bpf-map-pinning: fixes a few issues

* Update the documentation to reflect configuration
changes needed.
* Update the program to pin the xsk map to just use
xdp-loader. The previous c implementation had issues
and the version of libxdp in the container images is
too old for libxdp pinning support. Reverting to bpf
(for pinning support) would break the libxdp based
program unloading.
* Don't return an error from the bpf clean up function
when there's no program on the interface.

Signed-off-by: Maryam Tahhan <mtahhan@redhat.com>

README.md

@@ -411,6 +411,10 @@ UdsServerDisable is a Boolean configuration. If set to true, devices in this poo
 
 BpfMapPinningEnable is a Boolean configuration. If set to true, will use BPF map pinning instead of a UDS to share an XSK map with a pod. By default, this is set to false. Should set UdsServerDisable to true when using this configuration.
 
+> **_NOTE:_**  When using this setting it's important to adjust the securityContext for the DP Daemonset to `privileged: true` to allow for bidirectional propagation of the volume where the BPF maps are pinned. this will no longer be needed when the DP is integrated with bpfman. An example deamonset configuration is shown in [deamonset-pinning.yaml](./deployments/daemonset-pinning.yaml)
+
+> **_NOTE:_**  If the kernel in the Pod image is <= 5.18, CAP_BPF capability should be added to the container.
+
 #### UdsTimeout
 
 UdsTimeout is an integer configuration. This value sets the amount of time, in seconds, that the UDS server will wait while there is no activity on the UDS. When this timeout limit is reached, the UDS server terminates and the UDS is deleted from the filesystem. This can be a useful setting, for example, in scenarios where large batches of pods are created together. Large batches of pods tend to take some time to spin up, so it might be beneficial to have the UDS server sit waiting a little longer for the pod to start. The maximum allowed value is 300 seconds (5 min). The minimum and default value is 30 seconds.

cmd/deviceplugin/main.go

@@ -98,7 +98,7 @@ func main() {
 	}
 	logging.Infof("Host meets requirements")
 
-	//START THE SYNCER SERVER TODO CHECK BPF MAP
+	//Start the syncer server
 	dpCniSyncerServer, err := dpcnisyncerserver.NewSyncerServer()
 	if err != nil {
 		logging.Errorf("Error creating the DpCniSyncerServer")
@@ -143,7 +143,6 @@ func main() {
 			logging.Errorf("Termination error: %v", err)
 		}
 	}
-
 }
 
 func configureLogging(cfg deviceplugin.PluginConfig) error {

constants/constants.go

@@ -84,6 +84,7 @@ var (
 	udsPodSock    = "/afxdp.sock"
 
 	/* BPF*/
+	pinMapBaseDir = "/var/run/afxdp_dp/"
 	bpfMapPodPath = "/tmp/afxdp_dp/"
 	xsk_map       = "/xsks_map"
 
@@ -222,6 +223,7 @@ type uds struct {
 }
 
 type bpf struct {
+	PinMapBaseDir string
 	BpfMapPodPath string
 	Xsk_map       string
 }
@@ -349,6 +351,7 @@ func init() {
 	}
 
 	Bpf = bpf{
+		PinMapBaseDir: pinMapBaseDir,
 		BpfMapPodPath: bpfMapPodPath,
 		Xsk_map:       xsk_map,
 	}

deployments/daemonset-pinning.yaml

@@ -0,0 +1,113 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: afxdp-dp-config
+  namespace: kube-system
+data:
+  config.json: |
+    {
+       "logLevel":"debug",
+       "logFile":"afxdp-dp.log",
+       "pools":[
+          {
+             "name":"myPool",
+             "mode":"primary",
+             "drivers":[
+                {
+                   "name":"i40e"
+                },
+                {
+                   "name":"ice"
+                }
+             ]
+          }
+       ]
+    }
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: afxdp-device-plugin
+  namespace: kube-system
+---
+apiVersion: apps/v1
+kind: DaemonSet
+metadata:
+  name: kube-afxdp-device-plugin
+  namespace: kube-system
+  labels:
+    tier: node
+    app: afxdp
+spec:
+  selector:
+    matchLabels:
+      name: afxdp-device-plugin
+  template:
+    metadata:
+      labels:
+        name: afxdp-device-plugin
+        tier: node
+        app: afxdp
+    spec:
+      hostNetwork: true
+      nodeSelector:
+        kubernetes.io/arch: amd64
+      tolerations:
+        - key: node-role.kubernetes.io/master
+          operator: Exists
+          effect: NoSchedule
+      serviceAccountName: afxdp-device-plugin
+      containers:
+        - name: kube-afxdp
+          image: afxdp-device-plugin:latest
+          imagePullPolicy: IfNotPresent
+          securityContext:
+            privileged: true
+          resources:
+            requests:
+              cpu: "250m"
+              memory: "40Mi"
+            limits:
+              cpu: "1"
+              memory: "200Mi"
+          volumeMounts:
+            - name: unixsock
+              mountPath: /tmp/afxdp_dp/
+            - name: bpfmappinning
+              mountPath: /var/run/afxdp_dp/
+              mountPropagation: Bidirectional
+            - name: devicesock
+              mountPath: /var/lib/kubelet/device-plugins/
+            - name: resources
+              mountPath: /var/lib/kubelet/pod-resources/
+            - name: config-volume
+              mountPath: /afxdp/config
+            - name: log
+              mountPath: /var/log/afxdp-k8s-plugins/
+            - name: cnibin
+              mountPath: /opt/cni/bin/
+      volumes:
+        - name: unixsock
+          hostPath:
+            path: /tmp/afxdp_dp/
+        - name: bpfmappinning
+          hostPath:
+            path: /var/run/afxdp_dp/
+        - name: devicesock
+          hostPath:
+            path: /var/lib/kubelet/device-plugins/
+        - name: resources
+          hostPath:
+            path: /var/lib/kubelet/pod-resources/
+        - name: config-volume
+          configMap:
+            name: afxdp-dp-config
+            items:
+              - key: config.json
+                path: config.json
+        - name: log
+          hostPath:
+            path: /var/log/afxdp-k8s-plugins/
+        - name: cnibin
+          hostPath:
+            path: /opt/cni/bin/

deployments/daemonset.yml

@@ -78,6 +78,8 @@ spec:
           volumeMounts:
             - name: unixsock
               mountPath: /tmp/afxdp_dp/
+            - name: bpfmappinning
+              mountPath: /var/run/afxdp_dp/
             - name: devicesock
               mountPath: /var/lib/kubelet/device-plugins/
             - name: resources
@@ -92,6 +94,9 @@ spec:
         - name: unixsock
           hostPath:
             path: /tmp/afxdp_dp/
+        - name: bpfmappinning
+          hostPath:
+            path: /var/run/afxdp_dp/
         - name: devicesock
           hostPath:
             path: /var/lib/kubelet/device-plugins/

examples/cndp-0-0.yaml

@@ -13,12 +13,11 @@ spec:
       image:  quay.io/mtahhan/cndp-map-pinning:latest
       imagePullPolicy: IfNotPresent
       securityContext:
-        privileged: true
-          #capabilities:
-          #add:
-          #  - NET_RAW
-          #  - IPC_LOCK
-          #  - BPF
+        capabilities:
+          add:
+            - NET_RAW
+            - IPC_LOCK
+            #- BPF                                 # Only needed if Kernel version <= 5.18
       resources:
         requests:
           afxdp/myPool: '1'

examples/kind-pod-spec.yaml

@@ -17,7 +17,7 @@ spec:
         add:
           - NET_RAW
           - IPC_LOCK
-          - BPF
+          - BPF                                # Only needed if kernel version <= 5.18
     resources:
       requests:
         afxdp/myPool: '1'                      # The resource requested needs to match the device plugin pool name / resource type

examples/pod-spec.yaml

@@ -12,6 +12,11 @@ spec:
     image: docker-image:latest                 # Specify your docker image here, along with PullPolicy and command
     imagePullPolicy: IfNotPresent
     command: ["tail", "-f", "/dev/null"]
+    # capabilities:                            # Should be configured if using DPDK/CNDP with BPF Map pinning.
+    #     add:
+    #       - NET_RAW
+    #       - IPC_LOCK
+    #       - BPF                             # Only needed if kernel version <= 5.18
     resources:
       requests:
         afxdp/myPool: '1'                      # The resource requested needs to match the device plugin pool name / resource type

images/amd64.dockerfile

@@ -28,13 +28,14 @@ WORKDIR /usr/src/afxdp_k8s_plugins
 RUN apk add --no-cache build-base~=0.5-r3 \
 && apk add --no-cache libbsd-dev~=0.11.7 \
 && apk add --no-cache libxdp-dev~=1.2.10-r0 \
+&& apk add --no-cache libbpf-dev~=1.0.1-r0 \
 && apk add --no-cache llvm15~=15.0.7-r0 \
 && apk add --no-cache clang15~=15.0.7-r0 \
 && make builddp
 
 FROM amd64/alpine:3.18@sha256:25fad2a32ad1f6f510e528448ae1ec69a28ef81916a004d3629874104f8a7f70
 RUN apk --no-cache -U add iproute2-rdma~=6.3.0-r0 acl~=2.3 \
-      && apk add --no-cache libxdp~=1.2.10-r0
+      && apk add --no-cache xdp-tools~=1.2.10-r0
 COPY --from=cnibuilder /usr/src/afxdp_k8s_plugins/bin/afxdp /afxdp/afxdp
 COPY --from=dpbuilder /usr/src/afxdp_k8s_plugins/bin/afxdp-dp /afxdp/afxdp-dp
 COPY --from=dpbuilder /usr/src/afxdp_k8s_plugins/images/entrypoint.sh /afxdp/entrypoint.sh

internal/bpf/bpfWrapper.c

@@ -158,13 +158,12 @@ int Clean_bpf(char *ifname) {
 
 	mp = xdp_multiprog__get_from_ifindex(if_index);
 	if (!mp) {
-		Log_Error("%s: unable to receive correct multi_prog reference : %s", __FUNCTION__,
-			  mp);
-		return -1;
+		Log_Info("%s: No programs loaded on : %s", __FUNCTION__, ifname);
+		return 0;
 	}
 
 	err = xdp_multiprog__detach(mp);
-	if (err) {
+	if (err && err != -EINVAL) { // -EINVAL == No program attached
 		Log_Error("%s: Removal of xdp program failed, returned: "
 			  "returned: %d",
 			  __FUNCTION__, err);
@@ -174,102 +173,3 @@ int Clean_bpf(char *ifname) {
 	Log_Info("%s: removed xdp program from interface %s (%d)", __FUNCTION__, ifname, if_index);
 	return 0;
 }
-
-int Load_attach_bpf_xdp_pass(char *ifname) {
-	int prog_fd = -1, err, ifindex;
-	char *filename = "/afxdp/xdp_pass.o";
-	struct bpf_object *obj;
-	struct xdp_program *prog;
-	__u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST | XDP_FLAGS_DRV_MODE;
-
-	Log_Info("%s: disovering if_index for interface %s", __FUNCTION__, ifname);
-
-	ifindex = if_nametoindex(ifname);
-	if (!ifindex) {
-		Log_Error("%s: if_index not valid: %s", __FUNCTION__, ifname);
-		return -1;
-	}
-	Log_Info("%s: if_index for interface %s is %d", __FUNCTION__, ifname, ifindex);
-
-	if (access(filename, O_RDONLY) < 0) {
-		Log_Error("%s:error accessing file %s: %s\n", __FUNCTION__, filename,
-			  strerror(errno));
-		return err;
-	}
-
-	Log_Info("%s: starting setup of xdp-pass program on "
-		 "interface %s (%d)",
-		 __FUNCTION__, ifname, ifindex);
-
-	/* Load the BPF program */
-	prog = xdp_program__open_file(filename, NULL, NULL);
-	err = libxdp_get_error(prog);
-	if (err) {
-		libxdp_strerror(err, "Couldn’t load XDP program",
-				sizeof("Couldn’t load XDP program"));
-		Log_Error("%s: Couldn’t load XDP program\n", __FUNCTION__, filename);
-		return err;
-	}
-
-	/* Attach the program to the interface at the xdp hook */
-	err = xdp_program__attach(prog, ifindex, XDP_FLAGS_UPDATE_IF_NOEXIST, 0);
-	if (err) {
-		libxdp_strerror(err, "Couldn't attach the xdp pass program",
-				sizeof("Couldn't attach the xdp pass program"));
-		Log_Error("%s: Couldn't attach the XDP PASS PROGRAM TO %s\n", __FUNCTION__, ifname);
-		return err;
-	}
-
-	Log_Info("%s: xdp-pass program loaded on %s (%d)", __FUNCTION__, ifname, ifindex);
-
-	return 0;
-}
-
-int Load_bpf_pin_xsk_map(char *ifname, char *pin_path) {
-	struct bpf_object *obj;
-	struct xdp_program *prog;
-	struct bpf_link *link;
-	int ifindex, map_fd = -1;
-	int err;
-	const char *prog_name = "xdp_afxdp_redirect";
-	char *filename = "/afxdp/xdp_afxdp_redirect.o";
-	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, bpf_opts, .pin_root_path = pin_path);
-
-	ifindex = if_nametoindex(ifname);
-	if (!ifindex) {
-		Log_Error("%s: if_index not valid: %s", __FUNCTION__, ifname);
-		return -1;
-	}
-	Log_Info("%s: if_index for interface %s is %d", __FUNCTION__, ifname, ifindex);
-
-	if (access(filename, O_RDONLY) < 0) {
-		Log_Error("%s:error accessing file %s: %s\n", __FUNCTION__, filename,
-			  strerror(errno));
-		return err;
-	}
-
-	Log_Info("%s: starting setup of xdp-redirect program on "
-		 "interface %s (%d)",
-		 __FUNCTION__, ifname, ifindex);
-
-	/* Load the BPF program */
-	prog = xdp_program__open_file(filename, NULL, NULL);
-	err = libxdp_get_error(prog);
-	if (err) {
-		libxdp_strerror(err, "Couldn’t load XDP program",
-				sizeof("Couldn’t load XDP program"));
-		Log_Error("%s: Couldn’t load XDP program\n", __FUNCTION__, filename);
-		return err;
-	}
-
-	/* Attach the program to the interface at the xdp hook */
-	err = xdp_program__attach(prog, ifindex, XDP_FLAGS_UPDATE_IF_NOEXIST, 0);
-	if (err) {
-		libxdp_strerror(err, "Couldn't attach the xdp pass program",
-				sizeof("Couldn't attach the xdp pass program"));
-		Log_Error("%s: Couldn't attach the XDP PASS PROGRAM TO %s\n", __FUNCTION__, ifname);
-		return err;
-	}
-
-	return 0;
-}