diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index 2eb729dff5..0f37cf056a 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -29,6 +29,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/log.h"
 #include "hw/i386/pc.h"
 #include "hw/pci-host/q35.h"
 #include "hw/qdev-properties.h"
@@ -318,6 +319,8 @@ static void mch_update_pciexbar(MCHPCIState *mch)
         addr_mask |= MCH_HOST_BRIDGE_PCIEXBAR_64ADMSK;
         break;
     case MCH_HOST_BRIDGE_PCIEXBAR_LENGTH_RVD:
+        qemu_log_mask(LOG_GUEST_ERROR, "Q35: Reserved PCIEXBAR LENGTH\n");
+        return;
     default:
         abort();
     }