Messages in this thread | | | Date | Tue, 17 May 2022 10:13:24 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 2/5] iommu: Add blocking_domain_ops field in iommu_ops |
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On Tue, May 17, 2022 at 01:43:03PM +0100, Robin Murphy wrote:
> FWIW from my point of view I'm happy with having a .detach_dev_pasid op > meaning implicitly-blocked access for now.
If this is the path then lets not call it attach/detach please. 'set_dev_pasid' and 'set_dev_blocking_pasid' are clearer names.
> On SMMUv3, PASIDs don't mix with our current notion of > IOMMU_DOMAIN_IDENTITY (nor the potential one for > IOMMU_DOMAIN_BLOCKED), so giving PASIDs functional symmetry with > devices would need significantly more work anyway.
There is no extra work in the driver, beyond SMMU having to implement a blocking domain. The blocking domain's set_dev_pasid op simply is whatever set_dev_blocking_pasid would have done on the unmanaged domain.
identity doesn't come into this, identity domains should have a NULL set_dev_pasid op if the driver can't support using it on a PASID.
IMHO blocking_domain->ops->set_dev_pasid() is just a more logical name than domain->ops->set_dev_blocking_pasid() - especially since VFIO would like drivers to implement blocking domain anyhow.
Jason
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