aboutsummaryrefslogtreecommitdiff
path: root/hw
diff options
context:
space:
mode:
authorStefan Hajnoczi <stefanha@redhat.com>2016-09-19 14:28:05 +0100
committerMichael S. Tsirkin <mst@redhat.com>2016-10-10 01:16:58 +0300
commitd4c19cdeeb2f1e474bc426a6da261f1d7346eb5b (patch)
treeca6257b6196dbfa2857984b4c87646ece6553f2f /hw
parent97b93c8ad2242c5a5f89ac50f9e696289c5b4947 (diff)
virtio-serial: add missing virtio_detach_element() call
Ports enter a "throttled" state when writing to the chardev would block. The current output VirtQueueElement is kept around until the chardev becomes writable again. There are several places in the virtio-serial lifecycle where the VirtQueueElement should be thrown away. For example, if the virtio device is reset then virtqueue elements are no longer valid. This patch adds the discard_throttle_data() function to unmap the scatter-gather list and decrement vq->inuse. This ensures that the VirtQueueElement is freed properly. Cc: amit.shah@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Tested-by: Ladi Prosek <lprosek@redhat.com> Reviewed-by: Ladi Prosek <lprosek@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r--hw/char/virtio-serial-bus.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index db2a9f19bc..3955f0f741 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -145,6 +145,15 @@ static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
virtio_notify(vdev, vq);
}
+static void discard_throttle_data(VirtIOSerialPort *port)
+{
+ if (port->elem) {
+ virtqueue_detach_element(port->ovq, port->elem, 0);
+ g_free(port->elem);
+ port->elem = NULL;
+ }
+}
+
static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
VirtIODevice *vdev)
{
@@ -267,6 +276,7 @@ int virtio_serial_close(VirtIOSerialPort *port)
* consume, reset the throttling flag and discard the data.
*/
port->throttled = false;
+ discard_throttle_data(port);
discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 0);
@@ -591,6 +601,9 @@ static void guest_reset(VirtIOSerial *vser)
QTAILQ_FOREACH(port, &vser->ports, next) {
vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
+
+ discard_throttle_data(port);
+
if (port->guest_connected) {
port->guest_connected = false;
if (vsc->set_guest_connected) {
@@ -901,6 +914,7 @@ static void remove_port(VirtIOSerial *vser, uint32_t port_id)
assert(port);
/* Flush out any unconsumed buffers first */
+ discard_throttle_data(port);
discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_REMOVE, 1);