Messages in this thread | | | Date | Wed, 18 May 2022 14:43:33 +0800 | Subject | Re: [PATCH 2/5] iommu: Add blocking_domain_ops field in iommu_ops | From | Baolu Lu <> |
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On 2022/5/17 21:13, Jason Gunthorpe wrote: > 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.
Sure. And with the blocking domain implemented, the set_dev_blocking_pasid could be deprecated.
> >> 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.
Perhaps implementing blocking domains for intel and smmuv3 iommu drivers seem to be a more practical start.
Best regards, baolu
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