qemu-img \
create \
-f luks \
--object secret,id=LuksDemo.img_encrypt0,file=/path/to/secretFile \
-o key-secret=LuksDemo.img_encrypt0,cipher-alg=serpent-256,cipher-mode=cbc,\
hash-alg=sha256,ivgen-alg=plain64,\
ivgen-hash-alg=sha256 /var/lib/libvirt/images/LuksDemo.img 5242880K