l2-cache-size

Hello, I've read this article: http://blogs.igalia.com/berto/2015/12/17/improving-disk-io-performance-in-qemu-2-5-with-the-qcow2-l2-cache/ I would like to do some test using the -disk parameter l2-cache-size: is there a way to pass from proxmox this disk parameter ? I see in man vm.conf that...