When using testpmd inside the guest, we only currently support building igb_uio from the source packages and binding nics to this driver which is downloaded during ./build_base_machine.sh script execution. We should add some default options to allow for different drivers to be used such as uio_pci_generic or vfio with no iommu which is available with 16.04 and newer kernels.

In case of SR-IOV if uio_pci_generic is selected it should revert back to building igb_uio as uio_pci_generic only supports legacy interrupts.