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 the log will be out of sync to the playback.
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/2010 Acked-by: Pavel Dovgalyuk <pavel.dovgal...@ispras.ru> Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org> Reviewed-by: Richard Henderson <richard.hender...@linaro.org> Signed-off-by: Alex Bennée <alex.ben...@linaro.org> Message-Id: <20231211091346.14616-13-alex.ben...@linaro.org> diff --git a/chardev/char.c b/chardev/char.c index 996a024c7a2..48f28881c28 100644 --- a/chardev/char.c +++ b/chardev/char.c @@ -171,6 +171,18 @@ int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all) return res; } + if (replay_mode == REPLAY_MODE_RECORD) { + /* + * When recording we don't want temporary conditions to + * perturb the result. By ensuring we write everything we can + * while recording we avoid playback being out of sync if it + * doesn't encounter the same temporary conditions (usually + * triggered by external programs not reading the chardev fast + * enough and pipes filling up). + */ + write_all = true; + } + res = qemu_chr_write_buffer(s, buf, len, &offset, write_all); if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) { -- 2.39.2
