Research And Implement On Mechanism Of Memory Management In Virtual Machine Monitor

Computing system of virtualization provide a dynamic approach to organize the resource of computer, it can eliminate relationship of dependence between architecture of hardware and software system, it can also construct a computing environment that meet many requirement of different application, therefor it can enhance the efficiency of resource in computer.Virtualization has to be an important direction to the development of technology of computer in future, Virtual Machine Monitor(VMM) is the base when implementing virtualization.Memory as one of the most importance resource in computing system, it has two problems in system of virtualization. Firstly, memory often faces lacking in quantity and low efficiency when using. Secondly, VMM needs to provide a indistinctive executing environment compared with physical machine for Guest Operating System, thereby ensure that Guest Operating System can accomplish detecting and management to memory with its original manner. So VMM need to provide a reasonable and effective mechanism to solve two problems associate with memory mentioned above.In the frame of a VMM based cooperation model,this thesis designe and implement several memory managers aiming at the request of memory management in this model, avoiding vice in two quomodoes of memory management mentioned above. The four contributions of this thesis are that:First, various quomodoes of memory management existing can not meet special needing of the VMM based cooperation model, this thesis implement isolation and intercommunion in aspect of memory resource between double systems adopting approach of partition management.Second, arithmetic of buddy has its limitation in manner of combination for page blocks, it is easy products fragment, this thesis adopts an approach in which memory blocks of arbitrary neighbor can be combined, thus decrease the amount of small memory blocks, so as to improve the efficiency of allocation.Third, current allocator of slab has certain shortage, this thesis adopts an adapted kernel memory management of slab, and decrease waste of memory during the course of combination between VMM and IOPM.Fourth, two blue print of memory virtualization are achieved based shadow page and Extended Page Table in this thesis, and it adopts a mechanism of dynamic adjustment, thus improving efficiency of memory usage.Physical memory manager, kernel memory manager, and memory virtualization are designed and implemented in the prototype system of VMM this thesis, and strategy of memory management is tested aiming at efficiency. The result shows that interrelated task in this thesis can meet various need of VMM in memory, and have upper efficiency in memory management of general and memory virtualization.