Convert the VirtualBox image to a raw image format using the following command:

VBoxManage clonehd „image.vdi“ „image.img“ –format RAW

Convert the raw image to a qcow image using the following command:

qemu-img convert -f raw image.img -O qcow2 image.qcow

Test your new image image.qcow:

kvm -m 512 -usbdevice tablet -hda image.qcow