Abstract: This paper presents a priority-scheduled strategy for I/O Virtualization with a Driver Domain Grant Table Set mechanism. The optimized mechanism calculates the priority for each new I/O request based on different weight of both domains and resources required, and reschedules the Virtual I/O request queue. The experiment results show that this strategy improves the throughput while giving consideration to domains’ priorities and the Driver Domain Grant Table Set has greatly decreased the overheads on granting and mapping operation.