[PATCH] iommu/virtio: Constrain return value of viommu_attach_dev()

[Jean-Philippe Brucker]

Ensure viommu_attach_dev() only return errno values expected from the
attach_dev() op. In particular, only return EINVAL when we're sure that
the device is incompatible with the domain.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
---
 drivers/iommu/virtio-iommu.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index 08eeafc9529f..582ff5a33b52 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -669,13 +669,13 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev,
 		dev_err(vdev->dev,
 			"granule 0x%lx larger than system page size 0x%lx\n",
 			viommu_page_size, PAGE_SIZE);
-		return -EINVAL;
+		return -ENODEV;
 	}
 
 	ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
 			      viommu->last_domain, GFP_KERNEL);
 	if (ret < 0)
-		return ret;
+		return -ENOMEM;
 
 	vdomain->id		= (unsigned int)ret;
 
@@ -696,7 +696,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev,
 		if (ret) {
 			ida_free(&viommu->domain_ids, vdomain->id);
 			vdomain->viommu = NULL;
-			return -EOPNOTSUPP;
+			return -ENODEV;
 		}
 	}
 
@@ -734,7 +734,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		ret = viommu_domain_finalise(vdev, domain);
 	} else if (vdomain->viommu != vdev->viommu) {
 		dev_err(dev, "cannot attach to foreign vIOMMU\n");
-		ret = -EXDEV;
+		ret = -EINVAL;
 	}
 	mutex_unlock(&vdomain->mutex);
 
@@ -769,7 +769,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 
 		ret = viommu_send_req_sync(vdomain->viommu, &req, sizeof(req));
 		if (ret)
-			return ret;
+			return -ENODEV;
 	}
 
 	if (!vdomain->nr_endpoints) {
@@ -779,7 +779,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		 */
 		ret = viommu_replay_mappings(vdomain);
 		if (ret)
-			return ret;
+			return -ENODEV;
 	}
 
 	vdomain->nr_endpoints++;
-- 
2.37.3