From 4b71b3a9e37d06da2ecc48e06eea7e4a4ae1cfe9 Mon Sep 17 00:00:00 2001 From: Fam Zheng Date: Thu, 18 May 2017 09:21:20 +0200 Subject: [PATCH 07/18] serial: poll the serial console with G_IO_HUP MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Fam Zheng Message-id: <20170518092131.16571-8-famz@redhat.com> Patchwork-id: 75297 O-Subject: [RHEL-7.4 qemu-kvm PATCH v3 07/18] serial: poll the serial console with G_IO_HUP Bugzilla: 1451470 RH-Acked-by: Paolo Bonzini RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Eduardo Habkost From: Roger Pau Monne On FreeBSD polling a master pty while the other end is not connected with G_IO_OUT only results in an endless wait. This is different from the Linux behaviour, that returns immediately. In order to demonstrate this, I have the following example code: http://xenbits.xen.org/people/royger/test_poll.c When executed on Linux: $ ./test_poll In callback On FreeBSD instead, the callback never gets called: $ ./test_poll So, in order to workaround this, poll the source with G_IO_HUP (which makes the code behave the same way on both Linux and FreeBSD). Signed-off-by: Roger Pau Monné Cc: Peter Crosthwaite Cc: Michael Tokarev Cc: "Andreas Färber" Cc: Paolo Bonzini Cc: xen-devel@lists.xenproject.org [Add hw/char/cadence_uart.c too. - Paolo] Signed-off-by: Paolo Bonzini (cherry picked from commit e02bc6de30c44fd668dc0d6e1cd1804f2eed3ed3) Signed-off-by: Fam Zheng Signed-off-by: Miroslav Rezanina Conflicts: hw/char/cadence_uart.c Downstream doesn't use qemu_chr_fe_add_watch because we don't have 38acd64b1c etc. monitor.c The changed line is different because we don't have 6cff3e8594 (monitor: protect outbuf and mux_out with mutex). --- hw/char/serial.c | 2 +- hw/char/virtio-console.c | 3 ++- hw/usb/redirect.c | 2 +- monitor.c | 2 +- 4 files changed, 5 insertions(+), 4 deletions(-) diff --git a/hw/char/serial.c b/hw/char/serial.c index e020b0e..add4738 100644 --- a/hw/char/serial.c +++ b/hw/char/serial.c @@ -246,7 +246,7 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) serial_receive1(s, &s->tsr, 1); } else if (qemu_chr_fe_write(s->chr, &s->tsr, 1) != 1) { if (s->tsr_retry >= 0 && s->tsr_retry < MAX_XMIT_RETRY && - qemu_chr_fe_add_watch(s->chr, G_IO_OUT, serial_xmit, s) > 0) { + qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, serial_xmit, s) > 0) { s->tsr_retry++; return FALSE; } diff --git a/hw/char/virtio-console.c b/hw/char/virtio-console.c index 1b01dcd..69dd95a 100644 --- a/hw/char/virtio-console.c +++ b/hw/char/virtio-console.c @@ -66,7 +66,8 @@ static ssize_t flush_buf(VirtIOSerialPort *port, if (!k->is_console) { virtio_serial_throttle_port(port, true); if (!vcon->watch) { - vcon->watch = qemu_chr_fe_add_watch(vcon->chr, G_IO_OUT, + vcon->watch = qemu_chr_fe_add_watch(vcon->chr, + G_IO_OUT|G_IO_HUP, chr_write_unblocked, vcon); } } diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c index e3b9f32..3fe2106 100644 --- a/hw/usb/redirect.c +++ b/hw/usb/redirect.c @@ -284,7 +284,7 @@ static int usbredir_write(void *priv, uint8_t *data, int count) r = qemu_chr_fe_write(dev->cs, data, count); if (r < count) { if (!dev->watch) { - dev->watch = qemu_chr_fe_add_watch(dev->cs, G_IO_OUT, + dev->watch = qemu_chr_fe_add_watch(dev->cs, G_IO_OUT|G_IO_HUP, usbredir_write_unblocked, dev); } if (r < 0) { diff --git a/monitor.c b/monitor.c index 1b28ff3..393a508 100644 --- a/monitor.c +++ b/monitor.c @@ -300,7 +300,7 @@ void monitor_flush(Monitor *mon) mon->outbuf = tmp; } if (mon->watch == 0) { - mon->watch = qemu_chr_fe_add_watch(mon->chr, G_IO_OUT, + mon->watch = qemu_chr_fe_add_watch(mon->chr, G_IO_OUT|G_IO_HUP, monitor_unblocked, mon); } } -- 1.8.3.1