libvirt users - Oct 2016 - Passing "migratable=no" to qemu in domain's XML

Hi,

I want to use Invariant TSC with qemu, and to do that qemu must get the 
following args: "-cpu host,migratable=no,+invtsc". invtsc works only
if
migratable=no is passed too.

The "+invtsc" part is sucessfully handled by using

<feature name="invtsc"/>

inside domain's XML, however I don't how/where to put the 
"migratable=no" there.

Is there an elegant way to pass "migratable=no" to qemu via
domain's XML
without using <qemu:arg/> tags?