fpga: add mode CLI switch

By default the fpga plugin announce regions' interface IDs. With
added `-mode af` switch the plugins announces IDs of accelerator
functions instead of regions.

cmd/fpga_plugin/fpga_plugin.go

@@ -39,12 +39,32 @@ const (
 	devfsDirectory = "/dev"
 	deviceRE       = `^intel-fpga-dev.[0-9]+$`
 	portRE         = `^intel-fpga-port.[0-9]+$`
+	fmeRE          = `^intel-fpga-fme.[0-9]+$`
 
 	// Device plugin settings.
 	pluginEndpointPrefix = "intel-fpga"
 	resourceNamePrefix   = "intel.com/fpga"
 )
 
+type pluginMode int
+
+const (
+	wrongMode pluginMode = iota
+	afMode
+	regionMode
+)
+
+func parseMode(input string) pluginMode {
+	switch input {
+	case "af":
+		return afMode
+	case "region":
+		return regionMode
+	}
+
+	return wrongMode
+}
+
 // deviceManager manages Intel FPGA devices.
 type deviceManager struct {
 	srv     deviceplugin.Server
@@ -52,21 +72,24 @@ type deviceManager struct {
 	name    string
 	devices map[string]deviceplugin.DeviceInfo
 	root    string
+	mode    pluginMode
 }
 
-func newDeviceManager(resourceName string, fpgaId string, rootDir string) *deviceManager {
+func newDeviceManager(resourceName string, fpgaId string, rootDir string, mode pluginMode) *deviceManager {
 	return &deviceManager{
 		fpgaId:  fpgaId,
 		name:    resourceName,
 		devices: make(map[string]deviceplugin.DeviceInfo),
 		root:    rootDir,
+		mode:    mode,
 	}
 }
 
 // Discovers all FPGA devices available on the local node by walking `/sys/class/fpga` directory.
-func discoverFPGAs(sysfsDir string, devfsDir string) (map[string]map[string]deviceplugin.DeviceInfo, error) {
+func discoverFPGAs(sysfsDir string, devfsDir string, mode pluginMode) (map[string]map[string]deviceplugin.DeviceInfo, error) {
 	deviceReg := regexp.MustCompile(deviceRE)
 	portReg := regexp.MustCompile(portRE)
+	fmeReg := regexp.MustCompile(fmeRE)
 
 	result := make(map[string]map[string]deviceplugin.DeviceInfo)
 
@@ -78,15 +101,43 @@ func discoverFPGAs(sysfsDir string, devfsDir string) (map[string]map[string]devi
 	for _, fpgaFile := range fpgaFiles {
 		fname := fpgaFile.Name()
 		if deviceReg.MatchString(fname) {
+			var interfaceId string
+
 			deviceFolder := path.Join(sysfsDir, fname)
 			deviceFiles, err := ioutil.ReadDir(deviceFolder)
 			if err != nil {
 				return nil, err
 			}
 			fpgaNodes := make(map[string][]string)
+
+			if mode == regionMode {
+				for _, deviceFile := range deviceFiles {
+					name := deviceFile.Name()
+					if fmeReg.MatchString(name) {
+						if len(interfaceId) > 0 {
+							return nil, fmt.Errorf("Detected more than one FPGA region for device %s. Only one region per FPGA device is supported", fname)
+						}
+						interfaceIdFile := path.Join(deviceFolder, name, "pr", "interface_id")
+						data, err := ioutil.ReadFile(interfaceIdFile)
+						if err != nil {
+							return nil, err
+						}
+						interfaceId = strings.TrimSpace(string(data))
+						fpgaNodes[interfaceId] = append(fpgaNodes[interfaceId], name)
+					}
+				}
+			}
+
 			for _, deviceFile := range deviceFiles {
 				name := deviceFile.Name()
 				if portReg.MatchString(name) {
+					switch mode {
+					case regionMode:
+						if len(interfaceId) == 0 {
+							return nil, fmt.Errorf("No FPGA region found for %s", fname)
+						}
+						fpgaNodes[interfaceId] = append(fpgaNodes[interfaceId], name)
+					case afMode:
 						afuFile := path.Join(deviceFolder, name, "afu_id")
 						data, err := ioutil.ReadFile(afuFile)
 						if err != nil {
@@ -94,6 +145,9 @@ func discoverFPGAs(sysfsDir string, devfsDir string) (map[string]map[string]devi
 						}
 						afuID := strings.TrimSpace(string(data))
 						fpgaNodes[afuID] = append(fpgaNodes[afuID], name)
+					default:
+						glog.Fatal("Unsupported mode")
+					}
 				}
 			}
 			if len(fpgaNodes) == 0 {
@@ -133,7 +187,7 @@ func (dm *deviceManager) ListAndWatch(empty *pluginapi.Empty, stream pluginapi.D
 	sysfsDir := path.Join(dm.root, sysfsDirectory)
 	devfsDir := path.Join(dm.root, devfsDirectory)
 	for {
-		devs, err := discoverFPGAs(sysfsDir, devfsDir)
+		devs, err := discoverFPGAs(sysfsDir, devfsDir, dm.mode)
 		if err != nil {
 			dm.srv.Stop()
 			return fmt.Errorf("Device discovery failed: %+v", err)
@@ -173,10 +227,19 @@ func (dm *deviceManager) PreStartContainer(ctx context.Context, rqt *pluginapi.P
 }
 
 func main() {
-	flag.Parse()
+	var modeStr string
-	fmt.Println("FPGA device plugin started")
 
-	devs, err := discoverFPGAs(sysfsDirectory, devfsDirectory)
+	flag.StringVar(&modeStr, "mode", "af", "device plugin mode: 'af' (default) or 'region'")
+	flag.Parse()
+
+	mode := parseMode(modeStr)
+	if mode == wrongMode {
+		glog.Fatal("Wrong mode: ", modeStr)
+	}
+
+	fmt.Println("FPGA device plugin started in", modeStr, "mode")
+
+	devs, err := discoverFPGAs(sysfsDirectory, devfsDirectory, mode)
 	if err != nil {
 		glog.Fatalf("Device discovery failed: %+v", err)
 	}
@@ -190,7 +253,7 @@ func main() {
 	for fpgaId, _ := range devs {
 		resourceName := resourceNamePrefix + "-" + fpgaId
 		pPrefix := pluginEndpointPrefix + "-" + fpgaId
-		dm := newDeviceManager(resourceName, fpgaId, "/")
+		dm := newDeviceManager(resourceName, fpgaId, "/", mode)
 
 		go func() {
 			ch <- dm.srv.Serve(dm, resourceName, pPrefix)

cmd/fpga_plugin/fpga_plugin_test.go

@@ -66,20 +66,24 @@ func TestDiscoverFPGAs(t *testing.T) {
 		sysfsfiles     map[string][]byte
 		expectedResult map[string]map[string]deviceplugin.DeviceInfo
 		expectedErr    bool
+		mode           pluginMode
 	}{
 		{
 			expectedResult: nil,
 			expectedErr:    true,
+			mode:           afMode,
 		},
 		{
 			sysfsdirs:      []string{"intel-fpga-dev.0"},
 			expectedResult: nil,
 			expectedErr:    true,
+			mode:           afMode,
 		},
 		{
 			sysfsdirs:      []string{"intel-fpga-dev.0/intel-fpga-port.0"},
 			expectedResult: nil,
 			expectedErr:    true,
+			mode:           afMode,
 		},
 		{
 			sysfsdirs: []string{
@@ -90,6 +94,7 @@ func TestDiscoverFPGAs(t *testing.T) {
 			},
 			expectedResult: nil,
 			expectedErr:    true,
+			mode:           afMode,
 		},
 		{
 			sysfsdirs: []string{
@@ -135,6 +140,81 @@ func TestDiscoverFPGAs(t *testing.T) {
 				},
 			},
 			expectedErr: false,
+			mode:        afMode,
+		},
+		{
+			sysfsdirs: []string{
+				"intel-fpga-dev.0/intel-fpga-fme.0/pr",
+				"intel-fpga-dev.0/intel-fpga-fme.1/pr",
+			},
+			sysfsfiles: map[string][]byte{
+				"intel-fpga-dev.0/intel-fpga-fme.0/pr/interface_id": []byte("d8424dc4a4a3c413f89e433683f9040b\n"),
+				"intel-fpga-dev.0/intel-fpga-fme.1/pr/interface_id": []byte("d8424dc4a4a3c413f89e433683f9040b\n"),
+			},
+			expectedResult: nil,
+			expectedErr:    true,
+			mode:           regionMode,
+		},
+		{
+			sysfsdirs: []string{
+				"intel-fpga-dev.0/intel-fpga-port.0",
+				"intel-fpga-dev.1/intel-fpga-port.1",
+			},
+			expectedResult: nil,
+			expectedErr:    true,
+			mode:           regionMode,
+		},
+		{
+			sysfsdirs: []string{
+				"intel-fpga-dev.0/intel-fpga-port.0",
+				"intel-fpga-dev.0/intel-fpga-fme.0/pr",
+				"intel-fpga-dev.1/intel-fpga-port.1",
+				"intel-fpga-dev.1/intel-fpga-fme.1/pr",
+				"intel-fpga-dev.2/intel-fpga-port.2",
+				"intel-fpga-dev.2/intel-fpga-fme.2/pr",
+			},
+			sysfsfiles: map[string][]byte{
+				"intel-fpga-dev.0/intel-fpga-port.0/afu_id":         []byte("d8424dc4a4a3c413f89e433683f9040b\n"),
+				"intel-fpga-dev.1/intel-fpga-port.1/afu_id":         []byte("d8424dc4a4a3c413f89e433683f9040b\n"),
+				"intel-fpga-dev.2/intel-fpga-port.2/afu_id":         []byte("47595d0fae972fbed0c51b4a41c7a349\n"),
+				"intel-fpga-dev.0/intel-fpga-fme.0/pr/interface_id": []byte("ce48969398f05f33946d560708be108a\n"),
+				"intel-fpga-dev.1/intel-fpga-fme.1/pr/interface_id": []byte("ce48969398f05f33946d560708be108a\n"),
+				"intel-fpga-dev.2/intel-fpga-fme.2/pr/interface_id": []byte("fd967345645f05f338462a0748be0091\n"),
+			},
+			devfsdirs: []string{
+				"intel-fpga-port.0", "intel-fpga-fme.0",
+				"intel-fpga-port.1", "intel-fpga-fme.1",
+				"intel-fpga-port.2", "intel-fpga-fme.2",
+			},
+			expectedResult: map[string]map[string]deviceplugin.DeviceInfo{
+				"ce48969398f05f33946d560708be108a": map[string]deviceplugin.DeviceInfo{
+					"intel-fpga-dev.0": deviceplugin.DeviceInfo{
+						State: "Healthy",
+						Nodes: []string{
+							path.Join(tmpdir, "/dev/intel-fpga-fme.0"),
+							path.Join(tmpdir, "/dev/intel-fpga-port.0"),
+						},
+					},
+					"intel-fpga-dev.1": deviceplugin.DeviceInfo{
+						State: "Healthy",
+						Nodes: []string{
+							path.Join(tmpdir, "/dev/intel-fpga-fme.1"),
+							path.Join(tmpdir, "/dev/intel-fpga-port.1"),
+						},
+					},
+				},
+				"fd967345645f05f338462a0748be0091": map[string]deviceplugin.DeviceInfo{
+					"intel-fpga-dev.2": deviceplugin.DeviceInfo{
+						State: "Healthy",
+						Nodes: []string{
+							path.Join(tmpdir, "/dev/intel-fpga-fme.2"),
+							path.Join(tmpdir, "/dev/intel-fpga-port.2"),
+						},
+					},
+				},
+			},
+			expectedErr: false,
+			mode:        regionMode,
 		},
 	}
 
@@ -144,7 +224,7 @@ func TestDiscoverFPGAs(t *testing.T) {
 			t.Error(err)
 		}
 
-		result, err := discoverFPGAs(sysfs, devfs)
+		result, err := discoverFPGAs(sysfs, devfs, tcase.mode)
 		if tcase.expectedErr && err == nil {
 			t.Error("Expected error hasn't been triggered")
 		}
@@ -257,7 +337,7 @@ func TestListAndWatch(t *testing.T) {
 	}
 
 	resourceName := resourceNamePrefix + "-" + afuID
-	testDM := newDeviceManager(resourceName, afuID, tmpdir)
+	testDM := newDeviceManager(resourceName, afuID, tmpdir, afMode)
 	if testDM == nil {
 		t.Fatal("Failed to create a deviceManager")
 	}
@@ -306,7 +386,7 @@ func TestListAndWatch(t *testing.T) {
 }
 
 func TestAllocate(t *testing.T) {
-	testDM := newDeviceManager("", "", "")
+	testDM := newDeviceManager("", "", "", afMode)
 	if testDM == nil {
 		t.Fatal("Failed to create a deviceManager")
 	}
@@ -329,3 +409,29 @@ func TestAllocate(t *testing.T) {
 		t.Fatal("Allocated wrong number of devices")
 	}
 }
+
+func TestParseMode(t *testing.T) {
+	tcases := []struct {
+		input  string
+		output pluginMode
+	}{
+		{
+			input:  "af",
+			output: afMode,
+		},
+		{
+			input:  "region",
+			output: regionMode,
+		},
+		{
+			input:  "unparsable",
+			output: wrongMode,
+		},
+	}
+
+	for _, tcase := range tcases {
+		if parseMode(tcase.input) != tcase.output {
+			t.Error("Wrong output", tcase.output, "for the given input", tcase.input)
+		}
+	}
+}