Commit 33a8d5b7 authored by Peter Maydell's avatar Peter Maydell
Browse files

Merge remote-tracking branch 'remotes/amit/tags/vser-for-2.3-3' into staging 



virtio-serial api: guest_writable callback for users

# gpg: Signature made Thu Mar 19 12:06:55 2015 GMT using RSA key ID 854083B6
# gpg: Good signature from "Amit Shah <amit@amitshah.net>"
# gpg:                 aka "Amit Shah <amit@kernel.org>"
# gpg:                 aka "Amit Shah <amitshah@gmx.net>"

* remotes/amit/tags/vser-for-2.3-3:
  virtio: serial: expose a 'guest_writable' callback for users

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parents 7a9a5e72 4add73aa

hw/char/virtio-serial-bus.c

+31 −0
Original line number Diff line number Diff line
@@ -465,6 +465,37 @@ 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.  However, this call is

     * made for each buffer addition by the guest -- even though free

     * buffers existed prior to the current buffer addition.  This is

     * done so as not to maintain previous state, which will need

     * additional live-migration-related changes.

     */

    VirtIOSerial *vser;

    VirtIOSerialPort *port;

    VirtIOSerialPortClass *vsc;



    vser = VIRTIO_SERIAL(vdev);

    port = find_port_by_vq(vser, vq);



    if (!port) {

        return;

    }

    vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);



    /*

     * If guest_connected is false, this call is being made by the

     * early-boot queueing up of descriptors, which is just noise for

     * the host apps -- don't disturb them in that case.

     */

    if (port->guest_connected && port->host_connected && vsc->guest_writable) {

        vsc->guest_writable(port);

    }

}



static uint32_t get_features(VirtIODevice *vdev, uint32_t features)

include/hw/virtio/virtio-serial.h

+11 −0
Original line number Diff line number Diff line
@@ -60,6 +60,17 @@ typedef struct VirtIOSerialPortClass { 
        /* Guest is now ready to accept data (virtqueues set up). */

    void (*guest_ready)(VirtIOSerialPort *port);



        /*

         * Guest has enqueued a buffer for the host to write into.

         * Called each time a buffer is enqueued by the guest;

         * irrespective of whether there already were free buffers the

         * host could have consumed.

         *

         * This is dependent on both the guest and host end being

         * connected.

         */

    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