anchor.diff:      # video driver the host uses.
       services.xserver.videoDrivers = mkVMOverride [ "modesetting" ];
       services.xserver.defaultDepth = mkVMOverride 0;
  -    services.xserver.resolutions = mkVMOverride [ { x = 1024; y = 768; } ];
  +    services.xserver.resolutions = mkVMOverride [ cfg.resolution ];
       services.xserver.monitorSection =
         ''
           # Set a higher refresh rate so that resolutions > 800x600 work.
  
positive.code:         then driveDeviceName 2 # second disk
          else cfg.bootDevice
      );
  
      boot.initrd.extraUtilsCommands =
        ''
  
negative.code:             '';
        };
  
      virtualisation.resolution =
        mkOption {
          type = options.services.xserver.resolutions.type.nestedTypes.elemType;
          default = { x = 1024; y = 768; };
          description =
            ''
              The resolution of the virtual machine display.
            '';
        };
  
      virtualisation.cores =
        mkOption {
          type = types.ints.positive;
  