From 69cff40f1dfebdc9f9b225bf18bbc02698e0ec6e Mon Sep 17 00:00:00 2001
From: Varun Ramachandra Sekar <vsekar@nvidia.com>
Date: Thu, 5 Dec 2024 11:22:13 -0800
Subject: [PATCH] use nsenter to run kernel tasks

Signed-off-by: Varun Ramachandra Sekar <vsekar@nvidia.com>
---
 cmd/nvidia-dra-plugin/vfio-device.go | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/cmd/nvidia-dra-plugin/vfio-device.go b/cmd/nvidia-dra-plugin/vfio-device.go
index fb5076dd..d4c8fc8e 100644
--- a/cmd/nvidia-dra-plugin/vfio-device.go
+++ b/cmd/nvidia-dra-plugin/vfio-device.go
@@ -17,6 +17,7 @@
 package main
 
 import (
+	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -26,6 +27,7 @@ import (
 )
 
 const (
+	hostNamespaceMount     = "/proc/1/ns/mnt"
 	vfioPciModule          = "vfio_pci"
 	vfioPciDriver          = "vfio-pci"
 	nvidiaDriver           = "nvidia"
@@ -80,8 +82,7 @@ func (vm *VfioPciManager) isVfioPCIModuleLoaded() bool {
 }
 
 func (vm *VfioPciManager) loadVfioPciModule() error {
-	cmd := exec.Command("modprobe", vm.vfioPciModule) //nolint:gosec
-	_, err := cmd.CombinedOutput()
+	_, err := execCommandInHostNamespace("modprobe", []string{vm.vfioPciModule}) //nolint:gosec
 	if err != nil {
 		return err
 	}
@@ -149,8 +150,7 @@ func changeDriver(pciAddress, driver string) error {
 }
 
 func unbindFromDriver(pciAddress, driverResetRetries string) error {
-	cmd := exec.Command(unbindFromDriverScript, pciAddress, driverResetRetries) //nolint:gosec
-	_, err := cmd.CombinedOutput()
+	_, err := execCommandInHostNamespace(unbindFromDriverScript, []string{pciAddress, driverResetRetries}) //nolint:gosec
 	if err != nil {
 		return err
 	}
@@ -158,8 +158,7 @@ func unbindFromDriver(pciAddress, driverResetRetries string) error {
 }
 
 func bindToDriver(pciAddress, driver string) error {
-	cmd := exec.Command(bindToDriverScript, pciAddress, driver) //nolint:gosec
-	_, err := cmd.CombinedOutput()
+	_, err := execCommandInHostNamespace(bindToDriverScript, []string{pciAddress, driver}) //nolint:gosec
 	if err != nil {
 		return err
 	}
@@ -190,3 +189,9 @@ func (vm *VfioPciManager) GetCDIContainerEdits(info *GpuInfo) *cdiapi.ContainerE
 		},
 	}
 }
+
+func execCommandInHostNamespace(cmd string, args []string) ([]byte, error) {
+	nsenterArgs := []string{fmt.Sprintf("--mount=%s", hostNamespaceMount), "--", cmd}
+	nsenterArgs = append(nsenterArgs, args...)
+	return exec.Command("nsenter", nsenterArgs...).CombinedOutput()
+}