This allows to change the port's backend runtime, e.g. change it from
file to a socket making it possible to establish a debug session with
WinDbg
> qemu-system [..] -chardev file,id=charchannel2,path=/tmp/charchannel2 \
-device isa-serial,chardev=charchannel2,id=channel2
QEMU 2.9.50 monitor - type 'help' for more information
(qemu) chardev-change charchannel2 \
socket,host=127.0.0.1,port=4242,server,nowait
For a backend change, a number of ioctls has to be replayed to sync
the current setup of a frontend to a backend tty. This is hopefully
enough so we don't have to track, store and replay the whole original
control byte sequence.
Signed-off-by: Anton Nefedov <anton.nefe...@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
hw/char/serial.c | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)
diff --git a/hw/char/serial.c b/hw/char/serial.c
index 09157f9..9aec6c6 100644
--- a/hw/char/serial.c
+++ b/hw/char/serial.c
@@ -891,6 +891,34 @@ static void serial_reset(void *opaque)
s->msr &= ~UART_MSR_ANY_DELTA;
}
+static int serial_be_change(void *opaque)
+{
+ SerialState *s = opaque;
+
+ qemu_chr_fe_set_handlers(&s->chr, serial_can_receive1, serial_receive1,
+ serial_event, serial_be_change, s, NULL, true);
+
+ serial_update_parameters(s);
+
+ qemu_chr_fe_ioctl(&s->chr, CHR_IOCTL_SERIAL_SET_BREAK,
+ &s->last_break_enable);
+
+ s->poll_msl = (s->ier & UART_IER_MSI) ? 1 : 0;
+ serial_update_msl(s);
+
+ if (s->poll_msl >= 0 && !(s->mcr & UART_MCR_LOOP)) {
+ serial_update_tiocm(s);
+ }
+
+ if (s->watch_tag > 0) {
+ g_source_remove(s->watch_tag);
+ s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP,
+ serial_watch_cb, s);
+ }
+
+ return 0;
+}
+
void serial_realize_core(SerialState *s, Error **errp)
{
if (!qemu_chr_fe_backend_connected(&s->chr)) {
@@ -904,7 +932,7 @@ void serial_realize_core(SerialState *s, Error **errp)
qemu_register_reset(serial_reset, s);
qemu_chr_fe_set_handlers(&s->chr, serial_can_receive1, serial_receive1,
- serial_event, NULL, s, NULL, true);
+ serial_event, serial_be_change, s, NULL, true);
fifo8_create(&s->recv_fifo, UART_FIFO_LENGTH);
fifo8_create(&s->xmit_fifo, UART_FIFO_LENGTH);
serial_reset(s);
--
2.7.4
