Hi Felix, On Tue, Mar 09, 2021 at 11:30:19AM -0500, Felix Kuehling wrote: > > I think the proper fix would be to not rely on custom hooks into a particular > > IOMMU driver, but to instead ensure that the amdgpu driver can do everything > > it needs through the regular linux/iommu.h interfaces. I realize this > > is more work, > > but I wonder if you've tried that, and why it didn't work out. > > As far as I know this hasn't been tried. I see that intel-iommu has its > own SVM thing, which seems to be similar to what our IOMMUv2 does. I > guess we'd have to abstract that into a common API. The common API was added in 26b25a2b98e4 and implemented by the Intel driver in 064a57d7ddfc. To support it an IOMMU driver implements new IOMMU ops: .dev_has_feat() .dev_feat_enabled() .dev_enable_feat() .dev_disable_feat() .sva_bind() .sva_unbind() .sva_get_pasid() And a device driver calls iommu_dev_enable_feature(IOMMU_DEV_FEAT_SVA) followed by iommu_sva_bind_device(). If I remember correctly the biggest obstacle for KFD is the PASID allocation, done by the GPU driver instead of the IOMMU driver, but there may be others. Thanks, Jean _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
