hw/virtio-serial-bus.c

   1 /*
   2  * A bus for connecting virtio serial and console ports
   3  *
   4  * Copyright (C) 2009, 2010 Red Hat, Inc.
   5  *
   6  * Author(s):
   7  *  Amit Shah <amit.shah@redhat.com>
   8  *
   9  * Some earlier parts are:
  10  *  Copyright IBM, Corp. 2008
  11  * authored by
  12  *  Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
  13  *
  14  * This work is licensed under the terms of the GNU GPL, version 2.  See
  15  * the COPYING file in the top-level directory.
  16  */
  17
  18 #include "iov.h"
  19 #include "monitor.h"
  20 #include "qemu-queue.h"
  21 #include "sysbus.h"
  22 #include "virtio-serial.h"
  23
  24 /* The virtio-serial bus on top of which the ports will ride as devices */
  25 struct VirtIOSerialBus {
  26     BusState qbus;
  27
  28     /* This is the parent device that provides the bus for ports. */
  29     VirtIOSerial *vser;
  30
  31     /* The maximum number of ports that can ride on top of this bus */
  32     uint32_t max_nr_ports;
  33 };
  34
  35 struct VirtIOSerial {
  36     VirtIODevice vdev;
  37
  38     VirtQueue *c_ivq, *c_ovq;
  39     /* Arrays of ivqs and ovqs: one per port */
  40     VirtQueue **ivqs, **ovqs;
  41
  42     VirtIOSerialBus *bus;
  43
  44     QTAILQ_HEAD(, VirtIOSerialPort) ports;
  45
  46     /* bitmap for identifying active ports */
  47     uint32_t *ports_map;
  48
  49     struct virtio_console_config config;
  50 };
  51
  52 static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
  53 {
  54     VirtIOSerialPort *port;
  55
  56     if (id == VIRTIO_CONSOLE_BAD_ID) {
  57         return NULL;
  58     }
  59
  60     QTAILQ_FOREACH(port, &vser->ports, next) {
  61         if (port->id == id)
  62             return port;
  63     }
  64     return NULL;
  65 }
  66
  67 static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
  68 {
  69     VirtIOSerialPort *port;
  70
  71     QTAILQ_FOREACH(port, &vser->ports, next) {
  72         if (port->ivq == vq || port->ovq == vq)
  73             return port;
  74     }
  75     return NULL;
  76 }
  77
  78 static bool use_multiport(VirtIOSerial *vser)
  79 {
  80     return vser->vdev.guest_features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
  81 }
  82
  83 static size_t write_to_port(VirtIOSerialPort *port,
  84                             const uint8_t *buf, size_t size)
  85 {
  86     VirtQueueElement elem;
  87     VirtQueue *vq;
  88     size_t offset;
  89
  90     vq = port->ivq;
  91     if (!virtio_queue_ready(vq)) {
  92         return 0;
  93     }
  94
  95     offset = 0;
  96     while (offset < size) {
  97         size_t len;
  98
  99         if (!virtqueue_pop(vq, &elem)) {
 100             break;
 101         }
 102
 103         len = iov_from_buf(elem.in_sg, elem.in_num,
 104                            buf + offset, size - offset);
 105         offset += len;
 106
 107         virtqueue_push(vq, &elem, len);
 108     }
 109
 110     virtio_notify(&port->vser->vdev, vq);
 111     return offset;
 112 }
 113
 114 static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
 115                                  VirtIODevice *vdev, bool discard)
 116 {
 117     VirtQueueElement elem;
 118
 119     assert(port || discard);
 120
 121     while ((discard || !port->throttled) && virtqueue_pop(vq, &elem)) {
 122         uint8_t *buf;
 123         size_t ret, buf_size;
 124
 125         if (!discard) {
 126             buf_size = iov_size(elem.out_sg, elem.out_num);
 127             buf = qemu_malloc(buf_size);
 128             ret = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, buf_size);
 129
 130             port->info->have_data(port, buf, ret);
 131             qemu_free(buf);
 132         }
 133         virtqueue_push(vq, &elem, 0);
 134     }
 135     virtio_notify(vdev, vq);
 136 }
 137
 138 static void flush_queued_data(VirtIOSerialPort *port, bool discard)
 139 {
 140     assert(port);
 141
 142     do_flush_queued_data(port, port->ovq, &port->vser->vdev, discard);
 143 }
 144
 145 static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len)
 146 {
 147     VirtQueueElement elem;
 148     VirtQueue *vq;
 149     struct virtio_console_control *cpkt;
 150
 151     vq = port->vser->c_ivq;
 152     if (!virtio_queue_ready(vq)) {
 153         return 0;
 154     }
 155     if (!virtqueue_pop(vq, &elem)) {
 156         return 0;
 157     }
 158
 159     cpkt = (struct virtio_console_control *)buf;
 160     stl_p(&cpkt->id, port->id);
 161     memcpy(elem.in_sg[0].iov_base, buf, len);
 162
 163     virtqueue_push(vq, &elem, len);
 164     virtio_notify(&port->vser->vdev, vq);
 165     return len;
 166 }
 167
 168 static size_t send_control_event(VirtIOSerialPort *port, uint16_t event,
 169                                  uint16_t value)
 170 {
 171     struct virtio_console_control cpkt;
 172
 173     stw_p(&cpkt.event, event);
 174     stw_p(&cpkt.value, value);
 175
 176     return send_control_msg(port, &cpkt, sizeof(cpkt));
 177 }
 178
 179 /* Functions for use inside qemu to open and read from/write to ports */
 180 int virtio_serial_open(VirtIOSerialPort *port)
 181 {
 182     /* Don't allow opening an already-open port */
 183     if (port->host_connected) {
 184         return 0;
 185     }
 186     /* Send port open notification to the guest */
 187     port->host_connected = true;
 188     send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
 189
 190     return 0;
 191 }
 192
 193 int virtio_serial_close(VirtIOSerialPort *port)
 194 {
 195     port->host_connected = false;
 196     /*
 197      * If there's any data the guest sent which the app didn't
 198      * consume, reset the throttling flag and discard the data.
 199      */
 200     port->throttled = false;
 201     flush_queued_data(port, true);
 202
 203     send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
 204
 205     return 0;
 206 }
 207
 208 /* Individual ports/apps call this function to write to the guest. */
 209 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 210                             size_t size)
 211 {
 212     if (!port || !port->host_connected || !port->guest_connected) {
 213         return 0;
 214     }
 215     return write_to_port(port, buf, size);
 216 }
 217
 218 /*
 219  * Readiness of the guest to accept data on a port.
 220  * Returns max. data the guest can receive
 221  */
 222 size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
 223 {
 224     VirtQueue *vq = port->ivq;
 225
 226     if (!virtio_queue_ready(vq) ||
 227         !(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
 228         virtio_queue_empty(vq)) {
 229         return 0;
 230     }
 231     if (use_multiport(port->vser) && !port->guest_connected) {
 232         return 0;
 233     }
 234
 235     if (virtqueue_avail_bytes(vq, 4096, 0)) {
 236         return 4096;
 237     }
 238     if (virtqueue_avail_bytes(vq, 1, 0)) {
 239         return 1;
 240     }
 241     return 0;
 242 }
 243
 244 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
 245 {
 246     if (!port) {
 247         return;
 248     }
 249
 250     port->throttled = throttle;
 251     if (throttle) {
 252         return;
 253     }
 254
 255     flush_queued_data(port, false);
 256 }
 257
 258 /* Guest wants to notify us of some event */
 259 static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
 260 {
 261     struct VirtIOSerialPort *port;
 262     struct virtio_console_control cpkt, *gcpkt;
 263     uint8_t *buffer;
 264     size_t buffer_len;
 265
 266     gcpkt = buf;
 267
 268     if (len < sizeof(cpkt)) {
 269         /* The guest sent an invalid control packet */
 270         return;
 271     }
 272
 273     cpkt.event = lduw_p(&gcpkt->event);
 274     cpkt.value = lduw_p(&gcpkt->value);
 275
 276     port = find_port_by_id(vser, ldl_p(&gcpkt->id));
 277     if (!port && cpkt.event != VIRTIO_CONSOLE_DEVICE_READY)
 278         return;
 279
 280     switch(cpkt.event) {
 281     case VIRTIO_CONSOLE_DEVICE_READY:
 282         if (!cpkt.value) {
 283             error_report("virtio-serial-bus: Guest failure in adding device %s\n",
 284                          vser->bus->qbus.name);
 285             break;
 286         }
 287         /*
 288          * The device is up, we can now tell the device about all the
 289          * ports we have here.
 290          */
 291         QTAILQ_FOREACH(port, &vser->ports, next) {
 292             send_control_event(port, VIRTIO_CONSOLE_PORT_ADD, 1);
 293         }
 294         break;
 295
 296     case VIRTIO_CONSOLE_PORT_READY:
 297         if (!cpkt.value) {
 298             error_report("virtio-serial-bus: Guest failure in adding port %u for device %s\n",
 299                          port->id, vser->bus->qbus.name);
 300             break;
 301         }
 302         /*
 303          * Now that we know the guest asked for the port name, we're
 304          * sure the guest has initialised whatever state is necessary
 305          * for this port. Now's a good time to let the guest know if
 306          * this port is a console port so that the guest can hook it
 307          * up to hvc.
 308          */
 309         if (port->is_console) {
 310             send_control_event(port, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
 311         }
 312
 313         if (port->name) {
 314             stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
 315             stw_p(&cpkt.value, 1);
 316
 317             buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
 318             buffer = qemu_malloc(buffer_len);
 319
 320             memcpy(buffer, &cpkt, sizeof(cpkt));
 321             memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
 322             buffer[buffer_len - 1] = 0;
 323
 324             send_control_msg(port, buffer, buffer_len);
 325             qemu_free(buffer);
 326         }
 327
 328         if (port->host_connected) {
 329             send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);
 330         }
 331
 332         /*
 333          * When the guest has asked us for this information it means
 334          * the guest is all setup and has its virtqueues
 335          * initialised. If some app is interested in knowing about
 336          * this event, let it know.
 337          */
 338         if (port->info->guest_ready) {
 339             port->info->guest_ready(port);
 340         }
 341         break;
 342
 343     case VIRTIO_CONSOLE_PORT_OPEN:
 344         port->guest_connected = cpkt.value;
 345         if (cpkt.value && port->info->guest_open) {
 346             /* Send the guest opened notification if an app is interested */
 347             port->info->guest_open(port);
 348         }
 349
 350         if (!cpkt.value && port->info->guest_close) {
 351             /* Send the guest closed notification if an app is interested */
 352             port->info->guest_close(port);
 353         }
 354         break;
 355     }
 356 }
 357
 358 static void control_in(VirtIODevice *vdev, VirtQueue *vq)
 359 {
 360 }
 361
 362 static void control_out(VirtIODevice *vdev, VirtQueue *vq)
 363 {
 364     VirtQueueElement elem;
 365     VirtIOSerial *vser;
 366     uint8_t *buf;
 367     size_t len;
 368
 369     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 370
 371     len = 0;
 372     buf = NULL;
 373     while (virtqueue_pop(vq, &elem)) {
 374         size_t cur_len, copied;
 375
 376         cur_len = iov_size(elem.out_sg, elem.out_num);
 377         /*
 378          * Allocate a new buf only if we didn't have one previously or
 379          * if the size of the buf differs
 380          */
 381         if (cur_len > len) {
 382             qemu_free(buf);
 383
 384             buf = qemu_malloc(cur_len);
 385             len = cur_len;
 386         }
 387         copied = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, len);
 388
 389         handle_control_message(vser, buf, copied);
 390         virtqueue_push(vq, &elem, 0);
 391     }
 392     qemu_free(buf);
 393     virtio_notify(vdev, vq);
 394 }
 395
 396 /* Guest wrote something to some port. */
 397 static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
 398 {
 399     VirtIOSerial *vser;
 400     VirtIOSerialPort *port;
 401     bool discard;
 402
 403     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 404     port = find_port_by_vq(vser, vq);
 405
 406     discard = false;
 407     if (!port || !port->host_connected || !port->info->have_data) {
 408         discard = true;
 409     }
 410
 411     if (!discard && port->throttled) {
 412         return;
 413     }
 414
 415     do_flush_queued_data(port, vq, vdev, discard);
 416 }
 417
 418 static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
 419 {
 420 }
 421
 422 static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
 423 {
 424     VirtIOSerial *vser;
 425
 426     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 427
 428     if (vser->bus->max_nr_ports > 1) {
 429         features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
 430     }
 431     return features;
 432 }
 433
 434 /* Guest requested config info */
 435 static void get_config(VirtIODevice *vdev, uint8_t *config_data)
 436 {
 437     VirtIOSerial *vser;
 438
 439     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 440     memcpy(config_data, &vser->config, sizeof(struct virtio_console_config));
 441 }
 442
 443 static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
 444 {
 445     struct virtio_console_config config;
 446
 447     memcpy(&config, config_data, sizeof(config));
 448 }
 449
 450 static void virtio_serial_save(QEMUFile *f, void *opaque)
 451 {
 452     VirtIOSerial *s = opaque;
 453     VirtIOSerialPort *port;
 454     uint32_t nr_active_ports;
 455     unsigned int i;
 456
 457     /* The virtio device */
 458     virtio_save(&s->vdev, f);
 459
 460     /* The config space */
 461     qemu_put_be16s(f, &s->config.cols);
 462     qemu_put_be16s(f, &s->config.rows);
 463
 464     qemu_put_be32s(f, &s->config.max_nr_ports);
 465
 466     /* The ports map */
 467
 468     for (i = 0; i < (s->config.max_nr_ports + 31) / 32; i++) {
 469         qemu_put_be32s(f, &s->ports_map[i]);
 470     }
 471
 472     /* Ports */
 473
 474     nr_active_ports = 0;
 475     QTAILQ_FOREACH(port, &s->ports, next) {
 476         nr_active_ports++;
 477     }
 478
 479     qemu_put_be32s(f, &nr_active_ports);
 480
 481     /*
 482      * Items in struct VirtIOSerialPort.
 483      */
 484     QTAILQ_FOREACH(port, &s->ports, next) {
 485         qemu_put_be32s(f, &port->id);
 486         qemu_put_byte(f, port->guest_connected);
 487         qemu_put_byte(f, port->host_connected);
 488     }
 489 }
 490
 491 static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
 492 {
 493     VirtIOSerial *s = opaque;
 494     VirtIOSerialPort *port;
 495     size_t ports_map_size;
 496     uint32_t max_nr_ports, nr_active_ports, *ports_map;
 497     unsigned int i;
 498
 499     if (version_id > 2) {
 500         return -EINVAL;
 501     }
 502
 503     /* The virtio device */
 504     virtio_load(&s->vdev, f);
 505
 506     if (version_id < 2) {
 507         return 0;
 508     }
 509
 510     /* The config space */
 511     qemu_get_be16s(f, &s->config.cols);
 512     qemu_get_be16s(f, &s->config.rows);
 513
 514     qemu_get_be32s(f, &max_nr_ports);
 515     if (max_nr_ports > s->config.max_nr_ports) {
 516         /* Source could have had more ports than us. Fail migration. */
 517         return -EINVAL;
 518     }
 519
 520     ports_map_size = sizeof(uint32_t) * (max_nr_ports + 31) / 32;
 521     ports_map = qemu_malloc(ports_map_size);
 522
 523     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 524         qemu_get_be32s(f, &ports_map[i]);
 525
 526         if (ports_map[i] != s->ports_map[i]) {
 527             /*
 528              * Ports active on source and destination don't
 529              * match. Fail migration.
 530              */
 531             qemu_free(ports_map);
 532             return -EINVAL;
 533         }
 534     }
 535     qemu_free(ports_map);
 536
 537     qemu_get_be32s(f, &nr_active_ports);
 538
 539     /* Items in struct VirtIOSerialPort */
 540     for (i = 0; i < nr_active_ports; i++) {
 541         uint32_t id;
 542         bool host_connected;
 543
 544         id = qemu_get_be32(f);
 545         port = find_port_by_id(s, id);
 546
 547         port->guest_connected = qemu_get_byte(f);
 548         host_connected = qemu_get_byte(f);
 549         if (host_connected != port->host_connected) {
 550             /*
 551              * We have to let the guest know of the host connection
 552              * status change
 553              */
 554             send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN,
 555                                port->host_connected);
 556         }
 557     }
 558     return 0;
 559 }
 560
 561 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
 562
 563 static struct BusInfo virtser_bus_info = {
 564     .name      = "virtio-serial-bus",
 565     .size      = sizeof(VirtIOSerialBus),
 566     .print_dev = virtser_bus_dev_print,
 567 };
 568
 569 static VirtIOSerialBus *virtser_bus_new(DeviceState *dev)
 570 {
 571     VirtIOSerialBus *bus;
 572
 573     bus = FROM_QBUS(VirtIOSerialBus, qbus_create(&virtser_bus_info, dev, NULL));
 574     bus->qbus.allow_hotplug = 1;
 575
 576     return bus;
 577 }
 578
 579 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
 580 {
 581     VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev);
 582     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
 583
 584     monitor_printf(mon, "%*s dev-prop-int: id: %u\n",
 585                    indent, "", port->id);
 586     monitor_printf(mon, "%*s dev-prop-int: guest_connected: %d\n",
 587                    indent, "", port->guest_connected);
 588     monitor_printf(mon, "%*s dev-prop-int: host_connected: %d\n",
 589                    indent, "", port->host_connected);
 590     monitor_printf(mon, "%*s dev-prop-int: throttled: %d\n",
 591                    indent, "", port->throttled);
 592 }
 593
 594 /* This function is only used if a port id is not provided by the user */
 595 static uint32_t find_free_port_id(VirtIOSerial *vser)
 596 {
 597     unsigned int i;
 598
 599     for (i = 0; i < (vser->config.max_nr_ports + 31) / 32; i++) {
 600         uint32_t map, bit;
 601
 602         map = vser->ports_map[i];
 603         bit = ffs(~map);
 604         if (bit) {
 605             return (bit - 1) + i * 32;
 606         }
 607     }
 608     return VIRTIO_CONSOLE_BAD_ID;
 609 }
 610
 611 static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
 612 {
 613     unsigned int i;
 614
 615     i = port_id / 32;
 616     vser->ports_map[i] |= 1U << (port_id % 32);
 617 }
 618
 619 static void add_port(VirtIOSerial *vser, uint32_t port_id)
 620 {
 621     mark_port_added(vser, port_id);
 622
 623     send_control_event(find_port_by_id(vser, port_id),
 624                        VIRTIO_CONSOLE_PORT_ADD, 1);
 625 }
 626
 627 static void remove_port(VirtIOSerial *vser, uint32_t port_id)
 628 {
 629     VirtIOSerialPort *port;
 630     unsigned int i;
 631
 632     i = port_id / 32;
 633     vser->ports_map[i] &= ~(1U << (port_id % 32));
 634
 635     port = find_port_by_id(vser, port_id);
 636     /* Flush out any unconsumed buffers first */
 637     flush_queued_data(port, true);
 638
 639     send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1);
 640 }
 641
 642 static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base)
 643 {
 644     VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev);
 645     VirtIOSerialPortInfo *info = DO_UPCAST(VirtIOSerialPortInfo, qdev, base);
 646     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
 647     VirtIOSerialBus *bus = DO_UPCAST(VirtIOSerialBus, qbus, qdev->parent_bus);
 648     int ret;
 649     bool plugging_port0;
 650
 651     port->vser = bus->vser;
 652
 653     /*
 654      * Is the first console port we're seeing? If so, put it up at
 655      * location 0. This is done for backward compatibility (old
 656      * kernel, new qemu).
 657      */
 658     plugging_port0 = port->is_console && !find_port_by_id(port->vser, 0);
 659
 660     if (find_port_by_id(port->vser, port->id)) {
 661         error_report("virtio-serial-bus: A port already exists at id %u\n",
 662                      port->id);
 663         return -1;
 664     }
 665
 666     if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 667         if (plugging_port0) {
 668             port->id = 0;
 669         } else {
 670             port->id = find_free_port_id(port->vser);
 671             if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 672                 error_report("virtio-serial-bus: Maximum port limit for this device reached\n");
 673                 return -1;
 674             }
 675         }
 676     }
 677
 678     if (port->id >= port->vser->config.max_nr_ports) {
 679         error_report("virtio-serial-bus: Out-of-range port id specified, max. allowed: %u\n",
 680                      port->vser->config.max_nr_ports - 1);
 681         return -1;
 682     }
 683
 684     dev->info = info;
 685     ret = info->init(dev);
 686     if (ret) {
 687         return ret;
 688     }
 689
 690     if (!use_multiport(port->vser)) {
 691         /*
 692          * Allow writes to guest in this case; we have no way of
 693          * knowing if a guest port is connected.
 694          */
 695         port->guest_connected = true;
 696     }
 697
 698     QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
 699     port->ivq = port->vser->ivqs[port->id];
 700     port->ovq = port->vser->ovqs[port->id];
 701
 702     add_port(port->vser, port->id);
 703
 704     /* Send an update to the guest about this new port added */
 705     virtio_notify_config(&port->vser->vdev);
 706
 707     return ret;
 708 }
 709
 710 static int virtser_port_qdev_exit(DeviceState *qdev)
 711 {
 712     VirtIOSerialDevice *dev = DO_UPCAST(VirtIOSerialDevice, qdev, qdev);
 713     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
 714     VirtIOSerial *vser = port->vser;
 715
 716     remove_port(port->vser, port->id);
 717
 718     QTAILQ_REMOVE(&vser->ports, port, next);
 719
 720     if (port->info->exit)
 721         port->info->exit(dev);
 722
 723     return 0;
 724 }
 725
 726 void virtio_serial_port_qdev_register(VirtIOSerialPortInfo *info)
 727 {
 728     info->qdev.init = virtser_port_qdev_init;
 729     info->qdev.bus_info = &virtser_bus_info;
 730     info->qdev.exit = virtser_port_qdev_exit;
 731     info->qdev.unplug = qdev_simple_unplug_cb;
 732     qdev_register(&info->qdev);
 733 }
 734
 735 VirtIODevice *virtio_serial_init(DeviceState *dev, uint32_t max_nr_ports)
 736 {
 737     VirtIOSerial *vser;
 738     VirtIODevice *vdev;
 739     uint32_t i;
 740
 741     if (!max_nr_ports)
 742         return NULL;
 743
 744     vdev = virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE,
 745                               sizeof(struct virtio_console_config),
 746                               sizeof(VirtIOSerial));
 747
 748     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 749
 750     /* Spawn a new virtio-serial bus on which the ports will ride as devices */
 751     vser->bus = virtser_bus_new(dev);
 752     vser->bus->vser = vser;
 753     QTAILQ_INIT(&vser->ports);
 754
 755     vser->bus->max_nr_ports = max_nr_ports;
 756     vser->ivqs = qemu_malloc(max_nr_ports * sizeof(VirtQueue *));
 757     vser->ovqs = qemu_malloc(max_nr_ports * sizeof(VirtQueue *));
 758
 759     /* Add a queue for host to guest transfers for port 0 (backward compat) */
 760     vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
 761     /* Add a queue for guest to host transfers for port 0 (backward compat) */
 762     vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
 763
 764     /* control queue: host to guest */
 765     vser->c_ivq = virtio_add_queue(vdev, 16, control_in);
 766     /* control queue: guest to host */
 767     vser->c_ovq = virtio_add_queue(vdev, 16, control_out);
 768
 769     for (i = 1; i < vser->bus->max_nr_ports; i++) {
 770         /* Add a per-port queue for host to guest transfers */
 771         vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
 772         /* Add a per-per queue for guest to host transfers */
 773         vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
 774     }
 775
 776     vser->config.max_nr_ports = max_nr_ports;
 777     vser->ports_map = qemu_mallocz(((max_nr_ports + 31) / 32)
 778         * sizeof(vser->ports_map[0]));
 779     /*
 780      * Reserve location 0 for a console port for backward compat
 781      * (old kernel, new qemu)
 782      */
 783     mark_port_added(vser, 0);
 784
 785     vser->vdev.get_features = get_features;
 786     vser->vdev.get_config = get_config;
 787     vser->vdev.set_config = set_config;
 788
 789     /*
 790      * Register for the savevm section with the virtio-console name
 791      * to preserve backward compat
 792      */
 793     register_savevm("virtio-console", -1, 2, virtio_serial_save,
 794                     virtio_serial_load, vser);
 795
 796     return vdev;
 797 }