[lvc-project] [PATCH] iommu: fix crash in report_iommu_fault()

[Jason Gunthorpe]

On Thu, Apr 10, 2025 at 05:29:51AM +0000, Tian, Kevin wrote:

> It sounds a general requirement to all IOMMU drivers, but in reality
> only a subset of iommu drivers call it (e.g. intel/smmuv3 don't). So
> there seems to be an implicit assumption from drivers on whether
> the underlying IOMMU provides such facility...

Yeah, it's a bit wonky. And a different intersection calls the new
fault handling API instead :\

There are only 3 things using iommu_set_fault_handler():
 - drivers/gpu/drm/msm
   Seems to actually do restartable page faulting?? Maybe it needs to
   move to the PRI API..

 - drivers/infiniband/hw/usnic
   This just prints a log, we should remove it

 - drivers/remoteproc
   This prints a log and does some crash_handler

I just quickly typed in a small series to improve on this..

Jason