return offset;
}
-static void flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
- VirtIODevice *vdev, bool discard)
+static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
+ VirtIODevice *vdev, bool discard)
{
VirtQueueElement elem;
assert(port || discard);
- while (virtqueue_pop(vq, &elem)) {
+ while ((discard || !port->throttled) && virtqueue_pop(vq, &elem)) {
uint8_t *buf;
size_t ret, buf_size;
virtio_notify(vdev, vq);
}
+static void flush_queued_data(VirtIOSerialPort *port, bool discard)
+{
+ assert(port || discard);
+
+ do_flush_queued_data(port, port->ovq, &port->vser->vdev, discard);
+}
+
static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len)
{
VirtQueueElement elem;
int virtio_serial_close(VirtIOSerialPort *port)
{
port->host_connected = false;
+ /*
+ * If there's any data the guest sent which the app didn't
+ * consume, reset the throttling flag and discard the data.
+ */
+ port->throttled = false;
+ flush_queued_data(port, true);
+
send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
return 0;
return 0;
}
+void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
+{
+ if (!port) {
+ return;
+ }
+
+ port->throttled = throttle;
+ if (throttle) {
+ return;
+ }
+
+ flush_queued_data(port, false);
+}
+
/* Guest wants to notify us of some event */
static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
{
discard = true;
}
- flush_queued_data(port, vq, vdev, discard);
+ if (!discard && port->throttled) {
+ return;
+ }
+
+ do_flush_queued_data(port, vq, vdev, discard);
}
static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
indent, "", port->guest_connected);
monitor_printf(mon, "%*s dev-prop-int: host_connected: %d\n",
indent, "", port->host_connected);
+ monitor_printf(mon, "%*s dev-prop-int: throttled: %d\n",
+ indent, "", port->throttled);
}
/* This function is only used if a port id is not provided by the user */
static void remove_port(VirtIOSerial *vser, uint32_t port_id)
{
+ VirtIOSerialPort *port;
unsigned int i;
i = port_id / 32;
vser->ports_map[i] &= ~(1U << (port_id % 32));
- send_control_event(find_port_by_id(vser, port_id),
- VIRTIO_CONSOLE_PORT_REMOVE, 1);
+ port = find_port_by_id(vser, port_id);
+ /* Flush out any unconsumed buffers first */
+ flush_queued_data(port, true);
+
+ send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1);
}
static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base)