|
USENIX 2nd Symposium on
OS Design and Implementation (OSDI '96)
Microkernels Meet Recursive Virtual Machines
Bryan Ford,
Mike Hibler,
Jay Lepreau,
Patrick Tullmann,
Godmar Back and
Stephen Clawson
University of Utah
Abstract
This paper describes a novel approach to providing modular and
extensible operating system functionality and encapsulated
environments based on a synthesis of microkernel and virtual machine
concepts. We have developed a software-based virtualizable
architecture called Fluke that allows recursive virtual machines
(virtual machines running on other virtual machines) to be implemented
efficiently by a microkernel running on generic hardware. A complete
virtual machine interface is provided at each level; efficiency
derives from needing to implement only new functionality at each
level. This infrastructure allows common OS functionality, such as
process management, demand paging, fault tolerance, and debugging
support, to be provided by cleanly modularized, independent, stackable
virtual machine monitors, implemented as user processes. It can also
provide uncommon or unique OS features, including the above features
specialized for particular applications' needs, virtual machines
transparently distributed cross-node, or security monitors that allow
arbitrary untrusted binaries to be executed safely. Our prototype
implementation of this model indicates that it is practical to
modularize operating systems this way. Some types of virtual machine
layers impose almost no overhead at all, while others impose some
overhead (typically 0--35%), but only on certain classes of
applications.
|
Need help? Use our Contacts page.
Conference Index