virtio-serial: Flow control

Hello,

This patchset adds support for virtio-serial flow control. This is a rework of the method used earlier. The new method doesn't copy over the entire guest buffers to host, instead it uses the guest buffer and adds some state to the port struct.

save/restore support for the new state is to be done. That involves saving/restoring items from the VirtQueueElement struct, which needs a bit of work.

Amit Shah (3):
virtio-serial: Let virtio-serial-bus know if all data was consumed
virtio-serial: Add support for flow control
virtio-console: Enable port throttling when chardev is slow to
consume data

 hw/virtio-console.c    |   15 ++++++++++++-
 hw/virtio-serial-bus.c |   50 +++++++++++++++++++++++++++++++++++++----------
 hw/virtio-serial.h     |   24 ++++++++++++++++++++--
 3 files changed, 73 insertions(+), 16 deletions(-)

1.7.3.4