Add gpu settings

hosts/herugrim/default.nix

@@ -56,6 +56,7 @@
         virtual-machine = false;
       };
       cpu.type = "intel";
+      gpu.type = "nvidia";
       hasTPM = true;
     };
 

options/device/hardware.nix

@@ -14,6 +14,16 @@ in
       '';
     };
 
+    gpu.type = mkOption {
+      type = with types; nullOr (enum [ "nvidia" "amd" "intel" ]);
+      default = null;
+      description = ''
+        The manifaturer/type of the primary system GPU.
+
+        Allows the correct GPU drivers to be loaded, potentially optimizing video output performance.
+      '';
+    };
+
     hasTPM = mkOption {
       type = lib.types.bool;
       default = false;

system/shared/hardware/default.nix

@@ -1,6 +1,7 @@
 _: {
   imports = [
     ./cpu
+    ./gpu
     ./tpm.nix
     ./generic.nix
   ];

system/shared/hardware/gpu/amd.nix

@@ -0,0 +1,39 @@
+# WARNING: This file is currently untested 
+# (I didn't yet run this NixOS config on any AMD GPU systems)
+{ config, lib, pkgs, ... }:
+let
+  dev = config.myOptions.device;
+in
+{
+  config = lib.mkIf (dev.gpu.type == "amd") {
+    services.xserver.videoDrivers = lib.mkDefault ["modesetting" "amdgpu"];
+
+    boot = {
+      initrd.kernelModules = ["amdgpu"];  # load amdgpu kernel module as early as initrd
+      kernelModules = ["amdgpu"]; # if loading somehow fails during initrd but the boot continues, try again later
+    };
+
+    environment.systemPackages = with pkgs; [
+      mesa
+
+      vulkan-tools
+      vulkan-loader
+      vulkan-validation-layers
+      vulkan-extension-layer
+    ];
+
+    # Enable OpenGL
+    hardware.opengl = {
+      enable = true;
+
+      # Enable OpenCL and AMDVLK
+      extraPackages = with pkgs; [
+        amdvlk
+        rcomPackages.clr.icd
+      ];
+      extraPackages32 = with pkgs; [
+        driversi686Linux.amdvlk
+      ];
+    };
+  };
+}

system/shared/hardware/gpu/default.nix

@@ -0,0 +1,7 @@
+_: {
+  imports = [
+    ./amd.nix
+    ./nvidia.nix
+  ];
+}
+

system/shared/hardware/gpu/nvidia.nix

@@ -0,0 +1,78 @@
+{ config, lib, pkgs, ... }:
+let
+  dev = config.myOptions.device;
+in
+{
+  config = lib.mkIf (dev.gpu.type == "nvidia") {
+    # Nvidia drivers are unfree software
+    nixpkgs.config.allowUnfree = true;
+
+    # Enable nvidia driver for Xorg and Wayland
+    services.xserver.videoDrivers = ["nvidia"];
+
+    hardware = {
+      nvidia = {
+        # modeestting is required
+        modesetting.enable = lib.mkDefault true;
+
+        # Nvidia power managerment. Experimental, and can cause sleep/suspend to fail.
+        # Enable this if you have graphical corruption issues or application crashes after waking
+        # up from sleep. This fixes it by saving the entire VRAM memory to /tmp/ instead of just
+        # the bare essentials
+        powerManagement.enable = lib.mkDefault true;
+
+        # Fine-grained power management. Turns off GPU when not in use.
+        # Experimental and only works on modern Nvidia GPUs (Turing or newer)
+        powerManagement.finegrained = lib.mkDefault false;
+
+        # Use the NVidia open source kernel module (not to be confused with the
+        # independent third-party "nouveau" open source driver).
+        # Support is limited to the Turing and later architectures. Full list of
+        # supported GPUs is at: https://github.com/NVIDIA/open-gpu-kernel-modules#compatible-gpus 
+        #
+        # Enable this by default, hosts may override this option if their gpu is not 
+        # supported by the open source drivers
+        open = lib.mkDefault true;
+
+        # Add the Nvidia settings package, accessible via `nvidia-settings`.
+        # (useless on NixOS)
+        nvidiaSettings = false;
+
+        # This ensures all GPUs stay awake even during headless mode.
+        nvidiaPersistenced = true;
+      };
+
+      # Enable OpenGL
+      opengl = {
+        enable = true;
+
+        # VA-API implementation using NVIDIA's NVDEC
+        extraPackages = with pkgs; [nvidia-vaapi-driver];
+        extraPackages32 = with pkgs.pkgsi686Linux; [nvidia-vaapi-driver];
+      };
+    };
+
+    # blacklist nouveau module so that it does not conflict with nvidia drm stuff
+    # also the nouveau performance is horrible in comparison.
+    boot.blacklistedKernelModules = ["nouveau"];
+
+    environment = {
+      systemPackages = with pkgs; [
+        mesa
+
+        vulkan-tools
+        vulkan-loader
+        vulkan-validation-layers
+        vulkan-extension-layer
+
+        libva
+        libva-utils
+      ];
+
+      sessionVariables = {
+        LIBVA_DRIVER_NAME = "nvidia";
+        WLR_NO_HARDWARE_CURSORS = "1";
+      };
+    };
+  };
+}