On Wed, Jun 26, 2019 at 12:31:08PM -0600, Logan Gunthorpe wrote: > > we have a hole behind len where we could store flag. Preferably > > optionally based on a P2P or other magic memory types config > > option so that 32-bit systems with 32-bit phys_addr_t actually > > benefit from the smaller and better packing structure. > > That seems sensible. The one thing that's unclear though is how to get > the PCI Bus address when appropriate. Can we pass that in instead of the > phys_addr with an appropriate flag? Or will we need to pass the actual > physical address and then, at the map step, the driver has to some how > lookup the PCI device to figure out the bus offset? Yes, I think we'll need a lookup mechanism of some kind.