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  * 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 "qemu/iov.h"
  22 #include "monitor/monitor.h"
  23 #include "qemu/queue.h"
  24 #include "hw/sysbus.h"
  25 #include "trace.h"
  26 #include "hw/virtio-serial.h"
  27
  28 static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
  29 {
  30     VirtIOSerialPort *port;
  31
  32     if (id == VIRTIO_CONSOLE_BAD_ID) {
  33         return NULL;
  34     }
  35
  36     QTAILQ_FOREACH(port, &vser->ports, next) {
  37         if (port->id == id)
  38             return port;
  39     }
  40     return NULL;
  41 }
  42
  43 static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
  44 {
  45     VirtIOSerialPort *port;
  46
  47     QTAILQ_FOREACH(port, &vser->ports, next) {
  48         if (port->ivq == vq || port->ovq == vq)
  49             return port;
  50     }
  51     return NULL;
  52 }
  53
  54 static bool use_multiport(VirtIOSerial *vser)
  55 {
  56     return vser->vdev.guest_features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
  57 }
  58
  59 static size_t write_to_port(VirtIOSerialPort *port,
  60                             const uint8_t *buf, size_t size)
  61 {
  62     VirtQueueElement elem;
  63     VirtQueue *vq;
  64     size_t offset;
  65
  66     vq = port->ivq;
  67     if (!virtio_queue_ready(vq)) {
  68         return 0;
  69     }
  70
  71     offset = 0;
  72     while (offset < size) {
  73         size_t len;
  74
  75         if (!virtqueue_pop(vq, &elem)) {
  76             break;
  77         }
  78
  79         len = iov_from_buf(elem.in_sg, elem.in_num, 0,
  80                            buf + offset, size - offset);
  81         offset += len;
  82
  83         virtqueue_push(vq, &elem, len);
  84     }
  85
  86     virtio_notify(&port->vser->vdev, vq);
  87     return offset;
  88 }
  89
  90 static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
  91 {
  92     VirtQueueElement elem;
  93
  94     if (!virtio_queue_ready(vq)) {
  95         return;
  96     }
  97     while (virtqueue_pop(vq, &elem)) {
  98         virtqueue_push(vq, &elem, 0);
  99     }
 100     virtio_notify(vdev, vq);
 101 }
 102
 103 static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
 104                                  VirtIODevice *vdev)
 105 {
 106     VirtIOSerialPortClass *vsc;
 107
 108     assert(port);
 109     assert(virtio_queue_ready(vq));
 110
 111     vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 112
 113     while (!port->throttled) {
 114         unsigned int i;
 115
 116         /* Pop an elem only if we haven't left off a previous one mid-way */
 117         if (!port->elem.out_num) {
 118             if (!virtqueue_pop(vq, &port->elem)) {
 119                 break;
 120             }
 121             port->iov_idx = 0;
 122             port->iov_offset = 0;
 123         }
 124
 125         for (i = port->iov_idx; i < port->elem.out_num; i++) {
 126             size_t buf_size;
 127             ssize_t ret;
 128
 129             buf_size = port->elem.out_sg[i].iov_len - port->iov_offset;
 130             ret = vsc->have_data(port,
 131                                   port->elem.out_sg[i].iov_base
 132                                   + port->iov_offset,
 133                                   buf_size);
 134             if (port->throttled) {
 135                 port->iov_idx = i;
 136                 if (ret > 0) {
 137                     port->iov_offset += ret;
 138                 }
 139                 break;
 140             }
 141             port->iov_offset = 0;
 142         }
 143         if (port->throttled) {
 144             break;
 145         }
 146         virtqueue_push(vq, &port->elem, 0);
 147         port->elem.out_num = 0;
 148     }
 149     virtio_notify(vdev, vq);
 150 }
 151
 152 static void flush_queued_data(VirtIOSerialPort *port)
 153 {
 154     assert(port);
 155
 156     if (!virtio_queue_ready(port->ovq)) {
 157         return;
 158     }
 159     do_flush_queued_data(port, port->ovq, &port->vser->vdev);
 160 }
 161
 162 static size_t send_control_msg(VirtIOSerial *vser, void *buf, size_t len)
 163 {
 164     VirtQueueElement elem;
 165     VirtQueue *vq;
 166
 167     vq = vser->c_ivq;
 168     if (!virtio_queue_ready(vq)) {
 169         return 0;
 170     }
 171     if (!virtqueue_pop(vq, &elem)) {
 172         return 0;
 173     }
 174
 175     memcpy(elem.in_sg[0].iov_base, buf, len);
 176
 177     virtqueue_push(vq, &elem, len);
 178     virtio_notify(&vser->vdev, vq);
 179     return len;
 180 }
 181
 182 static size_t send_control_event(VirtIOSerial *vser, uint32_t port_id,
 183                                  uint16_t event, uint16_t value)
 184 {
 185     struct virtio_console_control cpkt;
 186
 187     stl_p(&cpkt.id, port_id);
 188     stw_p(&cpkt.event, event);
 189     stw_p(&cpkt.value, value);
 190
 191     trace_virtio_serial_send_control_event(port_id, event, value);
 192     return send_control_msg(vser, &cpkt, sizeof(cpkt));
 193 }
 194
 195 /* Functions for use inside qemu to open and read from/write to ports */
 196 int virtio_serial_open(VirtIOSerialPort *port)
 197 {
 198     /* Don't allow opening an already-open port */
 199     if (port->host_connected) {
 200         return 0;
 201     }
 202     /* Send port open notification to the guest */
 203     port->host_connected = true;
 204     send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
 205
 206     return 0;
 207 }
 208
 209 int virtio_serial_close(VirtIOSerialPort *port)
 210 {
 211     port->host_connected = false;
 212     /*
 213      * If there's any data the guest sent which the app didn't
 214      * consume, reset the throttling flag and discard the data.
 215      */
 216     port->throttled = false;
 217     discard_vq_data(port->ovq, &port->vser->vdev);
 218
 219     send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 0);
 220
 221     return 0;
 222 }
 223
 224 /* Individual ports/apps call this function to write to the guest. */
 225 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 226                             size_t size)
 227 {
 228     if (!port || !port->host_connected || !port->guest_connected) {
 229         return 0;
 230     }
 231     return write_to_port(port, buf, size);
 232 }
 233
 234 /*
 235  * Readiness of the guest to accept data on a port.
 236  * Returns max. data the guest can receive
 237  */
 238 size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
 239 {
 240     VirtQueue *vq = port->ivq;
 241     unsigned int bytes;
 242
 243     if (!virtio_queue_ready(vq) ||
 244         !(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
 245         virtio_queue_empty(vq)) {
 246         return 0;
 247     }
 248     if (use_multiport(port->vser) && !port->guest_connected) {
 249         return 0;
 250     }
 251     virtqueue_get_avail_bytes(vq, &bytes, NULL, 4096, 0);
 252     return bytes;
 253 }
 254
 255 static void flush_queued_data_bh(void *opaque)
 256 {
 257     VirtIOSerialPort *port = opaque;
 258
 259     flush_queued_data(port);
 260 }
 261
 262 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
 263 {
 264     if (!port) {
 265         return;
 266     }
 267
 268     trace_virtio_serial_throttle_port(port->id, throttle);
 269     port->throttled = throttle;
 270     if (throttle) {
 271         return;
 272     }
 273     qemu_bh_schedule(port->bh);
 274 }
 275
 276 /* Guest wants to notify us of some event */
 277 static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
 278 {
 279     struct VirtIOSerialPort *port;
 280     VirtIOSerialPortClass *vsc;
 281     struct virtio_console_control cpkt, *gcpkt;
 282     uint8_t *buffer;
 283     size_t buffer_len;
 284
 285     gcpkt = buf;
 286
 287     if (len < sizeof(cpkt)) {
 288         /* The guest sent an invalid control packet */
 289         return;
 290     }
 291
 292     cpkt.event = lduw_p(&gcpkt->event);
 293     cpkt.value = lduw_p(&gcpkt->value);
 294
 295     trace_virtio_serial_handle_control_message(cpkt.event, cpkt.value);
 296
 297     if (cpkt.event == VIRTIO_CONSOLE_DEVICE_READY) {
 298         if (!cpkt.value) {
 299             error_report("virtio-serial-bus: Guest failure in adding device %s",
 300                          vser->bus.qbus.name);
 301             return;
 302         }
 303         /*
 304          * The device is up, we can now tell the device about all the
 305          * ports we have here.
 306          */
 307         QTAILQ_FOREACH(port, &vser->ports, next) {
 308             send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_ADD, 1);
 309         }
 310         return;
 311     }
 312
 313     port = find_port_by_id(vser, ldl_p(&gcpkt->id));
 314     if (!port) {
 315         error_report("virtio-serial-bus: Unexpected port id %u for device %s",
 316                      ldl_p(&gcpkt->id), vser->bus.qbus.name);
 317         return;
 318     }
 319
 320     trace_virtio_serial_handle_control_message_port(port->id);
 321
 322     vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 323
 324     switch(cpkt.event) {
 325     case VIRTIO_CONSOLE_PORT_READY:
 326         if (!cpkt.value) {
 327             error_report("virtio-serial-bus: Guest failure in adding port %u for device %s",
 328                          port->id, vser->bus.qbus.name);
 329             break;
 330         }
 331         /*
 332          * Now that we know the guest asked for the port name, we're
 333          * sure the guest has initialised whatever state is necessary
 334          * for this port. Now's a good time to let the guest know if
 335          * this port is a console port so that the guest can hook it
 336          * up to hvc.
 337          */
 338         if (vsc->is_console) {
 339             send_control_event(vser, port->id, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
 340         }
 341
 342         if (port->name) {
 343             stl_p(&cpkt.id, port->id);
 344             stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
 345             stw_p(&cpkt.value, 1);
 346
 347             buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
 348             buffer = g_malloc(buffer_len);
 349
 350             memcpy(buffer, &cpkt, sizeof(cpkt));
 351             memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
 352             buffer[buffer_len - 1] = 0;
 353
 354             send_control_msg(vser, buffer, buffer_len);
 355             g_free(buffer);
 356         }
 357
 358         if (port->host_connected) {
 359             send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
 360         }
 361
 362         /*
 363          * When the guest has asked us for this information it means
 364          * the guest is all setup and has its virtqueues
 365          * initialised. If some app is interested in knowing about
 366          * this event, let it know.
 367          */
 368         if (vsc->guest_ready) {
 369             vsc->guest_ready(port);
 370         }
 371         break;
 372
 373     case VIRTIO_CONSOLE_PORT_OPEN:
 374         port->guest_connected = cpkt.value;
 375         if (vsc->set_guest_connected) {
 376             /* Send the guest opened notification if an app is interested */
 377             vsc->set_guest_connected(port, cpkt.value);
 378         }
 379         break;
 380     }
 381 }
 382
 383 static void control_in(VirtIODevice *vdev, VirtQueue *vq)
 384 {
 385 }
 386
 387 static void control_out(VirtIODevice *vdev, VirtQueue *vq)
 388 {
 389     VirtQueueElement elem;
 390     VirtIOSerial *vser;
 391     uint8_t *buf;
 392     size_t len;
 393
 394     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 395
 396     len = 0;
 397     buf = NULL;
 398     while (virtqueue_pop(vq, &elem)) {
 399         size_t cur_len;
 400
 401         cur_len = iov_size(elem.out_sg, elem.out_num);
 402         /*
 403          * Allocate a new buf only if we didn't have one previously or
 404          * if the size of the buf differs
 405          */
 406         if (cur_len > len) {
 407             g_free(buf);
 408
 409             buf = g_malloc(cur_len);
 410             len = cur_len;
 411         }
 412         iov_to_buf(elem.out_sg, elem.out_num, 0, buf, cur_len);
 413
 414         handle_control_message(vser, buf, cur_len);
 415         virtqueue_push(vq, &elem, 0);
 416     }
 417     g_free(buf);
 418     virtio_notify(vdev, vq);
 419 }
 420
 421 /* Guest wrote something to some port. */
 422 static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
 423 {
 424     VirtIOSerial *vser;
 425     VirtIOSerialPort *port;
 426
 427     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 428     port = find_port_by_vq(vser, vq);
 429
 430     if (!port || !port->host_connected) {
 431         discard_vq_data(vq, vdev);
 432         return;
 433     }
 434
 435     if (!port->throttled) {
 436         do_flush_queued_data(port, vq, vdev);
 437         return;
 438     }
 439 }
 440
 441 static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
 442 {
 443 }
 444
 445 static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
 446 {
 447     VirtIOSerial *vser;
 448
 449     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 450
 451     if (vser->bus.max_nr_ports > 1) {
 452         features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
 453     }
 454     return features;
 455 }
 456
 457 /* Guest requested config info */
 458 static void get_config(VirtIODevice *vdev, uint8_t *config_data)
 459 {
 460     VirtIOSerial *vser;
 461
 462     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 463     memcpy(config_data, &vser->config, sizeof(struct virtio_console_config));
 464 }
 465
 466 static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
 467 {
 468     struct virtio_console_config config;
 469
 470     memcpy(&config, config_data, sizeof(config));
 471 }
 472
 473 static void guest_reset(VirtIOSerial *vser)
 474 {
 475     VirtIOSerialPort *port;
 476     VirtIOSerialPortClass *vsc;
 477
 478     QTAILQ_FOREACH(port, &vser->ports, next) {
 479         vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 480         if (port->guest_connected) {
 481             port->guest_connected = false;
 482             if (vsc->set_guest_connected) {
 483                 vsc->set_guest_connected(port, false);
 484             }
 485         }
 486     }
 487 }
 488
 489 static void set_status(VirtIODevice *vdev, uint8_t status)
 490 {
 491     VirtIOSerial *vser;
 492     VirtIOSerialPort *port;
 493
 494     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 495     port = find_port_by_id(vser, 0);
 496
 497     if (port && !use_multiport(port->vser)
 498         && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 499         /*
 500          * Non-multiport guests won't be able to tell us guest
 501          * open/close status.  Such guests can only have a port at id
 502          * 0, so set guest_connected for such ports as soon as guest
 503          * is up.
 504          */
 505         port->guest_connected = true;
 506     }
 507     if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 508         guest_reset(vser);
 509     }
 510 }
 511
 512 static void vser_reset(VirtIODevice *vdev)
 513 {
 514     VirtIOSerial *vser;
 515
 516     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 517     guest_reset(vser);
 518 }
 519
 520 static void virtio_serial_save(QEMUFile *f, void *opaque)
 521 {
 522     VirtIOSerial *s = opaque;
 523     VirtIOSerialPort *port;
 524     uint32_t nr_active_ports;
 525     unsigned int i, max_nr_ports;
 526
 527     /* The virtio device */
 528     virtio_save(&s->vdev, f);
 529
 530     /* The config space */
 531     qemu_put_be16s(f, &s->config.cols);
 532     qemu_put_be16s(f, &s->config.rows);
 533
 534     qemu_put_be32s(f, &s->config.max_nr_ports);
 535
 536     /* The ports map */
 537     max_nr_ports = tswap32(s->config.max_nr_ports);
 538     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 539         qemu_put_be32s(f, &s->ports_map[i]);
 540     }
 541
 542     /* Ports */
 543
 544     nr_active_ports = 0;
 545     QTAILQ_FOREACH(port, &s->ports, next) {
 546         nr_active_ports++;
 547     }
 548
 549     qemu_put_be32s(f, &nr_active_ports);
 550
 551     /*
 552      * Items in struct VirtIOSerialPort.
 553      */
 554     QTAILQ_FOREACH(port, &s->ports, next) {
 555         uint32_t elem_popped;
 556
 557         qemu_put_be32s(f, &port->id);
 558         qemu_put_byte(f, port->guest_connected);
 559         qemu_put_byte(f, port->host_connected);
 560
 561         elem_popped = 0;
 562         if (port->elem.out_num) {
 563             elem_popped = 1;
 564         }
 565         qemu_put_be32s(f, &elem_popped);
 566         if (elem_popped) {
 567             qemu_put_be32s(f, &port->iov_idx);
 568             qemu_put_be64s(f, &port->iov_offset);
 569
 570             qemu_put_buffer(f, (unsigned char *)&port->elem,
 571                             sizeof(port->elem));
 572         }
 573     }
 574 }
 575
 576 static void virtio_serial_post_load_timer_cb(void *opaque)
 577 {
 578     uint32_t i;
 579     VirtIOSerial *s = opaque;
 580     VirtIOSerialPort *port;
 581     uint8_t host_connected;
 582
 583     if (!s->post_load) {
 584         return;
 585     }
 586     for (i = 0 ; i < s->post_load->nr_active_ports; ++i) {
 587         port = s->post_load->connected[i].port;
 588         host_connected = s->post_load->connected[i].host_connected;
 589         if (host_connected != port->host_connected) {
 590             /*
 591              * We have to let the guest know of the host connection
 592              * status change
 593              */
 594             send_control_event(s, port->id, VIRTIO_CONSOLE_PORT_OPEN,
 595                                port->host_connected);
 596         }
 597     }
 598     g_free(s->post_load->connected);
 599     qemu_free_timer(s->post_load->timer);
 600     g_free(s->post_load);
 601     s->post_load = NULL;
 602 }
 603
 604 static int fetch_active_ports_list(QEMUFile *f, int version_id,
 605                                    VirtIOSerial *s, uint32_t nr_active_ports)
 606 {
 607     uint32_t i;
 608
 609     s->post_load = g_malloc0(sizeof(*s->post_load));
 610     s->post_load->nr_active_ports = nr_active_ports;
 611     s->post_load->connected =
 612         g_malloc0(sizeof(*s->post_load->connected) * nr_active_ports);
 613
 614     s->post_load->timer = qemu_new_timer_ns(vm_clock,
 615                                             virtio_serial_post_load_timer_cb,
 616                                             s);
 617
 618     /* Items in struct VirtIOSerialPort */
 619     for (i = 0; i < nr_active_ports; i++) {
 620         VirtIOSerialPort *port;
 621         uint32_t id;
 622
 623         id = qemu_get_be32(f);
 624         port = find_port_by_id(s, id);
 625         if (!port) {
 626             return -EINVAL;
 627         }
 628
 629         port->guest_connected = qemu_get_byte(f);
 630         s->post_load->connected[i].port = port;
 631         s->post_load->connected[i].host_connected = qemu_get_byte(f);
 632
 633         if (version_id > 2) {
 634             uint32_t elem_popped;
 635
 636             qemu_get_be32s(f, &elem_popped);
 637             if (elem_popped) {
 638                 qemu_get_be32s(f, &port->iov_idx);
 639                 qemu_get_be64s(f, &port->iov_offset);
 640
 641                 qemu_get_buffer(f, (unsigned char *)&port->elem,
 642                                 sizeof(port->elem));
 643                 virtqueue_map_sg(port->elem.in_sg, port->elem.in_addr,
 644                                  port->elem.in_num, 1);
 645                 virtqueue_map_sg(port->elem.out_sg, port->elem.out_addr,
 646                                  port->elem.out_num, 1);
 647
 648                 /*
 649                  *  Port was throttled on source machine.  Let's
 650                  *  unthrottle it here so data starts flowing again.
 651                  */
 652                 virtio_serial_throttle_port(port, false);
 653             }
 654         }
 655     }
 656     qemu_mod_timer(s->post_load->timer, 1);
 657     return 0;
 658 }
 659
 660 static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
 661 {
 662     VirtIOSerial *s = opaque;
 663     uint32_t max_nr_ports, nr_active_ports, ports_map;
 664     unsigned int i;
 665     int ret;
 666
 667     if (version_id > 3) {
 668         return -EINVAL;
 669     }
 670
 671     /* The virtio device */
 672     ret = virtio_load(&s->vdev, f);
 673     if (ret) {
 674         return ret;
 675     }
 676
 677     if (version_id < 2) {
 678         return 0;
 679     }
 680
 681     /* The config space */
 682     qemu_get_be16s(f, &s->config.cols);
 683     qemu_get_be16s(f, &s->config.rows);
 684
 685     qemu_get_be32s(f, &max_nr_ports);
 686     tswap32s(&max_nr_ports);
 687     if (max_nr_ports > tswap32(s->config.max_nr_ports)) {
 688         /* Source could have had more ports than us. Fail migration. */
 689         return -EINVAL;
 690     }
 691
 692     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 693         qemu_get_be32s(f, &ports_map);
 694
 695         if (ports_map != s->ports_map[i]) {
 696             /*
 697              * Ports active on source and destination don't
 698              * match. Fail migration.
 699              */
 700             return -EINVAL;
 701         }
 702     }
 703
 704     qemu_get_be32s(f, &nr_active_ports);
 705
 706     if (nr_active_ports) {
 707         ret = fetch_active_ports_list(f, version_id, s, nr_active_ports);
 708         if (ret) {
 709             return ret;
 710         }
 711     }
 712     return 0;
 713 }
 714
 715 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
 716
 717 static Property virtser_props[] = {
 718     DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
 719     DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
 720     DEFINE_PROP_END_OF_LIST()
 721 };
 722
 723 #define TYPE_VIRTIO_SERIAL_BUS "virtio-serial-bus"
 724 #define VIRTIO_SERIAL_BUS(obj) \
 725       OBJECT_CHECK(VirtIOSerialBus, (obj), TYPE_VIRTIO_SERIAL_BUS)
 726
 727 static void virtser_bus_class_init(ObjectClass *klass, void *data)
 728 {
 729     BusClass *k = BUS_CLASS(klass);
 730     k->print_dev = virtser_bus_dev_print;
 731 }
 732
 733 static const TypeInfo virtser_bus_info = {
 734     .name = TYPE_VIRTIO_SERIAL_BUS,
 735     .parent = TYPE_BUS,
 736     .instance_size = sizeof(VirtIOSerialBus),
 737     .class_init = virtser_bus_class_init,
 738 };
 739
 740 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
 741 {
 742     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 743
 744     monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
 745                    indent, "", port->id,
 746                    port->guest_connected ? "on" : "off",
 747                    port->host_connected ? "on" : "off",
 748                    port->throttled ? "on" : "off");
 749 }
 750
 751 /* This function is only used if a port id is not provided by the user */
 752 static uint32_t find_free_port_id(VirtIOSerial *vser)
 753 {
 754     unsigned int i, max_nr_ports;
 755
 756     max_nr_ports = tswap32(vser->config.max_nr_ports);
 757     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 758         uint32_t map, bit;
 759
 760         map = vser->ports_map[i];
 761         bit = ffs(~map);
 762         if (bit) {
 763             return (bit - 1) + i * 32;
 764         }
 765     }
 766     return VIRTIO_CONSOLE_BAD_ID;
 767 }
 768
 769 static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
 770 {
 771     unsigned int i;
 772
 773     i = port_id / 32;
 774     vser->ports_map[i] |= 1U << (port_id % 32);
 775 }
 776
 777 static void add_port(VirtIOSerial *vser, uint32_t port_id)
 778 {
 779     mark_port_added(vser, port_id);
 780     send_control_event(vser, port_id, VIRTIO_CONSOLE_PORT_ADD, 1);
 781 }
 782
 783 static void remove_port(VirtIOSerial *vser, uint32_t port_id)
 784 {
 785     VirtIOSerialPort *port;
 786     unsigned int i;
 787
 788     i = port_id / 32;
 789     vser->ports_map[i] &= ~(1U << (port_id % 32));
 790
 791     port = find_port_by_id(vser, port_id);
 792     /*
 793      * This function is only called from qdev's unplug callback; if we
 794      * get a NULL port here, we're in trouble.
 795      */
 796     assert(port);
 797
 798     /* Flush out any unconsumed buffers first */
 799     discard_vq_data(port->ovq, &port->vser->vdev);
 800
 801     send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_REMOVE, 1);
 802 }
 803
 804 static int virtser_port_qdev_init(DeviceState *qdev)
 805 {
 806     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 807     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 808     VirtIOSerialBus *bus = DO_UPCAST(VirtIOSerialBus, qbus, qdev->parent_bus);
 809     int ret, max_nr_ports;
 810     bool plugging_port0;
 811
 812     port->vser = bus->vser;
 813     port->bh = qemu_bh_new(flush_queued_data_bh, port);
 814
 815     assert(vsc->have_data);
 816
 817     /*
 818      * Is the first console port we're seeing? If so, put it up at
 819      * location 0. This is done for backward compatibility (old
 820      * kernel, new qemu).
 821      */
 822     plugging_port0 = vsc->is_console && !find_port_by_id(port->vser, 0);
 823
 824     if (find_port_by_id(port->vser, port->id)) {
 825         error_report("virtio-serial-bus: A port already exists at id %u",
 826                      port->id);
 827         return -1;
 828     }
 829
 830     if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 831         if (plugging_port0) {
 832             port->id = 0;
 833         } else {
 834             port->id = find_free_port_id(port->vser);
 835             if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 836                 error_report("virtio-serial-bus: Maximum port limit for this device reached");
 837                 return -1;
 838             }
 839         }
 840     }
 841
 842     max_nr_ports = tswap32(port->vser->config.max_nr_ports);
 843     if (port->id >= max_nr_ports) {
 844         error_report("virtio-serial-bus: Out-of-range port id specified, max. allowed: %u",
 845                      max_nr_ports - 1);
 846         return -1;
 847     }
 848
 849     ret = vsc->init(port);
 850     if (ret) {
 851         return ret;
 852     }
 853
 854     port->elem.out_num = 0;
 855
 856     QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
 857     port->ivq = port->vser->ivqs[port->id];
 858     port->ovq = port->vser->ovqs[port->id];
 859
 860     add_port(port->vser, port->id);
 861
 862     /* Send an update to the guest about this new port added */
 863     virtio_notify_config(&port->vser->vdev);
 864
 865     return ret;
 866 }
 867
 868 static int virtser_port_qdev_exit(DeviceState *qdev)
 869 {
 870     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 871     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 872     VirtIOSerial *vser = port->vser;
 873
 874     qemu_bh_delete(port->bh);
 875     remove_port(port->vser, port->id);
 876
 877     QTAILQ_REMOVE(&vser->ports, port, next);
 878
 879     if (vsc->exit) {
 880         vsc->exit(port);
 881     }
 882     return 0;
 883 }
 884
 885 VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *conf)
 886 {
 887     VirtIOSerial *vser;
 888     VirtIODevice *vdev;
 889     uint32_t i, max_supported_ports;
 890
 891     if (!conf->max_virtserial_ports)
 892         return NULL;
 893
 894     /* Each port takes 2 queues, and one pair is for the control queue */
 895     max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
 896
 897     if (conf->max_virtserial_ports > max_supported_ports) {
 898         error_report("maximum ports supported: %u", max_supported_ports);
 899         return NULL;
 900     }
 901
 902     vdev = virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE,
 903                               sizeof(struct virtio_console_config),
 904                               sizeof(VirtIOSerial));
 905
 906     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 907
 908     /* Spawn a new virtio-serial bus on which the ports will ride as devices */
 909     qbus_create_inplace(&vser->bus.qbus, TYPE_VIRTIO_SERIAL_BUS, dev, NULL);
 910     vser->bus.qbus.allow_hotplug = 1;
 911     vser->bus.vser = vser;
 912     QTAILQ_INIT(&vser->ports);
 913
 914     vser->bus.max_nr_ports = conf->max_virtserial_ports;
 915     vser->ivqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
 916     vser->ovqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
 917
 918     /* Add a queue for host to guest transfers for port 0 (backward compat) */
 919     vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
 920     /* Add a queue for guest to host transfers for port 0 (backward compat) */
 921     vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
 922
 923     /* TODO: host to guest notifications can get dropped
 924      * if the queue fills up. Implement queueing in host,
 925      * this might also make it possible to reduce the control
 926      * queue size: as guest preposts buffers there,
 927      * this will save 4Kbyte of guest memory per entry. */
 928
 929     /* control queue: host to guest */
 930     vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
 931     /* control queue: guest to host */
 932     vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
 933
 934     for (i = 1; i < vser->bus.max_nr_ports; i++) {
 935         /* Add a per-port queue for host to guest transfers */
 936         vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
 937         /* Add a per-per queue for guest to host transfers */
 938         vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
 939     }
 940
 941     vser->config.max_nr_ports = tswap32(conf->max_virtserial_ports);
 942     vser->ports_map = g_malloc0(((conf->max_virtserial_ports + 31) / 32)
 943         * sizeof(vser->ports_map[0]));
 944     /*
 945      * Reserve location 0 for a console port for backward compat
 946      * (old kernel, new qemu)
 947      */
 948     mark_port_added(vser, 0);
 949
 950     vser->vdev.get_features = get_features;
 951     vser->vdev.get_config = get_config;
 952     vser->vdev.set_config = set_config;
 953     vser->vdev.set_status = set_status;
 954     vser->vdev.reset = vser_reset;
 955
 956     vser->qdev = dev;
 957
 958     vser->post_load = NULL;
 959
 960     /*
 961      * Register for the savevm section with the virtio-console name
 962      * to preserve backward compat
 963      */
 964     register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
 965                     virtio_serial_load, vser);
 966
 967     return vdev;
 968 }
 969
 970 void virtio_serial_exit(VirtIODevice *vdev)
 971 {
 972     VirtIOSerial *vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 973
 974     unregister_savevm(vser->qdev, "virtio-console", vser);
 975
 976     g_free(vser->ivqs);
 977     g_free(vser->ovqs);
 978     g_free(vser->ports_map);
 979     if (vser->post_load) {
 980         g_free(vser->post_load->connected);
 981         qemu_del_timer(vser->post_load->timer);
 982         qemu_free_timer(vser->post_load->timer);
 983         g_free(vser->post_load);
 984     }
 985     virtio_cleanup(vdev);
 986 }
 987
 988 static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
 989 {
 990     DeviceClass *k = DEVICE_CLASS(klass);
 991     k->init = virtser_port_qdev_init;
 992     k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
 993     k->exit = virtser_port_qdev_exit;
 994     k->unplug = qdev_simple_unplug_cb;
 995     k->props = virtser_props;
 996 }
 997
 998 static const TypeInfo virtio_serial_port_type_info = {
 999     .name = TYPE_VIRTIO_SERIAL_PORT,
1000     .parent = TYPE_DEVICE,
1001     .instance_size = sizeof(VirtIOSerialPort),
1002     .abstract = true,
1003     .class_size = sizeof(VirtIOSerialPortClass),
1004     .class_init = virtio_serial_port_class_init,
1005 };
1006
1007 static void virtio_serial_register_types(void)
1008 {
1009     type_register_static(&virtser_bus_info);
1010     type_register_static(&virtio_serial_port_type_info);
1011 }
1012
1013 type_init(virtio_serial_register_types)