Whonix 18.2.1.7 (internal developers-only release) comes with virtualbox-guest-additions-iso installed by default (sourced from Oracle virtualbox.org, installed using vbox-guest-installer (during vm-config-dist.postinst).
Systemd user unit vboxclient-wayland.service executes /usr/bin/VBoxClient --foreground --wayland.
On a Windows test machine with a Kicksecure or Whonix guest:
- VM to host copy/paste: Functional.
- Host to VM copy/paste: Functional.
Using VirtualBox host software version 7.2.12.