Messages in this thread | | | Date | Thu, 28 Jul 2022 14:27:30 +0800 | From | Baolu Lu <> | Subject | Re: [PATCH v10 04/12] iommu: Add attach/detach_dev_pasid iommu interface |
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On 2022/7/28 10:44, Baolu Lu wrote: >> >> If the fabric routes PASID properly then groups are not an issue - all >> agree on this? > > I still think the singleton group is required, but it's not related to > the PCI fabric routing discussed here. > > We have a single array for PASIDs in the iommu group. All devices > sitting in the group should share a single PASID namespace. However both > the translation structures for IOMMU hardware or the device drivers can > only adapt to per-device PASID namespace. Hence, it's reasonable to > require the singleton group.
Further, conceptually, we cannot support pasid attach/detach on multi- device groups. If multiple devices cannot be isolated, it is difficult to ensure that their pasid spaces are isolated from each other. Therefore, it is wrong to attach a domain to the pasid of a device. All devices in the group must share a domain.
Best regards, baolu
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