Hi Maryam,

Apologies for making it confusing.

As per the afxdp-plugins-for-kubernetes code it looks like the udsPodPath or udsSockDir[1] and udsPodSock[1] are constant and not changing. Only the interface name is changing and we are already passing the interface name through the command line. So I was suggesting we can write a logic to create sock path from these logic.

If I am wrong please correct me, Isn’t that the logic afxdp-plugins-for-kubernetes doing? [2]

This is only a suggestions.

[1] https://github.com/intel/afxdp-plugins-for-kubernetes/blob/main/constants/constants.go#L84

[2] https://github.com/intel/afxdp-plugins-for-kubernetes/blob/main/internal/deviceplugin/poolManager_test.go#L99

I had added 2 small comment earlier in the code.

Regards,

Shibin

From: Maryam Tahhan <mtahhan@redhat.com>
Sent: Monday, December 4, 2023 6:41 PM
To: Koikkara Reeny, Shibin <shibin.koikkara.reeny@intel.com>; ferruh.yigit@amd.com; stephen@networkplumber.org; lihuisong@huawei.com; fengchengwen@huawei.com; liuyonglong@huawei.com
Cc: dev@dpdk.org
Subject: Re: [v2] net/af_xdp: enable a sock path alongside use_cni

Hi Shibin

I'm not really sure what you are suggesting, is to make an assumption on the path part where the socket resides (aka hard code it) and then try to build the full UDS path in DPDK?

Yes the plugin is using constants ATM for certain parts of the UDS path, but that's not say that it's something that won't become configurable later on. Someone may not want to use "/tmp/afxdp_dp/" as the base directory. Then we'd have to change DPDK's implementation again. These are not really things that are configured by hand and are generated by initialization scripts (typically). I would rather build this with the idea that things can change in the future without having to change the DPDK implementation again.

BR
Maryam

On 04/12/2023 17:18, Koikkara Reeny, Shibin wrote:

Hi Maryam,
 
Apologies for asking this question bit late. 
The UDS sock name will be afxdp.sock only and addition director is created between the sock name and the uds filepath (/tmp/afxdp_dp/<interface name>/afxdp.sock).
 
As per the command " --vdev net_af_xdp0,iface=<interface name>,use_cni=1,uds_path=/tmp/afxdp_dp/<interface name>/afxdp.sock"
We are already passing the interface name(iface=<interface name> . So can't we create the uds_path inside the program uds_path="/tmp/afxdp_dp/"+ iface + "afxdp.sock"
 
 
If you check the code afxdp-plugins-for-kubernetes constants.go [1] they still have the constants and also they are using these constants to create the path [2]
 
[1] https://github.com/intel/afxdp-plugins-for-kubernetes/blob/main/constants/constants.go#L84 
[2] https://github.com/intel/afxdp-plugins-for-kubernetes/blob/main/internal/deviceplugin/poolManager_test.go#L78
 
If we are able to create path in the program then user won't have to pass along argument value.
 
Regards,
Shibin
 

-----Original Message-----
From: Maryam Tahhan <mtahhan@redhat.com>
Sent: Monday, December 4, 2023 10:31 AM
To: ferruh.yigit@amd.com; stephen@networkplumber.org;
lihuisong@huawei.com; fengchengwen@huawei.com;
liuyonglong@huawei.com; Koikkara Reeny, Shibin
<shibin.koikkara.reeny@intel.com>
Cc: dev@dpdk.org; Tahhan, Maryam <mtahhan@redhat.com>
Subject: [v2] net/af_xdp: enable a sock path alongside use_cni
 
With the original 'use_cni' implementation, (using a hardcoded socket rather
than a configurable one), if a single pod is requesting multiple net devices
and these devices are from different pools, then the container 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 alongside
the 'use_cni' param.
Tested with the AF_XDP DP CNI PR 81.
 
v2:
* Rename sock_path to uds_path.
* Update documentation to reflect when CAP_BPF is needed.
* Fix testpmd arguments in the provided example for Pods.
* Use AF_XDP API to update the xskmap entry.
 
Signed-off-by: Maryam Tahhan <mtahhan@redhat.com>
---
 doc/guides/howto/af_xdp_cni.rst     | 24 ++++++-----
 drivers/net/af_xdp/rte_eth_af_xdp.c | 62 ++++++++++++++++++-----------
 2 files changed, 54 insertions(+), 32 deletions(-)
 
diff --git a/doc/guides/howto/af_xdp_cni.rst
b/doc/guides/howto/af_xdp_cni.rst index a1a6d5b99c..7829526b40 100644
--- a/doc/guides/howto/af_xdp_cni.rst
+++ b/doc/guides/howto/af_xdp_cni.rst
@@ -38,9 +38,10 @@ The XSKMAP is a BPF map of AF_XDP sockets (XSK).
 The client can then proceed with creating an AF_XDP socket  and inserting
that socket into the XSKMAP pointed to by the descriptor.
 
-The EAL vdev argument ``use_cni`` is used to indicate that the user wishes -
to run the PMD in unprivileged mode and to receive the XSKMAP file
descriptor -from the CNI.
+The EAL vdev arguments ``use_cni`` and ``uds_path`` are used to
+indicate that the user wishes to run the PMD in unprivileged mode and
+to receive the XSKMAP file descriptor from the CNI.
+
 When this flag is set,
 the ``XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD`` libbpf flag  should be
used when creating the socket @@ -49,7 +50,7 @@ Instead the loading is
handled by the CNI.
 
 .. note::
 
-   The Unix Domain Socket file path appear in the end user is
"/tmp/afxdp.sock".
+   The Unix Domain Socket file path appears to the end user at
"/tmp/afxdp_dp/<netdev>/afxdp.sock".
 
 
 Prerequisites
@@ -223,8 +224,7 @@ Howto run dpdk-testpmd with CNI plugin:
          securityContext:
           capabilities:
              add:
-               - CAP_NET_RAW
-               - CAP_BPF
+               - NET_RAW

 
Need to update the 1.3. Prerequisites.
 
 

          resources:
            requests:
              hugepages-2Mi: 2Gi
@@ -239,14 +239,20 @@ Howto run dpdk-testpmd with CNI plugin:
 
   .. _pod.yaml: https://github.com/intel/afxdp-plugins-for-
kubernetes/blob/v0.0.2/test/e2e/pod-1c1d.yaml
 
+.. note::
+
+   For Kernel versions older than 5.19 `CAP_BPF` is also required in
+   the container capabilities stanza.
+
 * Run DPDK with a command like the following:
 
   .. 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> \
-           -- --no-mlockall --in-memory
+           /<Path>/dpdk-testpmd -l 0-2 --no-pci --main-lcore=2 \
+           --vdev net_af_xdp0,iface=<interface
name>,use_cni=1,uds_path=/tmp/afxdp_dp/<interface name>/afxdp.sock
\
+           --vdev net_af_xdp1,iface=e<interface
name>,use_cni=1,uds_path=/tmp/afxdp_dp/<interface name>/afxdp.sock

 
There is a typo " iface=e<interface " == "iface=<interface"
 

\
+           -- -i --a --nb-cores=2 --rxq=1 --txq=1
+ --forward-mode=macswap;
 
 For further reference please use the `e2e`_ test case in `AF_XDP Plugin for
Kubernetes`_
 
diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 353c8688ec..505ed6cf1e 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -88,7 +88,6 @@ RTE_LOG_REGISTER_DEFAULT(af_xdp_logtype,
NOTICE);
 #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 +170,7 @@ struct pmd_internals {
  bool custom_prog_configured;
  bool force_copy;
  bool use_cni;
+ char uds_path[PATH_MAX];
  struct bpf_map *map;
 
  struct rte_ether_addr eth_addr;
@@ -191,6 +191,7 @@ 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_USE_CNI_UDS_PATH_ARG "uds_path"
 
 static const char * const valid_arguments[] = {
  ETH_AF_XDP_IFACE_ARG,
@@ -201,6 +202,7 @@ 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_USE_CNI_UDS_PATH_ARG,
  NULL
 };
 
@@ -1351,7 +1353,7 @@ 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 *uds_path)
 {
  int sock;
 
@@ -1362,7 +1364,7 @@ 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, uds_path, sizeof(server->sun_path));
 
  if (connect(sock, (struct sockaddr *)server, sizeof(struct
sockaddr_un)) < 0) {
          close(sock);
@@ -1382,7 +1384,7 @@ struct msg_internal {  };
 
 static int
-send_msg(int sock, char *request, int *fd)
+send_msg(int sock, char *request, int *fd, const char *uds_path)
 {
  int snd;
  struct iovec iov;
@@ -1393,7 +1395,7 @@ 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, uds_path, sizeof(dst.sun_path));
 
  /* Initialize message header structure */
  memset(&msgh, 0, sizeof(msgh));
@@ -1471,7 +1473,7 @@ 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)
+          int *req_fd, char *response, int *out_fd, const char
*uds_path)
 {
  int rval;
 
@@ -1483,7 +1485,7 @@ 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, uds_path);
 
  if (rval < 0) {
          AF_XDP_LOG(ERR, "Write error %s\n", strerror(errno)); @@
-1507,7 +1509,7 @@ check_response(char *response, char *exp_resp, long
size)  }
 
 static int
-get_cni_fd(char *if_name)
+get_cni_fd(char *if_name, const char *uds_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 +1522,14 @@
get_cni_fd(char *if_name)
          return -1;
 
  memset(&server, 0, sizeof(server));
- sock = init_uds_sock(&server);
+ sock = init_uds_sock(&server, uds_path);
  if (sock < 0)
          return -1;
 
  /* Initiates handshake to CNI 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_cni(sock, &server, request, NULL, response,
&out_fd,
+uds_path) < 0) {
          AF_XDP_LOG(ERR, "Error in processing cmd [%s]\n",
request);
          goto err_close;
  }
@@ -1541,7 +1543,7 @@ 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_cni(sock, &server, request, NULL, response,
&out_fd,
+uds_path) < 0) {
          AF_XDP_LOG(ERR, "Error in processing cmd [%s]\n",
request);
          goto err_close;
  }
@@ -1549,7 +1551,7 @@ 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_cni(sock, &server, request, NULL, response,
&out_fd,
+uds_path) < 0) {
          AF_XDP_LOG(ERR, "Error in processing cmd [%s]\n",
request);
          goto err_close;
  }
@@ -1571,7 +1573,7 @@ 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_cni(sock, &server, request, NULL, response,
&out_fd,
+uds_path) < 0) {
          AF_XDP_LOG(ERR, "Error in processing cmd [%s]\n",
request);
          goto err_close;
  }
@@ -1695,17 +1697,16 @@ 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);
+         map_fd = get_cni_fd(internals->if_name, internals-

uds_path);

          if (map_fd < 0) {
                  AF_XDP_LOG(ERR, "Failed to receive CNI plugin
fd\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;
@@ -2023,7 +2024,8 @@ 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 *uds_path)
 {
  int ret;
 
@@ -2069,6 +2071,11 @@ 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_USE_CNI_UDS_PATH_ARG,
+                         &parse_prog_arg, uds_path);
+ if (ret < 0)
+         goto free_kvlist;
+
 free_kvlist:
  rte_kvargs_free(kvlist);
  return ret;
@@ -2108,7 +2115,7 @@ 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 *uds_path)
 {
  const char *name = rte_vdev_device_name(dev);
  const unsigned int numa_node = dev->device.numa_node; @@ -
2138,6 +2145,7 @@ 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->uds_path, uds_path, PATH_MAX);
 
  if (xdp_get_channels_info(if_name, &internals->max_queue_cnt,
                           &internals->combined_queue_cnt)) { @@ -
2328,6 +2336,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
  int busy_budget = -1, ret;
  int force_copy = 0;
  int use_cni = 0;
+ char uds_path[PATH_MAX] = {'\0'};
  struct rte_eth_dev *eth_dev = NULL;
  const char *name = rte_vdev_device_name(dev);
 
@@ -2370,7 +2379,7 @@ 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,
uds_path) < 0) {
          AF_XDP_LOG(ERR, "Invalid kvargs value\n");
          return -EINVAL;
  }
@@ -2387,6 +2396,12 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device
*dev)
                  return -EINVAL;
  }
 
+ if (use_cni && !strnlen(uds_path, PATH_MAX)) {
+         AF_XDP_LOG(ERR, "When '%s' parameter is used, '%s' must
also be provided\n",
+                 ETH_AF_XDP_USE_CNI_ARG,
ETH_AF_XDP_USE_CNI_UDS_PATH_ARG);
+                 return -EINVAL;
+ }
+
  if (strlen(if_name) == 0) {
          AF_XDP_LOG(ERR, "Network interface must be
specified\n");
          return -EINVAL;
@@ -2410,7 +2425,7 @@ 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,
uds_path);
  if (eth_dev == NULL) {
          AF_XDP_LOG(ERR, "Failed to init internals\n");
          return -1;
@@ -2471,4 +2486,5 @@
RTE_PMD_REGISTER_PARAM_STRING(net_af_xdp,
                        "xdp_prog=<string> "
                        "busy_budget=<int> "
                        "force_copy=<int> "
-                       "use_cni=<int> ");
+                       "use_cni=<int> "
+                       "uds_path=<string> ");
--
2.41.0