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