Comment 2 for bug 1000219

I can reproduce within a precise amd64 cloud image using:

iso_url=http://releases.ubuntu.com/12.04/ubuntu-12.04-server-amd64.iso
iso=${iso_url##*/}

pkgs="cobbler-web kvm"
v=$(uname -r) && [ "${v%-virtual}" != "${v}" ] &&
  pkgs="$pkgs linux-image-extra-virtual"

sudo apt-get install $pkgs

sudo modprobe kvm_intel
sudo modprobe kvm_amd
sudo chmod 666 /dev/kvm

wget "$iso_url" -O "$iso"
mkdir mp
sudo mount -o loop,ro "$iso" $PWD/mp
sudo cobbler import "--path=$PWD/mp" --name=precise
sudo umount $PWD/mp

qemu-img create -f qcow2 disk.img 4G
kvm -m 256 -boot n -display vnc=:1 \
   -drive file=disk.img,if=virtio \
   -net user,tftp=/var/lib/tftpboot,bootfile=/pxelinux.0 \
   -net nic,model=virtio