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