The Taub Faculty of Computer Science Events and Talks

Machine virtualization, where many virtual machines run on a single physical machine, has become an increasingly popular area of research and development in the last decade. Despite the introduction of hardware support for machine virtualization in commodity servers, many workloads still suffer from degraded performance when run in virtual machines. This degradation can be particularly acute when an unmodified virtual machine -- a VM that is not aware it is running in a virtual environment -- is used to run the workload. The degradation is is caused primarily by the lack of physical hardware transparency: instead of exposing the underlying physical hardware transparently to virtual machines, the hypervisor -- the software layer that controls the virtual machines -- usually exposes hardware "abstractions" instead. This talk will present results from two recent projects that improved VM performance by increasing physical transparency: the first increased device emulation throughput threefold using sidecore emulation, and the second improved I/O throughput by 30%-60% using direct interrupt delivery to VMs. Joint work with Muli Ben-Yehuda, Abel Gordon, Nadav Har'El, Alex Landau, Assaf Schuster, and Dan Tsafrir.