中文摘要：

虚拟化技术在实时嵌入式系统中的应用日趋广泛，但是目前虚拟化环境中常见的调度与负载均衡算法并不适用于硬实时系统中。为满足多核平台上虚拟化环境中对实时任务的支持，通过对Xen虚拟化环境中的SEDF调度算法进行改进，提供了一种在多核硬件平台下虚拟化环境中的准入控制与负载均衡算法。该算法能够保证每个处理器核上的工作量不会超载，并保证每个虚拟机中任务的实时性及其服务质量。算法实现较为简单、运行时开销较小。

英文摘要：

Virtualization technology is increasingly being applied to real time embedded systems, but traditional scheduling and load-balancing algorithms in todays virtualization environment are not applicable to hard real-time systems. In order to solve the problem of providing real-time guarantees to tasks in the Xen virtualization environment on a multicore hardware platform, the design and implementation of load-balancing and admission control algorithms within Xen are presented, by improving the Xen simple earliest deadline first （SEDF） scheduling algorithm. Our algorithms can ensure that the workload on each processor core does not cause overload, and reaLtime tasks in each virtual machine meet their deadlines and QoS requirements. The algorithms are simple to implement and have low runtime overheads.