern "C" {
> > +#endif
> > +
> > +/** @internal
> > + *
> > + * Slow path feature node info list
> > + */
> > +struct rte_graph_feature_node_list {
> > +	/** Next feature */
> > +	STAILQ_ENTRY(rte_graph_feature_node_list) next_feature;
> > +
> > +	/** node representing feature */
> > +	struct rte_node_register *feature_node;
> > +
> > +	/** How many indexes/interfaces using this feature */
> > +	int32_t ref_count;
> > +
> > +	/* node_index in list (after feature_enable())*/
> > +	uint32_t node_index;
> > +
> > +	/** Back pointer to feature arc */
> > +	void *feature_arc;
> > +
> > +	/** rte_edge_t to this feature node from feature_arc->start_node */
> > +	rte_edge_t edge_to_this_feature;
> > +};
> > +
> > +/**
> > + * Fast path holding rte_edge_t and next enabled feature for an feature
> > + */
> > +typedef struct __rte_packed rte_graph_feature_data {
> > +	/* next node to which current mbuf should go*/
> > +	rte_edge_t next_edge;
> > +
> > +	/* next enabled feature on this arc for current index */
> > +	union {
> > +		uint16_t reserved;
> > +		struct {
> > +			rte_graph_feature_t next_enabled_feature;
> > +		};
> > +	};
> > +
> > +	/* user_data */
> > +	int32_t user_data;
> > +} rte_graph_feature_data_t;
> > +
> > +/**
> > + * Fast path feature structure. Holds re_graph_feature_data_t per index
> > + */
> > +struct __rte_cache_aligned rte_graph_feature {
> > +	uint16_t this_feature_index;
> > +
> > +	/* Array of size arc->feature_data_size
> > +	 * [data-index-0][data-index-1]...
> > +	 * Each index of size: sizeof(rte_graph_feature_data_t)
> > +	 */
> > +	uint8_t feature_data_by_index[];
> > +};
> > +
> > +/**
> > + * fast path cache aligned feature list holding all features
> > + * There are two feature lists: active, passive
> > + *
> > + * Fast APIs works on active list while control plane updates passive list
> > + * A atomic update to arc->active_feature_list is done to switch between
> > active
> > + * and passive
> > + */
> > +typedef struct __rte_cache_aligned rte_graph_feature_list {
> > +	/**
> > +	 * fast path array holding per_feature data.
> > +	 * Duplicate entry as feature-arc also hold this pointer
> > +	 * arc->features[]
> > +	 *
> > +	 *<-------------feature-0 ---------><CEIL><---------feature-1 --------------
> > >...
> > +	 *[index-0][index-1]...[max_index-1]      [index-0][index-1]
> > ...[max_index-1]...
> > +	 */
> > +	struct rte_graph_feature *indexed_by_features;
> > +	/*
> > +	 * fast path array holding first enabled feature per index
> > +	 * (Required in start_node. In non start_node, mbuf can hold next
> > enabled
> > +	 * feature)
> > +	 */
> > +	rte_graph_feature_t first_enabled_feature_by_index[];
> > +} rte_graph_feature_list_t;
> > +
> > +/**
> > + * rte_graph feature arc object
> > + *
> > + * A feature-arc can only hold RTE_GRAPH_FEATURE_MAX_PER_ARC
> features
> > but no
> > + * limit to interface index
> > + *
> > + * Representing a feature arc holding all features which are
> enabled/disabled
> > + * on any interfaces
> > + */
> > +struct __rte_cache_aligned rte_graph_feature_arc {
> > +	/* First 64B is fast path variables */
> > +	RTE_MARKER fast_path_variables;
> > +
> > +	/** runtime active feature list */
> > +	rte_graph_feature_rt_list_t active_feature_list;
> > +
> > +	/* Actual Size of feature_list0 */
> > +	uint16_t feature_list_size;
> > +
> > +	/**
> > +	 * Size each feature in fastpath.
> > +	 * sizeof(arc->active_list->indexed_by_feature[0])
> > +	 */
> > +	uint16_t feature_size;
> > +
> > +	/* Size of arc->max_index * sizeof(rte_graph_feature_data_t) */
> > +	uint16_t feature_data_size;
> > +
> > +	/**
> > +	 * Fast path bitmask indicating if a feature is enabled or not Number
> > +	 * of bits: RTE_GRAPH_FEATURE_MAX_PER_ARC
> > +	 */
> > +	uint64_t feature_enable_bitmask[2];
> > +	rte_graph_feature_list_t *feature_list[2];
> > +	struct rte_graph_feature *features[2];
> > +
> > +	/** index in feature_arc_main */
> > +	uint16_t feature_arc_index;
> > +
> > +	uint16_t reserved[3];
> > +
> > +	/** Slow path variables follows*/
> > +	RTE_MARKER slow_path_variables;
> > +
> > +	/** feature arc name */
> > +	char feature_arc_name[RTE_GRAPH_FEATURE_ARC_NAMELEN];
> > +
> > +	/** All feature lists */
> > +	STAILQ_HEAD(, rte_graph_feature_node_list) all_features;
> > +
> > +	uint32_t runtime_enabled_features;
> > +
> > +	/** Back pointer to feature_arc_main */
> > +	void *feature_arc_main;
> > +
> > +	/* start_node */
> > +	struct rte_node_register *start_node;
> > +
> > +	/* maximum number of features supported by this arc */
> > +	uint32_t max_features;
> > +
> > +	/* maximum number of index supported by this arc */
> > +	uint32_t max_indexes;
> > +
> > +	/* Slow path bit mask per feature per index */
> > +	uint64_t feature_bit_mask_by_index[];
> > +};
> > +
> > +/** Feature arc main */
> > +typedef struct feature_arc_main {
> > +	/** number of feature arcs created by application */
> > +	uint32_t num_feature_arcs;
> > +
> > +	/** max features arcs allowed */
> > +	uint32_t max_feature_arcs;
> > +
> > +	/** feature arcs */
> > +	rte_graph_feature_arc_t feature_arcs[];
> > +} rte_graph_feature_arc_main_t;
> > +
> > +/** @internal Get feature arc pointer from object */
> > +#define rte_graph_feature_arc_get(arc) ((struct rte_graph_feature_arc
> *)arc)
> > +
> > +extern rte_graph_feature_arc_main_t *__feature_arc_main;
> > +
> > +/**
> > + * API to know if feature is valid or not
> > + */
> > +
> > +static __rte_always_inline int
> > +rte_graph_feature_is_valid(rte_graph_feature_t feature)
> > +{
> > +	return (feature != RTE_GRAPH_FEATURE_INVALID);
> > +}
> > +
> > +/**
> > + * Get rte_graph_feature object with no checks
> > + *
> > + * @param arc
> > + *   Feature arc pointer
> > + * @param feature
> > + *   Feature index
> > + * @param feature_list
> > + *   active feature list retrieved from
> > rte_graph_feature_arc_has_any_feature()
> > + *   or rte_graph_feature_arc_has_feature()
> > + *
> > + *   @return
> > + *     Internal feature object.
> > + */
> > +static __rte_always_inline struct rte_graph_feature *
> > +__rte_graph_feature_get(struct rte_graph_feature_arc *arc,
> > rte_graph_feature_t feature,
> > +			const rte_graph_feature_rt_list_t feature_list)
> > +{
> > +	return ((struct rte_graph_feature *)((uint8_t *)(arc-
> > >features[feature_list] +
> > +					     (feature * arc->feature_size))));
> > +}
> > +
> > +/**
> > + * Get rte_graph_feature object for a given interface/index from feature arc
> > + *
> > + * @param arc
> > + *   Feature arc pointer
> > + * @param feature
> > + *   Feature index
> > + *
> > + *   @return
> > + *     Internal feature object.
> > + */
> > +static __rte_always_inline struct rte_graph_feature *
> > +rte_graph_feature_get(struct rte_graph_feature_arc *arc,
> > rte_graph_feature_t feature)
> > +{
> > +	RTE_VERIFY(feature < arc->max_features);
> > +
> > +	if (likely(rte_graph_feature_is_valid(feature)))
> > +		return __rte_graph_feature_get(arc, feature, arc-
> > >active_feature_list);
> > +
> > +	return NULL;
> > +}
> > +
> > +static __rte_always_inline rte_graph_feature_data_t *
> > +__rte_graph_feature_data_get(struct rte_graph_feature_arc *arc, struct
> > rte_graph_feature *feature,
> > +			     uint8_t index)
> > +{
> > +	RTE_SET_USED(arc);
> > +	return ((rte_graph_feature_data_t *)(feature->feature_data_by_index
> > +
> > +					   (index *
> > sizeof(rte_graph_feature_data_t))));
> > +}
> > +
> > +/**
> > + * Get rte_graph feature data object for a index in feature
> > + *
> > + * @param arc
> > + *   feature arc
> > + * @param feature
> > + *  Pointer to feature object
> > + * @param index
> > + *  Index of feature maintained in slow path linked list
> > + *
> > + * @return
> > + *   Valid feature data
> > + */
> > +static __rte_always_inline rte_graph_feature_data_t *
> > +rte_graph_feature_data_get(struct rte_graph_feature_arc *arc, struct
> > rte_graph_feature *feature,
> > +			   uint8_t index)
> > +{
> > +	if (likely(index < arc->max_indexes))
> > +		return __rte_graph_feature_data_get(arc, feature, index);
> > +
> > +	RTE_VERIFY(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
> > + * @param[out] plist
> > + *   Pointer to runtime active feature list which needs to be provided to
> other
> > + *   fast path APIs
> > + *
> > + * @return
> > + * 0: If no feature enabled
> > + * Non-Zero: Bitmask of features enabled. plist is valid
> > + *
> > + */
> > +static __rte_always_inline uint64_t
> > +rte_graph_feature_arc_has_any_feature(struct rte_graph_feature_arc *arc,
> > +				      rte_graph_feature_rt_list_t *plist)
> > +{
> > +	*plist = __atomic_load_n(&arc->active_feature_list,
> > __ATOMIC_RELAXED);
> > +
> > +	return (__atomic_load_n(arc->feature_enable_bitmask +
> > (uint8_t)*plist,
> > +				__ATOMIC_RELAXED));
> > +}
> > +
> > +/**
> > + * Fast path API to check if provided feature is enabled on any
> interface/index
> > + * or not
> > + *
> > + * @param arc
> > + *   Feature arc object
> > + * @param feature
> > + *   Input rte_graph_feature_t that needs to be checked
> > + * @param[out] plist
> > + *  Returns active list to caller which needs to be provided to other fast
> path
> > + *  APIs
> > + *
> > + * @return
> > + * 1: If feature is enabled in arc
> > + * 0: If feature is not enabled in arc
> > + */
> > +static __rte_always_inline int
> > +rte_graph_feature_arc_has_feature(struct rte_graph_feature_arc *arc,
> > +				  rte_graph_feature_t feature,
> > +				  rte_graph_feature_rt_list_t *plist)
> > +{
> > +	uint64_t bitmask = RTE_BIT64(feature);
> > +
> > +	*plist = __atomic_load_n(&arc->active_feature_list,
> > __ATOMIC_RELAXED);
> > +
> > +	return (bitmask & __atomic_load_n(arc->feature_enable_bitmask +
> > (uint8_t)*plist,
> > +					  __ATOMIC_RELAXED));
> > +}
> > +
> > +/**
> > + * Prefetch feature arc fast path cache line
> > + *
> > + * @param arc
> > + *   RTE_GRAPH feature arc object
> > + */
> > +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 related fast path cache line
> > + *
> > + * @param arc
> > + *   RTE_GRAPH feature arc object
> > + * @param list
> > + *  Pointer to runtime active feature list from
> > rte_graph_feature_arc_has_any_feature();
> > + * @param feature
> > + *   Pointer to feature object
> > + */
> > +static __rte_always_inline void
> > +rte_graph_feature_arc_feature_prefetch(struct rte_graph_feature_arc *arc,
> > +				       const rte_graph_feature_rt_list_t list,
> > +				       rte_graph_feature_t feature)
> > +{
> > +	/* feature cache line */
> > +	if (likely(rte_graph_feature_is_valid(feature)))
> > +		rte_prefetch0((void *)__rte_graph_feature_get(arc, feature,
> > list));
> > +}
> > +
> > +/**
> > + * Prefetch feature data upfront. Perform sanity
> > + *
> > + * @param _arc
> > + *   RTE_GRAPH feature arc object
> > + * @param list
> > + *  Pointer to runtime active feature list from
> > rte_graph_feature_arc_has_any_feature();
> > + * @param feature
> > + *   Pointer to feature object returned from @ref
> > + *   rte_graph_feature_arc_first_feature_get()
> > + * @param index
> > + *   Interface/index
> > + */
> > +static __rte_always_inline void
> > +rte_graph_feature_arc_data_prefetch(struct rte_graph_feature_arc *arc,
> > +				    const rte_graph_feature_rt_list_t list,
> > +				    rte_graph_feature_t feature, uint32_t
> index)
> > +{
> > +	if (likely(rte_graph_feature_is_valid(feature)))
> > +		rte_prefetch0((void *)((uint8_t *)arc->features[list] +
> > +			      offsetof(struct rte_graph_feature,
> > feature_data_by_index) +
> > +			      (index * sizeof(rte_graph_feature_data_t))));
> > +}
> > +
> > +/**
> > + * Fast path API to get first enabled feature on interface index
> > + * Typically required in arc->start_node so that from returned feature,
> > + * feature-data can be retrieved to steer packets
> > + *
> > + * @param arc
> > + *   Feature arc object
> > + * @param list
> > + *   Pointer to runtime active feature list from
> > + *   rte_graph_feature_arc_has_any_feature() or
> > + *   rte_graph_feature_arc_has_feature()
> > + * @param index
> > + *  Interface Index
> > + * @param[out] feature
> > + *  Pointer to rte_graph_feature_t.
> > + *
> > + * @return
> > + * 0. Success. feature field is valid
> > + * 1. Failure. feature field is invalid
> > + *
> > + */
> > +static __rte_always_inline int
> > +rte_graph_feature_arc_first_feature_get(struct rte_graph_feature_arc *arc,
> > +					const rte_graph_feature_rt_list_t list,
> > +					uint32_t index,
> > +					rte_graph_feature_t *feature)
> > +{
> > +	struct rte_graph_feature_list *feature_list = arc->feature_list[list];
> > +
> > +	*feature = feature_list->first_enabled_feature_by_index[index];
> > +
> > +	return rte_graph_feature_is_valid(*feature);
> > +}
> > +
> > +/**
> > + * Fast path API to get next enabled feature on interface index with
> provided
> > + * input feature
> > + *
> > + * @param arc
> > + *   Feature arc object
> > + * @param list
> > + *   Pointer to runtime active feature list from
> > + *   rte_graph_feature_arc_has_any_feature() or
> > + * @param index
> > + *   Interface Index
> > + * @param[in][out] feature
> > + *   Pointer to rte_graph_feature_t. Input feature set to next enabled
> feature
> > + *   after success return
> > + * @param[out] next_edge
> > + *    Edge from current feature to next feature. Valid only if next feature is
> > valid
> > + *
> > + * @return
> > + * 0. Success. next enabled feature is valid.
> > + * 1. Failure. next enabled feature is invalid
> > + */
> > +static __rte_always_inline int
> > +rte_graph_feature_arc_next_feature_get(struct rte_graph_feature_arc
> *arc,
> > +				       const rte_graph_feature_rt_list_t list,
> > +				       uint32_t index,
> > +				       rte_graph_feature_t *feature,
> > +				       rte_edge_t *next_edge)
> > +{
> > +	rte_graph_feature_data_t *feature_data = NULL;
> > +	struct rte_graph_feature *f = NULL;
> > +
> > +	if (likely(rte_graph_feature_is_valid(*feature))) {
> > +		f = __rte_graph_feature_get(arc, *feature, list);
> > +		feature_data = rte_graph_feature_data_get(arc, f, index);
> > +		*feature = feature_data->next_enabled_feature;
> > +		*next_edge = feature_data->next_edge;
> > +		return (*feature == RTE_GRAPH_FEATURE_INVALID);
> > +	}
> > +
> > +	return 1;
> > +}
> > +
> > +/**
> > + * Set fields with respect to first enabled feature in an arc and return edge
> > + * Typically returned feature and interface index must be saved in
> rte_mbuf
> > + * structure to pass this information to next feature node
> > + *
> > + * @param arc
> > + *   Feature arc object
> > + * @param list
> > + *   Pointer to runtime active feature list from
> > rte_graph_feature_arc_has_any_feature();
> > + * @param index
> > + *  Index (of interface)
> > + * @param[out] gf
> > + *  Pointer to rte_graph_feature_t. Valid if API returns Success
> > + * @param[out] edge
> > + *  Edge to steer packet from arc->start_node to first enabled feature. Valid
> > + *  only if API returns Success
> > + *
> > + * @return
> > + * 0: If valid feature is set by API
> > + * 1: If valid feature is NOT set by API
> > + */
> > +static __rte_always_inline rte_graph_feature_t
> > +rte_graph_feature_arc_feature_set(struct rte_graph_feature_arc *arc,
> > +				  const rte_graph_feature_rt_list_t list,
> > +				  uint32_t index,
> > +				  rte_graph_feature_t *gf,
> > +				  rte_edge_t *edge)
> > +{
> > +	struct rte_graph_feature_list *feature_list = arc->feature_list[list];
> > +	struct rte_graph_feature_data *feature_data = NULL;
> > +	struct rte_graph_feature *feature = NULL;
> > +	rte_graph_feature_t f;
> > +
> > +	/* reset */
> > +	*gf = RTE_GRAPH_FEATURE_INVALID;
> > +	f = feature_list->first_enabled_feature_by_index[index];
> > +
> > +	if (unlikely(rte_graph_feature_is_valid(f))) {
> > +		feature = __rte_graph_feature_get(arc, f, list);
> > +		feature_data = rte_graph_feature_data_get(arc, feature,
> > index);
> > +		*gf = f;
> > +		*edge = feature_data->next_edge;
> > +		return 0;
> > +	}
> > +
> > +	return 1;
> > +}
> > +
> > +/**
> > + * Get user data corresponding to current feature set by application in
> > + * rte_graph_feature_enable()
> > + *
> > + * @param arc
> > + *  Feature arc object
> > + * @param list
> > + *  Pointer to runtime active feature list from
> > rte_graph_feature_arc_has_any_feature();
> > + * @param feature
> > + *  Feature index
> > + * @param index
> > + *  Interface index
> > + *
> > + *  @return
> > + *  UINT32_MAX: Failure
> > + *  Valid user data: Success
> > + */
> > +static __rte_always_inline uint32_t
> > +rte_graph_feature_user_data_get(struct rte_graph_feature_arc *arc,
> > +				const rte_graph_feature_rt_list_t list,
> > +				rte_graph_feature_t feature,
> > +				uint32_t index)
> > +{
> > +	rte_graph_feature_data_t *fdata = NULL;
> > +	struct rte_graph_feature *f = NULL;
> > +
> > +	if (likely(rte_graph_feature_is_valid(feature))) {
> > +		f = __rte_graph_feature_get(arc, feature, list);
> > +		fdata = rte_graph_feature_data_get(arc, f, index);
> > +		return fdata->user_data;
> > +	}
> > +
> > +	return UINT32_MAX;
> > +}
> > +#ifdef __cplusplus
> > +}
> > +#endif
> > +#endif
> > diff --git a/lib/graph/version.map b/lib/graph/version.map
> > index 2c83425ddc..82b2469fba 100644
> > --- a/lib/graph/version.map
> > +++ b/lib/graph/version.map
> > @@ -52,3 +52,20 @@ DPDK_25 {
> >
> >  	local: *;
> >  };
> > +
> > +EXPERIMENTAL {
> > +	global:
> > +
> > +	# added in 24.11
> > +	rte_graph_feature_arc_init;
> > +	rte_graph_feature_arc_create;
> > +	rte_graph_feature_arc_lookup_by_name;
> > +	rte_graph_feature_add;
> > +	rte_graph_feature_enable;
> > +	rte_graph_feature_validate;
> > +	rte_graph_feature_disable;
> > +	rte_graph_feature_lookup;
> > +	rte_graph_feature_arc_destroy;
> > +	rte_graph_feature_arc_cleanup;
> > +	rte_graph_feature_arc_num_enabled_features;
> > +};
> > --
> > 2.43.0