From 803f4c2a676504d4d3d92311a5c4f080218659e7 Mon Sep 17 00:00:00 2001
From: Evan Lezar <elezar@nvidia.com>
Date: Tue, 6 Jan 2026 14:07:52 +0100
Subject: [PATCH 1/2] fix: Don't filter device nodes when
 disable-multiple-csv-devices is enabled

This change allows the "multiple-csv-devices" feature to be disabled
using the feature flag. Without this change the /dev/nvidia1 device node
is filtered out of the required set of devices which breaks certain
applications.

Signed-off-by: Evan Lezar <elezar@nvidia.com>
---
 pkg/nvcdi/lib-csv.go | 49 +++++++++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 14 deletions(-)

diff --git a/pkg/nvcdi/lib-csv.go b/pkg/nvcdi/lib-csv.go
index 77fcd95b3..cea5ffc11 100644
--- a/pkg/nvcdi/lib-csv.go
+++ b/pkg/nvcdi/lib-csv.go
@@ -46,11 +46,7 @@ var _ deviceSpecGeneratorFactory = (*csvlib)(nil)
 // If NVML is not available or the disable-multiple-csv-devices feature flag is
 // enabled, a single device is assumed.
 func (l *csvlib) DeviceSpecGenerators(ids ...string) (DeviceSpecGenerator, error) {
-	if l.featureFlags[FeatureDisableMultipleCSVDevices] {
-		return l.purecsvDeviceSpecGenerators(ids...)
-	}
-	hasNVML, _ := l.infolib.HasNvml()
-	if !hasNVML {
+	if l.usePureCSVDeviceSpecGenerator() {
 		return l.purecsvDeviceSpecGenerators(ids...)
 	}
 	mixed, err := l.mixedDeviceSpecGenerators(ids...)
@@ -61,6 +57,24 @@ func (l *csvlib) DeviceSpecGenerators(ids ...string) (DeviceSpecGenerator, error
 	return mixed, nil
 }
 
+func (l *csvlib) usePureCSVDeviceSpecGenerator() bool {
+	if l.featureFlags[FeatureDisableMultipleCSVDevices] {
+		return true
+	}
+	hasNVML, _ := l.infolib.HasNvml()
+	if !hasNVML {
+		return true
+	}
+	asNvmlLib := (*nvmllib)(l)
+	err := asNvmlLib.init()
+	if err != nil {
+		return true
+	}
+	defer asNvmlLib.tryShutdown()
+
+	return false
+}
+
 func (l *csvlib) purecsvDeviceSpecGenerators(ids ...string) (DeviceSpecGenerator, error) {
 	for _, id := range ids {
 		switch id {
@@ -74,6 +88,9 @@ func (l *csvlib) purecsvDeviceSpecGenerators(ids ...string) (DeviceSpecGenerator
 		csvlib: l,
 		index:  0,
 		uuid:   "",
+		// We set noFilterDeviceNodes to true to ensure that the /dev/nvidia[0-1]
+		// device nodes in the CSV files on the system are consumed as-is.
+		noFilterDeviceNodes: true,
 	}
 	return g, nil
 }
@@ -86,8 +103,9 @@ func (l *csvlib) mixedDeviceSpecGenerators(ids ...string) (DeviceSpecGenerator,
 // platform-specific CSV files.
 type csvDeviceGenerator struct {
 	*csvlib
-	index int
-	uuid  string
+	index               int
+	uuid                string
+	noFilterDeviceNodes bool
 }
 
 func (l *csvDeviceGenerator) GetUUID() (string, error) {
@@ -132,14 +150,17 @@ func (l *csvDeviceGenerator) GetDeviceSpecs() ([]specs.Device, error) {
 //     particular device is added to the set of device nodes to be discovered.
 func (l *csvDeviceGenerator) deviceNodeDiscoverer() (discover.Discover, error) {
 	mountSpecs := tegra.Transform(
-		tegra.Transform(
-			tegra.MountSpecsFromCSVFiles(l.logger, l.csvFiles...),
-			// We remove non-device nodes.
-			tegra.OnlyDeviceNodes(),
-		),
-		// We remove the regular (nvidia[0-9]+) device nodes.
-		tegra.WithoutRegularDeviceNodes(),
+		tegra.MountSpecsFromCSVFiles(l.logger, l.csvFiles...),
+		// We remove non-device nodes.
+		tegra.OnlyDeviceNodes(),
 	)
+	if !l.noFilterDeviceNodes {
+		mountSpecs = tegra.Transform(
+			mountSpecs,
+			// We remove the regular (nvidia[0-9]+) device nodes.
+			tegra.WithoutRegularDeviceNodes(),
+		)
+	}
 	return tegra.New(
 		tegra.WithLogger(l.logger),
 		tegra.WithDriverRoot(l.driverRoot),

From 7c8d40a5a2305aae9839d52c890d6ee8481a45c1 Mon Sep 17 00:00:00 2001
From: Evan Lezar <elezar@nvidia.com>
Date: Tue, 6 Jan 2026 14:11:26 +0100
Subject: [PATCH 2/2] fix: Use pure CSV mode when a single device is found

This change ensure that the pure CSV mode (with no device
node filtering) is used when a single device is present on
the system. This enables use cases such as VPI applications where
the /dev/nvidia1 device node is used even though an iGPU is present.

Signed-off-by: Evan Lezar <elezar@nvidia.com>
---
 pkg/nvcdi/lib-csv.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/pkg/nvcdi/lib-csv.go b/pkg/nvcdi/lib-csv.go
index cea5ffc11..c01115462 100644
--- a/pkg/nvcdi/lib-csv.go
+++ b/pkg/nvcdi/lib-csv.go
@@ -72,7 +72,12 @@ func (l *csvlib) usePureCSVDeviceSpecGenerator() bool {
 	}
 	defer asNvmlLib.tryShutdown()
 
-	return false
+	numDevices, ret := l.nvmllib.DeviceGetCount()
+	if ret != nvml.SUCCESS {
+		return true
+	}
+
+	return numDevices <= 1
 }
 
 func (l *csvlib) purecsvDeviceSpecGenerators(ids ...string) (DeviceSpecGenerator, error) {