Discreet-PARA: Rowhammer Defense with Low Cost and High Efficiency

Abstract

DRAM rowhammer attack is a severe security concern on computer systems using DRAM memories. A number of defense mechanisms have been proposed, but all with short-coming in either performance overhead, storage requirement, or defense strength. In this paper, we present a novel design called discreet-PARA. It creatively integrates two new components, namely Disturbance Bin Counting (DBC) and PARA-cache, into the existing PARA (Probabilistic Adjacent Row Activation) defense. The two components only require small counter and cache storages but can eliminate or significantly reduce the performance overhead of PARA. Our evaluation using SPEC CPU2017 workloads confirms that discreet-PARA can achieve very high defense strength with a performance overhead much lower than the original PARA.