[libvirt] ipv6 slirp network

Hello. I have now slirp qemu network with ipv4 address, but for tests i need also ipv6 addresses in slirp network. How can i provide this args for qemu via libvirt or (best) via qemu args? I found some commits about ipv6 slirp network but can't find args needed to enable it. -- Vasiliy Tolstov, e-mail: v.tolstov@selfip.ru jabber: vase@selfip.ru