Messages in this thread | | | Date | Thu, 9 Jun 2022 20:53:03 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v8 01/11] iommu: Add max_pasids field in struct iommu_device |
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On Thu, Jun 09, 2022 at 05:25:42PM +0000, Raj, Ashok wrote: > > On Tue, Jun 07, 2022 at 09:49:32AM +0800, Lu Baolu wrote: > > Use this field to keep the number of supported PASIDs that an IOMMU > > hardware is able to support. This is a generic attribute of an IOMMU > > and lifting it into the per-IOMMU device structure makes it possible > > There is also a per-device attribute that tells what width is supported on > each device. When a device enables SVM, for simplicity we were proposing to > disable SVM on devices that don't support the full width, since it adds > additional complexity on the allocation interface. Is that factored into > this?
I would like to see the concept of a 'global PASID' and this is the only place we'd union all the per-device limits together. SVM can optionally use a global PASID and ENQCMD requires it, but I don't want to see the core code assuming everything is ENQCMD.
Jason
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