Got this question at work a lot. Thought I’d finally get around to putting it down since it’s came up for me. I’ve got a virtual machine using virtio passthrough for my pcie, and I found actually that disk access via the qcow2 is pretty naff.
sudo apt-get install qemu-kvm qemu-img convert windows10cloudimage.qcow2 -O raw diskimage.img dd if=/path/to/windos10cloudimage.qcow2 of=/dev/sdc2
Please note in my case the physical partition I’d made was sdc2. I’d actually resized another 5TB disk I have in my system using gparted. Just so I can attach a physical partition with libvirtd. Evidently though libvirtd-manager doesn’t allow this business so I have to edit the xlm file in /etc/qemu/windows10.xml .
root@adam:/etc/libvirt/qemu# virsh define /etc/libvirt/qemu/win10-uefi.xml Domain win10-uefi defined from /etc/libvirt/qemu/win10-uefi.xml root@adam:/etc/libvirt/qemu# virt-manager
qemu-img convert windows10.qcow2 -O raw /dev/sdc