[dpdk-dev] [PATCH v1] net/mlx5: fix RSS expansion for L2/L3 VXLAN

[Lior Margalit <lmargalit@nvidia.com>]

The RSS expansion algorithm is using a graph to find the possible
expansion paths. The current implementation does not differentiate
between standard (L2) VXLAN and L3 VXLAN. As result the flow is expanded
with all possible paths.
For example:
testpmd> flow create... / vxlan / end actions rss level 2 / end
It is currently expanded to the following paths:
ETH IPV4 UDP VXLAN END
ETH IPV4 UDP VXLAN ETH IPV4 END
ETH IPV4 UDP VXLAN ETH IPV6 END
ETH IPV4 UDP VXLAN IPV4 END
ETH IPV4 UDP VXLAN IPV6 END

The fix is to adjust the expansion according to the outer UDP destination
port. In case flow pattern defines a match on the standard udp port, 4789,
or does not define a match on the destination port, which also implies
setting the standard one, the expansion for the above example will be:
ETH IPV4 UDP VXLAN END
ETH IPV4 UDP VXLAN ETH IPV4 END
ETH IPV4 UDP VXLAN ETH IPV6 END
Otherwise, the expansion will be:
ETH IPV4 UDP VXLAN END
ETH IPV4 UDP VXLAN IPV4 END
ETH IPV4 UDP VXLAN IPV6 END

Fixes: f4f06e361516 ("net/mlx5: add flow VXLAN item")
Cc: stable@dpdk.org

Signed-off-by: Lior Margalit <lmargalit@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>

---
 drivers/net/mlx5/mlx5_flow.c | 71 +++++++++++++++++++++++++++++++++---
 1 file changed, 66 insertions(+), 5 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index c914a7120c..509ca01859 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -132,6 +132,12 @@ struct mlx5_flow_expand_rss {
 static void
 mlx5_dbg__print_pattern(const struct rte_flow_item *item);
 
+static const struct mlx5_flow_expand_node *
+mlx5_flow_expand_rss_adjust_node(const struct rte_flow_item *pattern,
+		unsigned int item_idx,
+		const struct mlx5_flow_expand_node graph[],
+		const struct mlx5_flow_expand_node *node);
+
 static bool
 mlx5_flow_is_rss_expandable_item(const struct rte_flow_item *item)
 {
@@ -318,7 +324,7 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, size_t size,
 	const int *stack[MLX5_RSS_EXP_ELT_N];
 	int stack_pos = 0;
 	struct rte_flow_item flow_items[MLX5_RSS_EXP_ELT_N];
-	unsigned int i;
+	unsigned int i, item_idx, last_expand_item_idx = 0;
 	size_t lsize;
 	size_t user_pattern_size = 0;
 	void *addr = NULL;
@@ -326,7 +332,7 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, size_t size,
 	struct rte_flow_item missed_item;
 	int missed = 0;
 	int elt = 0;
-	const struct rte_flow_item *last_item = NULL;
+	const struct rte_flow_item *last_expand_item = NULL;
 
 	memset(&missed_item, 0, sizeof(missed_item));
 	lsize = offsetof(struct mlx5_flow_expand_rss, entry) +
@@ -337,12 +343,15 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, size_t size,
 	buf->entry[0].pattern = (void *)&buf->entry[MLX5_RSS_EXP_ELT_N];
 	buf->entries = 0;
 	addr = buf->entry[0].pattern;
-	for (item = pattern; item->type != RTE_FLOW_ITEM_TYPE_END; item++) {
+	for (item = pattern, item_idx = 0;
+			item->type != RTE_FLOW_ITEM_TYPE_END;
+			item++, item_idx++) {
 		if (!mlx5_flow_is_rss_expandable_item(item)) {
 			user_pattern_size += sizeof(*item);
 			continue;
 		}
-		last_item = item;
+		last_expand_item = item;
+		last_expand_item_idx = item_idx;
 		i = 0;
 		while (node->next && node->next[i]) {
 			next = &graph[node->next[i]];
@@ -374,7 +383,7 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, size_t size,
 	 * Check if the last valid item has spec set, need complete pattern,
 	 * and the pattern can be used for expansion.
 	 */
-	missed_item.type = mlx5_flow_expand_rss_item_complete(last_item);
+	missed_item.type = mlx5_flow_expand_rss_item_complete(last_expand_item);
 	if (missed_item.type == RTE_FLOW_ITEM_TYPE_END) {
 		/* Item type END indicates expansion is not required. */
 		return lsize;
@@ -409,6 +418,9 @@ mlx5_flow_expand_rss(struct mlx5_flow_expand_rss *buf, size_t size,
 			addr = (void *)(((uintptr_t)addr) +
 					elt * sizeof(*item));
 		}
+	} else if (last_expand_item != NULL) {
+		node = mlx5_flow_expand_rss_adjust_node(pattern,
+				last_expand_item_idx, graph, node);
 	}
 	memset(flow_items, 0, sizeof(flow_items));
 	next_node = mlx5_flow_expand_rss_skip_explicit(graph,
@@ -495,6 +507,8 @@ enum mlx5_expansion {
 	MLX5_EXPANSION_OUTER_IPV6_UDP,
 	MLX5_EXPANSION_OUTER_IPV6_TCP,
 	MLX5_EXPANSION_VXLAN,
+	MLX5_EXPANSION_STD_VXLAN,
+	MLX5_EXPANSION_L3_VXLAN,
 	MLX5_EXPANSION_VXLAN_GPE,
 	MLX5_EXPANSION_GRE,
 	MLX5_EXPANSION_NVGRE,
@@ -591,6 +605,15 @@ static const struct mlx5_flow_expand_node mlx5_support_expansion[] = {
 						  MLX5_EXPANSION_IPV6),
 		.type = RTE_FLOW_ITEM_TYPE_VXLAN,
 	},
+	[MLX5_EXPANSION_STD_VXLAN] = {
+			.next = MLX5_FLOW_EXPAND_RSS_NEXT(MLX5_EXPANSION_ETH),
+					.type = RTE_FLOW_ITEM_TYPE_VXLAN,
+	},
+	[MLX5_EXPANSION_L3_VXLAN] = {
+			.next = MLX5_FLOW_EXPAND_RSS_NEXT(MLX5_EXPANSION_IPV4,
+					MLX5_EXPANSION_IPV6),
+					.type = RTE_FLOW_ITEM_TYPE_VXLAN,
+	},
 	[MLX5_EXPANSION_VXLAN_GPE] = {
 		.next = MLX5_FLOW_EXPAND_RSS_NEXT(MLX5_EXPANSION_ETH,
 						  MLX5_EXPANSION_IPV4,
@@ -9416,3 +9439,41 @@ mlx5_dbg__print_pattern(const struct rte_flow_item *item)
 	}
 	printf("END\n");
 }
+
+static int
+mlx5_flow_is_std_vxlan_port(const struct rte_flow_item *udp_item)
+{
+	const struct rte_flow_item_udp *spec = udp_item->spec;
+	const struct rte_flow_item_udp *mask = udp_item->mask;
+	uint16_t udp_dport = 0;
+
+	if (spec != NULL) {
+		if (!mask)
+			mask = &rte_flow_item_udp_mask;
+		udp_dport = rte_be_to_cpu_16(spec->hdr.dst_port &
+				mask->hdr.dst_port);
+	}
+	return (!udp_dport || udp_dport == MLX5_UDP_PORT_VXLAN);
+}
+
+static const struct mlx5_flow_expand_node *
+mlx5_flow_expand_rss_adjust_node(const struct rte_flow_item *pattern,
+		unsigned int item_idx,
+		const struct mlx5_flow_expand_node graph[],
+		const struct mlx5_flow_expand_node *node)
+{
+	const struct rte_flow_item *item = pattern + item_idx, *prev_item;
+	switch (item->type) {
+	case RTE_FLOW_ITEM_TYPE_VXLAN:
+		MLX5_ASSERT(item_idx > 0);
+		prev_item = pattern + item_idx - 1;
+		MLX5_ASSERT(prev_item->type == RTE_FLOW_ITEM_TYPE_UDP);
+		if (mlx5_flow_is_std_vxlan_port(prev_item))
+			return &graph[MLX5_EXPANSION_STD_VXLAN];
+		else
+			return &graph[MLX5_EXPANSION_L3_VXLAN];
+		break;
+	default:
+		return node;
+	}
+}
-- 
2.25.1