> From: Ethan Zhao <haifeng.zhao@xxxxxxxxxxxxxxx> > Sent: Thursday, December 28, 2023 8:17 AM > > @@ -181,6 +181,7 @@ static void __flush_svm_range_dev(struct intel_svm > *svm, > > qi_flush_piotlb(sdev->iommu, sdev->did, svm->pasid, address, pages, > ih); > if (info->ats_enabled) { > + info->iommu->flush_target_dev = info->dev; > qi_flush_dev_iotlb_pasid(sdev->iommu, sdev->sid, info- > >pfsid, > svm->pasid, sdev->qdep, address, > order_base_2(pages)); this is wrong both in concept and function. an iommu instance can be shared by many devices which may all have ongoing ATS invalidation requests to handle. Using a per-iommu field to store the flush target is limiting (and there is no lock protection at all). if there is a real need of passing dev pointer to qi helpers, just change the helper to accept an explicit parameter.