A chardev may stop trying to write if the associated can_read() callback returned 0. This happens when the monitor is suspended. The frontend is supposed to call qemu_chr_fe_accept_input() when it is ready to accept data again.
An issue was observed with a spice port: pending commands may be delayed, as the chardev is not flushed. Most chardev don't use the accept_input() callback, and instead check regularly if they can write. The ones that do use it are braille, mux, msmouse, spice (abstract), spicevmc, spiceport, wctablet. Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com> Acked-by: Markus Armbruster <arm...@redhat.com> --- monitor.c | 1 + 1 file changed, 1 insertion(+) diff --git a/monitor.c b/monitor.c index a1999e396c..33823b035a 100644 --- a/monitor.c +++ b/monitor.c @@ -4407,6 +4407,7 @@ void monitor_resume(Monitor *mon) assert(mon->rs); readline_show_prompt(mon->rs); } + qemu_chr_fe_accept_input(&mon->chr); } trace_monitor_suspend(mon, -1); } -- 2.18.0.547.g1d89318c48