Re: [v10 2/3] net/af_xdp: fix multi interface support for K8s

[Maryam Tahhan <mtahhan@redhat.com>]

On 29/02/2024 13:01, Maryam Tahhan wrote:
> The original 'use_cni' implementation, was added
> to enable support for the AF_XDP PMD in a K8s env
> without any escalated privileges.
> However 'use_cni' used a hardcoded socket rather
> than a configurable one. If a DPDK pod is requesting
> multiple net devices and these devices are from
> different pools, then the AF_XDP PMD attempts to
> mount all the netdev UDSes in the pod as /tmp/afxdp.sock.
> Which means that at best only 1 netdev will handshake
> correctly with the AF_XDP DP. This patch addresses
> this by making the socket parameter configurable using
> a new vdev param called 'dp_path' alongside the
> original 'use_cni' param. If the 'dp_path' parameter
> is not set alongside the 'use_cni' parameter, then
> it's configured inside the AF_XDP PMD (transparently
> to the user). This change has been tested
> with the AF_XDP DP PR 81[1], with both single and
> multiple interfaces.
>
> [1] https://github.com/intel/afxdp-plugins-for-kubernetes/pull/81
>
> Fixes: 7fc6ae50369d ("net/af_xdp: support CNI Integration")
> Cc: stable@dpdk.org
>
> Signed-off-by: Maryam Tahhan <mtahhan@redhat.com>
> ---
>   doc/guides/howto/af_xdp_dp.rst         | 62 +++++++++++------
>   doc/guides/nics/af_xdp.rst             | 14 ++++
>   doc/guides/rel_notes/release_24_03.rst |  7 ++
>   drivers/net/af_xdp/rte_eth_af_xdp.c    | 94 ++++++++++++++++----------
>   4 files changed, 121 insertions(+), 56 deletions(-)
>
> diff --git a/doc/guides/howto/af_xdp_dp.rst b/doc/guides/howto/af_xdp_dp.rst
> index 7166d904bd..ec348c3b82 100644
> --- a/doc/guides/howto/af_xdp_dp.rst
> +++ b/doc/guides/howto/af_xdp_dp.rst
> @@ -52,29 +52,33 @@ should be used when creating the socket
>   to instruct libbpf not to load the default libbpf program on the netdev.
>   Instead the loading is handled by the AF_XDP Device Plugin.
>   
> -Limitations
> ------------
> +The EAL vdev argument ``dp_path`` is used alongside the ``use_cni`` argument
> +to explicitly tell the AF_XDP PMD where to find the UDS to interact with the
> +AF_XDP Device Plugin. If this argument is not passed alongside the ``use_cni``
> +argument then the AF_XDP PMD configures it internally.
>   
> -For DPDK versions <= v23.11 the Unix Domain Socket file path appears in
> -the pod at "/tmp/afxdp.sock". The handshake implementation in the AF_XDP PMD
> -is only compatible with the AF_XDP Device Plugin up to commit id `38317c2`_
> -and the pod is limited to a single netdev.
> +.. note::
> +
> +    DPDK AF_XDP PMD <= v23.11 will only work with the AF_XDP Device Plugin
> +    <= commit id `38317c2`_.
>   
>   .. note::
>   
> -    DPDK AF_XDP PMD <= v23.11 will not work with the latest version of the
> -    AF_XDP Device Plugin.
> +    DPDK AF_XDP PMD > v23.11 will work with latest version of the
> +    AF_XDP Device Plugin through a combination of the ``dp_path`` and/or
> +    the ``use_cni`` parameter. In these versions of the PMD if a user doesn't
> +    explicitly set the ``dp_path``parameter when using ``use_cni`` then that
I see the typo - will respin - sorry, it's been a long day already
> +    path is transparently configured in the AF_XDP PMD to the default
> +    `AF_XDP Device Plugin for Kubernetes`_ mount point path. The path can
> +    be overriden by explicitly setting the ``dp_path`` param.
>   
> -The issue is if a single pod requests different devices from different pools it
> -results in multiple UDS servers serving the pod with the container using only a
> -single mount point for their UDS as ``/tmp/afxdp.sock``. This means that at best one
> -device might be able to complete the handshake. This has been fixed in the AF_XDP
> -Device Plugin so that the mount point in the pods for the UDS appear at
> -``/tmp/afxdp_dp/<netdev>/afxdp.sock``. Later versions of DPDK fix this hardcoded path
> -in the PMD alongside the ``use_cni`` parameter.
> +.. note::
>   
> -.. _38317c2: https://github.com/intel/afxdp-plugins-for-kubernetes/commit/38317c256b5c7dfb39e013a0f76010c2ded03669
> +    DPDK AF_XDP PMD > v23.11 is backwards compatible with (older) versions
> +    of the AF_XDP DP <= commit id `38317c2`_ by explicitly setting ``dp_path`` to
> +    ``/tmp/afxdp.sock``.
>   
> +.. _38317c2: https://github.com/intel/afxdp-plugins-for-kubernetes/commit/38317c256b5c7dfb39e013a0f76010c2ded03669
>   
>   Prerequisites
>   -------------
> @@ -105,10 +109,10 @@ Device Plugin and DPDK container prerequisites:
>   
>     .. code-block:: console
>   
> -     cat << EOF | sudo tee /etc/systemd/system/containerd.service.d/limits.conf
> -     [Service]
> -     LimitMEMLOCK=infinity
> -     EOF
> +    cat << EOF | sudo tee /etc/systemd/system/containerd.service.d/limits.conf
> +    [Service]
> +    LimitMEMLOCK=infinity
> +    EOF
>   
>   * dpdk-testpmd application should have AF_XDP feature enabled.
>   
> @@ -284,7 +288,7 @@ Run dpdk-testpmd with the AF_XDP Device Plugin + CNI
>           emptyDir:
>             medium: HugePages
>   
> -  For further reference please use the `pod.yaml`_
> +  For further reference please see the `pod.yaml`_
>   
>     .. _pod.yaml: https://github.com/intel/afxdp-plugins-for-kubernetes/blob/main/examples/pod-spec.yaml
>   
> @@ -297,3 +301,19 @@ Run dpdk-testpmd with the AF_XDP Device Plugin + CNI
>              --vdev=net_af_xdp0,use_cni=1,iface=<interface name> \
>              --no-mlockall --in-memory \
>              -- -i --a --nb-cores=2 --rxq=1 --txq=1 --forward-mode=macswap;
> +
> +  Or
> +
> +  .. code-block:: console
> +
> +     kubectl exec -i <Pod name> --container <containers name> -- \
> +           /<Path>/dpdk-testpmd -l 0,1 --no-pci \
> +           --vdev=net_af_xdp0,use_cni=1,iface=<interface name>,dp_path="/tmp/afxdp_dp/<interface name>/afxdp.sock" \
> +           --no-mlockall --in-memory \
> +           -- -i --a --nb-cores=2 --rxq=1 --txq=1 --forward-mode=macswap;
> +
> +.. note::
> +
> +    If the ``dp_path`` parameter isn't explicitly set (like the example above)
> +    the AF_XDP PMD will set the parameter value to
> +    ``/tmp/afxdp_dp/<<interface name>>/afxdp.sock``.
> diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
> index 4dd9c73742..7f8651beda 100644
> --- a/doc/guides/nics/af_xdp.rst
> +++ b/doc/guides/nics/af_xdp.rst
> @@ -171,6 +171,20 @@ enable the `AF_XDP Device Plugin for Kubernetes`_ with a DPDK application/pod.
>      so enabling and disabling of the promiscuous mode through the DPDK application
>      is also not supported.
>   
> +dp_path
> +~~~~~~~
> +
> +The EAL vdev argument ``dp_path`` is used alongside the ``use_cni`` argument
> +to explicitly tell the AF_XDP PMD where to find the UDS to interact with the
> +`AF_XDP Device Plugin for Kubernetes`_. If this argument is not passed
> +alongside the ``use_cni`` argument then the AF_XDP PMD configures it internally.
> +
> +.. _AF_XDP Device Plugin for Kubernetes: https://github.com/intel/afxdp-plugins-for-kubernetes
> +
> +.. code-block:: console
> +
> +   --vdev=net_af_xdp0,use_cni=1,dp_path="/tmp/afxdp_dp/<<interface name>>/afxdp.sock"
> +
>   Limitations
>   -----------
>   
> diff --git a/doc/guides/rel_notes/release_24_03.rst b/doc/guides/rel_notes/release_24_03.rst
> index 879bb4944c..b2b1f2566f 100644
> --- a/doc/guides/rel_notes/release_24_03.rst
> +++ b/doc/guides/rel_notes/release_24_03.rst
> @@ -138,6 +138,13 @@ New Features
>       to support TLS v1.2, TLS v1.3 and DTLS v1.2.
>     * Added PMD API to allow raw submission of instructions to CPT.
>   
> +* **Enabled AF_XDP PMD multi interface (UDS) support with AF_XDP Device Plugin**.
> +
> +  The EAL vdev argument for the AF_XDP PMD ``use_cni`` previously limited
> +  a pod to using only a single netdev/interface. The latest changes (adding
> +  the ``dp_path`` parameter) remove this limitation and maintain backward
> +  compatibility for any applications already using the ``use_cni`` vdev
> +  argument with the AF_XDP Device Plugin.
>   
>   Removed Items
>   -------------
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 2d151e45c7..3fb0c6a3b9 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -83,12 +83,13 @@ RTE_LOG_REGISTER_DEFAULT(af_xdp_logtype, NOTICE);
>   
>   #define ETH_AF_XDP_MP_KEY "afxdp_mp_send_fds"
>   
> +#define DP_BASE_PATH			"/tmp/afxdp_dp"
> +#define DP_UDS_SOCK             "afxdp.sock"
>   #define MAX_LONG_OPT_SZ			64
>   #define UDS_MAX_FD_NUM			2
>   #define UDS_MAX_CMD_LEN			64
>   #define UDS_MAX_CMD_RESP		128
>   #define UDS_XSK_MAP_FD_MSG		"/xsk_map_fd"
> -#define UDS_SOCK			"/tmp/afxdp.sock"
>   #define UDS_CONNECT_MSG			"/connect"
>   #define UDS_HOST_OK_MSG			"/host_ok"
>   #define UDS_HOST_NAK_MSG		"/host_nak"
> @@ -171,6 +172,7 @@ struct pmd_internals {
>   	bool custom_prog_configured;
>   	bool force_copy;
>   	bool use_cni;
> +	char dp_path[PATH_MAX];
>   	struct bpf_map *map;
>   
>   	struct rte_ether_addr eth_addr;
> @@ -191,6 +193,7 @@ struct pmd_process_private {
>   #define ETH_AF_XDP_BUDGET_ARG			"busy_budget"
>   #define ETH_AF_XDP_FORCE_COPY_ARG		"force_copy"
>   #define ETH_AF_XDP_USE_CNI_ARG			"use_cni"
> +#define ETH_AF_XDP_DP_PATH_ARG			"dp_path"
>   
>   static const char * const valid_arguments[] = {
>   	ETH_AF_XDP_IFACE_ARG,
> @@ -201,6 +204,7 @@ static const char * const valid_arguments[] = {
>   	ETH_AF_XDP_BUDGET_ARG,
>   	ETH_AF_XDP_FORCE_COPY_ARG,
>   	ETH_AF_XDP_USE_CNI_ARG,
> +	ETH_AF_XDP_DP_PATH_ARG,
>   	NULL
>   };
>   
> @@ -1351,7 +1355,7 @@ configure_preferred_busy_poll(struct pkt_rx_queue *rxq)
>   }
>   
>   static int
> -init_uds_sock(struct sockaddr_un *server)
> +init_uds_sock(struct sockaddr_un *server, const char *dp_path)
>   {
>   	int sock;
>   
> @@ -1362,7 +1366,7 @@ init_uds_sock(struct sockaddr_un *server)
>   	}
>   
>   	server->sun_family = AF_UNIX;
> -	strlcpy(server->sun_path, UDS_SOCK, sizeof(server->sun_path));
> +	strlcpy(server->sun_path, dp_path, sizeof(server->sun_path));
>   
>   	if (connect(sock, (struct sockaddr *)server, sizeof(struct sockaddr_un)) < 0) {
>   		close(sock);
> @@ -1382,7 +1386,7 @@ struct msg_internal {
>   };
>   
>   static int
> -send_msg(int sock, char *request, int *fd)
> +send_msg(int sock, char *request, int *fd, const char *dp_path)
>   {
>   	int snd;
>   	struct iovec iov;
> @@ -1393,7 +1397,7 @@ send_msg(int sock, char *request, int *fd)
>   
>   	memset(&dst, 0, sizeof(dst));
>   	dst.sun_family = AF_UNIX;
> -	strlcpy(dst.sun_path, UDS_SOCK, sizeof(dst.sun_path));
> +	strlcpy(dst.sun_path, dp_path, sizeof(dst.sun_path));
>   
>   	/* Initialize message header structure */
>   	memset(&msgh, 0, sizeof(msgh));
> @@ -1470,8 +1474,8 @@ read_msg(int sock, char *response, struct sockaddr_un *s, int *fd)
>   }
>   
>   static int
> -make_request_cni(int sock, struct sockaddr_un *server, char *request,
> -		 int *req_fd, char *response, int *out_fd)
> +make_request_dp(int sock, struct sockaddr_un *server, char *request,
> +		 int *req_fd, char *response, int *out_fd, const char *dp_path)
>   {
>   	int rval;
>   
> @@ -1483,7 +1487,7 @@ make_request_cni(int sock, struct sockaddr_un *server, char *request,
>   	if (req_fd == NULL)
>   		rval = write(sock, request, strlen(request));
>   	else
> -		rval = send_msg(sock, request, req_fd);
> +		rval = send_msg(sock, request, req_fd, dp_path);
>   
>   	if (rval < 0) {
>   		AF_XDP_LOG(ERR, "Write error %s\n", strerror(errno));
> @@ -1507,7 +1511,7 @@ check_response(char *response, char *exp_resp, long size)
>   }
>   
>   static int
> -get_cni_fd(char *if_name)
> +uds_get_xskmap_fd(char *if_name, const char *dp_path)
>   {
>   	char request[UDS_MAX_CMD_LEN], response[UDS_MAX_CMD_RESP];
>   	char hostname[MAX_LONG_OPT_SZ], exp_resp[UDS_MAX_CMD_RESP];
> @@ -1520,14 +1524,14 @@ get_cni_fd(char *if_name)
>   		return -1;
>   
>   	memset(&server, 0, sizeof(server));
> -	sock = init_uds_sock(&server);
> +	sock = init_uds_sock(&server, dp_path);
>   	if (sock < 0)
>   		return -1;
>   
> -	/* Initiates handshake to CNI send: /connect,hostname */
> +	/* Initiates handshake to the AF_XDP Device Plugin send: /connect,hostname */
>   	snprintf(request, sizeof(request), "%s,%s", UDS_CONNECT_MSG, hostname);
>   	memset(response, 0, sizeof(response));
> -	if (make_request_cni(sock, &server, request, NULL, response, &out_fd) < 0) {
> +	if (make_request_dp(sock, &server, request, NULL, response, &out_fd, dp_path) < 0) {
>   		AF_XDP_LOG(ERR, "Error in processing cmd [%s]\n", request);
>   		goto err_close;
>   	}
> @@ -1541,7 +1545,7 @@ get_cni_fd(char *if_name)
>   	/* Request for "/version" */
>   	strlcpy(request, UDS_VERSION_MSG, UDS_MAX_CMD_LEN);
>   	memset(response, 0, sizeof(response));
> -	if (make_request_cni(sock, &server, request, NULL, response, &out_fd) < 0) {
> +	if (make_request_dp(sock, &server, request, NULL, response, &out_fd, dp_path) < 0) {
>   		AF_XDP_LOG(ERR, "Error in processing cmd [%s]\n", request);
>   		goto err_close;
>   	}
> @@ -1549,7 +1553,7 @@ get_cni_fd(char *if_name)
>   	/* Request for file descriptor for netdev name*/
>   	snprintf(request, sizeof(request), "%s,%s", UDS_XSK_MAP_FD_MSG, if_name);
>   	memset(response, 0, sizeof(response));
> -	if (make_request_cni(sock, &server, request, NULL, response, &out_fd) < 0) {
> +	if (make_request_dp(sock, &server, request, NULL, response, &out_fd, dp_path) < 0) {
>   		AF_XDP_LOG(ERR, "Error in processing cmd [%s]\n", request);
>   		goto err_close;
>   	}
> @@ -1571,7 +1575,7 @@ get_cni_fd(char *if_name)
>   	/* Initiate close connection */
>   	strlcpy(request, UDS_FIN_MSG, UDS_MAX_CMD_LEN);
>   	memset(response, 0, sizeof(response));
> -	if (make_request_cni(sock, &server, request, NULL, response, &out_fd) < 0) {
> +	if (make_request_dp(sock, &server, request, NULL, response, &out_fd, dp_path) < 0) {
>   		AF_XDP_LOG(ERR, "Error in processing cmd [%s]\n", request);
>   		goto err_close;
>   	}
> @@ -1695,17 +1699,16 @@ xsk_configure(struct pmd_internals *internals, struct pkt_rx_queue *rxq,
>   	}
>   
>   	if (internals->use_cni) {
> -		int err, fd, map_fd;
> +		int err, map_fd;
>   
> -		/* get socket fd from CNI plugin */
> -		map_fd = get_cni_fd(internals->if_name);
> +		/* get socket fd from AF_XDP Device Plugin */
> +		map_fd = uds_get_xskmap_fd(internals->if_name, internals->dp_path);
>   		if (map_fd < 0) {
> -			AF_XDP_LOG(ERR, "Failed to receive CNI plugin fd\n");
> +			AF_XDP_LOG(ERR, "Failed to receive xskmap fd from AF_XDP Device Plugin\n");
>   			goto out_xsk;
>   		}
> -		/* get socket fd */
> -		fd = xsk_socket__fd(rxq->xsk);
> -		err = bpf_map_update_elem(map_fd, &rxq->xsk_queue_idx, &fd, 0);
> +
> +		err = xsk_socket__update_xskmap(rxq->xsk, map_fd);
>   		if (err) {
>   			AF_XDP_LOG(ERR, "Failed to insert unprivileged xsk in map.\n");
>   			goto out_xsk;
> @@ -1881,13 +1884,13 @@ static const struct eth_dev_ops ops = {
>   	.get_monitor_addr = eth_get_monitor_addr,
>   };
>   
> -/* CNI option works in unprivileged container environment
> - * and ethernet device functionality will be reduced. So
> - * additional customiszed eth_dev_ops struct is needed
> - * for cni. Promiscuous enable and disable functionality
> - * is removed.
> +/* AF_XDP Device Plugin option works in unprivileged
> + * container environments and ethernet device functionality
> + * will be reduced. So additional customised eth_dev_ops
> + * struct is needed for the Device Plugin. Promiscuous
> + * enable and disable functionality is removed.
>    **/
> -static const struct eth_dev_ops ops_cni = {
> +static const struct eth_dev_ops ops_afxdp_dp = {
>   	.dev_start = eth_dev_start,
>   	.dev_stop = eth_dev_stop,
>   	.dev_close = eth_dev_close,
> @@ -2023,7 +2026,8 @@ xdp_get_channels_info(const char *if_name, int *max_queues,
>   static int
>   parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *start_queue,
>   		 int *queue_cnt, int *shared_umem, char *prog_path,
> -		 int *busy_budget, int *force_copy, int *use_cni)
> +		 int *busy_budget, int *force_copy, int *use_cni,
> +		 char *dp_path)
>   {
>   	int ret;
>   
> @@ -2069,6 +2073,11 @@ parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *start_queue,
>   	if (ret < 0)
>   		goto free_kvlist;
>   
> +	ret = rte_kvargs_process(kvlist, ETH_AF_XDP_DP_PATH_ARG,
> +				 &parse_prog_arg, dp_path);
> +	if (ret < 0)
> +		goto free_kvlist;
> +
>   free_kvlist:
>   	rte_kvargs_free(kvlist);
>   	return ret;
> @@ -2108,7 +2117,7 @@ static struct rte_eth_dev *
>   init_internals(struct rte_vdev_device *dev, const char *if_name,
>   	       int start_queue_idx, int queue_cnt, int shared_umem,
>   	       const char *prog_path, int busy_budget, int force_copy,
> -	       int use_cni)
> +	       int use_cni, const char *dp_path)
>   {
>   	const char *name = rte_vdev_device_name(dev);
>   	const unsigned int numa_node = dev->device.numa_node;
> @@ -2138,6 +2147,7 @@ init_internals(struct rte_vdev_device *dev, const char *if_name,
>   	internals->shared_umem = shared_umem;
>   	internals->force_copy = force_copy;
>   	internals->use_cni = use_cni;
> +	strlcpy(internals->dp_path, dp_path, PATH_MAX);
>   
>   	if (xdp_get_channels_info(if_name, &internals->max_queue_cnt,
>   				  &internals->combined_queue_cnt)) {
> @@ -2199,7 +2209,7 @@ init_internals(struct rte_vdev_device *dev, const char *if_name,
>   	if (!internals->use_cni)
>   		eth_dev->dev_ops = &ops;
>   	else
> -		eth_dev->dev_ops = &ops_cni;
> +		eth_dev->dev_ops = &ops_afxdp_dp;
>   
>   	eth_dev->rx_pkt_burst = eth_af_xdp_rx;
>   	eth_dev->tx_pkt_burst = eth_af_xdp_tx;
> @@ -2328,6 +2338,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
>   	int busy_budget = -1, ret;
>   	int force_copy = 0;
>   	int use_cni = 0;
> +	char dp_path[PATH_MAX] = {'\0'};
>   	struct rte_eth_dev *eth_dev = NULL;
>   	const char *name = rte_vdev_device_name(dev);
>   
> @@ -2370,7 +2381,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
>   
>   	if (parse_parameters(kvlist, if_name, &xsk_start_queue_idx,
>   			     &xsk_queue_cnt, &shared_umem, prog_path,
> -			     &busy_budget, &force_copy, &use_cni) < 0) {
> +			     &busy_budget, &force_copy, &use_cni, dp_path) < 0) {
>   		AF_XDP_LOG(ERR, "Invalid kvargs value\n");
>   		return -EINVAL;
>   	}
> @@ -2384,7 +2395,19 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
>   	if (use_cni && strnlen(prog_path, PATH_MAX)) {
>   		AF_XDP_LOG(ERR, "When '%s' parameter is used, '%s' parameter is not valid\n",
>   			ETH_AF_XDP_USE_CNI_ARG, ETH_AF_XDP_PROG_ARG);
> -			return -EINVAL;
> +		return -EINVAL;
> +	}
> +
> +	if (use_cni && !strnlen(dp_path, PATH_MAX)) {
> +		snprintf(dp_path, sizeof(dp_path), "%s/%s/%s", DP_BASE_PATH, if_name, DP_UDS_SOCK);
> +		AF_XDP_LOG(INFO, "'%s' parameter not provided, setting value to '%s'\n",
> +			ETH_AF_XDP_DP_PATH_ARG, dp_path);
> +	}
> +
> +	if (!use_cni && strnlen(dp_path, PATH_MAX)) {
> +		AF_XDP_LOG(ERR, "'%s' parameter is set, but '%s' was not enabled\n",
> +			ETH_AF_XDP_DP_PATH_ARG, ETH_AF_XDP_USE_CNI_ARG);
> +		return -EINVAL;
>   	}
>   
>   	if (strlen(if_name) == 0) {
> @@ -2410,7 +2433,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
>   
>   	eth_dev = init_internals(dev, if_name, xsk_start_queue_idx,
>   				 xsk_queue_cnt, shared_umem, prog_path,
> -				 busy_budget, force_copy, use_cni);
> +				 busy_budget, force_copy, use_cni, dp_path);
>   	if (eth_dev == NULL) {
>   		AF_XDP_LOG(ERR, "Failed to init internals\n");
>   		return -1;
> @@ -2471,4 +2494,5 @@ RTE_PMD_REGISTER_PARAM_STRING(net_af_xdp,
>   			      "xdp_prog=<string> "
>   			      "busy_budget=<int> "
>   			      "force_copy=<int> "
> -			      "use_cni=<int> ");
> +			      "use_cni=<int> "
> +			      "dp_path=<string> ");