Memory bandwidth reservation in the cloud to avoid information leakage in the memory controller

Multiple virtual machines (VMs) are typically co-scheduled on cloud servers. Each VM experiences different latencies when accessing shared resources, based on contention from other VMs. This introduces timing channels between VMs that can be exploited to launch attacks by an untrusted VM. This paper focuses on trying to eliminate the timing channel in the shared memory system. Unlike prior work that implements temporal partitioning, this paper proposes and evaluates bandwidth reservation. We show that while temporal partitioning can degrade performance by 61% in an 8-core platform, bandwidth reservation only degrades performance by under 1% on average.