smartnic 是一个网络接口卡（网络适配器），使用其自己的板载处理器（ASIC, FPGA, CPU），卸载CPU的网络处理功能。smartNIC可以执行加密/解密，防火墙，TCP / IP和HTTP处理的任意组合。 SmartNIC非常适合于高流量的Web服务器。
虚拟化场景常见的smartnic是进行ovs的功能卸载。
ovs的卸载分三种方式：
１． vDPA for on-prem
virtual data plane acceleration.
a virtio dataplane going directly from the NIC to the container while using a translation layer between the NICs control plane and the virtio control plane
２． Virtio full HW offloading (e.g. for Alibaba bare metal servers)
３． Mediator layers for public cloud
In the case of AWS since the ENA interface (see details in the AWS section) does not support virtio data plane/control plane, both planes need to pass through a translation layer.
相对来说，vDPA的设计，硬件相对来说简单一些。
retimer -> FPGA -> PCI -> host