Hi Jason, On Wed, 11 May 2022 13:12:37 -0300, Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > On Wed, May 11, 2022 at 08:35:18AM -0700, Jacob Pan wrote: > > > > Huh? The intel driver shares the same ops between UNMANAGED and DMA - > > > and in general I do not think we should be putting special knowledge > > > about the DMA domains in the drivers. Drivers should continue to treat > > > them identically to UNMANAGED. > > > > > OK, other than SVA domain, the rest domain types share the same default > > ops. I agree that the default ops should be the same for UNMANAGED, > > IDENTITY, and DMA domain types. Minor detail is that we need to treat > > IDENTITY domain slightly different when it comes down to PASID entry > > programming. > > I would be happy if IDENTITY had its own ops, if that makes sense > I have tried to have its own ops but there are complications around checking if a domain has ops. It would be a logic thing to clean up next. > > If not global, perhaps we could have a list of pasids (e.g. xarray) > > attached to the device_domain_info. The TLB flush logic would just go > > through the list w/o caring what the PASIDs are for. Does it make sense > > to you? > > Sort of, but we shouldn't duplicate xarrays - the group already has > this xarray - need to find some way to allow access to it from the > driver. > I am not following, here are the PASIDs for devTLB flush which is per device. Why group? We could retrieve PASIDs from the device PASID table but xa would be more efficient. > > > > Are you suggesting the dma-iommu API should be called > > > > iommu_set_dma_pasid instead of iommu_attach_dma_pasid? > > > > > > No that API is Ok - the driver ops API should be 'set' not > > > attach/detach > > Sounds good, this operation has little in common with > > domain_ops.dev_attach_pasid() used by SVA domain. So I will add a new > > domain_ops.dev_set_pasid() > > What? No, their should only be one operation, 'dev_set_pasid' and it > is exactly the same as the SVA operation. It configures things so that > any existing translation on the PASID is removed and the PASID > translates according to the given domain. > > SVA given domain or UNMANAGED given domain doesn't matter to the > higher level code. The driver should implement per-domain ops as > required to get the different behaviors. Perhaps some code to clarify, we have sva_domain_ops.dev_attach_pasid() = intel_svm_attach_dev_pasid; default_domain_ops.dev_attach_pasid() = intel_iommu_attach_dev_pasid; Consolidate pasid programming into dev_set_pasid() then called by both intel_svm_attach_dev_pasid() and intel_iommu_attach_dev_pasid(), right? Thanks, Jacob
