[Qemu-devel] [PATCH] Kick io-thread on qemu_chr_accept_input

[Jan Kiszka <jan.kiszka@siemens.com>]

Once a chr frontend is able to receive input again, we need to inform
the io-thread about this fact. Otherwise, main_loop_wait may continue to
select without the related backend file descriptor in its set. This can
cause high input latencies if only low-rate events arrive otherwise.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

/me wonders if a similar issue explains the slirp slowness under KVM
with in-kernel irqchip enabled. Need to check...

 qemu-char.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/qemu-char.c b/qemu-char.c
index 9a5be75..a589a84 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -177,6 +177,7 @@ void qemu_chr_accept_input(CharDriverState *s)
 {
     if (s->chr_accept_input)
         s->chr_accept_input(s);
+    qemu_notify_event();
 }
 
 void qemu_chr_fe_printf(CharDriverState *s, const char *fmt, ...)
-- 
1.7.3.4