This is for compatibility.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 include/hw/compat.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/hw/compat.h b/include/hw/compat.h
index 846b90e..ff08ec8 100644
--- a/include/hw/compat.h
+++ b/include/hw/compat.h
@@ -2,7 +2,11 @@
 #define HW_COMPAT_H
 
 #define HW_COMPAT_2_9 \
-    /* empty */
+    {\
+        .driver   = "intel-iommu",\
+        .property = "pt",\
+        .value    = "off",\
+    },
 
 #define HW_COMPAT_2_8 \
     {\
-- 
2.7.4