From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48813) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dSl5Y-00009V-6e for qemu-devel@nongnu.org; Wed, 05 Jul 2017 10:15:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dSl5V-0005qe-18 for qemu-devel@nongnu.org; Wed, 05 Jul 2017 10:15:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30442) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dSl5U-0005pf-Nd for qemu-devel@nongnu.org; Wed, 05 Jul 2017 10:15:28 -0400 Date: Wed, 5 Jul 2017 17:15:19 +0300 From: "Michael S. Tsirkin" Message-ID: <20170705171437-mutt-send-email-mst@kernel.org> References: <1499263324-15184-1-git-send-email-anton.nefedov@virtuozzo.com> <1499263324-15184-14-git-send-email-anton.nefedov@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1499263324-15184-14-git-send-email-anton.nefedov@virtuozzo.com> Subject: Re: [Qemu-devel] [PATCH v5 13/13] serial: chardev hotswap support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anton Nefedov Cc: qemu-devel@nongnu.org, den@virtuozzo.com, pbonzini@redhat.com, marcandre.lureau@redhat.com, amit@kernel.org On Wed, Jul 05, 2017 at 05:02:04PM +0300, Anton Nefedov wrote: > 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 > Reviewed-by: Vladimir Sementsov-Ogievskiy Could you please add a description of the feature here? How does one use it e.g. for windbg? > --- > hw/char/serial.c | 32 ++++++++++++++++++++++++++++++-- > 1 file changed, 30 insertions(+), 2 deletions(-) > > diff --git a/hw/char/serial.c b/hw/char/serial.c > index e47f0b6..9aec6c6 100644 > --- a/hw/char/serial.c > +++ b/hw/char/serial.c > @@ -891,9 +891,37 @@ 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_get_driver(&s->chr)) { > + if (!qemu_chr_fe_backend_connected(&s->chr)) { > error_setg(errp, "Can't create serial device, empty char device"); > return; > } > @@ -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