[libvirt-users] ballooning option xml

[udo1]

Hi everybody,

I need the ballooning option with kvm using libvirt xml file and virsh 
(virsh create domain.xml)
kvm line must be appended with the -balloon virtio switch to enable 
ballooning. (can be disabled if there no option or with -balloon none )

I currently using Ubuntu Lucid

How can I define this in the domain xml file, or what need I to do to 
get this option?
is there any option like
enabling with
<balloon>virtio</balloon>
or
disabling with
<balloon>none</balloon>


Thanks in Advance
Udo Attila Fischer