Hardware Accelerated Cross-Architecture Full-System Virtualization

Hardware virtualization solutions provide users with benefits ranging from application isolation through server consolidation to improved disaster recovery and faster server provisioning. While hardware assistance for virtualization is supported by all major processor architectures, including Intel, ARM, PowerPC & MIPS, these extensions are targeted at virtualization of the same architecture, e.g. an x86 guest on an x86 host system. Existing techniques for cross-architecture virtualization, e.g. an ARM guest on an x86 host, still incur a substantial overhead for CPU, memory and I/O virtualization due to the necessity for software emulation of these mismatched system components. In this article we present a new hardware accelerated hypervisor called CAPTIVE, employing a range of novel techniques, which exploit existing hardware virtualization extensions for improving the performance of full-system cross-platform virtualization. We illustrate how (1) guest MMU events and operations can be mapped onto host memory virtualization extensions, eliminating the need for costly software MMU emulation, (2) a block-based DBT engine inside the virtual machine can improve CPU virtualization performance, (3) memory mapped guest I/O can be efficiently translated to fast I/O specific calls to emulated devices, and (4) the cost for asynchronous guest interrupts can be reduced. For an ARM-based Linux guest system running on an x86 host with Intel VT support we demonstrate application performance levels, based on SPEC CPU2006 benchmarks, of up to 5.88x over state-of-the-art QEMU and 2.5x on average, achieving a guest dynamic instruction throughput of up to 1280 MIPS and 915.52 MIPS, on average

Técnicas para emulação de saltos indiretos em máquinas virtuais

Orientador: Edson BorinDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Tradução dinâmica de binários é uma técnica de emulação comumente utilizada na implementação de máquinas virtuais. Neste contexto, a emulação de saltos indiretos é uma das principais fontes de perda de eficiência, o que atrapalha a aplicabilidade de tradutores dinâmicos de binários. Essa dissertação descreve diversas técnicas que tentam melhorar o desempenho e a eficiência da emulação de saltos indiretos em máquinas virtuais eficientes. O DynamoRIO é uma máquina virtual que se enquadra nessa categoria e que utiliza características de diversas dessas técnicas. Nessa dissertação, nós apresentamos a implementação atual do DynamoRIO, modificamos seu código para incluir duas novas técnicas de emulação de saltos indiretos (Inline Caching e IBTC) e as comparamos com outras técnicas descritas na literaturaAbstract: Dynamic binary translation is an emulation technique commonly employed in the implementation of virtual machines. One of the main sources of overhead that hinder the applicability of dynamic binary translators is that caused by the emulation of indirect branch instructions. This master thesis describes several techniques that try to improve the performance and efficiency of indirect branch emulation in efficient virtual machines. DynamoRIO is one of such machines and it implements features used by several of those techniques. In this master thesis, we present current implementations of DynamoRIO, modify its code to include two new techniques (Inline Caching and IBTC) and compare it with other techniques described in the literatureMestradoCiência da ComputaçãoMestre em Ciência da Computaçã