diff options
author | Amit Shah <amit.shah@redhat.com> | 2010-04-27 18:04:11 +0530 |
---|---|---|
committer | Anthony Liguori <aliguori@us.ibm.com> | 2010-04-28 08:58:22 -0500 |
commit | 9ed7b059ef776a3921cfd085e891f45076922542 (patch) | |
tree | 422546b0e15528f3ee5f937c73c3b1818611c9d9 /hw/virtio-serial.h | |
parent | a69c76008597ccdffae7a933686ab856ca85e87c (diff) |
virtio-serial: Implement flow control for individual ports
Individual ports can now signal to the virtio-serial core to stop
sending data if the ports cannot immediately handle new data. When a
port later unthrottles, any data queued up in the virtqueue are sent to
the port.
Disable throttling once a port is closed (and we discard all the
unconsumed buffers in the vq).
The guest kernel can reclaim the buffers when it receives the port close
event or when a port is being removed. Ensure we free up the buffers
before we send out any events to the guest.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'hw/virtio-serial.h')
-rw-r--r-- | hw/virtio-serial.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/hw/virtio-serial.h b/hw/virtio-serial.h index 62d76a25fe..a93b5458b2 100644 --- a/hw/virtio-serial.h +++ b/hw/virtio-serial.h @@ -110,6 +110,8 @@ struct VirtIOSerialPort { bool guest_connected; /* Is this device open for IO on the host? */ bool host_connected; + /* Do apps not want to receive data? */ + bool throttled; }; struct VirtIOSerialPortInfo { @@ -173,4 +175,11 @@ ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf, */ size_t virtio_serial_guest_ready(VirtIOSerialPort *port); +/* + * Flow control: Ports can signal to the virtio-serial core to stop + * sending data or re-start sending data, depending on the 'throttle' + * value here. + */ +void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle); + #endif |