Messages in this thread | | | Date | Mon, 24 Jan 2022 13:44:04 -0400 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 0/7] iommu cleanup and refactoring |
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On Mon, Jan 24, 2022 at 09:46:26AM +0000, Tian, Kevin wrote: > > From: Lu Baolu <baolu.lu@linux.intel.com> > > Sent: Monday, January 24, 2022 3:11 PM > > > > Hi, > > > > The guest pasid and aux-domain related code are dead code in current > > iommu subtree. As we have reached a consensus that all these features > > should be based on the new iommufd framework (which is under active > > development), the first part of this series removes and cleanups all > > the dead code. > > > > The second part of this series refactors the iommu_domain by moving all > > domain-specific ops from iommu_ops to a new domain_ops. This makes an > > iommu_domain self-contained and represent the abstraction of an I/O > > translation table in the IOMMU subsystem. With different type of > > iommu_domain providing different set of ops, it's easier to support more > > types of I/O translation tables. > > You may want to give more background on this end goal. In general there > are four IOPT types in iommufd discussions: > > 1) The one currently tracked by iommu_domain, with a map/unmap semantics > 2) The one managed by mm and shared to iommu via sva_bind/unbind ops > 3) The one managed by userspace and bound to iommu via iommufd (require nesting) > 4) The one managed by KVM (e.g. EPT) and shared to iommu via a TBD interface
Yes, at least from an iommufd perspective I'd like to see one struct for all of these types, mainly so we can have a uniform alloc, attach and detatch flow for all io page table types.
If we want to use the iommu_domain, or make iommu_domain a sub-class of a new struct, can be determined as we go along.
Regardless, I think this cleanup stands on its own. Moving the ops and purging the dead code is clearly the right thing to do.
Thanks, Jason
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