+ if (mmap_size == 0) {
+ /*
+ * It could happen if initial mmap_size + alignment
+ * overflows the sizeof uint64, which could happen if
+ * either mmap_size or alignment value is wrong.
+ *
+ * mmap() kernel implementation would return an error,
+ * but better catch it before and provide useful info
+ * in the logs.
+ */
+ VHOST_LOG_CONFIG(ERR, "mmap size (0x%" PRIx64 ") "
+ "or alignment (0x%" PRIx64 ") is invalid\n",
+ reg->size + mmap_offset, alignment);
+ goto err_mmap;
+ }