[PATCH v4 19/22] iommu/intel-svm: do not flush iotlb for viommu

[Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

vIOMMU passdown invalidation will be inclusive, PASID cache invalidation
includes TLBs. See Intel VT-d Specification Ch 6.5.2.2 for details.

Signed-off-by: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/iommu/intel-svm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index bdda1b6..697d5c2 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -284,7 +284,9 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
 	rcu_read_lock();
 	list_for_each_entry_rcu(sdev, &svm->devs, list) {
 		intel_flush_pasid_dev(svm, sdev, svm->pasid);
-		intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm);
+		/* for emulated iommu, PASID cache invalidation implies IOTLB/DTLB */
+		if (!cap_caching_mode(svm->iommu->cap))
+			intel_flush_svm_range_dev(svm, sdev, 0, -1, 0, !svm->mm);
 	}
 	rcu_read_unlock();
 
-- 
2.7.4