Is it reasonable for ATS Invalidate Completion to check its RID width and report an fault if it is wider than that supported by the IOMMU mode？

riscv-non-isa / riscv-iommu

RISC-V IOMMU Specification

https://jira.riscv.org/browse/RVG-55

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Is it reasonable for ATS Invalidate Completion to check its RID width and report an fault if it is wider than that supported by the IOMMU mode？ #333

Closed wangyongzhen0322 closed 1 month ago

wangyongzhen0322 commented 1 month ago

There is no related check in the c_model. And if the fault is reported , will it be useful?

ved-rivos commented 1 month ago

If an IOMMU receives a invalidation completion where the combination of RID and iTAG does not match an outstanding invalidation then such messages are ignored. An IOMMU cannot receive a RID wider than its maximum supported width as these messages are received over a hardware bus from the root port.