当前位置：网站首页>[recognizing cloud Nativity] Chapter 4 cloud network section 4.9.4.2 - Implementation of smart network card

[recognizing cloud Nativity] Chapter 4 cloud network section 4.9.4.2 - Implementation of smart network card

2022-07-18 16:16:00 【Scattered people in the river】

1 Implementation of intelligent network card

SmartNIC Is by starting from Host CPU On Offload（ uninstall ） Workload to network card hardware , To improve Host CPU Processing performance of . Among them “ The workload ” not only Networking, It can also be Storage、Security etc. .

1.1 Smart NIC How to implement

According to the design of intelligent network card, adopt the form , Divide it into ：

1、 Multi core smart network card , Based on the inclusion of multiple CPU Kernel ASIC（ Special application integrated circuits ） chip ：ASIC It has a price advantage , But flexibility is limited , Although based on ASIC Of NIC Relatively easy to configure , But the ultimate functionality will be based on ASIC The limitation of the function defined in , This may result in some workloads not being supported .

2、 be based on FPGA（ Programmable gate array ） Smart network card of ：FPGA It's highly programmable , And it can support almost any function relatively effectively , But as we all know ,FPGA The biggest problem is that programming is difficult and expensive .

3、FPGA Enhanced intelligent network card , take FPGA And ASIC The combination of network controllers .

meanwhile , Because different vendors have different architectures , therefore SmartNIC Can be based on ASIC、FPGA And systems on chip （SOC） Three technologies are implemented .

The cost of intelligent network cards with different implementation methods 、 There are trade-offs between the simplicity and flexibility of programming .

- ASIC Very cost effective , Can provide the best cost performance , But its flexibility is affected by ASIC The limitation of the function defined in .
- be based on FPGA The intelligent network card can be within the constraints of the available logic gates , Spend enough time and cost to support almost any function relatively effectively . but FPGA Programming is not easy and expensive .
- For the more complicated 、 Broader use cases , be based on SoC（ Such as NVIDIA Of BlueField DPU） Provides the best intelligent network card implementation options ： Good cost performance 、 Easy to program and highly flexible .

Performance comparison between network card and intelligent network card （ As shown in the table 2 Shown ）

The above is organized from Consultant Sadie 《2021 China DPU Industry development white paper 》

1.2 Multi core smart network card

A multi-core smart NIC design may include an integration of many ASIC. these ASIC The kernel is usually better ARM processor , They process packets and send them from the main server CPU（ expensive ） Uninstall task on . Multi core smart network card ASIC It can also integrate fixed function hardware engine , They can unload well-defined tasks , Such as standardized security and storage protocols .

Multi core smart network card is limited by at least two factors ：

These smart network cards are based on software programmable processors , Due to the lack of processor parallelism , They are slower when used in network processing .
These are multicore ASIC The fixed function hardware engine in is lack of the data plane programmability and flexibility that the intelligent network card unloading function needs more and more .

The design of multi-core intelligent network card based on processor is in 10G This generation of network card has been widely used . However , As the Ethernet data rate in the data center changes from 10G Rise to 25G、40G、50G、100G Even higher , These software centric multi-core smart network cards are hard to keep up with .

These multi-core smart network cards can not achieve the required peak bandwidth under these high data rates . meanwhile , Multi core smart network card ASIC The fixed function engine in cannot be extended to handle new encryption or security algorithms , That's because they don't have enough programmability , It can only adapt to the subtle changes of the algorithm .

1.3 be based on FPGA Smart network card of

be based on FPGA Smart network card using FPGA Greater hardware programmability to build any data plane functionality required for tasks offloaded to the smart NIC . because FPGA It's reprogrammable , utilize FPGA The data plane function can be removed and reconfigured arbitrarily and in real time . All of these offloads run at hardware rather than software speed .

Compared with software based implementation , be based on FPGA The design of smart network card can speed up the network function by several orders of magnitude . In the design of intelligent network card FPGA It can provide the line speed performance and power efficiency of customized hardware , And it can create deep packets that support complex offloading tasks and improve the performance of single stream network / Network processing pipeline .

By using FPGA A lot of hardware parallelism inherent in to replicate these pipelines , Can provide huge big data performance , Enough to meet the high performance of the next generation data center architecture based on faster Ethernet network 、 High bandwidth 、 High throughput demand .

1.4 FPGA Enhanced intelligent network card

The need for backward compatibility leads to FPGA Enhanced intelligent network card , It adds FPGA function . Based on this design , The network card can be the existing multi-core smart network card , It can also be just a simple NIC （NIC ASIC）.

The network cards integrated into these designs provide backward compatibility , Especially for super hypervisor compatibility . therefore , Based on the existing network card FPGA Enhanced intelligent network card design , Plus... For extended functionality FPGA, Can realize its investment income immediately , Because it automatically connects with the existing network API Compatible with interface protocol , So you can use the existing API And drivers . One FPGA On board in the design of enhanced intelligent network card FPGA Can significantly improve performance and expand functionality .