Re: [PATCH 10/11] chardev: force write all when recording replay logs

[Philippe Mathieu-Daudé]

On 5/12/23 21:41, Alex Bennée wrote:
> This is mostly a problem within avocado as serial generally isn't busy
> enough to overfill pipes. However the consequences of recording a
> failed write will haunt us on replay when causing the log to go out of
> sync.
>
> Fixes: https://gitlab.com/qemu-project/qemu/-/issues/2010
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Cc: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
> ---
>   chardev/char.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/chardev/char.c b/chardev/char.c
> index 996a024c7a..6e5b4d7345 100644
> --- a/chardev/char.c
> +++ b/chardev/char.c
> @@ -171,7 +171,8 @@ int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, 
> bool write_all)
>           return res;
>       }

Please add a comment explaining why in the code. Maybe simpler
using:

       if (replay_mode == REPLAY_MODE_RECORD) {
           /* $explanation */
           write_all = true;
       }

> -    res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
> +    res = qemu_chr_write_buffer(s, buf, len, &offset,
> +                                replay_mode == REPLAY_MODE_RECORD ? true : 
> write_all);
With a comment:
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>