SR-IOV on ARM64 system with SMMU

[Martin Bayern]

hi Robin

Thank you so much for your support on this!

On 21.02.23 8:30 PM, Robin Murphy wrote:
> The only actual solution to that problem is to make the platform 
> device not be in the group to begin with. As mentioned, that is 
> presumably because the PCIe node in the DT has an "iommus = ..." 
> property (not to be confused with the "iommu-map" properties which are 
> for the PCI side). I'd expect you could probably get away with 
> removing that - the only reason I can imagine it being functionally 
> necessary is if the root complex has internal DMA engines that the 
> downstream kernel is using.
>
> But yeah, by that point it's arguably just an exercise in achieving 
> satisfaction by making *something* work, rather than a really 
> practical prospect

I search the keyword string "iommus" in NVIDIA Orin/Xavier related 
dts/dtsi, but there is no iommus attribute node, nor iommu-map. Relevant 
questions have been posted in the NVIDIA forum, and I hope NVIDIA can 
respond. Please let me know if you have any other thoughts/suggestions. 
I'm currently working on study of the drivers of smmu and iommu, trying 
to figure out the root cause of it.

kind regards,

Martin