The 4.2.14 maintenance release (2013-06-21) of Virtualbox has a fix for
the problem that stopped Plan 9 working with Virtualbox 4.2.
From https://www.virtualbox.org/wiki/Changelog :
BIOS: don't use the ENTER / LEAVE instructions in the BIOS as these
don't work in the real mode as set up by certain guests (e.g. Plan 9 and
QNX 4)
I've tried Labs Plan 9 and 9atom and they both seem to work well on an
Arch Linux host. 9front worked for me with 4.2 and also works with 4.2.14.
You need to use the Intel PRO/1000 MT Server emulation for networking
and Vesa for Video:
aux/vga -m vesa -p will list available video modes (you can define
custom modes for Virtualbox if your monitor resolution isn't supported)
aux/vga -m vesa -l 1600x1200x32 gives me a nice full screen display option
