On Tue, Jun 22, 2021 at 6:28 PM Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > On Tue, Jun 22, 2021 at 05:24:08PM +0200, Christian König wrote: > > > > > I will take two GAUDI devices and use one as an exporter and one as an > > > > importer. I want to see that the solution works end-to-end, with real > > > > device DMA from importer to exporter. > > > I can tell you it doesn't. Stuffing physical addresses directly into > > > the sg list doesn't involve any of the IOMMU code so any configuration > > > that requires IOMMU page table setup will not work. > > > > Sure it does. See amdgpu_vram_mgr_alloc_sgt: > > > > amdgpu_res_first(res, offset, length, &cursor); > ^^^^^^^^^^ > > I'm not talking about the AMD driver, I'm talking about this patch. > > + bar_address = hdev->dram_pci_bar_start + > + (pages[cur_page] - prop->dram_base_address); > + sg_dma_address(sg) = bar_address; > > Jason Yes, you are correct of course, but what will happen Jason, If I will add a call to dma_map_resource() like Christian said ? Won't that solve that specific issue ? That's why I want to try it... Oded
