Messages in this thread | | | Date | Tue, 22 Jun 2021 12:28:27 -0300 | From | Jason Gunthorpe <> | Subject | Re: [Linaro-mm-sig] [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF |
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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
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