Presented at UW/UC Berkeley/NYU Cloud Day. Abstract: In 1989, a number of U.S. research institutions and universities started collaborating on a set of Gigabit testbeds - trying to build the first networks that could deliver data to and from applications at the seemingly crazy speed of 1Gbps. As part of the Aurora testbed, we built a number of flexible “host-network interfaces” - flexible because we didn’t know what tasks would be done in the host and which should be offloaded. Our 1989 design - a couple of Intel CPUs, some big FPGAs, expensive optics - bore a striking similarity to the smartNICs of today. And in many ways we still don’t know which tasks should be offloaded, which is why we continue to see CPUs and FPGAs on NICs - although some tasks like TCP header processing & tunneling for network virtualization are now well established as offloadable. This talk examines the long-lived tradeoff between keeping network functions close to the application (in the host) and offloading them to the NIC in the hope of better performance, and considers some of the implications of recent announcements of running a full hypervisor on the smartNIC.

1. The accidental SmartNIC Bruce Davie
VMware and Systems Approach, LLC

2. SmartNICs: The NIC for people
who don’t know what they are doing
Bruce Davie
VMware and Systems Approach, LLC

3. Outline
❖ 1988: We need SmartNICs!
❖ Offloading – does it work?
❖ TCP offloads
❖ VXLAN and GENEVE
❖ OVS
❖ 2020: We need SmartNICs!
❖ 2021+: Hypervisor on a SmartNIC?

4. 1988: We need SmartNICs!
Davie, SIGCOMM 1991
Kanakia and Cheriton, SIGCOMM, 1988
Well…we needed FAST NICs, but did we need SMART NICs?

5. SmartNIC architecture 1990
Intel CPU
Framing,
Optics
FPGA
(SAR, DMA)
Control
Registers
Source: SIGCOMM ‘91

6. The Quest For Offloads
Source: Mellanox blog

7. TCP Offloads and Tunneling
❖ TCP Offloads to NICs became mainstream (Checksums, header parsing,
segmentation/reassembly)
❖ Completely broke tunneling & hence limited innovation
❖ STT VXLAN GENEVE→ →

8. OVS Offloads
❖ Always seemed more interesting to hardware vendors than OVS
implementors
❖ A small percentage of “special cases” can spoil the offload
❖ Performance of networking is a concern especially in telco clouds

9. A hypervisor on a NIC??
→ →

10. Another Smart Nick
Source: Nick McKeown, Stanford

11. Data Centre of the Future
x86 GPU/TPU Quantum Compute SmartNICs
Programmable
Switches