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The segment is encoded in the > devid isn't it? This is per-segment because the AMD IOMMU device table is per-segment. > This seems like a sketchy design to me, is it impossible to atomically > change the viommu used devids once they start being used? It seems > like this should be doable > > If so the algorithm would be simpler, just maintain an xarray of all > dev ids, if the entry is marked as a VIOMMU and PCI needs it then move > the VIOMMU out of the way and use the entry for PCI. > > No need to try to guess what ranges are usable or not. Thanks for suggestion. I'm implementing this in V4. Suravee