Add all printing support and add vm guest services module

hosts/familypc/config.nix

@@ -16,6 +16,7 @@ in
     ./users.nix
     ../../modules/amd-drivers.nix
     ../../modules/nvidia-drivers.nix
+    ../../modules/vm-guest-services.nix
   ];
 
   # Bootloader.
@@ -179,6 +180,17 @@ in
   services.libinput.enable = true;
   services.openssh.enable = true;
   services.printing.enable = true;
+  services.avahi = {
+    enable = true;
+    nssmdns4 = true;
+    openFirewall = true;
+  };
+  services.ipp-usb.enable = true;
+  hardware.sane = {
+    enable = true;
+    extraBackends = [ pkgs.sane-airscan ];
+    disabledDefaultBackends = [ "escl" ];
+  };
   # Enable sound with pipewire.
   sound.enable = true;
   hardware.pulseaudio.enable = false;
@@ -239,6 +251,7 @@ in
   # Extra Module Options
   drivers.amdgpu.enable = true;
   drivers.nvidia.enable = false;
+  vm.guest-services.enable = false;
 
   # Open ports in the firewall.
   # networking.firewall.allowedTCPPorts = [ ... ];

hosts/familypc/users.nix

@@ -19,6 +19,8 @@ in
         "networkmanager"
         "wheel"
         "libvirtd"
+        "scanner"
+        "lp"
       ];
       shell = pkgs.bash;
       ignoreShellProgramCheck = true;

modules/vm-guest-services.nix

@@ -0,0 +1,21 @@
+{
+  lib,
+  pkgs,
+  config,
+  ...
+}:
+with lib;
+let
+  cfg = config.vm.guest-services;
+in
+{
+  options.vm.guest-services = {
+    enable = mkEnableOption "Enable Virtual Machine Guest Services";
+  };
+
+  config = mkIf cfg.enable {
+    services.qemuGuest.enable = true;
+    services.spice-vdagentd.enable = true;
+    services.spice-webdavd.enable = true;
+  };
+}