Customizable Multimedia Devices in Virtual Environments Ankur Pai, Balasubramanian Seshasayee, Himanshu Raj and Karsten Schwan Center for Experimental Research in Computer Systems Georgia Institute of Technology Atlanta, Georgia 30332–0250 fpaiankur, bala, rhim,
[email protected] Abstract—The separation of logical from physical devices maintain a consistent view of physical devices by presenting provided by modern virtualization techniques can be used to only a common minimal set of device features is too limiting enhance device functionality, including by emulating non-native and worse, it cannot account for changes in the environmental device functions in software. Such logically extended devices are particularly promising in the mobile domain, for embedded conditions or contexts in which devices are used. machines, handhelds, or phones. Challenges arise, however, from We argue that device sharing and interoperation in mobile the highly heterogeneous nature of portables and the devices with systems requires models and interfaces with which virtual- which they can interact. This suggests that device extensions ization infrastructures can dynamically change device func- should be dynamic, varied at runtime to adjust to new user needs and/or changes in environmental conditions. This paper tionality to account for runtime changes in device use, con- presents a model for runtime device extension and for then using ditions, and contexts. This paper presents such a model. It such extended devices. The model provides uniform interfaces to implements the safe, runtime extension of device functionality, native and extended devices, permits the safe runtime extension by enabling the virtualization layer, guest operating systems, of device functionality, and can be shown to operate across both or applications to safely specify and deploy custom code that stationary and mobile platforms, and arbitrary operating systems and applications.