On Mon, Jul 29, 2019 at 05:25:35PM +0530, Sreekanth Reddy wrote: > > I agree with your above statement. But it is also possible that > 0xFFFFFFFF-FFFFFFFF falls under the DMA able range, e.g. SGE's start > address is 0xFFFFFFFF-FFFF000 and data length is 0x1000 bytes. So when > HBA tries to DMA the data at 0xFFFFFFFF-FFFFFFFF location then it will > faults the firmware due to it's hardware design. > > We have observed above example's SGE address and length on AMD systems > with SME & IOMMU enabled. Ok. Please slightly update the changelog to say dma ranges instead of a dma address, as that implicies the addr field in the sg to me. Otherwise looks ok: Reviewed-by: Christoph Hellwig <hch@xxxxxx>