I ported the initial code, so I should maintain it of course.

Signed-off-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211221054105.178795-3-git@xen0n.name>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>