On Tue, Mar 17, 2020 at 09:15:36AM -0300, Jason Gunthorpe wrote: > > Getting rid of HMM_PFN_DEVICE_PRIVATE seems reasonable to me since a driver can > > look at the struct page but what if a driver needs to fault in a page from > > another device's private memory? Should it call handle_mm_fault()? > > Isn't that what this series basically does? > > The dev_private_owner is set to the type of pgmap the device knows how > to handle, and everything else is automatically faulted for the > device. > > If the device does not know how to handle device_private then it sets > dev_private_owner to NULL and it never gets device_private pfns. > > Since the device_private pfn cannot be dma mapped, drivers must have > explicit support for them. No, with this series (and all actual callers before this series) we never fault in device private pages.
