Decide whether we can drop DKMS modules support

Building external (DKMS) modules is not supported by the grsec Debian kernel. See https://bugs.debian.org/820464 for details, and in particular the description of what needs to be done to fix that: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=820464#52

How bad would it be if we dropped DKMS modules entirely?

• Currently we include the VirtualBox one only. It seems that most VirtualBox functionality works anyway: in #11965-note_14 anonym wrote “for me everything works pretty nicely without the guest modules loaded: mouse-integration works, and host window resizing => guest resolution changes. IIRC these two did not work before without the guest additions, but I might be wrong. I guess filesystem sharing, host-to-guest time syncing and clipboard sharing are the only features missing with the 64-bit kernel”.
• There are plans to add more, e.g. #7505 (closed), but nothing critical (I mean, we’ve never supported this functionality and nobody felt the urge to add it).

So, is it OK to drop them?

Parent Task: #7649 (closed)

Related issues

• Related to #12048 (closed)
• Related to #12139 (closed)
• Related to #12357 (closed)
• Related to #12403

Original created by @intrigeri on 12104 (Redmine)