qerror: Add QERR_UNKNOWN_BLOCK_FORMAT_FEATURE

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/qerror.c b/qerror.c
index 9d0cdeb..4855604 100644
--- a/qerror.c
+++ b/qerror.c
@@ -201,6 +201,11 @@
         .desc      = "An undefined error has ocurred",
     },
     {
+        .error_fmt = QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
+        .desc      = "'%(device)' uses a %(format) feature which is not "
+                     "supported by this qemu version: %(feature)",
+    },
+    {
         .error_fmt = QERR_VNC_SERVER_FAILED,
         .desc      = "Could not start VNC server on %(target)",
     },