I have a running compute with ovs-dpdk. There is no ovs neutron agent, and the ovs is managed by odl on a controller node. The bridges ar br-int and br-ex, datapath type is netdev.

My question is, how does nova decide on nic type (i.e. virtio or vhostuser) when a VM is created (the call to qemu-system-x86_64)?

Specifically, can I instruct nova to choose vhostuser, or is it done automatically when the ovs bridge datapath type is netdev?