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If it is, means usually items are distinctive, so >>>> I would expect defining/listing them. If they are not distinctive, >>>> commit msg is incorrect. If the list is as simple as 1-to-1 channel >>>> mapping, just add it in the description how they are ordered. >>> >>> Yes, it is a 1-to-1 channel mapping to an IOMMU ID. The intent of making >>> it flexible is to allow non-consecutive IOMMU ID assignments as well. >>> This is particularly needed in virtualised environments where the >>> hypervisor may reserve certain stream IDs, and the guest VM can map only >>> the permitted ones. Shall I add a description here mentioning this >>> use-case? >> >> Isn't this already handled by the 'dma-channel-mask' property? The >> driver will skip over any channels that are not in specified by the mask. > > dma-channel-mask would not help if a channel is exposed, and the > corresponding IOMMU ID is not exposed. For instance say channel 15 is > available for a VM, but not the stream ID 0x80f. Is that a valid configuration? Above we said it is a 1-to-1 mapping which would imply the mapping is always constant. Ie. same channels maps to name SID. Is that not the case? Jon -- nvpublic