Research And Implementation Of IO Virtualization Technology Based On Microkernel

With the emergence of new application scenarios such as the Internet of Things,the complexity of application scenarios in the embedded field is increasing.In order to integrate a large number of input and output devices in embedded systems,embedded I/O virtualization technology has become a hot research topic in the embedded field.The current I/O virtualization approach is limited by the hypervisor architecture,and its components are highly coupled with other components at the privileged level.As the number of I/O devices increases,the privileged-level software becomes large and bloated,and the potential security threats make it difficult to meet the security requirements of embedded environments.At the same time,the hypervisor loses the I/O real-time information provided by the I/O tasks of the guest VMs in the virtualized environment,which makes it difficult for the current I/O virtualization solutions to meet the real-time requirements of the embedded environment.This thesis investigates existing hypervisor architectures and I/O virtualization solutions,adds virtualization extensions to the mginkgo microkernel developed by the faculty,and proposes I/O virtualization solutions and real-time optimization algorithms based on the microkernel architecture.The main contributions of this thesis are as follows.(1)This thesis adds virtualization extensions to the CPU,interrupt and memory management modules of the mginkgo microkernel,and completes the virtualization of the three major components of the interrupt controller.The interrupt management mechanism classifies all interrupts generated by the hardware platform and realizes the management of virtual interrupts.The virtualization extensions added in this thesis provide important basic functional support for the implementation of I/O virtualization.(2)Based on the design concept of microkernel architecture,this thesis implements the I/O virtualization components at the unprivileged level,which reduces the coupling between components and the size of the privileged-level software.Based on this,this thesis propose a standard interface for front-end and back-end driver communication and design a communication mechanism for data interaction between front-end and back-end drivers.The communication mechanism makes full use of the components of the microkernel,and enhances the security of the communication process by extending the inter-process communication component and the capability access control component to improve the I/O communication and security requirements in the embedded virtualization environment.(3)To address the problem that the hypervisor loses the real-time information of the I/O of the guest VMs,the real-time information object is proposed in this thesis.The real-time information object carries the real-time information of the application,and the hypervisor can sense the I/O real-time information of the guest VMs through the real-time information object.Based on the real-time information provided by the real-time information object,this thesis designs and implements the corresponding real-time optimization algorithm.Finally,this thesis implements the I/O virtualization solution on the ARMv8 hardware platform,and designs and implements functional and performance tests respectively.These include functional tests of each interface and interrupt related to the I/O virtualization solution,and testing the overhead of interrupt and I/O processing mechanisms.The solution has been proven to satisfy the I/O functional requirements in a virtualized environment with high security and low overhead.