On Wed, May 09, 2018 at 04:30:32PM +0000, Stephen Bates wrote:
> Now inside that page table you can point GPU virtual address
> to use GPU memory or use system memory. Those system memory entry can
> also be mark as ATS against a given PASID.
Thanks. This all makes sense.
But do you have examples of this in a kernel driver (if so can you point me too it) or is
this all done via user-space? Based on my grepping of the kernel code I see zero EP
drivers using in-kernel ATS functionality right now...
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:
Lot of codes there. The GPU code details do not really matter for
this discussions thought. You do not need to do much to use PASID.