RDMA/mlx5: Add support in steering default miss

User can configure default miss rule in order to skip matching in the user
domain and forward the packet to the kernel steering domain.  When user
requests a default miss rule, we add steering rule to forward the traffic
to the next namespace.

Link: https://lore.kernel.org/r/20200504053012.270689-5-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Zhang <markz@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/flow.c

@@ -69,19 +69,32 @@ static const struct uverbs_attr_spec mlx5_ib_flow_type[] = {
 
 static int get_dests(struct uverbs_attr_bundle *attrs,
 		     struct mlx5_ib_flow_matcher *fs_matcher, int *dest_id,
-		     int *dest_type, struct ib_qp **qp)
+		     int *dest_type, struct ib_qp **qp, bool *def_miss)
 {
 	bool dest_devx, dest_qp;
 	void *devx_obj;
+	u32 flags;
+	int err;
 
 	dest_devx = uverbs_attr_is_valid(attrs,
 					 MLX5_IB_ATTR_CREATE_FLOW_DEST_DEVX);
 	dest_qp = uverbs_attr_is_valid(attrs,
 				       MLX5_IB_ATTR_CREATE_FLOW_DEST_QP);
 
-	if (fs_matcher->ns_type == MLX5_FLOW_NAMESPACE_BYPASS &&
+	*def_miss = false;
-	    ((dest_devx && dest_qp) || (!dest_devx && !dest_qp)))
+	err = uverbs_get_flags32(&flags, attrs,
-		return -EINVAL;
+				 MLX5_IB_ATTR_CREATE_FLOW_FLAGS,
+				 MLX5_IB_ATTR_CREATE_FLOW_FLAGS_DEFAULT_MISS);
+	if (err)
+		return err;
+	*def_miss = flags & MLX5_IB_ATTR_CREATE_FLOW_FLAGS_DEFAULT_MISS;
+
+	if (fs_matcher->ns_type == MLX5_FLOW_NAMESPACE_BYPASS) {
+		if (dest_devx && (dest_qp || *def_miss))
+			return -EINVAL;
+		else if (dest_qp && *def_miss)
+			return -EINVAL;
+	}
 
 	/* Allow only DEVX object as dest when inserting to FDB */
 	if (fs_matcher->ns_type == MLX5_FLOW_NAMESPACE_FDB && !dest_devx)
@@ -153,6 +166,7 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_CREATE_FLOW)(
 	void *devx_obj, *cmd_in;
 	struct ib_uobject *uobj;
 	struct mlx5_ib_dev *dev;
+	bool def_miss;
 
 	if (!capable(CAP_NET_RAW))
 		return -EPERM;
@@ -162,9 +176,12 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_CREATE_FLOW)(
 	uobj =  uverbs_attr_get_uobject(attrs, MLX5_IB_ATTR_CREATE_FLOW_HANDLE);
 	dev = mlx5_udata_to_mdev(&attrs->driver_udata);
 
-	if (get_dests(attrs, fs_matcher, &dest_id, &dest_type, &qp))
+	if (get_dests(attrs, fs_matcher, &dest_id, &dest_type, &qp, &def_miss))
 		return -EINVAL;
 
+	if (def_miss)
+		flow_act.action |= MLX5_FLOW_CONTEXT_ACTION_FWD_NEXT_NS;
+
 	len = uverbs_attr_get_uobjs_arr(attrs,
 		MLX5_IB_ATTR_CREATE_FLOW_ARR_COUNTERS_DEVX, &arr_flow_actions);
 	if (len) {
@@ -636,7 +653,10 @@ DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_ATTR_PTR_IN(MLX5_IB_ATTR_CREATE_FLOW_ARR_COUNTERS_DEVX_OFFSET,
 			   UVERBS_ATTR_MIN_SIZE(sizeof(u32)),
 			   UA_OPTIONAL,
-			   UA_ALLOC_AND_COPY));
+			   UA_ALLOC_AND_COPY),
+	UVERBS_ATTR_FLAGS_IN(MLX5_IB_ATTR_CREATE_FLOW_FLAGS,
+			     enum mlx5_ib_create_flow_flags,
+			     UA_OPTIONAL));
 
 DECLARE_UVERBS_NAMED_METHOD_DESTROY(
 	MLX5_IB_METHOD_DESTROY_FLOW,

drivers/infiniband/hw/mlx5/main.c

@@ -4200,18 +4200,17 @@ mlx5_ib_raw_fs_rule_add(struct mlx5_ib_dev *dev,
 
 	if (dest_type == MLX5_FLOW_DESTINATION_TYPE_TIR) {
 		dst[dst_num].type = dest_type;
-		dst[dst_num].tir_num = dest_id;
+		dst[dst_num++].tir_num = dest_id;
 		flow_act->action |= MLX5_FLOW_CONTEXT_ACTION_FWD_DEST;
 	} else if (dest_type == MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE) {
 		dst[dst_num].type = MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE_NUM;
-		dst[dst_num].ft_num = dest_id;
+		dst[dst_num++].ft_num = dest_id;
 		flow_act->action |= MLX5_FLOW_CONTEXT_ACTION_FWD_DEST;
-	} else {
+	} else  if (dest_type == MLX5_FLOW_DESTINATION_TYPE_PORT) {
-		dst[dst_num].type = MLX5_FLOW_DESTINATION_TYPE_PORT;
+		dst[dst_num++].type = MLX5_FLOW_DESTINATION_TYPE_PORT;
 		flow_act->action |= MLX5_FLOW_CONTEXT_ACTION_ALLOW;
 	}
 
-	dst_num++;
 
 	if (flow_act->action & MLX5_FLOW_CONTEXT_ACTION_COUNT) {
 		dst[dst_num].type = MLX5_FLOW_DESTINATION_TYPE_COUNTER;

include/uapi/rdma/mlx5_user_ioctl_cmds.h

@@ -241,6 +241,10 @@ enum mlx5_ib_flow_type {
 	MLX5_IB_FLOW_TYPE_MC_DEFAULT,
 };
 
+enum mlx5_ib_create_flow_flags {
+	MLX5_IB_ATTR_CREATE_FLOW_FLAGS_DEFAULT_MISS = 1 << 0,
+};
+
 enum mlx5_ib_create_flow_attrs {
 	MLX5_IB_ATTR_CREATE_FLOW_HANDLE = (1U << UVERBS_ID_NS_SHIFT),
 	MLX5_IB_ATTR_CREATE_FLOW_MATCH_VALUE,
@@ -251,6 +255,7 @@ enum mlx5_ib_create_flow_attrs {
 	MLX5_IB_ATTR_CREATE_FLOW_TAG,
 	MLX5_IB_ATTR_CREATE_FLOW_ARR_COUNTERS_DEVX,
 	MLX5_IB_ATTR_CREATE_FLOW_ARR_COUNTERS_DEVX_OFFSET,
+	MLX5_IB_ATTR_CREATE_FLOW_FLAGS,
 };
 
 enum mlx5_ib_destoy_flow_attrs {