The Desing And Implementation Of DPDK In The Scene Of Virtual Machine Live Migration

With the rapid development of the cloud service industry,the scale of modern data centers has become larger and larger.Resource management and maintenance in the data center is becoming more and more important,and its cost also accounts for most of the daily cost of the data center.As a means of efficient configuration and integration of data center resources,virtual machine hot migration technology can effectively reduce the cost of management and maintenance.However,the traditional virtual machine hot migration process needs to be processed by the kernel protocol stack during the hot migration process,which consumes a large amount of CPU resources and has a long migration time,which affects the original service of the virtual machine.In addition to the traditional virtual machine I/O simulation because of the need to frequently switch between the virtual machine and the hypervisor,there will be a large number of context switches,reducing the virtual machine throughput.The throughput of traditional virtual machines can no longer meet the speed of 10 G network cards.In response to these problems,this article uses the DPDK suite to reduce the use of CPU resources,speed up the processing of data packets,and use the virtio virtualized I/O processing framework to improve the throughput of virtual machines by processing packets directly in the user mode.This paper first proposes a DPDK network optimization scheme based on the traditional hot migration network model.Through the PDK driver,ring lockless queue,memory pool,large page memory and other technologies provided by DPDK,most of the work of processing data packets is moved up.User mode bypasses the complex kernel stack.Moreover,the packet is sent and received in the user mode of active polling,which reduces a large number of hard interrupts and context switching overhead,and improves the efficiency of network packet processing.DPDK's Vhost library implements the backend of the virtio framework in user mode,directly exchanges data in the user state,reduces frequent switching between the virtual machine and the hypervisor,saves a lot of CPU consumption,and improves the performance of the virtual machine.Finally,test the optimized scheme and the traditional model scheme.The test results show that the system after DPDK network optimization can process GRE and non-GRE messages,and can effectively improve the throughput of the virtual machine.In the process of virtual machine hot migration,the total hot migration time and downtime can be reduced.