On 6/24/25 16:33, Tian, Kevin wrote:
From: Lu Baolu baolu.lu@linux.intel.com Sent: Friday, June 20, 2025 2:08 PM
Commit <4f1492efb495> ("iommu/vt-d: Revert ATS timing change to fix boot failure") placed the enabling of ATS in the probe_finalize callback. This occurs after the default domain attachment, which is when the ATS cache tag is assigned. Consequently, the device TLB cache tag is missed when the domain is attached, leading to the device TLB not being invalidated in the iommu_unmap paths.
Fix it by moving the ATS enabling to the default domain attachment path, ensuring ATS is enabled before the cache tag assignment.
this means ATS will never be enabled for drivers with driver_managed_dma set to '1', as they don't expect their devices attached to the default domain automatically.
You are right.
does it make more sense sticking to current way (enabling ATS in probe_finalize) and assigning cache tag for device tlb at that point?
Yes. I will post v2 with this approach.
Thanks, baolu