Hi Jerome
> As it is tie to PASID this is done using IOMMU so looks for caller
> of amd_iommu_bind_pasid() or intel_svm_bind_mm() in GPU the existing
> user is the AMD GPU driver see:
Ah thanks. This cleared things up for me. A quick search shows there are still
no users of intel_svm_bind_mm() but I see the AMD version used in that GPU
driver.
One thing I could not grok from the code how the GPU driver indicates which DMA
events require ATS translations and which do not. I am assuming the driver
implements someway of indicating that and its not just a global ON or OFF for
all DMAs? The reason I ask is that I looking at if NVMe was to support ATS what
would need to be added in the NVMe spec above and beyond what we have in PCI
ATS to support efficient use of ATS (for example would we need a flag in the
submission queue entries to indicate a particular IO's SGL/PRP should undergo
ATS).
Cheers
Stephen
