On 01/08/2018 10:10, Jan Beulich wrote: >> Furthermore, on by default is the only reasonable option. Dom0 is >> specifically given cpu mappings of the reserved regions, therefore it >> should have matching IOMMU mappings. > I don't think I can uniformly agree with this: There are reserved > regions which specifically would better not have IOMMU mappings: > LAPIC, IO-APIC, MMCFG just to name things I can immediately > think of.
Right, but that's not what I said. For any CPU mapping, we should have a matching IOMMU mapping. This is how hardware behaves in a native system, and is how all operating systems are written to behave. Breaking this expectation will break software in unexpected ways. For the items you list there, we don't give dom0 CPU mappings (because restricting them is indeed a sensible thing), and the "matching" mapping in the IOMMU is also not present. ~Andrew _______________________________________________ Xen-devel mailing list [email protected] https://lists.xenproject.org/mailman/listinfo/xen-devel
