USENIX 2001 Abstract
Virtualizing I/O Devices on VMware Workstation's Hosted Virtual
Jeremy Sugerman, Ganesh Venkitachalam, and Beng-Hong Lim, VMware, Inc.
Virtual machines were developed by IBM in the 1960's to provide
concurrent, interactive access to a mainframe computer. Each
virtual machine is a replica of the underlying physical machine
and users are given the illusion of running directly on the
physical machine. Virtual machines also provide benefits like
isolation and resource sharing, and the ability to run multiple
flavors and configurations of operating systems.
VMware Workstation brings such
mainframe-class virtual machine technology to PC-based desktop and
This paper focuses on VMware Workstation's approach to
virtualizing I/O devices. PCs have a staggering variety of
hardware, and are usually pre-installed with an operating system.
Instead of replacing the pre-installed OS, VMware Workstation uses
it to host a user-level application (VMApp) component, as well as to
schedule a privileged virtual machine monitor (VMM) component. The
VMM directly provides high-performance CPU virtualization while the
VMApp uses the host OS to virtualize I/O devices and shield the VMM
from the variety of devices. A crucial question is whether
virtualizing devices via such a hosted architecture can meet the
performance required of high throughput, low latency devices.
To this end, this paper studies the virtualization and performance
of an Ethernet adapter on VMware Workstation. Results indicate
that with optimizations, VMware Workstation's hosted
virtualization architecture can match native I/O throughput on
standard PCs. Although a straightforward hosted implementation is
CPU-limited due to virtualization overhead on a 733 MHz
Pentium III system on a 100 Mb/s Ethernet, a series of
optimizations targeted at reducing CPU utilization allows the
system to match native network throughput. Further optimizations
are discussed both within and outside a hosted architecture.
- View the full text of this paper in
The Proceedings are published as a collective work, © 2001 by the USENIX Association. All Rights Reserved. Rights
to individual papers remain with the author or the author's employer.
Permission is granted for the noncommercial reproduction of the complete
work for educational or research purposes. USENIX acknowledges all
trademarks within this paper.
- If you need the latest Adobe Acrobat Reader, you can download it from Adobe's site.
- To become a USENIX Member, please see our Membership Information.