Research On Shared Resources Access Protocol With Multi-Operating Systems Based On Xen Hypervisor

As computer performance and the demand for real-time applications increase,real-time virtualization has become an important research direction.Xen,as a widely used virtualization platform,has gained wide attention in the field of real-time systems.Currently,the real-time scheduling algorithms proposed for Xen in virtualization environments and their corresponding schedulability analysis methods do not consider the impact of priority inversion caused by mutual exclusion of shared resources on system real-time performance.In order to further improve the real-time performance of virtualized systems,this thesis studies the shared resource access protocol among multiple systems in a virtualization environment.Firstly,this thesis defines the system model under which priority inversion blocking may occur when tasks access shared resources and the applicable shared resource access protocol,and obtains the design goals of the shared resource access protocol.Secondly,based on the design goals and the problem that the virtual machine monitor cannot perceive the priority of application layer tasks,this thesis designs and implements a task priority-aware mechanism and a shared resource access protocol among multiple operating systems in a virtualization environment.Finally,this thesis performs a real-time analysis of the designed shared resource access protocol.The main innovations and contributions of this thesis are as follows:(1)This thesis designs a task-aware scheduling mechanism to provide a feasible solution for perceiving the urgency of virtual machine tasks,addressing the problem that the virtual machine monitor cannot perceive task priorities.(2)Based on the Multi-Processor Ceiling Protocol(MPCP)protocol for multi-operating system shared resource access and the priority inversion problem,this thesis designs a shared resource access protocol for multi-operating system environments,effectively limiting the uncontrolled priority inversion blocking in shared resource access between systems.(3)For the problem of real-time evaluation of shared resource access,based on the parallel task model,a linear programming-based blocking time analysis method is proposed under federated scheduling.This method effectively reduces the upper bound of task blocking time by narrowing the feasible domain.Based on the response time analysis-based schedulability analysis method,a schedulability testing experiment is designed to effectively verify the real-time performance of the shared resource access protocol.