create a vdsm network with QoS.. As you can see there is some problem passing the data to libvirt that makes the outbound average be used for inbound and the outbound to be ignored.

net_qos.py

from vdsm import vdscli
connection = vdscli.connect()
connection.addNetwork('toni', '', '', ['p1p3'], {'qosInbound':{'average': '1024'}, 'qosOutbound':{'average': '2400'}})

result_libvirt_dump.xml

<network>
  <name>vdsm-toni</name>
  <uuid>f3caf14b-8e84-dc5b-efd2-be62ab0e367e</uuid>
  <forward mode='bridge'/>
  <bridge name='toni' />
  <bandwidth>
    <inbound average='2400'/>
  </bandwidth>
</network>