to #28092200

commit d970a325561da5e611596cbb06475db3755ce823 upstream

Reported with "make W=1" due to -Wmissing-prototypes.
Reported-by: NQian Cai <cai@lca.pw>
Reviewed-by: NMiaohe Lin <linmiaohe@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nchenxiangzuo <cxz18821786681@linux.alibaba.com>
Reviewed-by: NCaspar Zhang <caspar@linux.alibaba.com>