hw/char/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  * Contributions after 2012-01-13 are licensed under the terms of the
  18  * GNU GPL, version 2 or (at your option) any later version.
  19  */
  20
  21 #include "standard-headers/linux/virtio_ids.h"
  22 #include "qemu/iov.h"
  23 #include "monitor/monitor.h"
  24 #include "qemu/queue.h"
  25 #include "hw/sysbus.h"
  26 #include "trace.h"
  27 #include "hw/virtio/virtio-serial.h"
  28 #include "hw/virtio/virtio-access.h"
  29
  30 static struct VirtIOSerialDevices {
  31     QLIST_HEAD(, VirtIOSerial) devices;
  32 } vserdevices;
  33
  34 static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
  35 {
  36     VirtIOSerialPort *port;
  37
  38     if (id == VIRTIO_CONSOLE_BAD_ID) {
  39         return NULL;
  40     }
  41
  42     QTAILQ_FOREACH(port, &vser->ports, next) {
  43         if (port->id == id)
  44             return port;
  45     }
  46     return NULL;
  47 }
  48
  49 static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
  50 {
  51     VirtIOSerialPort *port;
  52
  53     QTAILQ_FOREACH(port, &vser->ports, next) {
  54         if (port->ivq == vq || port->ovq == vq)
  55             return port;
  56     }
  57     return NULL;
  58 }
  59
  60 static VirtIOSerialPort *find_port_by_name(char *name)
  61 {
  62     VirtIOSerial *vser;
  63
  64     QLIST_FOREACH(vser, &vserdevices.devices, next) {
  65         VirtIOSerialPort *port;
  66
  67         QTAILQ_FOREACH(port, &vser->ports, next) {
  68             if (!strcmp(port->name, name)) {
  69                 return port;
  70             }
  71         }
  72     }
  73     return NULL;
  74 }
  75
  76 static bool use_multiport(VirtIOSerial *vser)
  77 {
  78     VirtIODevice *vdev = VIRTIO_DEVICE(vser);
  79     return virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT);
  80 }
  81
  82 static size_t write_to_port(VirtIOSerialPort *port,
  83                             const uint8_t *buf, size_t size)
  84 {
  85     VirtQueueElement elem;
  86     VirtQueue *vq;
  87     size_t offset;
  88
  89     vq = port->ivq;
  90     if (!virtio_queue_ready(vq)) {
  91         return 0;
  92     }
  93
  94     offset = 0;
  95     while (offset < size) {
  96         size_t len;
  97
  98         if (!virtqueue_pop(vq, &elem)) {
  99             break;
 100         }
 101
 102         len = iov_from_buf(elem.in_sg, elem.in_num, 0,
 103                            buf + offset, size - offset);
 104         offset += len;
 105
 106         virtqueue_push(vq, &elem, len);
 107     }
 108
 109     virtio_notify(VIRTIO_DEVICE(port->vser), vq);
 110     return offset;
 111 }
 112
 113 static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
 114 {
 115     VirtQueueElement elem;
 116
 117     if (!virtio_queue_ready(vq)) {
 118         return;
 119     }
 120     while (virtqueue_pop(vq, &elem)) {
 121         virtqueue_push(vq, &elem, 0);
 122     }
 123     virtio_notify(vdev, vq);
 124 }
 125
 126 static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
 127                                  VirtIODevice *vdev)
 128 {
 129     VirtIOSerialPortClass *vsc;
 130
 131     assert(port);
 132     assert(virtio_queue_ready(vq));
 133
 134     vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 135
 136     while (!port->throttled) {
 137         unsigned int i;
 138
 139         /* Pop an elem only if we haven't left off a previous one mid-way */
 140         if (!port->elem.out_num) {
 141             if (!virtqueue_pop(vq, &port->elem)) {
 142                 break;
 143             }
 144             port->iov_idx = 0;
 145             port->iov_offset = 0;
 146         }
 147
 148         for (i = port->iov_idx; i < port->elem.out_num; i++) {
 149             size_t buf_size;
 150             ssize_t ret;
 151
 152             buf_size = port->elem.out_sg[i].iov_len - port->iov_offset;
 153             ret = vsc->have_data(port,
 154                                   port->elem.out_sg[i].iov_base
 155                                   + port->iov_offset,
 156                                   buf_size);
 157             if (port->throttled) {
 158                 port->iov_idx = i;
 159                 if (ret > 0) {
 160                     port->iov_offset += ret;
 161                 }
 162                 break;
 163             }
 164             port->iov_offset = 0;
 165         }
 166         if (port->throttled) {
 167             break;
 168         }
 169         virtqueue_push(vq, &port->elem, 0);
 170         port->elem.out_num = 0;
 171     }
 172     virtio_notify(vdev, vq);
 173 }
 174
 175 static void flush_queued_data(VirtIOSerialPort *port)
 176 {
 177     assert(port);
 178
 179     if (!virtio_queue_ready(port->ovq)) {
 180         return;
 181     }
 182     do_flush_queued_data(port, port->ovq, VIRTIO_DEVICE(port->vser));
 183 }
 184
 185 static size_t send_control_msg(VirtIOSerial *vser, void *buf, size_t len)
 186 {
 187     VirtQueueElement elem;
 188     VirtQueue *vq;
 189
 190     vq = vser->c_ivq;
 191     if (!virtio_queue_ready(vq)) {
 192         return 0;
 193     }
 194     if (!virtqueue_pop(vq, &elem)) {
 195         return 0;
 196     }
 197
 198     memcpy(elem.in_sg[0].iov_base, buf, len);
 199
 200     virtqueue_push(vq, &elem, len);
 201     virtio_notify(VIRTIO_DEVICE(vser), vq);
 202     return len;
 203 }
 204
 205 static size_t send_control_event(VirtIOSerial *vser, uint32_t port_id,
 206                                  uint16_t event, uint16_t value)
 207 {
 208     VirtIODevice *vdev = VIRTIO_DEVICE(vser);
 209     struct virtio_console_control cpkt;
 210
 211     virtio_stl_p(vdev, &cpkt.id, port_id);
 212     virtio_stw_p(vdev, &cpkt.event, event);
 213     virtio_stw_p(vdev, &cpkt.value, value);
 214
 215     trace_virtio_serial_send_control_event(port_id, event, value);
 216     return send_control_msg(vser, &cpkt, sizeof(cpkt));
 217 }
 218
 219 /* Functions for use inside qemu to open and read from/write to ports */
 220 int virtio_serial_open(VirtIOSerialPort *port)
 221 {
 222     /* Don't allow opening an already-open port */
 223     if (port->host_connected) {
 224         return 0;
 225     }
 226     /* Send port open notification to the guest */
 227     port->host_connected = true;
 228     send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
 229
 230     return 0;
 231 }
 232
 233 int virtio_serial_close(VirtIOSerialPort *port)
 234 {
 235     port->host_connected = false;
 236     /*
 237      * If there's any data the guest sent which the app didn't
 238      * consume, reset the throttling flag and discard the data.
 239      */
 240     port->throttled = false;
 241     discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
 242
 243     send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 0);
 244
 245     return 0;
 246 }
 247
 248 /* Individual ports/apps call this function to write to the guest. */
 249 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 250                             size_t size)
 251 {
 252     if (!port || !port->host_connected || !port->guest_connected) {
 253         return 0;
 254     }
 255     return write_to_port(port, buf, size);
 256 }
 257
 258 /*
 259  * Readiness of the guest to accept data on a port.
 260  * Returns max. data the guest can receive
 261  */
 262 size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
 263 {
 264     VirtIODevice *vdev = VIRTIO_DEVICE(port->vser);
 265     VirtQueue *vq = port->ivq;
 266     unsigned int bytes;
 267
 268     if (!virtio_queue_ready(vq) ||
 269         !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) ||
 270         virtio_queue_empty(vq)) {
 271         return 0;
 272     }
 273     if (use_multiport(port->vser) && !port->guest_connected) {
 274         return 0;
 275     }
 276     virtqueue_get_avail_bytes(vq, &bytes, NULL, 4096, 0);
 277     return bytes;
 278 }
 279
 280 static void flush_queued_data_bh(void *opaque)
 281 {
 282     VirtIOSerialPort *port = opaque;
 283
 284     flush_queued_data(port);
 285 }
 286
 287 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
 288 {
 289     if (!port) {
 290         return;
 291     }
 292
 293     trace_virtio_serial_throttle_port(port->id, throttle);
 294     port->throttled = throttle;
 295     if (throttle) {
 296         return;
 297     }
 298     qemu_bh_schedule(port->bh);
 299 }
 300
 301 /* Guest wants to notify us of some event */
 302 static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
 303 {
 304     VirtIODevice *vdev = VIRTIO_DEVICE(vser);
 305     struct VirtIOSerialPort *port;
 306     VirtIOSerialPortClass *vsc;
 307     struct virtio_console_control cpkt, *gcpkt;
 308     uint8_t *buffer;
 309     size_t buffer_len;
 310
 311     gcpkt = buf;
 312
 313     if (len < sizeof(cpkt)) {
 314         /* The guest sent an invalid control packet */
 315         return;
 316     }
 317
 318     cpkt.event = virtio_lduw_p(vdev, &gcpkt->event);
 319     cpkt.value = virtio_lduw_p(vdev, &gcpkt->value);
 320
 321     trace_virtio_serial_handle_control_message(cpkt.event, cpkt.value);
 322
 323     if (cpkt.event == VIRTIO_CONSOLE_DEVICE_READY) {
 324         if (!cpkt.value) {
 325             error_report("virtio-serial-bus: Guest failure in adding device %s",
 326                          vser->bus.qbus.name);
 327             return;
 328         }
 329         /*
 330          * The device is up, we can now tell the device about all the
 331          * ports we have here.
 332          */
 333         QTAILQ_FOREACH(port, &vser->ports, next) {
 334             send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_ADD, 1);
 335         }
 336         return;
 337     }
 338
 339     port = find_port_by_id(vser, virtio_ldl_p(vdev, &gcpkt->id));
 340     if (!port) {
 341         error_report("virtio-serial-bus: Unexpected port id %u for device %s",
 342                      virtio_ldl_p(vdev, &gcpkt->id), vser->bus.qbus.name);
 343         return;
 344     }
 345
 346     trace_virtio_serial_handle_control_message_port(port->id);
 347
 348     vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 349
 350     switch(cpkt.event) {
 351     case VIRTIO_CONSOLE_PORT_READY:
 352         if (!cpkt.value) {
 353             error_report("virtio-serial-bus: Guest failure in adding port %u for device %s",
 354                          port->id, vser->bus.qbus.name);
 355             break;
 356         }
 357         /*
 358          * Now that we know the guest asked for the port name, we're
 359          * sure the guest has initialised whatever state is necessary
 360          * for this port. Now's a good time to let the guest know if
 361          * this port is a console port so that the guest can hook it
 362          * up to hvc.
 363          */
 364         if (vsc->is_console) {
 365             send_control_event(vser, port->id, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
 366         }
 367
 368         if (port->name) {
 369             virtio_stl_p(vdev, &cpkt.id, port->id);
 370             virtio_stw_p(vdev, &cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
 371             virtio_stw_p(vdev, &cpkt.value, 1);
 372
 373             buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
 374             buffer = g_malloc(buffer_len);
 375
 376             memcpy(buffer, &cpkt, sizeof(cpkt));
 377             memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
 378             buffer[buffer_len - 1] = 0;
 379
 380             send_control_msg(vser, buffer, buffer_len);
 381             g_free(buffer);
 382         }
 383
 384         if (port->host_connected) {
 385             send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
 386         }
 387
 388         /*
 389          * When the guest has asked us for this information it means
 390          * the guest is all setup and has its virtqueues
 391          * initialised. If some app is interested in knowing about
 392          * this event, let it know.
 393          */
 394         if (vsc->guest_ready) {
 395             vsc->guest_ready(port);
 396         }
 397         break;
 398
 399     case VIRTIO_CONSOLE_PORT_OPEN:
 400         port->guest_connected = cpkt.value;
 401         if (vsc->set_guest_connected) {
 402             /* Send the guest opened notification if an app is interested */
 403             vsc->set_guest_connected(port, cpkt.value);
 404         }
 405         break;
 406     }
 407 }
 408
 409 static void control_in(VirtIODevice *vdev, VirtQueue *vq)
 410 {
 411 }
 412
 413 static void control_out(VirtIODevice *vdev, VirtQueue *vq)
 414 {
 415     VirtQueueElement elem;
 416     VirtIOSerial *vser;
 417     uint8_t *buf;
 418     size_t len;
 419
 420     vser = VIRTIO_SERIAL(vdev);
 421
 422     len = 0;
 423     buf = NULL;
 424     while (virtqueue_pop(vq, &elem)) {
 425         size_t cur_len;
 426
 427         cur_len = iov_size(elem.out_sg, elem.out_num);
 428         /*
 429          * Allocate a new buf only if we didn't have one previously or
 430          * if the size of the buf differs
 431          */
 432         if (cur_len > len) {
 433             g_free(buf);
 434
 435             buf = g_malloc(cur_len);
 436             len = cur_len;
 437         }
 438         iov_to_buf(elem.out_sg, elem.out_num, 0, buf, cur_len);
 439
 440         handle_control_message(vser, buf, cur_len);
 441         virtqueue_push(vq, &elem, 0);
 442     }
 443     g_free(buf);
 444     virtio_notify(vdev, vq);
 445 }
 446
 447 /* Guest wrote something to some port. */
 448 static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
 449 {
 450     VirtIOSerial *vser;
 451     VirtIOSerialPort *port;
 452
 453     vser = VIRTIO_SERIAL(vdev);
 454     port = find_port_by_vq(vser, vq);
 455
 456     if (!port || !port->host_connected) {
 457         discard_vq_data(vq, vdev);
 458         return;
 459     }
 460
 461     if (!port->throttled) {
 462         do_flush_queued_data(port, vq, vdev);
 463         return;
 464     }
 465 }
 466
 467 static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
 468 {
 469 }
 470
 471 static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
 472 {
 473     VirtIOSerial *vser;
 474
 475     vser = VIRTIO_SERIAL(vdev);
 476
 477     if (vser->bus.max_nr_ports > 1) {
 478         virtio_add_feature(&features, VIRTIO_CONSOLE_F_MULTIPORT);
 479     }
 480     return features;
 481 }
 482
 483 /* Guest requested config info */
 484 static void get_config(VirtIODevice *vdev, uint8_t *config_data)
 485 {
 486     VirtIOSerial *vser = VIRTIO_SERIAL(vdev);
 487     struct virtio_console_config *config =
 488         (struct virtio_console_config *)config_data;
 489
 490     config->cols = 0;
 491     config->rows = 0;
 492     config->max_nr_ports = virtio_tswap32(vdev,
 493                                           vser->serial.max_virtserial_ports);
 494 }
 495
 496 static void guest_reset(VirtIOSerial *vser)
 497 {
 498     VirtIOSerialPort *port;
 499     VirtIOSerialPortClass *vsc;
 500
 501     QTAILQ_FOREACH(port, &vser->ports, next) {
 502         vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 503         if (port->guest_connected) {
 504             port->guest_connected = false;
 505             if (vsc->set_guest_connected) {
 506                 vsc->set_guest_connected(port, false);
 507             }
 508         }
 509     }
 510 }
 511
 512 static void set_status(VirtIODevice *vdev, uint8_t status)
 513 {
 514     VirtIOSerial *vser;
 515     VirtIOSerialPort *port;
 516
 517     vser = VIRTIO_SERIAL(vdev);
 518     port = find_port_by_id(vser, 0);
 519
 520     if (port && !use_multiport(port->vser)
 521         && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 522         /*
 523          * Non-multiport guests won't be able to tell us guest
 524          * open/close status.  Such guests can only have a port at id
 525          * 0, so set guest_connected for such ports as soon as guest
 526          * is up.
 527          */
 528         port->guest_connected = true;
 529     }
 530     if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 531         guest_reset(vser);
 532     }
 533 }
 534
 535 static void vser_reset(VirtIODevice *vdev)
 536 {
 537     VirtIOSerial *vser;
 538
 539     vser = VIRTIO_SERIAL(vdev);
 540     guest_reset(vser);
 541 }
 542
 543 static void virtio_serial_save(QEMUFile *f, void *opaque)
 544 {
 545     /* The virtio device */
 546     virtio_save(VIRTIO_DEVICE(opaque), f);
 547 }
 548
 549 static void virtio_serial_save_device(VirtIODevice *vdev, QEMUFile *f)
 550 {
 551     VirtIOSerial *s = VIRTIO_SERIAL(vdev);
 552     VirtIOSerialPort *port;
 553     uint32_t nr_active_ports;
 554     unsigned int i, max_nr_ports;
 555     struct virtio_console_config config;
 556
 557     /* The config space (ignored on the far end in current versions) */
 558     get_config(vdev, (uint8_t *)&config);
 559     qemu_put_be16s(f, &config.cols);
 560     qemu_put_be16s(f, &config.rows);
 561     qemu_put_be32s(f, &config.max_nr_ports);
 562
 563     /* The ports map */
 564     max_nr_ports = s->serial.max_virtserial_ports;
 565     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 566         qemu_put_be32s(f, &s->ports_map[i]);
 567     }
 568
 569     /* Ports */
 570
 571     nr_active_ports = 0;
 572     QTAILQ_FOREACH(port, &s->ports, next) {
 573         nr_active_ports++;
 574     }
 575
 576     qemu_put_be32s(f, &nr_active_ports);
 577
 578     /*
 579      * Items in struct VirtIOSerialPort.
 580      */
 581     QTAILQ_FOREACH(port, &s->ports, next) {
 582         uint32_t elem_popped;
 583
 584         qemu_put_be32s(f, &port->id);
 585         qemu_put_byte(f, port->guest_connected);
 586         qemu_put_byte(f, port->host_connected);
 587
 588         elem_popped = 0;
 589         if (port->elem.out_num) {
 590             elem_popped = 1;
 591         }
 592         qemu_put_be32s(f, &elem_popped);
 593         if (elem_popped) {
 594             qemu_put_be32s(f, &port->iov_idx);
 595             qemu_put_be64s(f, &port->iov_offset);
 596
 597             qemu_put_buffer(f, (unsigned char *)&port->elem,
 598                             sizeof(port->elem));
 599         }
 600     }
 601 }
 602
 603 static void virtio_serial_post_load_timer_cb(void *opaque)
 604 {
 605     uint32_t i;
 606     VirtIOSerial *s = VIRTIO_SERIAL(opaque);
 607     VirtIOSerialPort *port;
 608     uint8_t host_connected;
 609     VirtIOSerialPortClass *vsc;
 610
 611     if (!s->post_load) {
 612         return;
 613     }
 614     for (i = 0 ; i < s->post_load->nr_active_ports; ++i) {
 615         port = s->post_load->connected[i].port;
 616         host_connected = s->post_load->connected[i].host_connected;
 617         if (host_connected != port->host_connected) {
 618             /*
 619              * We have to let the guest know of the host connection
 620              * status change
 621              */
 622             send_control_event(s, port->id, VIRTIO_CONSOLE_PORT_OPEN,
 623                                port->host_connected);
 624         }
 625         vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 626         if (vsc->set_guest_connected) {
 627             vsc->set_guest_connected(port, port->guest_connected);
 628         }
 629     }
 630     g_free(s->post_load->connected);
 631     timer_free(s->post_load->timer);
 632     g_free(s->post_load);
 633     s->post_load = NULL;
 634 }
 635
 636 static int fetch_active_ports_list(QEMUFile *f, int version_id,
 637                                    VirtIOSerial *s, uint32_t nr_active_ports)
 638 {
 639     uint32_t i;
 640
 641     s->post_load = g_malloc0(sizeof(*s->post_load));
 642     s->post_load->nr_active_ports = nr_active_ports;
 643     s->post_load->connected =
 644         g_malloc0(sizeof(*s->post_load->connected) * nr_active_ports);
 645
 646     s->post_load->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
 647                                             virtio_serial_post_load_timer_cb,
 648                                             s);
 649
 650     /* Items in struct VirtIOSerialPort */
 651     for (i = 0; i < nr_active_ports; i++) {
 652         VirtIOSerialPort *port;
 653         uint32_t id;
 654
 655         id = qemu_get_be32(f);
 656         port = find_port_by_id(s, id);
 657         if (!port) {
 658             return -EINVAL;
 659         }
 660
 661         port->guest_connected = qemu_get_byte(f);
 662         s->post_load->connected[i].port = port;
 663         s->post_load->connected[i].host_connected = qemu_get_byte(f);
 664
 665         if (version_id > 2) {
 666             uint32_t elem_popped;
 667
 668             qemu_get_be32s(f, &elem_popped);
 669             if (elem_popped) {
 670                 qemu_get_be32s(f, &port->iov_idx);
 671                 qemu_get_be64s(f, &port->iov_offset);
 672
 673                 qemu_get_buffer(f, (unsigned char *)&port->elem,
 674                                 sizeof(port->elem));
 675                 virtqueue_map_sg(port->elem.in_sg, port->elem.in_addr,
 676                                  port->elem.in_num, 1);
 677                 virtqueue_map_sg(port->elem.out_sg, port->elem.out_addr,
 678                                  port->elem.out_num, 1);
 679
 680                 /*
 681                  *  Port was throttled on source machine.  Let's
 682                  *  unthrottle it here so data starts flowing again.
 683                  */
 684                 virtio_serial_throttle_port(port, false);
 685             }
 686         }
 687     }
 688     timer_mod(s->post_load->timer, 1);
 689     return 0;
 690 }
 691
 692 static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
 693 {
 694     if (version_id > 3) {
 695         return -EINVAL;
 696     }
 697
 698     /* The virtio device */
 699     return virtio_load(VIRTIO_DEVICE(opaque), f, version_id);
 700 }
 701
 702 static int virtio_serial_load_device(VirtIODevice *vdev, QEMUFile *f,
 703                                      int version_id)
 704 {
 705     VirtIOSerial *s = VIRTIO_SERIAL(vdev);
 706     uint32_t max_nr_ports, nr_active_ports, ports_map;
 707     unsigned int i;
 708     int ret;
 709     uint32_t tmp;
 710
 711     if (version_id < 2) {
 712         return 0;
 713     }
 714
 715     /* Unused */
 716     qemu_get_be16s(f, (uint16_t *) &tmp);
 717     qemu_get_be16s(f, (uint16_t *) &tmp);
 718     qemu_get_be32s(f, &tmp);
 719
 720     max_nr_ports = s->serial.max_virtserial_ports;
 721     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 722         qemu_get_be32s(f, &ports_map);
 723
 724         if (ports_map != s->ports_map[i]) {
 725             /*
 726              * Ports active on source and destination don't
 727              * match. Fail migration.
 728              */
 729             return -EINVAL;
 730         }
 731     }
 732
 733     qemu_get_be32s(f, &nr_active_ports);
 734
 735     if (nr_active_ports) {
 736         ret = fetch_active_ports_list(f, version_id, s, nr_active_ports);
 737         if (ret) {
 738             return ret;
 739         }
 740     }
 741     return 0;
 742 }
 743
 744 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
 745
 746 static Property virtser_props[] = {
 747     DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
 748     DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
 749     DEFINE_PROP_END_OF_LIST()
 750 };
 751
 752 #define TYPE_VIRTIO_SERIAL_BUS "virtio-serial-bus"
 753 #define VIRTIO_SERIAL_BUS(obj) \
 754       OBJECT_CHECK(VirtIOSerialBus, (obj), TYPE_VIRTIO_SERIAL_BUS)
 755
 756 static void virtser_bus_class_init(ObjectClass *klass, void *data)
 757 {
 758     BusClass *k = BUS_CLASS(klass);
 759     k->print_dev = virtser_bus_dev_print;
 760 }
 761
 762 static const TypeInfo virtser_bus_info = {
 763     .name = TYPE_VIRTIO_SERIAL_BUS,
 764     .parent = TYPE_BUS,
 765     .instance_size = sizeof(VirtIOSerialBus),
 766     .class_init = virtser_bus_class_init,
 767 };
 768
 769 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
 770 {
 771     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 772
 773     monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
 774                    indent, "", port->id,
 775                    port->guest_connected ? "on" : "off",
 776                    port->host_connected ? "on" : "off",
 777                    port->throttled ? "on" : "off");
 778 }
 779
 780 /* This function is only used if a port id is not provided by the user */
 781 static uint32_t find_free_port_id(VirtIOSerial *vser)
 782 {
 783     unsigned int i, max_nr_ports;
 784
 785     max_nr_ports = vser->serial.max_virtserial_ports;
 786     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 787         uint32_t map, bit;
 788
 789         map = vser->ports_map[i];
 790         bit = ffs(~map);
 791         if (bit) {
 792             return (bit - 1) + i * 32;
 793         }
 794     }
 795     return VIRTIO_CONSOLE_BAD_ID;
 796 }
 797
 798 static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
 799 {
 800     unsigned int i;
 801
 802     i = port_id / 32;
 803     vser->ports_map[i] |= 1U << (port_id % 32);
 804 }
 805
 806 static void add_port(VirtIOSerial *vser, uint32_t port_id)
 807 {
 808     mark_port_added(vser, port_id);
 809     send_control_event(vser, port_id, VIRTIO_CONSOLE_PORT_ADD, 1);
 810 }
 811
 812 static void remove_port(VirtIOSerial *vser, uint32_t port_id)
 813 {
 814     VirtIOSerialPort *port;
 815
 816     /*
 817      * Don't mark port 0 removed -- we explicitly reserve it for
 818      * backward compat with older guests, ensure a virtconsole device
 819      * unplug retains the reservation.
 820      */
 821     if (port_id) {
 822         unsigned int i;
 823
 824         i = port_id / 32;
 825         vser->ports_map[i] &= ~(1U << (port_id % 32));
 826     }
 827
 828     port = find_port_by_id(vser, port_id);
 829     /*
 830      * This function is only called from qdev's unplug callback; if we
 831      * get a NULL port here, we're in trouble.
 832      */
 833     assert(port);
 834
 835     /* Flush out any unconsumed buffers first */
 836     discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
 837
 838     send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_REMOVE, 1);
 839 }
 840
 841 static void virtser_port_device_realize(DeviceState *dev, Error **errp)
 842 {
 843     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
 844     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 845     VirtIOSerialBus *bus = VIRTIO_SERIAL_BUS(qdev_get_parent_bus(dev));
 846     int max_nr_ports;
 847     bool plugging_port0;
 848     Error *err = NULL;
 849
 850     port->vser = bus->vser;
 851     port->bh = qemu_bh_new(flush_queued_data_bh, port);
 852
 853     assert(vsc->have_data);
 854
 855     /*
 856      * Is the first console port we're seeing? If so, put it up at
 857      * location 0. This is done for backward compatibility (old
 858      * kernel, new qemu).
 859      */
 860     plugging_port0 = vsc->is_console && !find_port_by_id(port->vser, 0);
 861
 862     if (find_port_by_id(port->vser, port->id)) {
 863         error_setg(errp, "virtio-serial-bus: A port already exists at id %u",
 864                    port->id);
 865         return;
 866     }
 867
 868     if (port->name != NULL && find_port_by_name(port->name)) {
 869         error_setg(errp, "virtio-serial-bus: A port already exists by name %s",
 870                    port->name);
 871         return;
 872     }
 873
 874     if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 875         if (plugging_port0) {
 876             port->id = 0;
 877         } else {
 878             port->id = find_free_port_id(port->vser);
 879             if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 880                 error_setg(errp, "virtio-serial-bus: Maximum port limit for "
 881                                  "this device reached");
 882                 return;
 883             }
 884         }
 885     }
 886
 887     max_nr_ports = port->vser->serial.max_virtserial_ports;
 888     if (port->id >= max_nr_ports) {
 889         error_setg(errp, "virtio-serial-bus: Out-of-range port id specified, "
 890                          "max. allowed: %u", max_nr_ports - 1);
 891         return;
 892     }
 893
 894     vsc->realize(dev, &err);
 895     if (err != NULL) {
 896         error_propagate(errp, err);
 897         return;
 898     }
 899
 900     port->elem.out_num = 0;
 901 }
 902
 903 static void virtser_port_device_plug(HotplugHandler *hotplug_dev,
 904                                      DeviceState *dev, Error **errp)
 905 {
 906     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
 907
 908     QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
 909     port->ivq = port->vser->ivqs[port->id];
 910     port->ovq = port->vser->ovqs[port->id];
 911
 912     add_port(port->vser, port->id);
 913
 914     /* Send an update to the guest about this new port added */
 915     virtio_notify_config(VIRTIO_DEVICE(hotplug_dev));
 916 }
 917
 918 static void virtser_port_device_unrealize(DeviceState *dev, Error **errp)
 919 {
 920     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
 921     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(dev);
 922     VirtIOSerial *vser = port->vser;
 923
 924     qemu_bh_delete(port->bh);
 925     remove_port(port->vser, port->id);
 926
 927     QTAILQ_REMOVE(&vser->ports, port, next);
 928
 929     if (vsc->unrealize) {
 930         vsc->unrealize(dev, errp);
 931     }
 932 }
 933
 934 static void virtio_serial_device_realize(DeviceState *dev, Error **errp)
 935 {
 936     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 937     VirtIOSerial *vser = VIRTIO_SERIAL(dev);
 938     uint32_t i, max_supported_ports;
 939
 940     if (!vser->serial.max_virtserial_ports) {
 941         error_setg(errp, "Maximum number of serial ports not specified");
 942         return;
 943     }
 944
 945     /* Each port takes 2 queues, and one pair is for the control queue */
 946     max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
 947
 948     if (vser->serial.max_virtserial_ports > max_supported_ports) {
 949         error_setg(errp, "maximum ports supported: %u", max_supported_ports);
 950         return;
 951     }
 952
 953     virtio_init(vdev, "virtio-serial", VIRTIO_ID_CONSOLE,
 954                 sizeof(struct virtio_console_config));
 955
 956     /* Spawn a new virtio-serial bus on which the ports will ride as devices */
 957     qbus_create_inplace(&vser->bus, sizeof(vser->bus), TYPE_VIRTIO_SERIAL_BUS,
 958                         dev, vdev->bus_name);
 959     qbus_set_hotplug_handler(BUS(&vser->bus), DEVICE(vser), errp);
 960     vser->bus.vser = vser;
 961     QTAILQ_INIT(&vser->ports);
 962
 963     vser->bus.max_nr_ports = vser->serial.max_virtserial_ports;
 964     vser->ivqs = g_malloc(vser->serial.max_virtserial_ports
 965                           * sizeof(VirtQueue *));
 966     vser->ovqs = g_malloc(vser->serial.max_virtserial_ports
 967                           * sizeof(VirtQueue *));
 968
 969     /* Add a queue for host to guest transfers for port 0 (backward compat) */
 970     vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
 971     /* Add a queue for guest to host transfers for port 0 (backward compat) */
 972     vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
 973
 974     /* TODO: host to guest notifications can get dropped
 975      * if the queue fills up. Implement queueing in host,
 976      * this might also make it possible to reduce the control
 977      * queue size: as guest preposts buffers there,
 978      * this will save 4Kbyte of guest memory per entry. */
 979
 980     /* control queue: host to guest */
 981     vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
 982     /* control queue: guest to host */
 983     vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
 984
 985     for (i = 1; i < vser->bus.max_nr_ports; i++) {
 986         /* Add a per-port queue for host to guest transfers */
 987         vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
 988         /* Add a per-per queue for guest to host transfers */
 989         vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
 990     }
 991
 992     vser->ports_map = g_malloc0(((vser->serial.max_virtserial_ports + 31) / 32)
 993         * sizeof(vser->ports_map[0]));
 994     /*
 995      * Reserve location 0 for a console port for backward compat
 996      * (old kernel, new qemu)
 997      */
 998     mark_port_added(vser, 0);
 999
1000     vser->post_load = NULL;
1001
1002     /*
1003      * Register for the savevm section with the virtio-console name
1004      * to preserve backward compat
1005      */
1006     register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
1007                     virtio_serial_load, vser);
1008
1009     QLIST_INSERT_HEAD(&vserdevices.devices, vser, next);
1010 }
1011
1012 static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
1013 {
1014     DeviceClass *k = DEVICE_CLASS(klass);
1015
1016     set_bit(DEVICE_CATEGORY_INPUT, k->categories);
1017     k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
1018     k->realize = virtser_port_device_realize;
1019     k->unrealize = virtser_port_device_unrealize;
1020     k->props = virtser_props;
1021 }
1022
1023 static const TypeInfo virtio_serial_port_type_info = {
1024     .name = TYPE_VIRTIO_SERIAL_PORT,
1025     .parent = TYPE_DEVICE,
1026     .instance_size = sizeof(VirtIOSerialPort),
1027     .abstract = true,
1028     .class_size = sizeof(VirtIOSerialPortClass),
1029     .class_init = virtio_serial_port_class_init,
1030 };
1031
1032 static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp)
1033 {
1034     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
1035     VirtIOSerial *vser = VIRTIO_SERIAL(dev);
1036
1037     QLIST_REMOVE(vser, next);
1038
1039     unregister_savevm(dev, "virtio-console", vser);
1040
1041     g_free(vser->ivqs);
1042     g_free(vser->ovqs);
1043     g_free(vser->ports_map);
1044     if (vser->post_load) {
1045         g_free(vser->post_load->connected);
1046         timer_del(vser->post_load->timer);
1047         timer_free(vser->post_load->timer);
1048         g_free(vser->post_load);
1049     }
1050     virtio_cleanup(vdev);
1051 }
1052
1053 static Property virtio_serial_properties[] = {
1054     DEFINE_VIRTIO_SERIAL_PROPERTIES(VirtIOSerial, serial),
1055     DEFINE_PROP_END_OF_LIST(),
1056 };
1057
1058 static void virtio_serial_class_init(ObjectClass *klass, void *data)
1059 {
1060     DeviceClass *dc = DEVICE_CLASS(klass);
1061     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1062     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
1063
1064     QLIST_INIT(&vserdevices.devices);
1065
1066     dc->props = virtio_serial_properties;
1067     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
1068     vdc->realize = virtio_serial_device_realize;
1069     vdc->unrealize = virtio_serial_device_unrealize;
1070     vdc->get_features = get_features;
1071     vdc->get_config = get_config;
1072     vdc->set_status = set_status;
1073     vdc->reset = vser_reset;
1074     vdc->save = virtio_serial_save_device;
1075     vdc->load = virtio_serial_load_device;
1076     hc->plug = virtser_port_device_plug;
1077     hc->unplug = qdev_simple_device_unplug_cb;
1078 }
1079
1080 static const TypeInfo virtio_device_info = {
1081     .name = TYPE_VIRTIO_SERIAL,
1082     .parent = TYPE_VIRTIO_DEVICE,
1083     .instance_size = sizeof(VirtIOSerial),
1084     .class_init = virtio_serial_class_init,
1085     .interfaces = (InterfaceInfo[]) {
1086         { TYPE_HOTPLUG_HANDLER },
1087         { }
1088     }
1089 };
1090
1091 static void virtio_serial_register_types(void)
1092 {
1093     type_register_static(&virtser_bus_info);
1094     type_register_static(&virtio_serial_port_type_info);
1095     type_register_static(&virtio_device_info);
1096 }
1097
1098 type_init(virtio_serial_register_types)