If you have an arch base Linux system running in a virtual machine and want to access it using the spice / qxl interface, it may be useful to install the proper driver to have higher resolutions avaiblabe.
The driver can be found in package prebuild within the official arch repositories.
The agend for the spice virtual display is available from the AUR repositories. I use
yaourt to install the package. This might be dangerous if you are not careful. Just read the
PKGBUILD and other files provided by the package. If there is nothing suspicious, you may proceed and install it.
Finally the X-server needs to be configured to use the newly installed qxl driver. I use the command
sudo nano /usr/share/X11/xorg.conf.d/50-qxl.conf to start editing. You may use the following lines as content of the file.
After rebooting (or restarting X), you should be able to select higher resolutions for your display. This makes using the machine much more comfortable.