On Tue, Nov 18, 2025 at 09:30:29AM +0800, Chaoyi Chen wrote:

Hello Jason,

On 11/7/2025 4:34 AM, Jason Gunthorpe wrote:

quoted

report_iommu_fault() is an older API that has been superseded by
iommu_report_device_fault() which is capable to support PRI.

Only two external drivers consume this, drivers/remoteproc and
drivers/gpu/drm/msm. Ideally they would move over to the new APIs, but for
now protect against accidentally mix and matching the wrong components.

The iommu drivers support either the old iommu_set_fault_handler() via the
driver calling report_iommu_fault(), or they are newer server focused
drivers that call iommu_report_device_fault().

Include a flag in the iommu_ops if the driver calls report_iommu_fault()
and block iommu_set_fault_handler() for domain's of iommu drivers that
can't support it.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>

Sorry for the noise. Sometimes non-IOMMU drivers, such as DRM
devices, also want to handle IOMMU fault events, so they might use
iommu_set_fault_handler() before. What API should they use as an
alternative now?

The new flow is through iommu_report_device_fault() which an end user
can access by setting domain->iopf_handler currently.

Jason