Research And Implement Of Code Cache Management Policy In QEMU Emulator

Nowadays, binary translation has become an important method to implement codemigration through software. As the research on binary translation and relatedoptimization, have significant meaning in many fields such as code migration, virtualmachine, network application, computer security and hardware development, it hasbecome a hot issue in modern computer development field.In general, binary translator is divided into three kinds: the interpreter, the staticbinary translator and the dynamic binary translator. The interpreter translates oneinstruction one time and executes it immediately and does not store results, the staticbinary translator translates and analyzes the binary codes statically, and generatesoptimized native codes. On the other hand, dynamic binary translator execute thetranslated codes and translate them on the same time. It gathers the profile informationto optimize it, and store the translated code blocks. When these blocks are executedagain, they can be found in code cache. In dynamic binary translator, the sub-systemwhich is used to cache the code blocks is called Translated Code Cache.This thesis introduces the background and three means of binary translationfirstly.And then it introduces the QEMU platform. It focus on the research about thedesign and implement of the high efficient Translated Code Cache system of QEMUbinary translator to store translated code blocks. The research involves the factorsinfluencing the performance including the hit time,miss penalty and miss rate.On theother hand, it researches the self-allocation, the block allocation, and the replacement ofcode cache. By introducing existed replacement algorithm on the DBT systems andcomparing their performance, this thesis proposes the Translated Code Cachereplacement algorithm for QEMU platform according to its requirement.The two newalogrithms integrate the strongness of flush scheme,FIFO scheme and flush scheme,LRU scheme. We perform the experiment in the system mode, and also verify thereplacement algorithm by using the SPEC CPU2006program. The experimental resultsshows a good management scheme will improve the system performance. Besides, the replacement algorithm proposed in this thesis has great reference value for other DBTsystems.