基于地址空间标识符的QEMU动态跳转优化

Optimization of Dynamic Jump Handling in QEMU Based on Address Space Identifier

随着硬件技术的不断演进和软件需求的持续增长,人们对以QEMU为代表的指令集架构仿真平台的执行性能提出了更高的要求.本文针对目标架构支持虚拟内存的场景,分析了QEMU现有动态跳转处理机制及其存在的问题,根据常见虚拟内存系统的特点提出了基于地址空间标识符的动态跳转优化方案,并以RISC-V为目标架构在QEMU主线6.2.0版本上实现了该方案.实验表明,相较于原生QEMU,基于地址空间标识符的动态跳转方案提升了约12%的运行性能.

The continuous evolution of hardware and software technology demands higher execution performance from instruction set architecture emulators represented by QEMU. This study analyzes the limitations of QEMU’s existing dynamic jump handling mechanism in the scenario where the emulated architecture supports virtual memory, and proposes an optimized scheme based on address space identifiers suitable for common virtual memory systems. The proposed scheme is implemented for the RISC-V frontend in QEMU mainline 6.2.0 version. Evaluation results show that the dynamic jump scheme based on the address space identifier achieves an average performance improvement of 12%compared to the native QEMU.