Fix CDI spec generation to respect driver root for Tegra CSV files

internal/cdi/cdi.go

@@ -18,6 +18,7 @@ package cdi
 
 import (
 	"fmt"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -87,7 +88,8 @@ func New(infolib info.Interface, nvmllib nvml.Interface, devicelib device.Interf
 		return &null{}, nil
 	}
 	hasNVML, _ := infolib.HasNvml()
-	if !hasNVML {
+	platform := infolib.ResolvePlatform()
+	if !hasNVML && platform != info.PlatformTegra {
 		klog.Warning("No valid resources detected, creating a null CDI handler")
 		return &null{}, nil
 	}
@@ -128,6 +130,13 @@ func New(infolib info.Interface, nvmllib nvml.Interface, devicelib device.Interf
 		nvcdi.WithVendor(c.vendor),
 	}
 
+	// On Tegra (CSV mode), the default CSV files live under the driver root.
+	// Inject driver-root-aware paths explicitly so the nvcdi library does not
+	// fall back to the hardcoded absolute paths returned by csv.DefaultFileList().
+	if platform == info.PlatformTegra {
+		commonOptions = append(commonOptions, nvcdi.WithCSVFiles(csvFilesForRoot(c.driverRoot)))
+	}
+
 	c.cdilibs = make(map[string]nvcdi.SpecGenerator)
 
 	c.cdilibs["gpu"], err = nvcdi.New(
@@ -177,16 +186,6 @@ func (cdi *cdiHandler) CreateSpecFile() error {
 	for class, cdilib := range cdi.cdilibs {
 		cdi.logger.Infof("Generating CDI spec for resource: %s/%s", cdi.vendor, class)
 
-		if class == "gpu" {
-			ret := cdi.nvmllib.Init()
-			if ret != nvml.SUCCESS {
-				return fmt.Errorf("failed to initialize NVML: %v", ret)
-			}
-			defer func() {
-				_ = cdi.nvmllib.Shutdown()
-			}()
-		}
-
 		spec, err := cdilib.GetSpec()
 		if err != nil {
 			return fmt.Errorf("failed to get CDI spec: %v", err)
@@ -268,3 +267,33 @@ func (cdi *cdiHandler) AdditionalDevices() []string {
 	}
 	return devices
 }
+
+// defaultCSVMountSpecPath mirrors the constant defined in the nvidia-container-toolkit's
+// internal/platform-support/tegra/csv package.
+const defaultCSVMountSpecPath = "/etc/nvidia-container-runtime/host-files-for-container.d"
+
+var defaultCSVFileNames = []string{"devices.csv", "drivers.csv", "l4t.csv"}
+
+// csvFilesForRoot returns the Tegra CSV file paths to use for CDI spec generation.
+// It checks for the CSV directory at the driver root first, then falls back to the
+// absolute path. Returns nil if the directory is not found at either location,
+// allowing nvcdi to fall back to csv.DefaultFileList().
+func csvFilesForRoot(driverRoot string) []string {
+	roots := []string{driverRoot}
+	if driverRoot != "/" {
+		roots = append(roots, "/")
+	}
+	for _, root := range roots {
+		csvDir := filepath.Join(root, defaultCSVMountSpecPath)
+		stat, err := os.Stat(csvDir)
+		if err != nil || !stat.IsDir() {
+			continue
+		}
+		paths := make([]string, len(defaultCSVFileNames))
+		for i, f := range defaultCSVFileNames {
+			paths[i] = filepath.Join(csvDir, f)
+		}
+		return paths
+	}
+	return nil
+}

internal/cdi/csv_test.go

@@ -0,0 +1,68 @@
+/**
+# Copyright (c) NVIDIA CORPORATION.  All rights reserved.
+#
+# 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.
+**/
+
+package cdi
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCSVFilesForRoot(t *testing.T) {
+	testCases := []struct {
+		description   string
+		setup         func(t *testing.T) string // returns driverRoot
+		expectedPaths func(driverRoot string) []string
+	}{
+		{
+			description: "directory exists at driver root",
+			setup: func(t *testing.T) string {
+				root := t.TempDir()
+				csvDir := filepath.Join(root, defaultCSVMountSpecPath)
+				require.NoError(t, os.MkdirAll(csvDir, 0755))
+				return root
+			},
+			expectedPaths: func(driverRoot string) []string {
+				csvDir := filepath.Join(driverRoot, defaultCSVMountSpecPath)
+				return []string{
+					filepath.Join(csvDir, "devices.csv"),
+					filepath.Join(csvDir, "drivers.csv"),
+					filepath.Join(csvDir, "l4t.csv"),
+				}
+			},
+		},
+		{
+			description: "directory does not exist at driver root or absolute path",
+			setup: func(t *testing.T) string {
+				return t.TempDir()
+			},
+			expectedPaths: func(_ string) []string {
+				return nil
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.description, func(t *testing.T) {
+			driverRoot := tc.setup(t)
+			got := csvFilesForRoot(driverRoot)
+			require.Equal(t, tc.expectedPaths(driverRoot), got)
+		})
+	}
+}