On Fri, Jan 18, 2019 at 05:05:59PM -0700, Logan Gunthorpe wrote: > However, this doesn't create the IOVA entries necessary for addresses > mapped this way to work when the IOMMU is enabled. Thus, when the > IOMMU is enabled, drivers relying on dma_map_resource() will trigger > DMAR errors. We see this when running ntb_transport with the IOMMU > enabled, DMA, and switchtec hardware.
Which resources do you plan to map? At least for PCIe P2P adding an address translation seems wrong to me. > > The implementation for intel_map_resource() is nearly identical to > intel_map_page(), we just have to re-create __intel_map_single(). > dma_unmap_resource() uses intel_unmap_page() directly as the > functions are identical. Instead of having two tiny wrappers I'd just revert 964f2311a6862f1fbcc044d0828ad90030928b7f if we need to pass a real physical address now.
