Index: xen-4.0.1-testing/tools/ioemu-qemu-xen/block-vvfat.c
===================================================================
--- xen-4.0.1-testing.orig/tools/ioemu-qemu-xen/block-vvfat.c
+++ xen-4.0.1-testing/tools/ioemu-qemu-xen/block-vvfat.c
@@ -865,7 +865,8 @@ static int init_directories(BDRVVVFATSta
     {
 	direntry_t* entry=array_get_next(&(s->directory));
 	entry->attributes=0x28; /* archive | volume label */
-	snprintf((char*)entry->name,11,"QEMU VVFAT");
+	memcpy(entry->name,"QEMU VVF",8);
+	memcpy(entry->extension,"AT ",3);
     }
 
     /* Now build FAT, and write back information into directory */