Re: [PATCH 1/2] iommu: Add __iommu_debug_unmap_phys() to drop refs by physical address

[Jason Gunthorpe]

On Thu, Aug 27, 2026 at 10:58:54PM +0800, Yuanhe Shu wrote:
> The IOMMU_DEBUG_PAGEALLOC sanitizer takes a reference on each page at
> iommu_map() time, keyed by physical address, and the only way to drop
> them is the IOVA based iommu_debug_unmap_begin()/end().  A path that
> tears down a page table with mappings still installed has no IOVA to
> unmap with, so add a physical address based counterpart of
> __iommu_debug_map() for those paths, sharing the counting loop through
> __iommu_debug_update_phys().

This is not right. The following patch has the iova:

+                               iommu_debug_unmap_phys(&iommu_table->domain,
+                                                      pt_entry_oa(&pts), oasz);

Every pts has the iova of its current iteration location. Call
pt_index_to_va() and then pts->range->va is the current spot.

Jason