Abstract:
New I/O devices are rapidly emerging in computer systems. These devices include sensors and actuators in mobile systems and accelerators in datacenters. However, computer systems still treat these devices as second-class citizens, supporting them with ad hoc and poorly-developed system software. This challenges system reliability and security and hinders novel system services such as I/O sharing and virtualization.
 
We present our initial steps towards solving these challenges. Given that the fundamental service provided by many computer systems is I/O, we suggest that these systems should be treated as I/O servers that are accessible by software running anywhere. Towards this end, we introduce a novel split-stack boundary for remote access to I/O devices based on Unix device files and show that it achieves important properties of low engineering effort, support for legacy devices and applications, support for all the functions of I/O devices, and high performance. Moreover, we show that remote access at this boundary can be effectively used for I/O sharing between mobile systems and for I/O virtualization. We also present library drivers, a solution for enhancing the security of I/O servers by reducing the size and attack surface of the device driver Trusted Computing Base (TCB). We finally highlight new research directions as I/O devices are taking a central role in modern systems of various form factors.

Bio:
Ardalan Amiri Sani is an Assistant Professor in the Computer Science Department at the University of California, Irvine.
Ardalan's research interests are in the areas of mobile systems, operating systems, and virtualization. His research involves building efficient, high performance, and reliable system solutions. Recently, he has been working on the challenges and opportunities of the large number of Input and Output (I/O) devices appearing in modern computers from mobile systems to servers. His work on I/O sharing between mobile systems received the ACM MobiSys'14 best paper award. The systems that he has built for I/O sharing and virtualization are open source. He received his B.Sc. from Sharif University of Technology in 2008 and his M.Sc. and Ph.D. from Rice University in 2011 and 2015, respectively.