On Tue, Sep 29, 2020 at 03:13:25PM -0300, Jason Gunthorpe wrote: > My eventual hope is to be able to send this DMA page list to the HW > without having to parse and copy it like is done today. We already > have it in a linear array that can be DMA'd from. > > However, the HW knows 0 means need-fault (the flag bits are zero), it > doesn't know what to do with DMA_MAPPING_ERROR.. I think you are falling into the same traps as the original hmm code. The above might be true for mlx5 hardware, but this is generic infrastructure. Making any assumptions about being able to directly pass it on to hardware is just futile. Nevermind such pesky things as endianess conversions.
