On Mon, Mar 16, 2020 at 07:49:35PM +0100, Christoph Hellwig wrote: > On Mon, Mar 16, 2020 at 11:42:19AM -0700, Ralph Campbell wrote: > > > > On 3/16/20 10:52 AM, Christoph Hellwig wrote: > >> No driver has actually used properly wire up and support this feature. > >> There is various code related to it in nouveau, but as far as I can tell > >> it never actually got turned on, and the only changes since the initial > >> commit are global cleanups. > > > > This is not actually true. OpenCL 2.x does support SVM with nouveau and > > device private memory via clEnqueueSVMMigrateMem(). > > Also, Ben Skeggs has accepted a set of patches to map GPU memory after being > > migrated and this change would conflict with that. > > Can you explain me how we actually invoke this code? > > For that we'd need HMM_PFN_DEVICE_PRIVATE NVIF_VMM_PFNMAP_V0_VRAM > set in ->pfns before calling hmm_range_fault, which isn't happening. Ok, looks like the fault side is unused, but we need to keep the non-fault path in place. I'll fix up the patch.
