1b- SRIOV bypasses vrouter for passthrough networking
SR-IOV or sriov interfaces have both physical functions (PFs) and multiple virtual functions (VFs).
...
https://www.juniper.net/documentation/en_US/contrail4.0/topics/concept/sriov-with-vrouter-vnc.html
virtio: Para-Virtualization
https://wiki.libvirt.org/page/Virtio
virtio like vmxnet3 and xenvirt are part of the DPDK stack
...
VT-X technology is part of the HW assisted Virtualization
Paravirtualization: XenServer, VMware
KVM: can do both??