The performance density of modern hardware has forced the sharing of hardware resources across applications for better utilization and efficiency. Shared infrastructure, however, weakens isolation and risks interference, which can result in degraded performance and security breaches. This thesis explores the tension between isolation and sharing with three prototype systems: Xoar, Plastic, and Decibel. All three of these systems demonstrate the value of software mediation in providing isolation on shared hardware without sacrificing either hardware resource utilization or the performance of the underlying devices.
Xoar, Plastic, and Decibel provide isolation for different hardware resources: Xoar strengthens isolation between virtual machines, thereby allowing underutilized processors to be shared; Plastic transparently mitigates poor cache utilization and the performance artifacts caused by insufficient
cache line isolation across cores; and Decibel provides isolation in shared non-volatile storage and guarantees throughput, even in the face of competing workloads.Science, Faculty ofComputer Science, Department ofGraduat