Witko · hseg · Mar 31, 2020 · Mar 31, 2020 · Mar 31, 2020 · May 8, 2019
diff --git a/README.md b/README.md
@@ -8,7 +8,6 @@ It started with a revelation that bumblebee in current state offers very poor pe
   1. run `nvidia-xrun [app]`
   1. enjoy
 
-Currently sudo is required as the script needs to wake up GPU, modprobe the nvidia driver and perform cleanup afterwards.
 
 The systemd service can be used to completely remove the card from the kernel
 device tree (so that it won't even show in `lspci` output), and this will
@@ -23,6 +22,17 @@ The service can be enabled with this command:
 
 When the nvidia-xrun command is used, the device is added again to the tree so that the nvidia module can be loaded properly: nvidia-xrun will remove the device and enable PM again after the application terminates.
 
+### Passwordless `sudo`
+Whitelisting `nvidia-toggle` in your sudoer's file allows you to use `nvidia-xrun` without entering your password:
+
+```
+%users ALL=(root) NOPASSWD:/usr/bin/nvidia-toggle
+```
+
+...where `/usr/bin/nvidia-toggle` is the full path to the `nvidia-toggle` script.
+
+Note: it is a good practice to ensure binaries/scripts/etc. that are whitelisted for passwordless `sudo` are owned by root.
+
 ## Structure
 * **nvidia-xrun** - uses following dir structure:
 * **/usr/bin/nvidia-xrun** - the executable script

diff --git a/nvidia-toggle b/nvidia-toggle
@@ -0,0 +1,90 @@
+#!/bin/bash
+# nvidia-toggle [-d] (on | off | gpu-off)
+
+if [[ $EUID -ne 0 ]]; then
+   (>&2 echo "This script must be run as root")
+   exit 1
+fi
+
+DRY_RUN=0
+if [ "$1" == "-d" ]; then
+    DRY_RUN=1
+    shift 1
+fi
+
+function say { echo ">>Dry run. Command: $*"; }
+if [ $DRY_RUN -eq 1 ]; then
+    execute=say
+else
+    execute=eval
+fi
+
+function die {
+    (>&2 echo "$@")
+    exit 1
+}
+
+function turn_off_gpu {
+  if [[ "$ENABLE_PM" != '1' ]]; then return; fi
+  if [[ "$REMOVE_DEVICE" == '1' ]]; then
+    echo 'Removing Nvidia bus from the kernel'
+    $execute "tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/remove <<<1"
+  else
+    echo 'Enabling powersave for the graphic card'
+    $execute "tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/power/control <<<auto"
+  fi
+
+  echo 'Enabling powersave for the PCIe controller'
+  $execute "tee /sys/bus/pci/devices/${CONTROLLER_BUS_ID}/power/control <<<auto"
+}
+
+function turn_on_gpu {
+  if [[ "$ENABLE_PM" != '1' ]]; then return; fi
+  echo 'Turning the PCIe controller on to allow card rescan'
+  $execute "tee /sys/bus/pci/devices/${CONTROLLER_BUS_ID}/power/control <<<on"
+
+  echo 'Waiting 1 second'
+  $execute "sleep 1"
+
+  if [[ ! -d /sys/bus/pci/devices/${DEVICE_BUS_ID} ]]; then
+    echo 'Rescanning PCI devices'
+    $execute "tee /sys/bus/pci/rescan <<<1"
+    echo "Waiting ${BUS_RESCAN_WAIT_SEC} second for rescan"
+    $execute "sleep ${BUS_RESCAN_WAIT_SEC}"
+  fi
+
+  echo 'Turning the card on'
+  $execute "tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/power/control <<<on"
+}
+
+function load_modules {
+  for module in "${MODULES_LOAD[@]}"
+  do
+    echo "Loading module ${module}"
+    $execute "modprobe ${module}"
+  done
+}
+
+function unload_modules {
+  for module in "${MODULES_UNLOAD[@]}"
+  do
+    echo "Unloading module ${module}"
+    $execute "modprobe -r ${module}"
+  done
+}
+
+case $1 in
+on)
+    turn_on_gpu
+    load_modules
+    ;;
+off)
+    unload_modules
+    ;&
+gpu-off)
+    turn_off_gpu
+    ;;
+*)
+    die "nvidia-toggle [-d] (on | off | gpu-off)"
+    ;;
+esac
diff --git a/nvidia-xrun b/nvidia-xrun
@@ -1,6 +1,5 @@
 #!/usr/bin/env bash
 
-DRY_RUN=0
 function printHelp {
   echo "Utility to run games and applications in separate X on discrete Nvidia graphic card"
   echo "Usage: "
@@ -9,136 +8,79 @@ function printHelp {
   echo "  -d    Dry run - prints the final command but does not execute it"
 }
 
-function execute {
-  if [[ ${DRY_RUN} -eq 1 ]]
-    then
-    echo ">>Dry run. Command: $*"
-  else
-    eval $*
-  fi
-}
-
-function turn_off_gpu {
-  if [[ "$REMOVE_DEVICE" == '1' ]]; then
-    echo 'Removing Nvidia bus from the kernel'
-    execute "sudo tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/remove <<<1"
-  else
-    echo 'Enabling powersave for the graphic card'
-    execute "sudo tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/power/control <<<auto"
-  fi
-
-  echo 'Enabling powersave for the PCIe controller'
-  execute "sudo tee /sys/bus/pci/devices/${CONTROLLER_BUS_ID}/power/control <<<auto"
-}
-
-function turn_on_gpu {
-  echo 'Turning the PCIe controller on to allow card rescan'
-  execute "sudo tee /sys/bus/pci/devices/${CONTROLLER_BUS_ID}/power/control <<<on"
-
-  echo 'Waiting 1 second'
-  execute "sleep 1"
-
-  if [[ ! -d /sys/bus/pci/devices/${DEVICE_BUS_ID} ]]; then
-    echo 'Rescanning PCI devices'
-    execute "sudo tee /sys/bus/pci/rescan <<<1"
-    echo "Waiting ${BUS_RESCAN_WAIT_SEC} second for rescan"
-    execute "sleep ${BUS_RESCAN_WAIT_SEC}"
-  fi
-
-  echo 'Turning the card on'
-  execute "sudo tee /sys/bus/pci/devices/${DEVICE_BUS_ID}/power/control <<<on"
-}
-
-function load_modules {
-  for module in "${MODULES_LOAD[@]}"
-  do
-    echo "Loading module ${module}"
-    execute "sudo modprobe ${module}"
-  done
-}
-
-function unload_modules {
-  for module in "${MODULES_UNLOAD[@]}"
-  do
-    echo "Unloading module ${module}"
-    execute "sudo modprobe -r ${module}"
-  done
-}
-
-if [[ "$1" == "-d" ]]
-  then
+DRY_RUN=0
+if [ "$1" == "-d" ]; then
     DRY_RUN=1
     shift 1
 fi
 
+function say { echo ">>Dry run. Command: $*"; }
+if [ $DRY_RUN -eq 1 ]; then
+    execute='say'
+else
+    execute='eval'
+fi
+
+function die {
+    (>&2 echo "$@")
+    exit 1
+}
+
 # load config file
 . /etc/default/nvidia-xrun
 
-# this is used by the systemd service to turn off the gpu at boot
-if [[ "$TURN_OFF_GPU_ONLY" == '1' ]]; then
-  turn_off_gpu && exit 0
-fi
-
 if [[ $EUID -eq 0 ]]; then
-   echo "This script must not be run as root unless TURN_OFF_GPU_ONLY=1 is set" >&2
+   echo "This script must not be run as root" >&2
    exit 1
 fi
 
 # calculate current VT
-LVT=`fgconsole`
+LVT="vt$(fgconsole)"
 
 # calculate first usable display
-XNUM="-1"
-SOCK="something"
-while [[ ! -z "$SOCK" ]]
+XNUM=0
+SOCK=/tmp/.X11-unix/X$XNUM
+while [[ -e "$SOCK" ]]
 do
-  XNUM=$(( $XNUM + 1 ))
-  SOCK=$(ls -A -1 /tmp/.X11-unix | grep "X$XNUM" )
+  XNUM=$(( XNUM + 1 ))
+  SOCK=/tmp/.X11-unix/X$XNUM
 done
 
 NEWDISP=":$XNUM"
 
-if [[ ! -z "$*" ]] # generate exec line if arguments are given
+if [[ -n "$*" ]] # generate exec line if arguments are given
 then
   # test if executable exists in path
-  if [[ -x "$(which $1 2> /dev/null)" ]]
+  if [[ -x "$(command -v "$1" 2> /dev/null)" ]]
   then
     # generate exec line
-    EXECL="$(which $1)"
+    CMD="$(command -v "$1")"
   # test if executable exists on disk
   elif [[ -e "$(realpath "$1")" ]]
   then
     # generate exec line
-    EXECL="$(realpath "$1")"
+    CMD="$(realpath "$1")"
   else
     echo "$1: No such executable!"
     exit 1
   fi
   shift 1
-  EXECL="$EXECL $*"
+  ARGV=("$CMD" "$@")
 else # prepare to start new X sessions if no arguments passed
-  EXECL=""
+  ARGV=()
 fi
 
-EXECL="/etc/X11/xinit/nvidia-xinitrc \"$EXECL\""
-
-COMMAND="xinit $EXECL -- $NEWDISP vt$LVT -nolisten tcp -br -config nvidia-xorg.conf -configdir nvidia-xorg.conf.d"
+CLIENT=(/etc/X11/xinit/nvidia-xinitrc "${ARGV[*]}")
+SERVER=("$NEWDISP" "$LVT" -nolisten tcp -br -config nvidia-xorg.conf -configdir nvidia-xorg.conf.d)
+COMMAND=(xinit "${CLIENT[@]}" -- "${SERVER[@]}")
 
-# --------- TURNING ON GPU -----------
-if [[ "$ENABLE_PM" == '1' ]]; then
-  turn_on_gpu
-fi
-
-# ---------- LOADING MODULES ----------
-load_modules
+# ---------- TURNING ON GPU -----------
+echo 'Loading nvidia'
+$execute "sudo nvidia-toggle on" || die "Could not load nvidia"
 
 # ---------- EXECUTING COMMAND --------
-execute ${COMMAND}
-
-# ---------- UNLOADING MODULES --------
-unload_modules
+$execute "${COMMAND[*]}" || die "Could not execute command"
 
 # --------- TURNING OFF GPU ----------
-if [[ "$ENABLE_PM" == '1' ]]; then
-  turn_off_gpu
-fi
+echo 'Unloading nvidia'
+$execute "sudo nvidia-toggle off" || die "Could not unload nvidia"
diff --git a/nvidia-xrun-pm.service b/nvidia-xrun-pm.service
@@ -3,8 +3,7 @@ Description="Remove Nvidia GPU from kernel devices list and enable PM"
 
 [Service]
 Type=oneshot
-Environment="TURN_OFF_GPU_ONLY=1"
-ExecStart=/usr/bin/nvidia-xrun
+ExecStart=/usr/bin/nvidia-toggle gpu-off
 
 [Install]
 WantedBy=multi-user.target