title: How to set params for libvirt python api setBlockIoTune?
body: <p>I need set kvm virtual machine's disk IoTune by using python libvirt. After searching, i found a method "setBlockIoTune" at libvirt.py, it just call c api virDomainSetBlockIoTune, </p>
  
  <pre><code>int virDomainSetInterfaceParameters (virDomainPtr domain,
                   const char * device,
                   virTypedParameterPtr params,
                   int nparams,
                   unsigned int flags)
  </code></pre>
  
  <p>Here is the problem, I can't find how to set a value for "virTypedParameterPtr params" in in python livirt. The <a href="http://openstack-repo.cisco.com/openstack//cisco/pkgs/libvirt/docs/html/libvirt-libvirt.html#virDomainSetBlockIoTune" rel="nofollow">doc</a> does't talk about it.</p>
  
  <p>Please help me, Thanks!! </p>
  
  <p>orz</p>