From 8914f3b81d22130e1c2e0e61ec56658586f68559 Mon Sep 17 00:00:00 2001 From: Amit Shah Date: Tue, 27 Apr 2010 09:07:43 -0300 Subject: [PATCH 16/20] virtio-serial: Discard data that guest sends us when ports aren't connected RH-Author: Amit Shah Message-id: <1272359264-8464-17-git-send-email-amit.shah@redhat.com> Patchwork-id: 8862 O-Subject: [RHEL6 PATCH v4 16/17] virtio-serial: Discard data that guest sends us when ports aren't connected Bugzilla: 574296 RH-Acked-by: Gerd Hoffmann RH-Acked-by: Juan Quintela RH-Acked-by: Alon Levy Before the earlier patch, we relied on incorrect virtio api usage to signal to the guest that a particular buffer wasn't consumed by the host. After fixing that, we now just discard the data the guest sends us while a host port is disconnected or doesn't have a handler registered for consuming data. This commit really doesn't change anything from the current behaviour, just makes the code slightly better by spinning off data handling to ports in another function. Bugzilla: 574296 Upstream: Signed-off-by: Amit Shah --- hw/virtio-serial-bus.c | 68 ++++++++++++++++++++++-------------------------- 1 files changed, 31 insertions(+), 37 deletions(-) Signed-off-by: Eduardo Habkost --- hw/virtio-serial-bus.c | 68 ++++++++++++++++++++++-------------------------- 1 files changed, 31 insertions(+), 37 deletions(-) diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c index ad44127..0166780 100644 --- a/hw/virtio-serial-bus.c +++ b/hw/virtio-serial-bus.c @@ -111,6 +111,29 @@ static size_t write_to_port(VirtIOSerialPort *port, return offset; } +static void flush_queued_data(VirtIOSerialPort *port, bool discard) +{ + VirtQueue *vq; + VirtQueueElement elem; + + vq = port->ovq; + while (virtqueue_pop(vq, &elem)) { + uint8_t *buf; + size_t ret, buf_size; + + if (!discard) { + buf_size = iov_size(elem.out_sg, elem.out_num); + buf = qemu_malloc(buf_size); + ret = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, buf_size); + + port->info->have_data(port, buf, ret); + qemu_free(buf); + } + virtqueue_push(vq, &elem, 0); + } + virtio_notify(&port->vser->vdev, vq); +} + static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len) { VirtQueueElement elem; @@ -345,47 +368,18 @@ static void control_out(VirtIODevice *vdev, VirtQueue *vq) static void handle_output(VirtIODevice *vdev, VirtQueue *vq) { VirtIOSerial *vser; - VirtQueueElement elem; + VirtIOSerialPort *port; + bool discard; vser = DO_UPCAST(VirtIOSerial, vdev, vdev); + port = find_port_by_vq(vser, vq); - while (virtqueue_pop(vq, &elem)) { - VirtIOSerialPort *port; - uint8_t *buf; - size_t ret, buf_size; - - port = find_port_by_vq(vser, vq); - if (!port) { - ret = 0; - goto next_buf; - } - - if (!port->host_connected) { - ret = 0; - goto next_buf; - } - - /* - * A port may not have any handler registered for consuming the - * data that the guest sends or it may not have a chardev associated - * with it. Just ignore the data in that case. - */ - if (!port->info->have_data) { - ret = 0; - goto next_buf; - } - - buf_size = iov_size(elem.out_sg, elem.out_num); - buf = qemu_malloc(buf_size); - ret = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, buf_size); - - port->info->have_data(port, buf, ret); - qemu_free(buf); - - next_buf: - virtqueue_push(vq, &elem, 0); + discard = false; + if (!port || !port->host_connected || !port->info->have_data) { + discard = true; } - virtio_notify(vdev, vq); + + flush_queued_data(port, discard); } static void handle_input(VirtIODevice *vdev, VirtQueue *vq) -- 1.7.0.3