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:
- add assert(!ret)
---
 exec.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/exec.c b/exec.c
index 8b998974f8..5be8db6253 100644
--- a/exec.c
+++ b/exec.c
@@ -663,7 +663,7 @@ static void tcg_register_iommu_notifier(CPUState *cpu,
      */
     MemoryRegion *mr = MEMORY_REGION(iommu_mr);
     TCGIOMMUNotifier *notifier;
-    int i;
+    int i, ret;
 
     for (i = 0; i < cpu->iommu_notifiers->len; i++) {
         notifier = g_array_index(cpu->iommu_notifiers, TCGIOMMUNotifier *, i);
@@ -692,7 +692,9 @@ static void tcg_register_iommu_notifier(CPUState *cpu,
                             0,
                             HWADDR_MAX,
                             iommu_idx);
-        memory_region_register_iommu_notifier(notifier->mr, &notifier->n);
+        ret = memory_region_register_iommu_notifier(notifier->mr,
+                                                    &notifier->n);
+        assert(!ret);
     }
 
     if (!notifier->active) {
-- 
2.20.1