[libvirt] qemu smbios options in domain xml format

Hello, I could not find any explicit mention of support for the -smbios options which are present in qemu 0.10.5+ in the domain xml format or the qemu/kvm hypervisor driver pages. Is there some way to specify commands and options which are not described in the xml config by adjusting something in the way libvirt processes the xml? Or is providing smbios options just not supported currently?