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 (cpkt.value && vsc->guest_open) {
 376             /* Send the guest opened notification if an app is interested */
 377             vsc->guest_open(port);
 378         }
 379
 380         if (!cpkt.value && vsc->guest_close) {
 381             /* Send the guest closed notification if an app is interested */
 382             vsc->guest_close(port);
 383         }
 384         break;
 385     }
 386 }
 387
 388 static void control_in(VirtIODevice *vdev, VirtQueue *vq)
 389 {
 390 }
 391
 392 static void control_out(VirtIODevice *vdev, VirtQueue *vq)
 393 {
 394     VirtQueueElement elem;
 395     VirtIOSerial *vser;
 396     uint8_t *buf;
 397     size_t len;
 398
 399     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 400
 401     len = 0;
 402     buf = NULL;
 403     while (virtqueue_pop(vq, &elem)) {
 404         size_t cur_len;
 405
 406         cur_len = iov_size(elem.out_sg, elem.out_num);
 407         /*
 408          * Allocate a new buf only if we didn't have one previously or
 409          * if the size of the buf differs
 410          */
 411         if (cur_len > len) {
 412             g_free(buf);
 413
 414             buf = g_malloc(cur_len);
 415             len = cur_len;
 416         }
 417         iov_to_buf(elem.out_sg, elem.out_num, 0, buf, cur_len);
 418
 419         handle_control_message(vser, buf, cur_len);
 420         virtqueue_push(vq, &elem, 0);
 421     }
 422     g_free(buf);
 423     virtio_notify(vdev, vq);
 424 }
 425
 426 /* Guest wrote something to some port. */
 427 static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
 428 {
 429     VirtIOSerial *vser;
 430     VirtIOSerialPort *port;
 431
 432     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 433     port = find_port_by_vq(vser, vq);
 434
 435     if (!port || !port->host_connected) {
 436         discard_vq_data(vq, vdev);
 437         return;
 438     }
 439
 440     if (!port->throttled) {
 441         do_flush_queued_data(port, vq, vdev);
 442         return;
 443     }
 444 }
 445
 446 static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
 447 {
 448 }
 449
 450 static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
 451 {
 452     VirtIOSerial *vser;
 453
 454     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 455
 456     if (vser->bus.max_nr_ports > 1) {
 457         features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
 458     }
 459     return features;
 460 }
 461
 462 /* Guest requested config info */
 463 static void get_config(VirtIODevice *vdev, uint8_t *config_data)
 464 {
 465     VirtIOSerial *vser;
 466
 467     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 468     memcpy(config_data, &vser->config, sizeof(struct virtio_console_config));
 469 }
 470
 471 static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
 472 {
 473     struct virtio_console_config config;
 474
 475     memcpy(&config, config_data, sizeof(config));
 476 }
 477
 478 static void guest_reset(VirtIOSerial *vser)
 479 {
 480     VirtIOSerialPort *port;
 481     VirtIOSerialPortClass *vsc;
 482
 483     QTAILQ_FOREACH(port, &vser->ports, next) {
 484         vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 485         if (port->guest_connected) {
 486             port->guest_connected = false;
 487
 488             if (vsc->guest_close)
 489                 vsc->guest_close(port);
 490         }
 491     }
 492 }
 493
 494 static void set_status(VirtIODevice *vdev, uint8_t status)
 495 {
 496     VirtIOSerial *vser;
 497     VirtIOSerialPort *port;
 498
 499     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 500     port = find_port_by_id(vser, 0);
 501
 502     if (port && !use_multiport(port->vser)
 503         && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 504         /*
 505          * Non-multiport guests won't be able to tell us guest
 506          * open/close status.  Such guests can only have a port at id
 507          * 0, so set guest_connected for such ports as soon as guest
 508          * is up.
 509          */
 510         port->guest_connected = true;
 511     }
 512     if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 513         guest_reset(vser);
 514     }
 515 }
 516
 517 static void vser_reset(VirtIODevice *vdev)
 518 {
 519     VirtIOSerial *vser;
 520
 521     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 522     guest_reset(vser);
 523 }
 524
 525 static void virtio_serial_save(QEMUFile *f, void *opaque)
 526 {
 527     VirtIOSerial *s = opaque;
 528     VirtIOSerialPort *port;
 529     uint32_t nr_active_ports;
 530     unsigned int i, max_nr_ports;
 531
 532     /* The virtio device */
 533     virtio_save(&s->vdev, f);
 534
 535     /* The config space */
 536     qemu_put_be16s(f, &s->config.cols);
 537     qemu_put_be16s(f, &s->config.rows);
 538
 539     qemu_put_be32s(f, &s->config.max_nr_ports);
 540
 541     /* The ports map */
 542     max_nr_ports = tswap32(s->config.max_nr_ports);
 543     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 544         qemu_put_be32s(f, &s->ports_map[i]);
 545     }
 546
 547     /* Ports */
 548
 549     nr_active_ports = 0;
 550     QTAILQ_FOREACH(port, &s->ports, next) {
 551         nr_active_ports++;
 552     }
 553
 554     qemu_put_be32s(f, &nr_active_ports);
 555
 556     /*
 557      * Items in struct VirtIOSerialPort.
 558      */
 559     QTAILQ_FOREACH(port, &s->ports, next) {
 560         uint32_t elem_popped;
 561
 562         qemu_put_be32s(f, &port->id);
 563         qemu_put_byte(f, port->guest_connected);
 564         qemu_put_byte(f, port->host_connected);
 565
 566         elem_popped = 0;
 567         if (port->elem.out_num) {
 568             elem_popped = 1;
 569         }
 570         qemu_put_be32s(f, &elem_popped);
 571         if (elem_popped) {
 572             qemu_put_be32s(f, &port->iov_idx);
 573             qemu_put_be64s(f, &port->iov_offset);
 574
 575             qemu_put_buffer(f, (unsigned char *)&port->elem,
 576                             sizeof(port->elem));
 577         }
 578     }
 579 }
 580
 581 static void virtio_serial_post_load_timer_cb(void *opaque)
 582 {
 583     uint32_t i;
 584     VirtIOSerial *s = opaque;
 585     VirtIOSerialPort *port;
 586     uint8_t host_connected;
 587
 588     if (!s->post_load) {
 589         return;
 590     }
 591     for (i = 0 ; i < s->post_load->nr_active_ports; ++i) {
 592         port = s->post_load->connected[i].port;
 593         host_connected = s->post_load->connected[i].host_connected;
 594         if (host_connected != port->host_connected) {
 595             /*
 596              * We have to let the guest know of the host connection
 597              * status change
 598              */
 599             send_control_event(s, port->id, VIRTIO_CONSOLE_PORT_OPEN,
 600                                port->host_connected);
 601         }
 602     }
 603     g_free(s->post_load->connected);
 604     qemu_free_timer(s->post_load->timer);
 605     g_free(s->post_load);
 606     s->post_load = NULL;
 607 }
 608
 609 static int fetch_active_ports_list(QEMUFile *f, int version_id,
 610                                    VirtIOSerial *s, uint32_t nr_active_ports)
 611 {
 612     uint32_t i;
 613
 614     s->post_load = g_malloc0(sizeof(*s->post_load));
 615     s->post_load->nr_active_ports = nr_active_ports;
 616     s->post_load->connected =
 617         g_malloc0(sizeof(*s->post_load->connected) * nr_active_ports);
 618
 619     s->post_load->timer = qemu_new_timer_ns(vm_clock,
 620                                             virtio_serial_post_load_timer_cb,
 621                                             s);
 622
 623     /* Items in struct VirtIOSerialPort */
 624     for (i = 0; i < nr_active_ports; i++) {
 625         VirtIOSerialPort *port;
 626         uint32_t id;
 627
 628         id = qemu_get_be32(f);
 629         port = find_port_by_id(s, id);
 630         if (!port) {
 631             return -EINVAL;
 632         }
 633
 634         port->guest_connected = qemu_get_byte(f);
 635         s->post_load->connected[i].port = port;
 636         s->post_load->connected[i].host_connected = qemu_get_byte(f);
 637
 638         if (version_id > 2) {
 639             uint32_t elem_popped;
 640
 641             qemu_get_be32s(f, &elem_popped);
 642             if (elem_popped) {
 643                 qemu_get_be32s(f, &port->iov_idx);
 644                 qemu_get_be64s(f, &port->iov_offset);
 645
 646                 qemu_get_buffer(f, (unsigned char *)&port->elem,
 647                                 sizeof(port->elem));
 648                 virtqueue_map_sg(port->elem.in_sg, port->elem.in_addr,
 649                                  port->elem.in_num, 1);
 650                 virtqueue_map_sg(port->elem.out_sg, port->elem.out_addr,
 651                                  port->elem.out_num, 1);
 652
 653                 /*
 654                  *  Port was throttled on source machine.  Let's
 655                  *  unthrottle it here so data starts flowing again.
 656                  */
 657                 virtio_serial_throttle_port(port, false);
 658             }
 659         }
 660     }
 661     qemu_mod_timer(s->post_load->timer, 1);
 662     return 0;
 663 }
 664
 665 static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
 666 {
 667     VirtIOSerial *s = opaque;
 668     uint32_t max_nr_ports, nr_active_ports, ports_map;
 669     unsigned int i;
 670     int ret;
 671
 672     if (version_id > 3) {
 673         return -EINVAL;
 674     }
 675
 676     /* The virtio device */
 677     ret = virtio_load(&s->vdev, f);
 678     if (ret) {
 679         return ret;
 680     }
 681
 682     if (version_id < 2) {
 683         return 0;
 684     }
 685
 686     /* The config space */
 687     qemu_get_be16s(f, &s->config.cols);
 688     qemu_get_be16s(f, &s->config.rows);
 689
 690     qemu_get_be32s(f, &max_nr_ports);
 691     tswap32s(&max_nr_ports);
 692     if (max_nr_ports > tswap32(s->config.max_nr_ports)) {
 693         /* Source could have had more ports than us. Fail migration. */
 694         return -EINVAL;
 695     }
 696
 697     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 698         qemu_get_be32s(f, &ports_map);
 699
 700         if (ports_map != s->ports_map[i]) {
 701             /*
 702              * Ports active on source and destination don't
 703              * match. Fail migration.
 704              */
 705             return -EINVAL;
 706         }
 707     }
 708
 709     qemu_get_be32s(f, &nr_active_ports);
 710
 711     if (nr_active_ports) {
 712         ret = fetch_active_ports_list(f, version_id, s, nr_active_ports);
 713         if (ret) {
 714             return ret;
 715         }
 716     }
 717     return 0;
 718 }
 719
 720 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
 721
 722 static Property virtser_props[] = {
 723     DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
 724     DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
 725     DEFINE_PROP_END_OF_LIST()
 726 };
 727
 728 #define TYPE_VIRTIO_SERIAL_BUS "virtio-serial-bus"
 729 #define VIRTIO_SERIAL_BUS(obj) \
 730       OBJECT_CHECK(VirtIOSerialBus, (obj), TYPE_VIRTIO_SERIAL_BUS)
 731
 732 static void virtser_bus_class_init(ObjectClass *klass, void *data)
 733 {
 734     BusClass *k = BUS_CLASS(klass);
 735     k->print_dev = virtser_bus_dev_print;
 736 }
 737
 738 static const TypeInfo virtser_bus_info = {
 739     .name = TYPE_VIRTIO_SERIAL_BUS,
 740     .parent = TYPE_BUS,
 741     .instance_size = sizeof(VirtIOSerialBus),
 742     .class_init = virtser_bus_class_init,
 743 };
 744
 745 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
 746 {
 747     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 748
 749     monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
 750                    indent, "", port->id,
 751                    port->guest_connected ? "on" : "off",
 752                    port->host_connected ? "on" : "off",
 753                    port->throttled ? "on" : "off");
 754 }
 755
 756 /* This function is only used if a port id is not provided by the user */
 757 static uint32_t find_free_port_id(VirtIOSerial *vser)
 758 {
 759     unsigned int i, max_nr_ports;
 760
 761     max_nr_ports = tswap32(vser->config.max_nr_ports);
 762     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 763         uint32_t map, bit;
 764
 765         map = vser->ports_map[i];
 766         bit = ffs(~map);
 767         if (bit) {
 768             return (bit - 1) + i * 32;
 769         }
 770     }
 771     return VIRTIO_CONSOLE_BAD_ID;
 772 }
 773
 774 static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
 775 {
 776     unsigned int i;
 777
 778     i = port_id / 32;
 779     vser->ports_map[i] |= 1U << (port_id % 32);
 780 }
 781
 782 static void add_port(VirtIOSerial *vser, uint32_t port_id)
 783 {
 784     mark_port_added(vser, port_id);
 785     send_control_event(vser, port_id, VIRTIO_CONSOLE_PORT_ADD, 1);
 786 }
 787
 788 static void remove_port(VirtIOSerial *vser, uint32_t port_id)
 789 {
 790     VirtIOSerialPort *port;
 791     unsigned int i;
 792
 793     i = port_id / 32;
 794     vser->ports_map[i] &= ~(1U << (port_id % 32));
 795
 796     port = find_port_by_id(vser, port_id);
 797     /*
 798      * This function is only called from qdev's unplug callback; if we
 799      * get a NULL port here, we're in trouble.
 800      */
 801     assert(port);
 802
 803     /* Flush out any unconsumed buffers first */
 804     discard_vq_data(port->ovq, &port->vser->vdev);
 805
 806     send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_REMOVE, 1);
 807 }
 808
 809 static int virtser_port_qdev_init(DeviceState *qdev)
 810 {
 811     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 812     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 813     VirtIOSerialBus *bus = DO_UPCAST(VirtIOSerialBus, qbus, qdev->parent_bus);
 814     int ret, max_nr_ports;
 815     bool plugging_port0;
 816
 817     port->vser = bus->vser;
 818     port->bh = qemu_bh_new(flush_queued_data_bh, port);
 819
 820     assert(vsc->have_data);
 821
 822     /*
 823      * Is the first console port we're seeing? If so, put it up at
 824      * location 0. This is done for backward compatibility (old
 825      * kernel, new qemu).
 826      */
 827     plugging_port0 = vsc->is_console && !find_port_by_id(port->vser, 0);
 828
 829     if (find_port_by_id(port->vser, port->id)) {
 830         error_report("virtio-serial-bus: A port already exists at id %u",
 831                      port->id);
 832         return -1;
 833     }
 834
 835     if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 836         if (plugging_port0) {
 837             port->id = 0;
 838         } else {
 839             port->id = find_free_port_id(port->vser);
 840             if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 841                 error_report("virtio-serial-bus: Maximum port limit for this device reached");
 842                 return -1;
 843             }
 844         }
 845     }
 846
 847     max_nr_ports = tswap32(port->vser->config.max_nr_ports);
 848     if (port->id >= max_nr_ports) {
 849         error_report("virtio-serial-bus: Out-of-range port id specified, max. allowed: %u",
 850                      max_nr_ports - 1);
 851         return -1;
 852     }
 853
 854     ret = vsc->init(port);
 855     if (ret) {
 856         return ret;
 857     }
 858
 859     port->elem.out_num = 0;
 860
 861     QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
 862     port->ivq = port->vser->ivqs[port->id];
 863     port->ovq = port->vser->ovqs[port->id];
 864
 865     add_port(port->vser, port->id);
 866
 867     /* Send an update to the guest about this new port added */
 868     virtio_notify_config(&port->vser->vdev);
 869
 870     return ret;
 871 }
 872
 873 static int virtser_port_qdev_exit(DeviceState *qdev)
 874 {
 875     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 876     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 877     VirtIOSerial *vser = port->vser;
 878
 879     qemu_bh_delete(port->bh);
 880     remove_port(port->vser, port->id);
 881
 882     QTAILQ_REMOVE(&vser->ports, port, next);
 883
 884     if (vsc->exit) {
 885         vsc->exit(port);
 886     }
 887     return 0;
 888 }
 889
 890 VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *conf)
 891 {
 892     VirtIOSerial *vser;
 893     VirtIODevice *vdev;
 894     uint32_t i, max_supported_ports;
 895
 896     if (!conf->max_virtserial_ports)
 897         return NULL;
 898
 899     /* Each port takes 2 queues, and one pair is for the control queue */
 900     max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
 901
 902     if (conf->max_virtserial_ports > max_supported_ports) {
 903         error_report("maximum ports supported: %u", max_supported_ports);
 904         return NULL;
 905     }
 906
 907     vdev = virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE,
 908                               sizeof(struct virtio_console_config),
 909                               sizeof(VirtIOSerial));
 910
 911     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 912
 913     /* Spawn a new virtio-serial bus on which the ports will ride as devices */
 914     qbus_create_inplace(&vser->bus.qbus, TYPE_VIRTIO_SERIAL_BUS, dev, NULL);
 915     vser->bus.qbus.allow_hotplug = 1;
 916     vser->bus.vser = vser;
 917     QTAILQ_INIT(&vser->ports);
 918
 919     vser->bus.max_nr_ports = conf->max_virtserial_ports;
 920     vser->ivqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
 921     vser->ovqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
 922
 923     /* Add a queue for host to guest transfers for port 0 (backward compat) */
 924     vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
 925     /* Add a queue for guest to host transfers for port 0 (backward compat) */
 926     vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
 927
 928     /* TODO: host to guest notifications can get dropped
 929      * if the queue fills up. Implement queueing in host,
 930      * this might also make it possible to reduce the control
 931      * queue size: as guest preposts buffers there,
 932      * this will save 4Kbyte of guest memory per entry. */
 933
 934     /* control queue: host to guest */
 935     vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
 936     /* control queue: guest to host */
 937     vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
 938
 939     for (i = 1; i < vser->bus.max_nr_ports; i++) {
 940         /* Add a per-port queue for host to guest transfers */
 941         vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
 942         /* Add a per-per queue for guest to host transfers */
 943         vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
 944     }
 945
 946     vser->config.max_nr_ports = tswap32(conf->max_virtserial_ports);
 947     vser->ports_map = g_malloc0(((conf->max_virtserial_ports + 31) / 32)
 948         * sizeof(vser->ports_map[0]));
 949     /*
 950      * Reserve location 0 for a console port for backward compat
 951      * (old kernel, new qemu)
 952      */
 953     mark_port_added(vser, 0);
 954
 955     vser->vdev.get_features = get_features;
 956     vser->vdev.get_config = get_config;
 957     vser->vdev.set_config = set_config;
 958     vser->vdev.set_status = set_status;
 959     vser->vdev.reset = vser_reset;
 960
 961     vser->qdev = dev;
 962
 963     vser->post_load = NULL;
 964
 965     /*
 966      * Register for the savevm section with the virtio-console name
 967      * to preserve backward compat
 968      */
 969     register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
 970                     virtio_serial_load, vser);
 971
 972     return vdev;
 973 }
 974
 975 void virtio_serial_exit(VirtIODevice *vdev)
 976 {
 977     VirtIOSerial *vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 978
 979     unregister_savevm(vser->qdev, "virtio-console", vser);
 980
 981     g_free(vser->ivqs);
 982     g_free(vser->ovqs);
 983     g_free(vser->ports_map);
 984     if (vser->post_load) {
 985         g_free(vser->post_load->connected);
 986         qemu_del_timer(vser->post_load->timer);
 987         qemu_free_timer(vser->post_load->timer);
 988         g_free(vser->post_load);
 989     }
 990     virtio_cleanup(vdev);
 991 }
 992
 993 static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
 994 {
 995     DeviceClass *k = DEVICE_CLASS(klass);
 996     k->init = virtser_port_qdev_init;
 997     k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
 998     k->exit = virtser_port_qdev_exit;
 999     k->unplug = qdev_simple_unplug_cb;
1000     k->props = virtser_props;
1001 }
1002
1003 static const TypeInfo virtio_serial_port_type_info = {
1004     .name = TYPE_VIRTIO_SERIAL_PORT,
1005     .parent = TYPE_DEVICE,
1006     .instance_size = sizeof(VirtIOSerialPort),
1007     .abstract = true,
1008     .class_size = sizeof(VirtIOSerialPortClass),
1009     .class_init = virtio_serial_port_class_init,
1010 };
1011
1012 static void virtio_serial_register_types(void)
1013 {
1014     type_register_static(&virtser_bus_info);
1015     type_register_static(&virtio_serial_port_type_info);
1016 }
1017
1018 type_init(virtio_serial_register_types)