Research On Device Virtualization In Embedded System

Virtualization gains its wide attention and application on the x86platform, while itsapplication in platform of embedded system has just begun. The biggest challenge ofwhich is device virtualization. Most of traditional methods already proposed stressstabilization and security, while relatively paying less attention to performance.Against the features of embedded system, this essay means to give some idea aboutdevice virtualization of embedded system and propose a VMM-dominant (VirtualMachine Monitor, abbr. VMM) device virtualization in embedded system, based on thedevice virtualization in the platform of x86architecture and methods proposed in theplatform of embedded system. The method proposed here integrates all the drivers into theVMM and runs in the highest privileged mode with the VMM, and on the basis of whichthe method provides VMs with I/O interface through the hypercall mechanism, emulateshardware interrupt of VMs using event channel, with the help of shared memory andmemory-copy between VMs and the VMM, implementes device virtualization ofembedded system, achieve the purpose of sharing device among several VMs. Accordingto the method proposed by the essay, we designed and developed a new embeddedvirtualization system VNeo based on the open-source project Xen-ARM.As suggested by measurement, in case of one running Android VM, compared withnative Android, the total score of performance of reading and writing SD card decreasesby6.2%, the performance of drawing is approximate. In case of two running Android VM,compared with native Android, the total score of performance of reading and writing SDcard decreases by61.14%, which is half of that in case of one running Android VM, thetotal score of performance of drawing decreases by40.56%, which is also half of that incase of one running Android VM in general.