LXR qemu/hw/virtio-console.c

   1/*
   2 * Virtio Console and Generic Serial Port Devices
   3 *
   4 * Copyright Red Hat, Inc. 2009, 2010
   5 *
   6 * Authors:
   7 *  Amit Shah <amit.shah@redhat.com>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2.  See
  10 * the COPYING file in the top-level directory.
  11 */
  12
  13#include "char/char.h"
  14#include "qemu/error-report.h"
  15#include "trace.h"
  16#include "virtio-serial.h"
  17
  18typedef struct VirtConsole {
  19    VirtIOSerialPort port;
  20    CharDriverState *chr;
  21} VirtConsole;
  22
  23
  24/* Callback function that's called when the guest sends us data */
  25static ssize_t flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len)
  26{
  27    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
  28    ssize_t ret;
  29
  30    if (!vcon->chr) {
  31        /* If there's no backend, we can just say we consumed all data. */
  32        return len;
  33    }
  34
  35    ret = qemu_chr_fe_write(vcon->chr, buf, len);
  36    trace_virtio_console_flush_buf(port->id, len, ret);
  37
  38    if (ret < 0) {
  39        /*
  40         * Ideally we'd get a better error code than just -1, but
  41         * that's what the chardev interface gives us right now.  If
  42         * we had a finer-grained message, like -EPIPE, we could close
  43         * this connection.  Absent such error messages, the most we
  44         * can do is to return 0 here.
  45         *
  46         * This will prevent stray -1 values to go to
  47         * virtio-serial-bus.c and cause abort()s in
  48         * do_flush_queued_data().
  49         */
  50        ret = 0;
  51    }
  52    return ret;
  53}
  54
  55/* Callback function that's called when the guest opens the port */
  56static void guest_open(VirtIOSerialPort *port)
  57{
  58    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
  59
  60    if (!vcon->chr) {
  61        return;
  62    }
  63    qemu_chr_fe_open(vcon->chr);
  64}
  65
  66/* Callback function that's called when the guest closes the port */
  67static void guest_close(VirtIOSerialPort *port)
  68{
  69    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
  70
  71    if (!vcon->chr) {
  72        return;
  73    }
  74    qemu_chr_fe_close(vcon->chr);
  75}
  76
  77/* Readiness of the guest to accept data on a port */
  78static int chr_can_read(void *opaque)
  79{
  80    VirtConsole *vcon = opaque;
  81
  82    return virtio_serial_guest_ready(&vcon->port);
  83}
  84
  85/* Send data from a char device over to the guest */
  86static void chr_read(void *opaque, const uint8_t *buf, int size)
  87{
  88    VirtConsole *vcon = opaque;
  89
  90    trace_virtio_console_chr_read(vcon->port.id, size);
  91    virtio_serial_write(&vcon->port, buf, size);
  92}
  93
  94static void chr_event(void *opaque, int event)
  95{
  96    VirtConsole *vcon = opaque;
  97
  98    trace_virtio_console_chr_event(vcon->port.id, event);
  99    switch (event) {
 100    case CHR_EVENT_OPENED:
 101        virtio_serial_open(&vcon->port);
 102        break;
 103    case CHR_EVENT_CLOSED:
 104        virtio_serial_close(&vcon->port);
 105        break;
 106    }
 107}
 108
 109static int virtconsole_initfn(VirtIOSerialPort *port)
 110{
 111    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
 112    VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 113
 114    if (port->id == 0 && !k->is_console) {
 115        error_report("Port number 0 on virtio-serial devices reserved for virtconsole devices for backward compatibility.");
 116        return -1;
 117    }
 118
 119    if (vcon->chr) {
 120        qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
 121                              vcon);
 122    }
 123
 124    return 0;
 125}
 126
 127static Property virtconsole_properties[] = {
 128    DEFINE_PROP_CHR("chardev", VirtConsole, chr),
 129    DEFINE_PROP_END_OF_LIST(),
 130};
 131
 132static void virtconsole_class_init(ObjectClass *klass, void *data)
 133{
 134    DeviceClass *dc = DEVICE_CLASS(klass);
 135    VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_CLASS(klass);
 136
 137    k->is_console = true;
 138    k->init = virtconsole_initfn;
 139    k->have_data = flush_buf;
 140    k->guest_open = guest_open;
 141    k->guest_close = guest_close;
 142    dc->props = virtconsole_properties;
 143}
 144
 145static const TypeInfo virtconsole_info = {
 146    .name          = "virtconsole",
 147    .parent        = TYPE_VIRTIO_SERIAL_PORT,
 148    .instance_size = sizeof(VirtConsole),
 149    .class_init    = virtconsole_class_init,
 150};
 151
 152static Property virtserialport_properties[] = {
 153    DEFINE_PROP_CHR("chardev", VirtConsole, chr),
 154    DEFINE_PROP_END_OF_LIST(),
 155};
 156
 157static void virtserialport_class_init(ObjectClass *klass, void *data)
 158{
 159    DeviceClass *dc = DEVICE_CLASS(klass);
 160    VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_CLASS(klass);
 161
 162    k->init = virtconsole_initfn;
 163    k->have_data = flush_buf;
 164    k->guest_open = guest_open;
 165    k->guest_close = guest_close;
 166    dc->props = virtserialport_properties;
 167}
 168
 169static const TypeInfo virtserialport_info = {
 170    .name          = "virtserialport",
 171    .parent        = TYPE_VIRTIO_SERIAL_PORT,
 172    .instance_size = sizeof(VirtConsole),
 173    .class_init    = virtserialport_class_init,
 174};
 175
 176static void virtconsole_register_types(void)
 177{
 178    type_register_static(&virtconsole_info);
 179    type_register_static(&virtserialport_info);
 180}
 181
 182type_init(virtconsole_register_types)
 183