On Thu, 30 Jan 2025 12:38:54 -0600, Gaurav Batra wrote:

iommu_mem_notifier() is invoked when RAM is dynamically added/removed. This
notifier call is responsible to add/remove TCEs from the Dynamic DMA Window
(DDW) when TCEs are pre-mapped. TCEs are pre-mapped only for RAM and not
for persistent memory (pmemory). For DMA buffers in pmemory, TCEs are
dynamically mapped when the device driver instructs to do so.

The issue is 'daxctl' command is capable of adding pmemory as "System RAM"
after LPAR boot. The command to do so is -

[...]

Applied to powerpc/next.

[1/1] powerpc/pseries/iommu: memory notifier incorrectly adds TCEs for pmemory
      https://git.kernel.org/powerpc/c/6aa989ab2bd0d37540c812b4270006ff794662e7

Thanks