{
  config,
  lib,
  pkgs,
  ...
}: let
  nvidiaEnabled = (lib.elem "nvidia" config.services.xserver.videoDrivers);
  nvidia_x11 =
    if nvidiaEnabled || cfg.datacenter.enable
    then cfg.package
    else null;

  cfg = config.hardware.nvidia;

  pCfg = cfg.prime;
  syncCfg = pCfg.sync;
  offloadCfg = pCfg.offload;
  reverseSyncCfg = pCfg.reverseSync;
  primeEnabled = syncCfg.enable || reverseSyncCfg.enable || offloadCfg.enable;
  busIDType = lib.types.strMatching "([[:print:]]+[\:\@][0-9]{1,3}\:[0-9]{1,2}\:[0-9])?";
  ibtSupport = cfg.open || (nvidia_x11.ibtSupport or false);
  settingsFormat = pkgs.formats.keyValue {};
in {
  options = {
    hardware.nvidia = {
      datacenter.enable = lib.mkEnableOption (lib.mdDoc ''
        Data Center drivers for NVIDIA cards on a NVLink topology.
      '');
      datacenter.settings = lib.mkOption {
        type = settingsFormat.type;
        default = {
          LOG_LEVEL=4;
          LOG_FILE_NAME="/var/log/fabricmanager.log";
          LOG_APPEND_TO_LOG=1;
          LOG_FILE_MAX_SIZE=1024;
          LOG_USE_SYSLOG=0;
          DAEMONIZE=1;
          BIND_INTERFACE_IP="127.0.0.1";
          STARTING_TCP_PORT=16000;
          FABRIC_MODE=0;
          FABRIC_MODE_RESTART=0;
          STATE_FILE_NAME="/var/tmp/fabricmanager.state";
          FM_CMD_BIND_INTERFACE="127.0.0.1";
          FM_CMD_PORT_NUMBER=6666;
          FM_STAY_RESIDENT_ON_FAILURES=0;
          ACCESS_LINK_FAILURE_MODE=0;
          TRUNK_LINK_FAILURE_MODE=0;
          NVSWITCH_FAILURE_MODE=0;
          ABORT_CUDA_JOBS_ON_FM_EXIT=1;
          TOPOLOGY_FILE_PATH=nvidia_x11.fabricmanager + "/share/nvidia-fabricmanager/nvidia/nvswitch";
        };
        defaultText = lib.literalExpression ''
        {
          LOG_LEVEL=4;
          LOG_FILE_NAME="/var/log/fabricmanager.log";
          LOG_APPEND_TO_LOG=1;
          LOG_FILE_MAX_SIZE=1024;
          LOG_USE_SYSLOG=0;
          DAEMONIZE=1;
          BIND_INTERFACE_IP="127.0.0.1";
          STARTING_TCP_PORT=16000;
          FABRIC_MODE=0;
          FABRIC_MODE_RESTART=0;
          STATE_FILE_NAME="/var/tmp/fabricmanager.state";
          FM_CMD_BIND_INTERFACE="127.0.0.1";
          FM_CMD_PORT_NUMBER=6666;
          FM_STAY_RESIDENT_ON_FAILURES=0;
          ACCESS_LINK_FAILURE_MODE=0;
          TRUNK_LINK_FAILURE_MODE=0;
          NVSWITCH_FAILURE_MODE=0;
          ABORT_CUDA_JOBS_ON_FM_EXIT=1;
          TOPOLOGY_FILE_PATH=nvidia_x11.fabricmanager + "/share/nvidia-fabricmanager/nvidia/nvswitch";
        }
        '';
        description = lib.mdDoc ''
          Additional configuration options for fabricmanager.
        '';
      };

      powerManagement.enable = lib.mkEnableOption (lib.mdDoc ''
        experimental power management through systemd. For more information, see
        the NVIDIA docs, on Chapter 21. Configuring Power Management Support.
      '');

      powerManagement.finegrained = lib.mkEnableOption (lib.mdDoc ''
        experimental power management of PRIME offload. For more information, see
        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.

        Enabling this fixes screen tearing when using Optimus via PRIME (see
        {option}`hardware.nvidia.prime.sync.enable`. This is not enabled
        by default because it is not officially supported by NVIDIA and would not
        work with SLI.
      '');

      prime.nvidiaBusId = lib.mkOption {
        type = busIDType;
        default = "";
        example = "PCI:1:0:0";
        description = lib.mdDoc ''
          Bus ID of the NVIDIA GPU. You can find it using lspci; for example if lspci
          shows the NVIDIA GPU at "01:00.0", set this option to "PCI:1:0:0".
        '';
      };

      prime.intelBusId = lib.mkOption {
        type = busIDType;
        default = "";
        example = "PCI:0:2:0";
        description = lib.mdDoc ''
          Bus ID of the Intel GPU. You can find it using lspci; for example if lspci
          shows the Intel GPU at "00:02.0", set this option to "PCI:0:2:0".
        '';
      };

      prime.amdgpuBusId = lib.mkOption {
        type = busIDType;
        default = "";
        example = "PCI:4:0:0";
        description = lib.mdDoc ''
          Bus ID of the AMD APU. You can find it using lspci; for example if lspci
          shows the AMD APU at "04:00.0", set this option to "PCI:4:0:0".
        '';
      };

      prime.sync.enable = lib.mkEnableOption (lib.mdDoc ''
        NVIDIA Optimus support using the NVIDIA proprietary driver via PRIME.
        If enabled, the NVIDIA GPU will be always on and used for all rendering,
        while enabling output to displays attached only to the integrated Intel/AMD
        GPU without a multiplexer.

        Note that this option only has any effect if the "nvidia" driver is specified
        in {option}`services.xserver.videoDrivers`, and it should preferably
        be the only driver there.

        If this is enabled, then the bus IDs of the NVIDIA and Intel/AMD GPUs have to
        be specified ({option}`hardware.nvidia.prime.nvidiaBusId` and
        {option}`hardware.nvidia.prime.intelBusId` or
        {option}`hardware.nvidia.prime.amdgpuBusId`).

        If you enable this, you may want to also enable kernel modesetting for the
        NVIDIA driver ({option}`hardware.nvidia.modesetting.enable`) in order
        to prevent tearing.

        Note that this configuration will only be successful when a display manager
        for which the {option}`services.xserver.displayManager.setupCommands`
        option is supported is used.
      '');

      prime.allowExternalGpu = lib.mkEnableOption (lib.mdDoc ''
        configuring X to allow external NVIDIA GPUs when using Prime [Reverse] sync optimus.
      '');

      prime.offload.enable = lib.mkEnableOption (lib.mdDoc ''
        render offload support using the NVIDIA proprietary driver via PRIME.

        If this is enabled, then the bus IDs of the NVIDIA and Intel/AMD GPUs have to
        be specified ({option}`hardware.nvidia.prime.nvidiaBusId` and
        {option}`hardware.nvidia.prime.intelBusId` or
        {option}`hardware.nvidia.prime.amdgpuBusId`).
      '');

      prime.offload.enableOffloadCmd = lib.mkEnableOption (lib.mdDoc ''
        adding a `nvidia-offload` convenience script to {option}`environment.systemPackages`
        for offloading programs to an nvidia device. To work, should have also enabled
        {option}`hardware.nvidia.prime.offload.enable` or {option}`hardware.nvidia.prime.reverseSync.enable`.

        Example usage `nvidia-offload sauerbraten_client`.
      '');

      prime.reverseSync.enable = lib.mkEnableOption (lib.mdDoc ''
        NVIDIA Optimus support using the NVIDIA proprietary driver via reverse
        PRIME. If enabled, the Intel/AMD GPU will be used for all rendering, while
        enabling output to displays attached only to the NVIDIA GPU without a
        multiplexer.

        Warning: This feature is relatively new, depending on your system this might
        work poorly. AMD support, especially so.
        See: https://forums.developer.nvidia.com/t/the-all-new-outputsink-feature-aka-reverse-prime/129828

        Note that this option only has any effect if the "nvidia" driver is specified
        in {option}`services.xserver.videoDrivers`, and it should preferably
        be the only driver there.

        If this is enabled, then the bus IDs of the NVIDIA and Intel/AMD GPUs have to
        be specified ({option}`hardware.nvidia.prime.nvidiaBusId` and
        {option}`hardware.nvidia.prime.intelBusId` or
        {option}`hardware.nvidia.prime.amdgpuBusId`).

        If you enable this, you may want to also enable kernel modesetting for the
        NVIDIA driver ({option}`hardware.nvidia.modesetting.enable`) in order
        to prevent tearing.

        Note that this configuration will only be successful when a display manager
        for which the {option}`services.xserver.displayManager.setupCommands`
        option is supported is used.
      '');

      nvidiaSettings =
        (lib.mkEnableOption (lib.mdDoc ''
          nvidia-settings, NVIDIA's GUI configuration tool.
        ''))
        // {default = true;};

      nvidiaPersistenced = lib.mkEnableOption (lib.mdDoc ''
        nvidia-persistenced a update for NVIDIA GPU headless mode, i.e.
        It ensures all GPUs stay awake even during headless mode.
      '');

      forceFullCompositionPipeline = lib.mkEnableOption (lib.mdDoc ''
        forcefully the full composition pipeline.
        This sometimes fixes screen tearing issues.
        This has been reported to reduce the performance of some OpenGL applications and may produce issues in WebGL.
        It also drastically increases the time the driver needs to clock down after load.
      '');

      package = lib.mkOption {
        default = config.boot.kernelPackages.nvidiaPackages."${if cfg.datacenter.enable then "dc" else "stable"}";
        defaultText = lib.literalExpression ''
          config.boot.kernelPackages.nvidiaPackages."\$\{if cfg.datacenter.enable then "dc" else "stable"}"
        '';
        example = lib.mdDoc "config.boot.kernelPackages.nvidiaPackages.legacy_470";
        description = lib.mdDoc ''
          The NVIDIA driver package to use.
        '';
      };

      open = lib.mkEnableOption (lib.mdDoc ''
        the open source NVIDIA kernel module
      '');
    };
  };

  config = let
    igpuDriver =
      if pCfg.intelBusId != ""
      then "modesetting"
      else "amdgpu";
    igpuBusId =
      if pCfg.intelBusId != ""
      then pCfg.intelBusId
      else pCfg.amdgpuBusId;
  in
    lib.mkIf (nvidia_x11 != null) (lib.mkMerge [
      # Common
      ({
        assertions = [
          {
            assertion = !(nvidiaEnabled && cfg.datacenter.enable);
            message = "You cannot configure both X11 and Data Center drivers at the same time.";
          }
        ];
        boot = {
          blacklistedKernelModules = ["nouveau" "nvidiafb"];
          kernelModules = [ "nvidia-uvm" ];
        };
        systemd.tmpfiles.rules =
          lib.optional config.virtualisation.docker.enableNvidia
            "L+ /run/nvidia-docker/bin - - - - ${nvidia_x11.bin}/origBin";
        services.udev.extraRules =
        ''
          # Create /dev/nvidia-uvm when the nvidia-uvm module is loaded.
          KERNEL=="nvidia", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidiactl c $$(grep nvidia-frontend /proc/devices | cut -d \  -f 1) 255'"
          KERNEL=="nvidia", RUN+="${pkgs.runtimeShell} -c 'for i in $$(cat /proc/driver/nvidia/gpus/*/information | grep Minor | cut -d \  -f 4); do mknod -m 666 /dev/nvidia$${i} c $$(grep nvidia-frontend /proc/devices | cut -d \  -f 1) $${i}; done'"
          KERNEL=="nvidia_modeset", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-modeset c $$(grep nvidia-frontend /proc/devices | cut -d \  -f 1) 254'"
          KERNEL=="nvidia_uvm", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-uvm c $$(grep nvidia-uvm /proc/devices | cut -d \  -f 1) 0'"
          KERNEL=="nvidia_uvm", RUN+="${pkgs.runtimeShell} -c 'mknod -m 666 /dev/nvidia-uvm-tools c $$(grep nvidia-uvm /proc/devices | cut -d \  -f 1) 1'"
        '';
        hardware.opengl = {
          extraPackages = [
            nvidia_x11.out
          ];
          extraPackages32 = [
            nvidia_x11.lib32
          ];
        };
        environment.systemPackages = [
          nvidia_x11.bin
        ];
      })
      # X11
      (lib.mkIf nvidiaEnabled {
        assertions = [
        {
          assertion = primeEnabled -> pCfg.intelBusId == "" || pCfg.amdgpuBusId == "";
          message = "You cannot configure both an Intel iGPU and an AMD APU. Pick the one corresponding to your processor.";
        }

        {
          assertion = offloadCfg.enableOffloadCmd -> offloadCfg.enable || reverseSyncCfg.enable;
          message = "Offload command requires offloading or reverse prime sync to be enabled.";
        }

        {
          assertion = primeEnabled -> pCfg.nvidiaBusId != "" && (pCfg.intelBusId != "" || pCfg.amdgpuBusId != "");
          message = "When NVIDIA PRIME is enabled, the GPU bus IDs must be configured.";
        }

        {
          assertion = offloadCfg.enable -> lib.versionAtLeast nvidia_x11.version "435.21";
          message = "NVIDIA PRIME render offload is currently only supported on versions >= 435.21.";
        }

        {
          assertion = (reverseSyncCfg.enable && pCfg.amdgpuBusId != "") -> lib.versionAtLeast nvidia_x11.version "470.0";
          message = "NVIDIA PRIME render offload for AMD APUs is currently only supported on versions >= 470 beta.";
        }

        {
          assertion = !(syncCfg.enable && offloadCfg.enable);
          message = "PRIME Sync and Offload cannot be both enabled";
        }

        {
          assertion = !(syncCfg.enable && reverseSyncCfg.enable);
          message = "PRIME Sync and PRIME Reverse Sync cannot be both enabled";
        }

        {
          assertion = !(syncCfg.enable && cfg.powerManagement.finegrained);
          message = "Sync precludes powering down the NVIDIA GPU.";
        }

        {
          assertion = cfg.powerManagement.finegrained -> offloadCfg.enable;
          message = "Fine-grained power management requires offload to be enabled.";
        }

        {
          assertion = cfg.powerManagement.enable -> lib.versionAtLeast nvidia_x11.version "430.09";
          message = "Required files for driver based power management only exist on versions >= 430.09.";
        }

        {
          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:
        # - Specify the configured NVIDIA GPU bus ID in the Device section for the
        #   "nvidia" driver.
        # - Add the AllowEmptyInitialConfiguration option to the Screen section for the
        #   "nvidia" driver, in order to allow the X server to start without any outputs.
        # - Add a separate Device section for the Intel GPU, using the "modesetting"
        #   driver and with the configured BusID.
        # - OR add a separate Device section for the AMD APU, using the "amdgpu"
        #   driver and with the configures BusID.
        # - Reference that Device section from the ServerLayout section as an inactive
        #   device.
        # - Configure the display manager to run specific `xrandr` commands which will
        #   configure/enable displays connected to the Intel iGPU / AMD APU.

        # reverse sync implies offloading
        hardware.nvidia.prime.offload.enable = lib.mkDefault reverseSyncCfg.enable;

        services.xserver.drivers =
          lib.optional primeEnabled {
            name = igpuDriver;
            display = offloadCfg.enable;
            modules = lib.optional (igpuDriver == "amdgpu") pkgs.xorg.xf86videoamdgpu;
            deviceSection =
              ''
                BusID "${igpuBusId}"
              ''
              + lib.optionalString (syncCfg.enable && igpuDriver != "amdgpu") ''
                Option "AccelMethod" "none"
              '';
          }
          ++ lib.singleton {
            name = "nvidia";
            modules = [nvidia_x11.bin];
            display = !offloadCfg.enable;
            deviceSection =
              lib.optionalString primeEnabled
              ''
                BusID "${pCfg.nvidiaBusId}"
              ''
              + lib.optionalString pCfg.allowExternalGpu ''
                Option "AllowExternalGpus"
              '';
            screenSection =
              ''
                Option "RandRRotation" "on"
              ''
              + lib.optionalString syncCfg.enable ''
                Option "AllowEmptyInitialConfiguration"
              ''
              + lib.optionalString cfg.forceFullCompositionPipeline ''
                Option         "metamodes" "nvidia-auto-select +0+0 {ForceFullCompositionPipeline=On}"
                Option         "AllowIndirectGLXProtocol" "off"
                Option         "TripleBuffer" "on"
              '';
          };

        services.xserver.serverLayoutSection =
          lib.optionalString syncCfg.enable ''
            Inactive "Device-${igpuDriver}[0]"
          ''
          + lib.optionalString reverseSyncCfg.enable ''
            Inactive "Device-nvidia[0]"
          ''
          + lib.optionalString offloadCfg.enable ''
            Option "AllowNVIDIAGPUScreens"
          '';

        services.xserver.displayManager.setupCommands = let
          gpuProviderName =
            if igpuDriver == "amdgpu"
            then
              # find the name of the provider if amdgpu
              "`${lib.getExe pkgs.xorg.xrandr} --listproviders | ${lib.getExe pkgs.gnugrep} -i AMD | ${lib.getExe pkgs.gnused} -n 's/^.*name://p'`"
            else igpuDriver;
          providerCmdParams =
            if syncCfg.enable
            then "\"${gpuProviderName}\" NVIDIA-0"
            else "NVIDIA-G0 \"${gpuProviderName}\"";
        in
          lib.optionalString (syncCfg.enable || reverseSyncCfg.enable) ''
            # Added by nvidia configuration module for Optimus/PRIME.
            ${lib.getExe pkgs.xorg.xrandr} --setprovideroutputsource ${providerCmdParams}
            ${lib.getExe pkgs.xorg.xrandr} --auto
          '';

        environment.etc = {
          "nvidia/nvidia-application-profiles-rc" = lib.mkIf nvidia_x11.useProfiles {source = "${nvidia_x11.bin}/share/nvidia/nvidia-application-profiles-rc";};

          # 'nvidia_x11' installs it's files to /run/opengl-driver/...
          "egl/egl_external_platform.d".source = "/run/opengl-driver/share/egl/egl_external_platform.d/";
        };

        hardware.opengl = {
          extraPackages = [
            pkgs.nvidia-vaapi-driver
          ];
          extraPackages32 = [
            pkgs.pkgsi686Linux.nvidia-vaapi-driver
          ];
        };
        environment.systemPackages =
          lib.optional cfg.nvidiaSettings nvidia_x11.settings
          ++ lib.optional cfg.nvidiaPersistenced nvidia_x11.persistenced
          ++ lib.optional offloadCfg.enableOffloadCmd
          (pkgs.writeShellScriptBin "nvidia-offload" ''
            export __NV_PRIME_RENDER_OFFLOAD=1
            export __NV_PRIME_RENDER_OFFLOAD_PROVIDER=NVIDIA-G0
            export __GLX_VENDOR_LIBRARY_NAME=nvidia
            export __VK_LAYER_NV_optimus=NVIDIA_only
            exec "$@"
          '');

        systemd.packages = lib.optional cfg.powerManagement.enable nvidia_x11.out;

        systemd.services = let
          nvidiaService = state: {
            description = "NVIDIA system ${state} actions";
            path = [pkgs.kbd];
            serviceConfig = {
              Type = "oneshot";
              ExecStart = "${nvidia_x11.out}/bin/nvidia-sleep.sh '${state}'";
            };
            before = ["systemd-${state}.service"];
            requiredBy = ["systemd-${state}.service"];
          };
        in
          lib.mkMerge [
            (lib.mkIf cfg.powerManagement.enable {
              nvidia-suspend = nvidiaService "suspend";
              nvidia-hibernate = nvidiaService "hibernate";
              nvidia-resume =
                (nvidiaService "resume")
                // {
                  before = [];
                  after = ["systemd-suspend.service" "systemd-hibernate.service"];
                  requiredBy = ["systemd-suspend.service" "systemd-hibernate.service"];
                };
            })
            (lib.mkIf cfg.nvidiaPersistenced {
              "nvidia-persistenced" = {
                description = "NVIDIA Persistence Daemon";
                wantedBy = ["multi-user.target"];
                serviceConfig = {
                  Type = "forking";
                  Restart = "always";
                  PIDFile = "/var/run/nvidia-persistenced/nvidia-persistenced.pid";
                  ExecStart = "${lib.getExe nvidia_x11.persistenced} --verbose";
                  ExecStopPost = "${pkgs.coreutils}/bin/rm -rf /var/run/nvidia-persistenced";
                };
              };
            })
            (lib.mkIf cfg.dynamicBoost.enable {
              "nvidia-powerd" = {
                description = "nvidia-powerd service";
                path = [
                  pkgs.util-linux # nvidia-powerd wants lscpu
                ];
                wantedBy = ["multi-user.target"];
                serviceConfig = {
                  Type = "dbus";
                  BusName = "nvidia.powerd.server";
                  ExecStart = "${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 =
          lib.optional (nvidia_x11.persistenced != null && config.virtualisation.docker.enableNvidia)
          "L+ /run/nvidia-docker/extras/bin/nvidia-persistenced - - - - ${nvidia_x11.persistenced}/origBin/nvidia-persistenced";

        boot = {
          extraModulePackages =
            if cfg.open
            then [nvidia_x11.open]
            else [nvidia_x11.bin];
          # nvidia-uvm is required by CUDA applications.
          kernelModules =
            lib.optionals config.services.xserver.enable ["nvidia" "nvidia_modeset" "nvidia_drm"];

          # If requested enable modesetting via kernel parameter.
          kernelParams =
            lib.optional (offloadCfg.enable || cfg.modesetting.enable) "nvidia-drm.modeset=1"
            ++ lib.optional cfg.powerManagement.enable "nvidia.NVreg_PreserveVideoMemoryAllocations=1"
            ++ lib.optional cfg.open "nvidia.NVreg_OpenRmEnableUnsupportedGpus=1"
            ++ lib.optional (config.boot.kernelPackages.kernel.kernelAtLeast "6.2" && !ibtSupport) "ibt=off";

          # enable finegrained power management
          extraModprobeConfig = lib.optionalString cfg.powerManagement.finegrained ''
            options nvidia "NVreg_DynamicPowerManagement=0x02"
          '';
        };
        services.udev.extraRules =
          lib.optionalString cfg.powerManagement.finegrained (
          lib.optionalString (lib.versionOlder config.boot.kernelPackages.kernel.version "5.5") ''
            # Remove NVIDIA USB xHCI Host Controller devices, if present
            ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c0330", ATTR{remove}="1"

            # Remove NVIDIA USB Type-C UCSI devices, if present
            ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c8000", ATTR{remove}="1"

            # Remove NVIDIA Audio devices, if present
            ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x040300", ATTR{remove}="1"
          ''
          + ''
            # Enable runtime PM for NVIDIA VGA/3D controller devices on driver bind
            ACTION=="bind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030000", TEST=="power/control", ATTR{power/control}="auto"
            ACTION=="bind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030200", TEST=="power/control", ATTR{power/control}="auto"

            # Disable runtime PM for NVIDIA VGA/3D controller devices on driver unbind
            ACTION=="unbind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030000", TEST=="power/control", ATTR{power/control}="on"
            ACTION=="unbind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030200", TEST=="power/control", ATTR{power/control}="on"
          ''
        );
      })
      # Data Center
      (lib.mkIf (cfg.datacenter.enable) {
        boot.extraModulePackages = [
          nvidia_x11.bin
        ];
        systemd.services.nvidia-fabricmanager = {
          enable = true;
          description = "Start NVIDIA NVLink Management";
          wantedBy = [ "multi-user.target" ];
          unitConfig.After = [ "network-online.target" ];
          unitConfig.Requires = [ "network-online.target" ];
          serviceConfig = {
            Type = "forking";
            TimeoutStartSec = 240;
            ExecStart = let
              nv-fab-conf = settingsFormat.generate "fabricmanager.conf" cfg.datacenter.settings;
              in
                nvidia_x11.fabricmanager + "/bin/nv-fabricmanager -c " + nv-fab-conf;
            LimitCORE="infinity";
          };
        };
        environment.systemPackages =
          lib.optional cfg.datacenter.enable nvidia_x11.fabricmanager;
      })
    ]);
}