[PATCH] iommu/vt-d: Fix bind svm with multiple devices

[Jacob Pan]

If multiple devices try to bind to the same mm/PASID, we need to
set up first level PASID entries for all the devices. The current
code does not consider this case which results in failed DMA for
devices after the first bind.

Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Reported-by: Mike Campin <mike.campin@xxxxxxxxx>
---
 drivers/iommu/intel-svm.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 3a4b09a..f3d59d1 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -357,6 +357,21 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
 		}
 
 		list_add_tail(&svm->list, &global_svm_list);
+	} else {
+		/*
+		 * Binding a new device with existing PASID, need to setup
+		 * the PASID entry.
+		 */
+		spin_lock(&iommu->lock);
+		ret = intel_pasid_setup_first_level(iommu, dev,
+						mm ? mm->pgd : init_mm.pgd,
+						svm->pasid, FLPT_DEFAULT_DID,
+						mm ? 0 : PASID_FLAG_SUPERVISOR_MODE);
+		spin_unlock(&iommu->lock);
+		if (ret) {
+			kfree(sdev);
+			goto out;
+		}
 	}
 	list_add_rcu(&sdev->list, &svm->devs);
 
-- 
2.7.4