nvidia.nix

# NVIDIA drivers + CUDA — machines tagged gpu-nvidia
# Supports Turing+ GPUs (RTX 2070, RTX 4090, etc.) with open kernel modules.
{
  flake.modules.nixos.nvidia =
    {
      pkgs,
      config,
      ...
    }:
    {
      # allowUnfree is set once in modules/nixos/common.nix (always imported alongside this module).

      boot = {
        blacklistedKernelModules = [ "nouveau" ];
        kernelParams = [
          "nvidia_drm.modeset=1"
          "nvidia_drm.fbdev=1"
          "nvidia.NVreg_PreserveVideoMemoryAllocations=1"
          "nvidia.NVreg_TemporaryFilePath=/var/tmp" # Prevent tmpfs overflow on resume
          "nvidia.NVreg_EnableGpuFirmware=1" # GSP firmware offloading (Turing+)
        ];
      };

      hardware = {
        graphics = {
          enable = true;
          enable32Bit = true;
          extraPackages = with pkgs; [
            nvidia-vaapi-driver
            libvdpau-va-gl
          ];
          extraPackages32 = with pkgs.driversi686Linux; [ libvdpau-va-gl ];
        };

        nvidia-container-toolkit.enable = true;

        nvidia = {
          modesetting.enable = true;
          nvidiaSettings = true;
          open = true;
          powerManagement.enable = true;
          # Trying the "new_feature" branch (NVIDIA's current New Feature Branch).
          # This is newer (610.43.x) than the production/stable 595 series.
          # Revert to .stable (or .beta) if you hit instability, crashes, or regressions.
          package = config.boot.kernelPackages.nvidiaPackages.new_feature;
        };
      };

      # nvidia-container-toolkit-cdi-generator.service generates /run/cdi/nvidia.yaml
      # on boot so Podman/Docker can resolve nvidia.com/gpu=0 device requests.
      # The upstream NixOS service (hardware.nvidia-container-toolkit.enable = true above)
      # works correctly with the new_feature (610.43+) driver via NVML auto-detection.

      services.xserver.videoDrivers = [ "nvidia" ];

      environment.sessionVariables = {
        LIBVA_DRIVER_NAME = "nvidia";
        VDPAU_DRIVER = "va_gl";
        GBM_BACKEND = "nvidia-drm";
        __GLX_VENDOR_LIBRARY_NAME = "nvidia";
        NVD_BACKEND = "direct";
        __GL_GSYNC_ALLOWED = "1";
        __GL_VRR_ALLOWED = "1";
        NIXOS_OZONE_WL = "1";
        ELECTRON_OZONE_PLATFORM_HINT = "wayland";
      };

      environment.systemPackages = with pkgs; [
        libva
        libvdpau
        vdpauinfo
        libva-utils
        vulkan-tools
        mesa-demos
      ];
    };
}