If you are using VirtualBox to run your tools and want to use the image in P2C to save time, you can convert them to qcow2 format then upload the image. You need to install qemu first. VBoxManage and qemu-img commands are used.

$VBoxManage clonehd yourimage.vdi yourimage.raw --format raw
$qemu-img convert -f raw -O qcow2 yourimage.raw yourimage.qcow2