PAGE404: Breaking GPU Isolation Through Hardware-assisted Page Migration
The Grace Hopper superchip uses hardware-assisted page migration to move frequently accessed memory pages between CPU and GPU DRAM for better performance. This system is vulnerable because shared access counters across Multi-Instance GPU (MIG) partitions allow covert communication. Researchers found two channels: one via counter eviction sets and another through migration delay variations, proving that hardware isolation in this new architecture is weak.