Makes sense, i'm not looking for a solution immediately so when I get around to it i'll look for a libvirt way of doing things first - adding my own wrapper was an interesting thought but something I would pursue only as a last resort

Daniel P. Berrange wrote:
On Fri, Sep 12, 2008 at 10:10:42AM +0100, Richard W.M. Jones wrote:
  
On Tue, Sep 09, 2008 at 10:23:59PM +0100, Henri Cook wrote:
    
<cmdstring>{cmd} {options}</cmdstring> (default)
      
This isn't going into libvirt because the whole point of libvirt is to
be hypervisor independent.  Nevertheless, you can do this, and the
'nice' thing, by setting <emulator> to be your own custom shell
script.
    

Bear in mind that if you do this, we make *zero* guarentee about compatability
with future releases. We reserve the right to change the way we invoke KVM,
the args we pass, and OS interaction. So while you can run it via 'nice', 
it is conceivable that future libvirt will override whatever setting you
make.  

Daniel