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/*

 * Virtio Console and Generic Serial Port Devices

 *

 * Copyright Red Hat, Inc. 2009, 2010

 *

 * Authors:

 *  Amit Shah <amit.shah@redhat.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2.  See

 * the COPYING file in the top-level directory.

 */

#include "char/char.h"

#include "qemu/error-report.h"

#include "trace.h"

#include "virtio-serial.h"

typedef struct VirtConsole {

    VirtIOSerialPort port;

    CharDriverState *chr;

} VirtConsole;

/*

 * Callback function that's called from chardevs when backend becomes

 * writable.

 */

static gboolean chr_write_unblocked(GIOChannel *chan, GIOCondition cond,

                                    void *opaque)

{

    VirtConsole *vcon = opaque;

    virtio_serial_throttle_port(&vcon->port, false);

    return FALSE;

}

/* Callback function that's called when the guest sends us data */

static ssize_t flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len)

{

    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);

    ssize_t ret;

    if (!vcon->chr) {

        /* If there's no backend, we can just say we consumed all data. */

        return len;

    }

    ret = qemu_chr_fe_write(vcon->chr, buf, len);

    trace_virtio_console_flush_buf(port->id, len, ret);

    if (ret <= 0) {

        VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_GET_CLASS(port);

        /*

         * Ideally we'd get a better error code than just -1, but

         * that's what the chardev interface gives us right now.  If

         * we had a finer-grained message, like -EPIPE, we could close

         * this connection.

         */

        ret = 0;

        if (!k->is_console) {

            virtio_serial_throttle_port(port, true);

            qemu_chr_fe_add_watch(vcon->chr, G_IO_OUT, chr_write_unblocked,

                                  vcon);

        }

    }

    return ret;

}

/* Callback function that's called when the guest opens the port */

static void guest_open(VirtIOSerialPort *port)

{

    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);

    if (!vcon->chr) {

        return;

    }

    qemu_chr_fe_open(vcon->chr);

}

/* Callback function that's called when the guest closes the port */

static void guest_close(VirtIOSerialPort *port)

{

    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);

    if (!vcon->chr) {

        return;

    }

    qemu_chr_fe_close(vcon->chr);

}

/* Readiness of the guest to accept data on a port */

static int chr_can_read(void *opaque)

{

    VirtConsole *vcon = opaque;

    return virtio_serial_guest_ready(&vcon->port);

}

/* Send data from a char device over to the guest */

static void chr_read(void *opaque, const uint8_t *buf, int size)

{

    VirtConsole *vcon = opaque;

    trace_virtio_console_chr_read(vcon->port.id, size);

    virtio_serial_write(&vcon->port, buf, size);

}

static void chr_event(void *opaque, int event)

{

    VirtConsole *vcon = opaque;

    trace_virtio_console_chr_event(vcon->port.id, event);

    switch (event) {

    case CHR_EVENT_OPENED:

        virtio_serial_open(&vcon->port);

        break;

    case CHR_EVENT_CLOSED:

        virtio_serial_close(&vcon->port);

        break;

    }

}

static int virtconsole_initfn(VirtIOSerialPort *port)

{

    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);

    VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_GET_CLASS(port);

    if (port->id == 0 && !k->is_console) {

        error_report("Port number 0 on virtio-serial devices reserved for virtconsole devices for backward compatibility.");

        return -1;

    }

    if (vcon->chr) {

        qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,

                              vcon);

    }

    return 0;

}

static Property virtconsole_properties[] = {

    DEFINE_PROP_CHR("chardev", VirtConsole, chr),

    DEFINE_PROP_END_OF_LIST(),

};

static void virtconsole_class_init(ObjectClass *klass, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(klass);

    VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_CLASS(klass);

    k->is_console = true;

    k->init = virtconsole_initfn;

    k->have_data = flush_buf;

    k->guest_open = guest_open;

    k->guest_close = guest_close;

    dc->props = virtconsole_properties;

}

static const TypeInfo virtconsole_info = {

    .name          = "virtconsole",

    .parent        = TYPE_VIRTIO_SERIAL_PORT,

    .instance_size = sizeof(VirtConsole),

    .class_init    = virtconsole_class_init,

};

static Property virtserialport_properties[] = {

    DEFINE_PROP_CHR("chardev", VirtConsole, chr),

    DEFINE_PROP_END_OF_LIST(),

};

static void virtserialport_class_init(ObjectClass *klass, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(klass);

    VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_CLASS(klass);

    k->init = virtconsole_initfn;

    k->have_data = flush_buf;

    k->guest_open = guest_open;

    k->guest_close = guest_close;

    dc->props = virtserialport_properties;

}

static const TypeInfo virtserialport_info = {

    .name          = "virtserialport",

    .parent        = TYPE_VIRTIO_SERIAL_PORT,

    .instance_size = sizeof(VirtConsole),

    .class_init    = virtserialport_class_init,

};

static void virtconsole_register_types(void)

{

    type_register_static(&virtconsole_info);

    type_register_static(&virtserialport_info);

}

type_init(virtconsole_register_types)