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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 "qemu-char.h"

#include "qemu-error.h"

#include "trace.h"

#include "virtio-serial.h"

typedef struct VirtConsole {

    VirtIOSerialPort port;

    CharDriverState *chr;

} VirtConsole;

/* 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;

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

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

    if (ret < 0) {

        /*

         * 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.  Absent such error messages, the most we

         * can do is to return 0 here.

         *

         * This will prevent stray -1 values to go to

         * virtio-serial-bus.c and cause abort()s in

         * do_flush_queued_data().

         */

        ret = 0;

    }

    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);

    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);

    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);

    VirtIOSerialPortInfo *info = DO_UPCAST(VirtIOSerialPortInfo, qdev,

                                           vcon->port.dev.info);

    if (port->id == 0 && !info->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);

        info->have_data = flush_buf;

        info->guest_open = guest_open;

        info->guest_close = guest_close;

    }

    return 0;

}

static int virtconsole_exitfn(VirtIOSerialPort *port)

{

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

    if (vcon->chr) {

        /*

         * Instead of closing the chardev, free it so it can be used

         * for other purposes.

         */

        qemu_chr_add_handlers(vcon->chr, NULL, NULL, NULL, NULL);

    }

    return 0;

}

static VirtIOSerialPortInfo virtconsole_info = {

    .qdev.name     = "virtconsole",

    .qdev.size     = sizeof(VirtConsole),

    .is_console    = true,

    .init          = virtconsole_initfn,

    .exit          = virtconsole_exitfn,

    .qdev.props = (Property[]) {

        DEFINE_PROP_CHR("chardev", VirtConsole, chr),

        DEFINE_PROP_END_OF_LIST(),

    },

};

static void virtconsole_register(void)

{

    virtio_serial_port_qdev_register(&virtconsole_info);

}

device_init(virtconsole_register)

static VirtIOSerialPortInfo virtserialport_info = {

    .qdev.name     = "virtserialport",

    .qdev.size     = sizeof(VirtConsole),

    .init          = virtconsole_initfn,

    .exit          = virtconsole_exitfn,

    .qdev.props = (Property[]) {

        DEFINE_PROP_CHR("chardev", VirtConsole, chr),

        DEFINE_PROP_END_OF_LIST(),

    },

};

static void virtserialport_register(void)

{

    virtio_serial_port_qdev_register(&virtserialport_info);

}

device_init(virtserialport_register)