From: Lu Baolu baolu.lu@linux.intel.com Sent: Thursday, April 24, 2025 11:41 AM
The idxd driver attaches the default domain to a PASID of the device to perform kernel DMA using that PASID. The domain is attached to the device's PASID through iommu_attach_device_pasid(), which checks if the domain->owner matches the iommu_ops retrieved from the device. If they do not match, it returns a failure.
if (ops != domain->owner || pasid == IOMMU_NO_PASID) return -EINVAL;The static identity domain implemented by the intel iommu driver doesn't specify the domain owner. Therefore, kernel DMA with PASID doesn't work for the idxd driver if the device translation mode is set to passthrough.
Generally the owner field of static domains are not set because they are already part of iommu ops. Add a helper domain_iommu_ops_compatible() that checks if a domain is compatible with the device's iommu ops. This helper explicitly allows the static blocked and identity domains associated with the device's iommu_ops to be considered compatible.
Fixes: 2031c469f816 ("iommu/vt-d: Add support for static identity domain") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220031 Cc: stable@vger.kernel.org Suggested-by: Jason Gunthorpe jgg@nvidia.com Link: https://lore.kernel.org/linux- iommu/20250422191554.GC1213339@ziepe.ca/ Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Reviewed-by: Dave Jiang dave.jiang@intel.com Reviewed-by: Robin Murphy robin.murphy@arm.com
Reviewed-by: Kevin Tian kevin.tian@intel.com