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. First, we discuss how we have leveraged novel hardware features in ARM processors to enhance the security and privacy of mobile systems with respect to their I/O devices. Second, we discuss how we have built 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. 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, virtualization, and trustworthy systems. His research involves building efficient and trustworthy 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.