System/modules/linux/hardware.nix

{ config, lib, pkgs, ... }:
let nw = config.nathan.hardware;
in with lib; {
  config = mkMerge [
    {
      hardware.logitech.wireless = mkIf nw.logitech {
        enable = true;
        enableGraphical = true;
      };
    }
    (mkIf nw.amdPassthrough {
      # Turn on IOMMU and the needed drivers
      boot = {
        kernelParams = [ "amd_iommu=on" ];
        kernelModules = [ "kvm-amd" "vifo-pci" ];
      };
      # Enable libvirtd
      virtualisation.libvirtd = {
        enable = true;
        onBoot = "ignore";
        onShutdown = "shutdown";
        qemu = {
          ovmf = { enable = true; };
          runAsRoot = true;
          swtpm.enable = true;
        };
      };
    })
    (mkIf nw.printing {
      services.printing = {
        enable = true;
        drivers = with pkgs; [ canon-cups-ufr2 ];
      };
      environment.systemPackages = with pkgs; [ canon-cups-ufr2 ];
      # Enable avahi for printer discovery
      services.avahi = {
        enable = true;
        nssmdns = false;
        interfaces = [ "enp6s0" ];
        hostName = "levitation";
        domainName = "local";
        openFirewall = true;
      };
      system.nssModules = with pkgs.lib;
        optional (!config.services.avahi.nssmdns) pkgs.nssmdns;
      system.nssDatabases.hosts = with pkgs.lib;
        optionals (!config.services.avahi.nssmdns) (mkMerge [
          (mkOrder 900
            [ "mdns4_minimal [NOTFOUND=return]" ]) # must be before resolve
          (mkOrder 1501 [ "mdns4" ]) # 1501 to ensure it's after dns
        ]);
    })
  ];
}