@@ -3481,6 +3481,16 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length)
* so a userfault will trigger.
*/
#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
+ /*
+ * fallocate() will fail with readonly files. Let's print a
+ * proper error message.
+ */
+ if (rb->flags & RAM_READONLY_FD) {
+ error_report("ram_block_discard_range: Discarding RAM"
+ " with readonly files is not supported");
+ goto err;
+
+ }
/*
* We'll discard data from the actual file, even though we only
* have a MAP_PRIVATE mapping, possibly messing with other