nixos/nvidia: add Dynamic Boost support

nixos/modules/hardware/video/nvidia.nix

@@ -31,6 +31,12 @@ in {
         the NVIDIA docs, on Chapter 22. PCI-Express Runtime D3 (RTD3) Power Management.
       '');
 
+      dynamicBoost.enable = lib.mkEnableOption (lib.mdDoc ''
+        dynamic Boost balances power between the CPU and the GPU for improved
+        performance on supported laptops using the nvidia-powerd daemon. For more
+        information, see the NVIDIA docs, on Chapter 23. Dynamic Boost on Linux.
+      '');
+
       modesetting.enable = lib.mkEnableOption (lib.mdDoc ''
         kernel modesetting when using the NVIDIA proprietary driver.
 
@@ -238,6 +244,11 @@ in {
           assertion = cfg.open -> (cfg.package ? open && cfg.package ? firmware);
           message = "This version of NVIDIA driver does not provide a corresponding opensource kernel driver";
         }
+
+        {
+          assertion = cfg.dynamicBoost.enable -> lib.versionAtLeast nvidia_x11.version "510.39.01";
+          message = "NVIDIA's Dynamic Boost feature only exists on versions >= 510.39.01";
+        }
       ];
 
       # If Optimus/PRIME is enabled, we:
@@ -394,10 +405,26 @@ in {
               };
             };
           })
+          (lib.mkIf cfg.dynamicBoost.enable {
+            "nvidia-powerd" = {
+              description = "nvidia-powerd service";
+              path = [
+                pkgs.util-linux # nvidia-powerd wants lscpu
+              ];
+              wantedBy = ["multi-user.target"];
+              serviceConfig = {
+                Type = "dbus";
+                BusName = "nvidia.powerd.server";
+                ExecStart = "${nvidia_x11.bin}/bin/nvidia-powerd";
+              };
+            };
+          })
         ];
 
       services.acpid.enable = true;
 
+      services.dbus.packages = lib.optional cfg.dynamicBoost.enable nvidia_x11.bin;
+
       hardware.firmware = lib.optional cfg.open nvidia_x11.firmware;
 
       systemd.tmpfiles.rules =

pkgs/os-specific/linux/nvidia-x11/builder.sh

@@ -196,9 +196,12 @@ installPhase() {
         mkdir -p $bin/share/man/man1
         cp -p *.1.gz $bin/share/man/man1
         rm -f $bin/share/man/man1/{nvidia-xconfig,nvidia-settings,nvidia-persistenced}.1.gz
+        if [ -e "nvidia-dbus.conf" ]; then
+            install -Dm644 nvidia-dbus.conf $bin/share/dbus-1/system.d/nvidia-dbus.conf
+        fi
 
         # Install the programs.
-        for i in nvidia-cuda-mps-control nvidia-cuda-mps-server nvidia-smi nvidia-debugdump; do
+        for i in nvidia-cuda-mps-control nvidia-cuda-mps-server nvidia-smi nvidia-debugdump nvidia-powerd; do
             if [ -e "$i" ]; then
                 install -Dm755 $i $bin/bin/$i
                 # unmodified binary backup for mounting in containers

pkgs/os-specific/linux/nvidia-x11/generic.nix

@@ -51,6 +51,7 @@ let
     libdrm xorg.libXext xorg.libX11
     xorg.libXv xorg.libXrandr xorg.libxcb zlib stdenv.cc.cc
     wayland mesa libGL openssl
+    dbus # for nvidia-powerd
   ]);
 
   self = stdenv.mkDerivation {