You have to use a real time modified kernal for EMC. The highest easily supported is Hardy Heron.
You can load a live CD and run (Very slowly) off it.
DO you have any windows machine or a dos machine. Turbo CNC is totally free to use, easy to set up and runs under dos. It must be real dos not a dos prompt from windows, You can boot to real dos in WIn 95 and 98.
So if you want to test under Linux download a Live CD for EMC and boot to the CD. With CNC you are running hardware and virtual machines don't hack it.
A good place to start with EMC is here..
which I see you have been to but if you are trying to run as a virtual machine you must not have done much reading while there..a cut and paste follows and on the page there are hyperlinks..
"Here you'll find information about the software, how to get it, how to configure it, how to run it, and especially where to ask for help.
Community maintained wiki with lots of information and examples about configuration and using EMC."
Also if you have a win 2000 or newer installation with a "real" parallel port you can try Mach and run programs up to 500 lines of Gcode with the trial version.
I am replying on a 10.04 machine right now.