Remote Direct Memory Introspection
Hypervisors have played a critical role in cloud security, but they introduce a large trusted computing base (TCB) and incur a heavy performance tax. As of late, hypervisor offloading has become an emerging trend, where privileged functions are sunk into specially-designed hardware devices (e.g., Amazon's Nitro, AMD's Pensando) for better security with closer-to-baremetal performance. In light of this trend, this project rearchitects a classic security task that is often relegated to the hypervisor, memory introspection, while only using widely-available devices. Remote direct memory introspection (RDMI) couples two types of commodity programmable devices in a novel defense platform. It uses RDMA NICs for efficient memory access and programmable network devices for efficient computation, both operating at ASIC speeds. RDMI also provides a declarative language for users to articulate the introspection task, and its compiler automatically lowers the task to the hardware substrate for execution. Our evaluation shows that RDMI can protect baremetal machines without requiring a hypervisor, introspecting kernel state and detecting rootkits at high frequency and zero CPU overhead.