Design And Implementation Of Safe Device Driver Module Based On Virtual Machine Technology

In modern operating systems, many faults are due to unreliable kernelextensions, especially device drivers. In monolithic kernel design, these faultscan bring kernel down easily. Studies have shown that isolation of driversfrom other parts of kernel can effectively reduce kernel crash. In this paper,we have proposed a new architecture of device drivers– drivers run in user-mode java virtual machine (JVM). Therefore, they are taken out of kernel intoan independent user process, and isolated not only from kernel but also fromother user processes. JVM can capture faults in drivers, and handle themappropriately. Therefore, unreliable drivers are prevented from ruining thewhole kernel. Meanwhile, JVM also provides a universal platform for devicedriver execution. This architecture ensures that one copy of driver can run ondifferent underlying platforms which proposes a reusable driver architecture.We implement a prototype by porting USB protocol stack of Linux intothis architecture. In the whole process, we kept struggling a balance betweensystem safety and performance. We also use object-orient design conceptto implement the device drivers in JVM. This method provides an extensibledriver framework and also ensures easy maintainability. Evaluation of the sys-tem under buggy device drivers has shown great improvement of the stabilityand safety with acceptable performance overhead.In sum, this paper has proposed an safe device driver architecture witha good performance. It is a creative framework that using virtual machinetechnology to provide both a fault isolation and a universal execution domain.