From ef12a703b7d4894a851cbf3e94cca8fa25fc43f2 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marc-Andr=C3=A9=20Lureau?= Date: Thu, 6 Dec 2018 00:37:32 +0400 Subject: [PATCH] monitor: accept chardev input from iothread MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Chardev backends may not handle safely IO events from concurrent threads (may not handle I/O events from concurrent threads safely, only the write path is since commit > 9005b2a7589540a3733b3abdcfbccfe7746cd1a1). Better to wake up the chardev from the monitor IO thread if it's being used as the chardev context. Unify code paths by using a BH in all cases. Drop the now redundant aio_notify() call. Clean up control flow not to rely on mon->use_io_thread implying monitor_is_qmp(mon). Signed-off-by: Marc-André Lureau Reviewed-by: Peter Xu Reviewed-by: Markus Armbruster Message-Id: <20181205203737.9011-3-marcandre.lureau@redhat.com> Signed-off-by: Markus Armbruster --- monitor.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/monitor.c b/monitor.c index d531e8ccc9..79afe99079 100644 --- a/monitor.c +++ b/monitor.c @@ -4297,7 +4297,7 @@ int monitor_suspend(Monitor *mon) atomic_inc(&mon->suspend_cnt); - if (monitor_is_qmp(mon) && mon->use_io_thread) { + if (mon->use_io_thread) { /* * Kick I/O thread to make sure this takes effect. It'll be * evaluated again in prepare() of the watch object. @@ -4309,6 +4309,13 @@ int monitor_suspend(Monitor *mon) return 0; } +static void monitor_accept_input(void *opaque) +{ + Monitor *mon = opaque; + + qemu_chr_fe_accept_input(&mon->chr); +} + void monitor_resume(Monitor *mon) { if (monitor_is_hmp_non_interactive(mon)) { @@ -4316,20 +4323,22 @@ void monitor_resume(Monitor *mon) } if (atomic_dec_fetch(&mon->suspend_cnt) == 0) { - if (monitor_is_qmp(mon)) { - /* - * For QMP monitors that are running in the I/O thread, - * let's kick the thread in case it's sleeping. - */ - if (mon->use_io_thread) { - aio_notify(iothread_get_aio_context(mon_iothread)); - } + AioContext *ctx; + + if (mon->use_io_thread) { + ctx = iothread_get_aio_context(mon_iothread); } else { + ctx = qemu_get_aio_context(); + } + + if (!monitor_is_qmp(mon)) { assert(mon->rs); readline_show_prompt(mon->rs); } - qemu_chr_fe_accept_input(&mon->chr); + + aio_bh_schedule_oneshot(ctx, monitor_accept_input, mon); } + trace_monitor_suspend(mon, -1); } -- 2.11.4.GIT