aio flag for KVM guests

[Rangababu Chakravarthula <rbabu@xxxxxxxxxxxx>]

Hello,
We are using libvirt 0.8.3 to build KVM guests (KVM version is qemu-kvm 0.12.5). I see kvm supports aio flag with either native or threads option. Where in libvirt XML should we define aio option?

Thanks in advance
Ranga