Virtualization of reconfigurable coprocessors in HPRC systems with multicore architecture

HPRC (High-Performance Reconfigurable Computing) systems include multicore processors and reconfigurable devices acting as custom coprocessors. Due to economic constraints, the number of reconfigurable devices is usually smaller than the number of processor cores, thus preventing that a 1:1 mapping between cores and coprocessors could be achieved. This paper presents a solution to this problem, based on the virtualization of reconfigurable coprocessors. A Virtual Coprocessor Monitor (VCM) has been devised for the XtremeData XD2000i In-Socket Accelerator, and a thread-safe API is available for user applications to communicate with the VCM. Two reference applications, an IDEA cipher and an Euler CFD solver, have been implemented in order to validate the proposed architecture and execution model. Results show that the benefits arising from coprocessor virtualization outperform its overhead, specially when code has a significant software weight.