Kompiling in a virtual machine made fast

As you may have followed, I compiled my KDE in a virtual machine, described an example how it goes and even compared compile times in a mini-benchmark. I stopped using a virtual machine later because VirtualBox only gives you one virtual CPU, QEmu as well, and VMware Server only two. The good thing is I found KVM virtualization and learned how to set it up. It is a bit tedious and you will have to create a network bridge after every reboot, but the result is astonishing - I could compile Qt 4.6 in 20 minutes instead of 80.