[dpdk-dev] [PATCH v4 1/1] vfio: modify spapr iommu support to use static window sizing

[Thomas Monjalon]

Ping for review please

20/10/2020 14:05, Thomas Monjalon:
> Anatoly, please could you review this patch?
> 
> 15/10/2020 19:23, 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>