Using QEMU/Virt-Manager you can just create a new VM and instead of creating a virtual disk you just input the path to your drive manually. In my case it's mounted at /dev/sdb

This will pass your full drive to the VM and Windows will just boot up like magic

Edit: If you already have a Windows VM I would assume you could just edit it and change from virtual drive to your full Windows drive instead. I don't think you have to make a new one