[PULL 3/3] vhost: Fix memory region section comparison

[Michael S. Tsirkin]

From: "Dr. David Alan Gilbert" <address@hidden>

Using memcmp to compare structures wasn't safe,
as I found out on ARM when I was getting falce miscompares.

Use the helper function for comparing the MRSs.

Fixes: ade6d081fc33948e56e6 ("vhost: Regenerate region list from changed 
sections list")
Cc: address@hidden
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
 hw/virtio/vhost.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 34accdf615..2386b511f3 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -451,8 +451,13 @@ static void vhost_commit(MemoryListener *listener)
         changed = true;
     } else {
         /* Same size, lets check the contents */
-        changed = n_old_sections && memcmp(dev->mem_sections, old_sections,
-                         n_old_sections * sizeof(old_sections[0])) != 0;
+        for (int i = 0; i < n_old_sections; i++) {
+            if (!MemoryRegionSection_eq(&old_sections[i],
+                                        &dev->mem_sections[i])) {
+                changed = true;
+                break;
+            }
+        }
     }
 
     trace_vhost_commit(dev->started, changed);
-- 
MST