嵌入式实时Hypervisor：XtratuM (1)

摘  要

本论文是作者对XtratuM Hypervisor进行学习和研究的工作总结，涵盖了作者为XtratuM Hypervisor所做的研究内容：中断管理、Hypercall、任务管理、虚拟内存管理等模块向不同Linux内核上的移植，域间通信工具、设备驱动模型的设计和实现，基于XtratuM Hypervisor的应用实例(冗余实时控制系统)开发,XtratuM Hypervisor系统的重要功能模块的评测和分析。

在XtratuM Hypervisor系统的研究过程中，文章实现了两种域间通信工具：命名管道(FIFO)和共享内存(SHM：Share Memory)。在命名管道和共享内存设计和实现中，文章采用了Hypercall，Lock-Free，内存映射等多种技术，从而保证任务之间可以进行可靠有效的实时通信。为了提高系统的可用性，使XtratuM能够支持外接设备，文章构建了一种适合XtratuM系统的设备驱动模型：XMDEV，基于该设备驱动模型，作者实现了实时串口设备驱动。另外，为了提高XtratuM对不同Linux内核的支持，文章对XtratuM系统相关中断管理、Hypervall、任务管理等重要模块进行了优化和功能扩展，目前为止，XtratuM运行的最高Linux版本是2.6.24.4。针对XtratuM Hypervisor的特点，作者设计和实现了冗余实时控制系统。该冗余实时控制系统采用软备份冗余技术，当主模块发生异常退出时，备份模块将会被调度并恢复主模块的运行环境。最后，为了直观的评估系统，文章对反映系统整体性能的中断延迟、调度延迟、Hypercall延迟、FIFO通信以及串口通信进行了测试和分析。

 

 

 

 

关键字: Hypervisor，准虚拟化，实时系统，XtratuM Hypervisor，准虚拟化，实时系统，XtratuM

ABSTRACT

This thesis is the summary by the author for the study and research of XtratuM Hypervisor. It covers all work contributed by the author to XtratuM Hypervisor, porting the interrupt management, hypercall, task management, virtual memory to kinds of linux kernels, designing and implementing inter-domain communication tools, device driver model, building a case study based on XtratuM Hypervisor: RRTCS(Redundant Real-Time Control System), as well as benchmarking main system components.

In the thesis, FIFO and SHM(SHare Memory) are built for XtratuM Hypervisor. FIFO and SHM are the effective inter-domain communication tools, playing important roles in data transmission and task synchronization. The hypercall, lock-free and memory mapping technologies are adopted to implement the FIFO and SHM. A device driver model is designed for XtratuM in the thesis. In order to make XtratuM support more real-time device drivers, XMDEV(XtratuM DEVice Driver Model) is designed and built. Based on XMDEV, the thesis interprets how to implement UART device driver. Moreover, to make XtratuM run on more and more Linux kernel, the interrupt management, hypercall, domain management modules are refined or updated. Meanwhile, in order to evaluate the system, the thesis did many benchmaarks and analysis, including interrupt latency, scheduler latency, hypercall latency, translation speed of FIFO and UART driver. RRTCS(Redundant Real-Time Control System) based on XtratuM Hypervisor is designed and implemented in the thesis to introduce the usage area for XtratuM Hypervisor system.

 

 

 

Keywords: Hypervisor, Paravirtualization, real-time system, XtratuM

 

 

目  录

摘  要... I

ABSTRACT.. II

目  录... III

第1章     绪 论... 1

1.1       研究现状... 1

1.2       研究意义... 4

1.3       研究内容... 7

1.4       文章结构... 10

第2章     XtratuM Hypervisor.. 12

2.1       系统结构... 12

2.2       中断管理... 14

2.3       Hypercall. 16

2.4       任务管理... 18

2.4.1        域任务... 18

2.4.2        调度器... 19

2.5       内存管理... 21

2.6       域间通信工具... 23

2.6.1        命名管道... 24

2.6.2        共享内存... 33

2.7       设备驱动模型... 35

2.7.1        模型架构... 36

2.7.2     UART驱动... 38

2.8       系统移植... 41

2.8.1        中断管理... 42

2.8.2        系统调用... 45

2.8.3        任务切换... 46

第3章     性能测试与分析... 50

3.1       中断延迟... 50

3.2       Hypercall调用延迟... 52

3.3       任务调度延迟... 54

3.4       FIFO传输速度... 55

3.5       串口设备通信速率... 56

第4章     实例设计和实现... 59

4.1       技术背景... 59

4.2       系统设计... 60

4.3       系统实现... 63

第5章     总结与展望... 69

参考文献... 72