09/11/2020 21:35, David Christensen: > The SPAPR IOMMU requires that a DMA window size be defined before memory > can be mapped for DMA. Current code dynamically modifies the DMA window > size in response to every new memory allocation which is potentially > dangerous because all existing mappings need to be unmapped/remapped in > order to resize the DMA window, leaving hardware holding IOVA addresses > that are temporarily unmapped. The new SPAPR code statically assigns > the DMA window size on first use, using the largest physical memory > memory address when IOVA=PA and the highest existing memseg virtual > address when IOVA=VA. > > Signed-off-by: David Christensen <d...@linux.vnet.ibm.com>
Did you remove Anatoly's ack on purpose? He must review the patch again?