Add support for /sys/class/mei/mei0

sysfs/class_mei.go

@@ -0,0 +1,75 @@
+package sysfs
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+const meiClassPath = "class/mei/mei0"
+
+type MEIClass struct {
+	Dev           *string
+	DevState      *string
+	FWStatus      *string
+	FWVersion     *string
+	HBMVersion    *string
+	HBMVersionDrv *string
+	Kind          *string
+	Trc           *string
+	TxQueueLimit  *string
+}
+
+// MEIClass returns Management Engine Interface (DMI) information read from /sys/class/mei/.
+func (fs FS) MEIClass() (*MEIClass, error) {
+	path := fs.sys.Path(meiClassPath)
+
+	files, err := os.ReadDir(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read directory %q: %w", path, err)
+	}
+
+	var mei MEIClass
+	for _, f := range files {
+		if !f.Type().IsRegular() {
+			continue
+		}
+
+		name := f.Name()
+		if name == "uevent" {
+			continue
+		}
+
+		filename := filepath.Join(path, name)
+		value, err := util.SysReadFile(filename)
+		if err != nil {
+			// no check for perms since all files (well apart from tx_queue_limit) are 0444
+			return nil, fmt.Errorf("failed to read file %q: %w", filename, err)
+		}
+
+		switch name {
+		case "dev":
+			mei.Dev = &value
+		case "dev_state":
+			mei.DevState = &value
+		case "fw_status":
+			mei.FWStatus = &value
+		case "fw_ver":
+			mei.FWVersion = &value
+		case "hbm_ver":
+			mei.HBMVersion = &value
+		case "hbm_ver_drv":
+			mei.HBMVersionDrv = &value
+		case "kind":
+			mei.Kind = &value
+		case "trc":
+			mei.Trc = &value
+		case "tx_queue_limit":
+			mei.TxQueueLimit = &value
+		}
+	}
+
+	return &mei, nil
+}

sysfs/class_mei_test.go

@@ -0,0 +1,60 @@
+// Copyright The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build linux
+
+package sysfs
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestMEIClass(t *testing.T) {
+	fs, err := NewFS(sysTestFixtures)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	got, err := fs.MEIClass()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dev := "244:0"
+	devState := "ENABLED"
+	fwStatus := "90000245\n00110500\n00000020\n00000000\n02F41F03\n40000000"
+	fwVer := "0:18.0.5.2098\n0:18.0.5.2098\n0:18.0.5.2098"
+	hbmVer := "2.2"
+	hbmVerDrv := "2.2"
+	kind := "mei"
+	trc := "00000889"
+	txQueueLimit := "50"
+
+	want := &MEIClass{
+		Dev:           &dev,
+		DevState:      &devState,
+		FWStatus:      &fwStatus,
+		FWVersion:     &fwVer,
+		HBMVersion:    &hbmVer,
+		HBMVersionDrv: &hbmVerDrv,
+		Kind:          &kind,
+		Trc:           &trc,
+		TxQueueLimit:  &txQueueLimit,
+	}
+
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Fatalf("unexpected DMI class (-want +got):\n%s", diff)
+	}
+}

testdata/fixtures.ttar

@@ -6338,6 +6338,71 @@ Lines: 1
 4: ACTIVE
 Mode: 644
 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Directory: fixtures/sys/class/mei
+Mode: 755
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Directory: fixtures/sys/class/mei/mei0
+Mode: 755
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/dev
+Lines: 1
+244:0
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/dev_state
+Lines: 1
+ENABLEDEOF
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/fw_status
+Lines: 6
+90000245
+00110500
+00000020
+00000000
+02F41F03
+40000000
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/fw_ver
+Lines: 3
+0:18.0.5.2098
+0:18.0.5.2098
+0:18.0.5.2098
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/hbm_ver
+Lines: 1
+2.2
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/hbm_ver_drv
+Lines: 1
+2.2
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/kind
+Lines: 1
+mei
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/trc
+Lines: 1
+00000889
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/tx_queue_limit
+Lines: 1
+50
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+Path: fixtures/sys/class/mei/mei0/uevent
+Lines: 3
+MAJOR=244
+MINOR=0
+DEVNAME=mei0
+Mode: 644
+# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Directory: fixtures/sys/class/net
 Mode: 755
 # ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -