diff options
| -rw-r--r-- | hw/char/virtio-serial-bus.c | 18 | ||||
| -rw-r--r-- | include/hw/virtio/virtio-serial.h | 3 |
2 files changed, 21 insertions, 0 deletions
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c index 2b647b68d5..721e964f96 100644 --- a/hw/char/virtio-serial-bus.c +++ b/hw/char/virtio-serial-bus.c @@ -442,6 +442,24 @@ static void handle_output(VirtIODevice *vdev, VirtQueue *vq) static void handle_input(VirtIODevice *vdev, VirtQueue *vq) { + /* + * Users of virtio-serial would like to know when guest becomes + * writable again -- i.e. if a vq had stuff queued up and the + * guest wasn't reading at all, the host would not be able to + * write to the vq anymore. Once the guest reads off something, + * we can start queueing things up again. + */ + VirtIOSerial *vser; + VirtIOSerialPort *port; + VirtIOSerialPortClass *vsc; + + vser = VIRTIO_SERIAL(vdev); + port = find_port_by_vq(vser, vq); + vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port); + + if (vsc->guest_writable) { + vsc->guest_writable(port); + } } static uint32_t get_features(VirtIODevice *vdev, uint32_t features) diff --git a/include/hw/virtio/virtio-serial.h b/include/hw/virtio/virtio-serial.h index 4746312a83..3fd696b89b 100644 --- a/include/hw/virtio/virtio-serial.h +++ b/include/hw/virtio/virtio-serial.h @@ -98,6 +98,9 @@ typedef struct VirtIOSerialPortClass { /* Guest is now ready to accept data (virtqueues set up). */ void (*guest_ready)(VirtIOSerialPort *port); + /* Guest vq became writable again */ + void (*guest_writable)(VirtIOSerialPort *port); + /* * Guest wrote some data to the port. This data is handed over to * the app via this callback. The app can return a size less than |