memory_region_register_iommu_notifier now returns an error
in case of failure. Assert in such a case.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v1 -> v2:
- assert(!ret)
---
 hw/virtio/vhost.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 34accdf615..975cb4c28c 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -672,7 +672,7 @@ static void vhost_iommu_region_add(MemoryListener *listener,
                                          iommu_listener);
     struct vhost_iommu *iommu;
     Int128 end;
-    int iommu_idx;
+    int iommu_idx, ret;
     IOMMUMemoryRegion *iommu_mr;
 
     if (!memory_region_is_iommu(section->mr)) {
@@ -696,7 +696,8 @@ static void vhost_iommu_region_add(MemoryListener *listener,
     iommu->iommu_offset = section->offset_within_address_space -
                           section->offset_within_region;
     iommu->hdev = dev;
-    memory_region_register_iommu_notifier(section->mr, &iommu->n);
+    ret = memory_region_register_iommu_notifier(section->mr, &iommu->n);
+    assert(!ret);
     QLIST_INSERT_HEAD(&dev->iommu_list, iommu, iommu_next);
     /* TODO: can replay help performance here? */
 }
-- 
2.20.1