(no major updates with WS 2019)

In order to achieve native I/O for the network in virtual machines Windows Server 2012 (maintained with R2) added the ability to assign SR-IOV functionality from physical devices directly to virtual machines. This gives virtual machines the ability to bypass the software-based Hyper-V Virtual Switch, and directly access the network adapter. As a result, CPU overhead and latency is reduced, with a corresponding rise in throughput.

Requirements:
- host hardware that supports SR-IOV (e.g. CPU with Intel VT-d2, chipset support for interrupt and DMA remapping)
- SR-IOV-capable NIC in the virtualization host

Features:
- Live Migration is fully supported. You can Live Migrate a VM using SR-IOV to another host that either does or does not support SR-IOV, and back again. The VM will use SR-IOV if it is available on the target host, and if SR-IOV is unavailable, it will use the traditional software network path.

Limitations:
- Nick Teaming & SR-IOV: when a NIC team is created on top of SR-IOV capable physical NICs, the SR-IOV capability is not propagated. So you cant team in the parent partition and use the same NICs for SR-IOV in the vims at the same time (instead present two SR-IOV NICs to the vims and team them in the guest OS)
- SR-IOV causes the virtual machines traffic to bypass the Hyper-V Virtual Switch. If any switch port policies are set, SRIOV functionality is revoked for that virtual machine