hw/char/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 "sysemu/char.h"
  14 #include "qemu/error-report.h"
  15 #include "trace.h"
  16 #include "hw/virtio/virtio-serial.h"
  17
  18 #define TYPE_VIRTIO_CONSOLE "virtconsole"
  19 #define VIRTIO_CONSOLE(obj) \
  20     OBJECT_CHECK(VirtConsole, (obj), TYPE_VIRTIO_CONSOLE)
  21
  22 typedef struct VirtConsole {
  23     VirtIOSerialPort parent_obj;
  24
  25     CharDriverState *chr;
  26     guint watch;
  27 } VirtConsole;
  28
  29 /*
  30  * Callback function that's called from chardevs when backend becomes
  31  * writable.
  32  */
  33 static gboolean chr_write_unblocked(GIOChannel *chan, GIOCondition cond,
  34                                     void *opaque)
  35 {
  36     VirtConsole *vcon = opaque;
  37
  38     vcon->watch = 0;
  39     virtio_serial_throttle_port(VIRTIO_SERIAL_PORT(vcon), false);
  40     return FALSE;
  41 }
  42
  43 /* Callback function that's called when the guest sends us data */
  44 static ssize_t flush_buf(VirtIOSerialPort *port,
  45                          const uint8_t *buf, ssize_t len)
  46 {
  47     VirtConsole *vcon = VIRTIO_CONSOLE(port);
  48     ssize_t ret;
  49
  50     if (!vcon->chr) {
  51         /* If there's no backend, we can just say we consumed all data. */
  52         return len;
  53     }
  54
  55     ret = qemu_chr_fe_write(vcon->chr, buf, len);
  56     trace_virtio_console_flush_buf(port->id, len, ret);
  57
  58     if (ret < len) {
  59         VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_GET_CLASS(port);
  60
  61         /*
  62          * Ideally we'd get a better error code than just -1, but
  63          * that's what the chardev interface gives us right now.  If
  64          * we had a finer-grained message, like -EPIPE, we could close
  65          * this connection.
  66          */
  67         if (ret < 0)
  68             ret = 0;
  69         if (!k->is_console) {
  70             virtio_serial_throttle_port(port, true);
  71             if (!vcon->watch) {
  72                 vcon->watch = qemu_chr_fe_add_watch(vcon->chr, G_IO_OUT,
  73                                                     chr_write_unblocked, vcon);
  74             }
  75         }
  76     }
  77     return ret;
  78 }
  79
  80 /* Callback function that's called when the guest opens/closes the port */
  81 static void set_guest_connected(VirtIOSerialPort *port, int guest_connected)
  82 {
  83     VirtConsole *vcon = VIRTIO_CONSOLE(port);
  84
  85     if (!vcon->chr) {
  86         return;
  87     }
  88     qemu_chr_fe_set_open(vcon->chr, guest_connected);
  89 }
  90
  91 /* Readiness of the guest to accept data on a port */
  92 static int chr_can_read(void *opaque)
  93 {
  94     VirtConsole *vcon = opaque;
  95
  96     return virtio_serial_guest_ready(VIRTIO_SERIAL_PORT(vcon));
  97 }
  98
  99 /* Send data from a char device over to the guest */
 100 static void chr_read(void *opaque, const uint8_t *buf, int size)
 101 {
 102     VirtConsole *vcon = opaque;
 103     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(vcon);
 104
 105     trace_virtio_console_chr_read(port->id, size);
 106     virtio_serial_write(port, buf, size);
 107 }
 108
 109 static void chr_event(void *opaque, int event)
 110 {
 111     VirtConsole *vcon = opaque;
 112     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(vcon);
 113
 114     trace_virtio_console_chr_event(port->id, event);
 115     switch (event) {
 116     case CHR_EVENT_OPENED:
 117         virtio_serial_open(port);
 118         break;
 119     case CHR_EVENT_CLOSED:
 120         if (vcon->watch) {
 121             g_source_remove(vcon->watch);
 122             vcon->watch = 0;
 123         }
 124         virtio_serial_close(port);
 125         break;
 126     }
 127 }
 128
 129 static void virtconsole_realize(DeviceState *dev, Error **errp)
 130 {
 131     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
 132     VirtConsole *vcon = VIRTIO_CONSOLE(dev);
 133     VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_GET_CLASS(dev);
 134
 135     if (port->id == 0 && !k->is_console) {
 136         error_setg(errp, "Port number 0 on virtio-serial devices reserved "
 137                    "for virtconsole devices for backward compatibility.");
 138         return;
 139     }
 140
 141     if (vcon->chr) {
 142         vcon->chr->explicit_fe_open = 1;
 143         qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
 144                               vcon);
 145     }
 146 }
 147
 148 static void virtconsole_unrealize(DeviceState *dev, Error **errp)
 149 {
 150     VirtConsole *vcon = VIRTIO_CONSOLE(dev);
 151
 152     if (vcon->watch) {
 153         g_source_remove(vcon->watch);
 154     }
 155 }
 156
 157 static Property virtconsole_properties[] = {
 158     DEFINE_PROP_CHR("chardev", VirtConsole, chr),
 159     DEFINE_PROP_END_OF_LIST(),
 160 };
 161
 162 static void virtconsole_class_init(ObjectClass *klass, void *data)
 163 {
 164     DeviceClass *dc = DEVICE_CLASS(klass);
 165     VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_CLASS(klass);
 166
 167     k->is_console = true;
 168     k->realize = virtconsole_realize;
 169     k->unrealize = virtconsole_unrealize;
 170     k->have_data = flush_buf;
 171     k->set_guest_connected = set_guest_connected;
 172     dc->props = virtconsole_properties;
 173 }
 174
 175 static const TypeInfo virtconsole_info = {
 176     .name          = TYPE_VIRTIO_CONSOLE,
 177     .parent        = TYPE_VIRTIO_SERIAL_PORT,
 178     .instance_size = sizeof(VirtConsole),
 179     .class_init    = virtconsole_class_init,
 180 };
 181
 182 static Property virtserialport_properties[] = {
 183     DEFINE_PROP_CHR("chardev", VirtConsole, chr),
 184     DEFINE_PROP_END_OF_LIST(),
 185 };
 186
 187 static void virtserialport_class_init(ObjectClass *klass, void *data)
 188 {
 189     DeviceClass *dc = DEVICE_CLASS(klass);
 190     VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_CLASS(klass);
 191
 192     k->realize = virtconsole_realize;
 193     k->unrealize = virtconsole_unrealize;
 194     k->have_data = flush_buf;
 195     k->set_guest_connected = set_guest_connected;
 196     dc->props = virtserialport_properties;
 197 }
 198
 199 static const TypeInfo virtserialport_info = {
 200     .name          = "virtserialport",
 201     .parent        = TYPE_VIRTIO_SERIAL_PORT,
 202     .instance_size = sizeof(VirtConsole),
 203     .class_init    = virtserialport_class_init,
 204 };
 205
 206 static void virtconsole_register_types(void)
 207 {
 208     type_register_static(&virtconsole_info);
 209     type_register_static(&virtserialport_info);
 210 }
 211
 212 type_init(virtconsole_register_types)