Caching Techniques for Security Metadata in Integrity-Protected Fabric-Attached Memories

The constant need for larger memories and the diversity of workloads have driving the system vendors away from the conventional processor-centric architecture into a memory-centric architecture. Memorycentric architecture, allows multiple computing nodes to connect to a huge shared memory pool and access it directly. To improve the performance, each node uses a small local memory to cache the data. These architectures introduces several problems when memory encryption and integrity verification are implemented. For instance, using a single integrity tree to protect both memories can introduce unnecessary overheads. Therefore, we propose Split-Tree, which implements two separate integrity tree for each memory. Later, we analyze the system performance, and the security metadata caches behavior when separate trees are used. We use the gathered insights to improve the security metadata caching for the separate trees and ultimately improve the system performance.