On Wed, Sep 10, 2025 at 11:20:08AM +0800, Qinxin Xia wrote:

Ok, I see, my colleague Wang Zhou also released a version of io_ptdump
a long time ago, which is implemented in smmu debugfs. Will recommends that
io_ptdump be implemented in a way similar to CPU page table dump. Using
debugfs to expose the data and using format-specific callbacks to implement
specific data dumps, I'll talk to him about this as well.

I feel we should have a iommu subsystem debugfs and per-iommu_domain
directories to dump the page tables.

The smmu debugfs can report what iommu_domains each STE/CD is
referencing.

This also needs RCU freeing of page table levels as a locking
strategy.

Jason