On Thu, Mar 01, 2018 at 11:00:51PM +0000, Stephen Bates wrote: > > P2P is about offloading the memory and PCI subsystem of the host CPU > and this is achieved no matter which p2p_dev is used. Even within a device, memory attributes for its various regions may not be the same. There's a meaningful difference between writing to an NVMe CMB vs PMR, and a single device could have both. We don't want to lump these all together without knowing which region you're allocating from, right?