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 #include "qapi-event.h"
  18
  19 #define TYPE_VIRTIO_CONSOLE_SERIAL_PORT "virtserialport"
  20 #define VIRTIO_CONSOLE(obj) \
  21     OBJECT_CHECK(VirtConsole, (obj), TYPE_VIRTIO_CONSOLE_SERIAL_PORT)
  22
  23 typedef struct VirtConsole {
  24     VirtIOSerialPort parent_obj;
  25
  26     CharDriverState *chr;
  27     guint watch;
  28 } VirtConsole;
  29
  30 /*
  31  * Callback function that's called from chardevs when backend becomes
  32  * writable.
  33  */
  34 static gboolean chr_write_unblocked(GIOChannel *chan, GIOCondition cond,
  35                                     void *opaque)
  36 {
  37     VirtConsole *vcon = opaque;
  38
  39     vcon->watch = 0;
  40     virtio_serial_throttle_port(VIRTIO_SERIAL_PORT(vcon), false);
  41     return FALSE;
  42 }
  43
  44 /* Callback function that's called when the guest sends us data */
  45 static ssize_t flush_buf(VirtIOSerialPort *port,
  46                          const uint8_t *buf, ssize_t len)
  47 {
  48     VirtConsole *vcon = VIRTIO_CONSOLE(port);
  49     ssize_t ret;
  50
  51     if (!vcon->chr) {
  52         /* If there's no backend, we can just say we consumed all data. */
  53         return len;
  54     }
  55
  56     ret = qemu_chr_fe_write(vcon->chr, buf, len);
  57     trace_virtio_console_flush_buf(port->id, len, ret);
  58
  59     if (ret < len) {
  60         VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_GET_CLASS(port);
  61
  62         /*
  63          * Ideally we'd get a better error code than just -1, but
  64          * that's what the chardev interface gives us right now.  If
  65          * we had a finer-grained message, like -EPIPE, we could close
  66          * this connection.
  67          */
  68         if (ret < 0)
  69             ret = 0;
  70         if (!k->is_console) {
  71             virtio_serial_throttle_port(port, true);
  72             if (!vcon->watch) {
  73                 vcon->watch = qemu_chr_fe_add_watch(vcon->chr,
  74                                                     G_IO_OUT|G_IO_HUP,
  75                                                     chr_write_unblocked, vcon);
  76             }
  77         }
  78     }
  79     return ret;
  80 }
  81
  82 /* Callback function that's called when the guest opens/closes the port */
  83 static void set_guest_connected(VirtIOSerialPort *port, int guest_connected)
  84 {
  85     VirtConsole *vcon = VIRTIO_CONSOLE(port);
  86     DeviceState *dev = DEVICE(port);
  87
  88     if (vcon->chr) {
  89         qemu_chr_fe_set_open(vcon->chr, guest_connected);
  90     }
  91
  92     if (dev->id) {
  93         qapi_event_send_vserport_change(dev->id, guest_connected,
  94                                         &error_abort);
  95     }
  96 }
  97
  98 static void guest_writable(VirtIOSerialPort *port)
  99 {
 100     VirtConsole *vcon = VIRTIO_CONSOLE(port);
 101
 102     if (vcon->chr) {
 103         qemu_chr_accept_input(vcon->chr);
 104     }
 105 }
 106
 107 /* Readiness of the guest to accept data on a port */
 108 static int chr_can_read(void *opaque)
 109 {
 110     VirtConsole *vcon = opaque;
 111
 112     return virtio_serial_guest_ready(VIRTIO_SERIAL_PORT(vcon));
 113 }
 114
 115 /* Send data from a char device over to the guest */
 116 static void chr_read(void *opaque, const uint8_t *buf, int size)
 117 {
 118     VirtConsole *vcon = opaque;
 119     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(vcon);
 120
 121     trace_virtio_console_chr_read(port->id, size);
 122     virtio_serial_write(port, buf, size);
 123 }
 124
 125 static void chr_event(void *opaque, int event)
 126 {
 127     VirtConsole *vcon = opaque;
 128     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(vcon);
 129
 130     trace_virtio_console_chr_event(port->id, event);
 131     switch (event) {
 132     case CHR_EVENT_OPENED:
 133         virtio_serial_open(port);
 134         break;
 135     case CHR_EVENT_CLOSED:
 136         if (vcon->watch) {
 137             g_source_remove(vcon->watch);
 138             vcon->watch = 0;
 139         }
 140         virtio_serial_close(port);
 141         break;
 142     }
 143 }
 144
 145 static void virtconsole_realize(DeviceState *dev, Error **errp)
 146 {
 147     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
 148     VirtConsole *vcon = VIRTIO_CONSOLE(dev);
 149     VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_GET_CLASS(dev);
 150
 151     if (port->id == 0 && !k->is_console) {
 152         error_setg(errp, "Port number 0 on virtio-serial devices reserved "
 153                    "for virtconsole devices for backward compatibility.");
 154         return;
 155     }
 156
 157     if (vcon->chr) {
 158         vcon->chr->explicit_fe_open = 1;
 159         qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
 160                               vcon);
 161     }
 162 }
 163
 164 static void virtconsole_unrealize(DeviceState *dev, Error **errp)
 165 {
 166     VirtConsole *vcon = VIRTIO_CONSOLE(dev);
 167
 168     if (vcon->watch) {
 169         g_source_remove(vcon->watch);
 170     }
 171 }
 172
 173 static void virtconsole_class_init(ObjectClass *klass, void *data)
 174 {
 175     VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_CLASS(klass);
 176
 177     k->is_console = true;
 178 }
 179
 180 static const TypeInfo virtconsole_info = {
 181     .name          = "virtconsole",
 182     .parent        = TYPE_VIRTIO_CONSOLE_SERIAL_PORT,
 183     .class_init    = virtconsole_class_init,
 184 };
 185
 186 static Property virtserialport_properties[] = {
 187     DEFINE_PROP_CHR("chardev", VirtConsole, chr),
 188     DEFINE_PROP_END_OF_LIST(),
 189 };
 190
 191 static void virtserialport_class_init(ObjectClass *klass, void *data)
 192 {
 193     DeviceClass *dc = DEVICE_CLASS(klass);
 194     VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_CLASS(klass);
 195
 196     k->realize = virtconsole_realize;
 197     k->unrealize = virtconsole_unrealize;
 198     k->have_data = flush_buf;
 199     k->set_guest_connected = set_guest_connected;
 200     k->guest_writable = guest_writable;
 201     dc->props = virtserialport_properties;
 202 }
 203
 204 static const TypeInfo virtserialport_info = {
 205     .name          = TYPE_VIRTIO_CONSOLE_SERIAL_PORT,
 206     .parent        = TYPE_VIRTIO_SERIAL_PORT,
 207     .instance_size = sizeof(VirtConsole),
 208     .class_init    = virtserialport_class_init,
 209 };
 210
 211 static void virtconsole_register_types(void)
 212 {
 213     type_register_static(&virtserialport_info);
 214     type_register_static(&virtconsole_info);
 215 }
 216
 217 type_init(virtconsole_register_types)