[dpdk-dev] [PATCH v6 1/1] vfio: modify spapr iommu support to use static window sizing

Thomas Monjalon thomas at monjalon.net
Mon Nov 9 22:10:40 CET 2020


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 <drc at linux.vnet.ibm.com>

Did you remove Anatoly's ack on purpose?
He must review the patch again?





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