title: Does Epyc 2 have an equivalent to DDIO?
body: <p>Does Epyc 2 (Rome) (specifically a 7402P in my case) have anything equivalent to Intel's DDIO, where PCIe devices doing DMA can transfer directly to last-level cache? Or do DMA accesses all go directly to DRAM? What happens if it's a DMA write and the data is already present in some caches in the system?</p>