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 "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/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     VirtIODevice *vdev = VIRTIO_DEVICE(vser);
  57     return vdev->guest_features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
  58 }
  59
  60 static size_t write_to_port(VirtIOSerialPort *port,
  61                             const uint8_t *buf, size_t size)
  62 {
  63     VirtQueueElement elem;
  64     VirtQueue *vq;
  65     size_t offset;
  66
  67     vq = port->ivq;
  68     if (!virtio_queue_ready(vq)) {
  69         return 0;
  70     }
  71
  72     offset = 0;
  73     while (offset < size) {
  74         size_t len;
  75
  76         if (!virtqueue_pop(vq, &elem)) {
  77             break;
  78         }
  79
  80         len = iov_from_buf(elem.in_sg, elem.in_num, 0,
  81                            buf + offset, size - offset);
  82         offset += len;
  83
  84         virtqueue_push(vq, &elem, len);
  85     }
  86
  87     virtio_notify(VIRTIO_DEVICE(port->vser), vq);
  88     return offset;
  89 }
  90
  91 static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
  92 {
  93     VirtQueueElement elem;
  94
  95     if (!virtio_queue_ready(vq)) {
  96         return;
  97     }
  98     while (virtqueue_pop(vq, &elem)) {
  99         virtqueue_push(vq, &elem, 0);
 100     }
 101     virtio_notify(vdev, vq);
 102 }
 103
 104 static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
 105                                  VirtIODevice *vdev)
 106 {
 107     VirtIOSerialPortClass *vsc;
 108
 109     assert(port);
 110     assert(virtio_queue_ready(vq));
 111
 112     vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 113
 114     while (!port->throttled) {
 115         unsigned int i;
 116
 117         /* Pop an elem only if we haven't left off a previous one mid-way */
 118         if (!port->elem.out_num) {
 119             if (!virtqueue_pop(vq, &port->elem)) {
 120                 break;
 121             }
 122             port->iov_idx = 0;
 123             port->iov_offset = 0;
 124         }
 125
 126         for (i = port->iov_idx; i < port->elem.out_num; i++) {
 127             size_t buf_size;
 128             ssize_t ret;
 129
 130             buf_size = port->elem.out_sg[i].iov_len - port->iov_offset;
 131             ret = vsc->have_data(port,
 132                                   port->elem.out_sg[i].iov_base
 133                                   + port->iov_offset,
 134                                   buf_size);
 135             if (port->throttled) {
 136                 port->iov_idx = i;
 137                 if (ret > 0) {
 138                     port->iov_offset += ret;
 139                 }
 140                 break;
 141             }
 142             port->iov_offset = 0;
 143         }
 144         if (port->throttled) {
 145             break;
 146         }
 147         virtqueue_push(vq, &port->elem, 0);
 148         port->elem.out_num = 0;
 149     }
 150     virtio_notify(vdev, vq);
 151 }
 152
 153 static void flush_queued_data(VirtIOSerialPort *port)
 154 {
 155     assert(port);
 156
 157     if (!virtio_queue_ready(port->ovq)) {
 158         return;
 159     }
 160     do_flush_queued_data(port, port->ovq, VIRTIO_DEVICE(port->vser));
 161 }
 162
 163 static size_t send_control_msg(VirtIOSerial *vser, void *buf, size_t len)
 164 {
 165     VirtQueueElement elem;
 166     VirtQueue *vq;
 167
 168     vq = vser->c_ivq;
 169     if (!virtio_queue_ready(vq)) {
 170         return 0;
 171     }
 172     if (!virtqueue_pop(vq, &elem)) {
 173         return 0;
 174     }
 175
 176     memcpy(elem.in_sg[0].iov_base, buf, len);
 177
 178     virtqueue_push(vq, &elem, len);
 179     virtio_notify(VIRTIO_DEVICE(vser), vq);
 180     return len;
 181 }
 182
 183 static size_t send_control_event(VirtIOSerial *vser, uint32_t port_id,
 184                                  uint16_t event, uint16_t value)
 185 {
 186     struct virtio_console_control cpkt;
 187
 188     stl_p(&cpkt.id, port_id);
 189     stw_p(&cpkt.event, event);
 190     stw_p(&cpkt.value, value);
 191
 192     trace_virtio_serial_send_control_event(port_id, event, value);
 193     return send_control_msg(vser, &cpkt, sizeof(cpkt));
 194 }
 195
 196 /* Functions for use inside qemu to open and read from/write to ports */
 197 int virtio_serial_open(VirtIOSerialPort *port)
 198 {
 199     /* Don't allow opening an already-open port */
 200     if (port->host_connected) {
 201         return 0;
 202     }
 203     /* Send port open notification to the guest */
 204     port->host_connected = true;
 205     send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
 206
 207     return 0;
 208 }
 209
 210 int virtio_serial_close(VirtIOSerialPort *port)
 211 {
 212     port->host_connected = false;
 213     /*
 214      * If there's any data the guest sent which the app didn't
 215      * consume, reset the throttling flag and discard the data.
 216      */
 217     port->throttled = false;
 218     discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
 219
 220     send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 0);
 221
 222     return 0;
 223 }
 224
 225 /* Individual ports/apps call this function to write to the guest. */
 226 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 227                             size_t size)
 228 {
 229     if (!port || !port->host_connected || !port->guest_connected) {
 230         return 0;
 231     }
 232     return write_to_port(port, buf, size);
 233 }
 234
 235 /*
 236  * Readiness of the guest to accept data on a port.
 237  * Returns max. data the guest can receive
 238  */
 239 size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
 240 {
 241     VirtIODevice *vdev = VIRTIO_DEVICE(port->vser);
 242     VirtQueue *vq = port->ivq;
 243     unsigned int bytes;
 244
 245     if (!virtio_queue_ready(vq) ||
 246         !(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK) ||
 247         virtio_queue_empty(vq)) {
 248         return 0;
 249     }
 250     if (use_multiport(port->vser) && !port->guest_connected) {
 251         return 0;
 252     }
 253     virtqueue_get_avail_bytes(vq, &bytes, NULL, 4096, 0);
 254     return bytes;
 255 }
 256
 257 static void flush_queued_data_bh(void *opaque)
 258 {
 259     VirtIOSerialPort *port = opaque;
 260
 261     flush_queued_data(port);
 262 }
 263
 264 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
 265 {
 266     if (!port) {
 267         return;
 268     }
 269
 270     trace_virtio_serial_throttle_port(port->id, throttle);
 271     port->throttled = throttle;
 272     if (throttle) {
 273         return;
 274     }
 275     qemu_bh_schedule(port->bh);
 276 }
 277
 278 /* Guest wants to notify us of some event */
 279 static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
 280 {
 281     struct VirtIOSerialPort *port;
 282     VirtIOSerialPortClass *vsc;
 283     struct virtio_console_control cpkt, *gcpkt;
 284     uint8_t *buffer;
 285     size_t buffer_len;
 286
 287     gcpkt = buf;
 288
 289     if (len < sizeof(cpkt)) {
 290         /* The guest sent an invalid control packet */
 291         return;
 292     }
 293
 294     cpkt.event = lduw_p(&gcpkt->event);
 295     cpkt.value = lduw_p(&gcpkt->value);
 296
 297     trace_virtio_serial_handle_control_message(cpkt.event, cpkt.value);
 298
 299     if (cpkt.event == VIRTIO_CONSOLE_DEVICE_READY) {
 300         if (!cpkt.value) {
 301             error_report("virtio-serial-bus: Guest failure in adding device %s",
 302                          vser->bus.qbus.name);
 303             return;
 304         }
 305         /*
 306          * The device is up, we can now tell the device about all the
 307          * ports we have here.
 308          */
 309         QTAILQ_FOREACH(port, &vser->ports, next) {
 310             send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_ADD, 1);
 311         }
 312         return;
 313     }
 314
 315     port = find_port_by_id(vser, ldl_p(&gcpkt->id));
 316     if (!port) {
 317         error_report("virtio-serial-bus: Unexpected port id %u for device %s",
 318                      ldl_p(&gcpkt->id), vser->bus.qbus.name);
 319         return;
 320     }
 321
 322     trace_virtio_serial_handle_control_message_port(port->id);
 323
 324     vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 325
 326     switch(cpkt.event) {
 327     case VIRTIO_CONSOLE_PORT_READY:
 328         if (!cpkt.value) {
 329             error_report("virtio-serial-bus: Guest failure in adding port %u for device %s",
 330                          port->id, vser->bus.qbus.name);
 331             break;
 332         }
 333         /*
 334          * Now that we know the guest asked for the port name, we're
 335          * sure the guest has initialised whatever state is necessary
 336          * for this port. Now's a good time to let the guest know if
 337          * this port is a console port so that the guest can hook it
 338          * up to hvc.
 339          */
 340         if (vsc->is_console) {
 341             send_control_event(vser, port->id, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
 342         }
 343
 344         if (port->name) {
 345             stl_p(&cpkt.id, port->id);
 346             stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
 347             stw_p(&cpkt.value, 1);
 348
 349             buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
 350             buffer = g_malloc(buffer_len);
 351
 352             memcpy(buffer, &cpkt, sizeof(cpkt));
 353             memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
 354             buffer[buffer_len - 1] = 0;
 355
 356             send_control_msg(vser, buffer, buffer_len);
 357             g_free(buffer);
 358         }
 359
 360         if (port->host_connected) {
 361             send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
 362         }
 363
 364         /*
 365          * When the guest has asked us for this information it means
 366          * the guest is all setup and has its virtqueues
 367          * initialised. If some app is interested in knowing about
 368          * this event, let it know.
 369          */
 370         if (vsc->guest_ready) {
 371             vsc->guest_ready(port);
 372         }
 373         break;
 374
 375     case VIRTIO_CONSOLE_PORT_OPEN:
 376         port->guest_connected = cpkt.value;
 377         if (vsc->set_guest_connected) {
 378             /* Send the guest opened notification if an app is interested */
 379             vsc->set_guest_connected(port, cpkt.value);
 380         }
 381         break;
 382     }
 383 }
 384
 385 static void control_in(VirtIODevice *vdev, VirtQueue *vq)
 386 {
 387 }
 388
 389 static void control_out(VirtIODevice *vdev, VirtQueue *vq)
 390 {
 391     VirtQueueElement elem;
 392     VirtIOSerial *vser;
 393     uint8_t *buf;
 394     size_t len;
 395
 396     vser = VIRTIO_SERIAL(vdev);
 397
 398     len = 0;
 399     buf = NULL;
 400     while (virtqueue_pop(vq, &elem)) {
 401         size_t cur_len;
 402
 403         cur_len = iov_size(elem.out_sg, elem.out_num);
 404         /*
 405          * Allocate a new buf only if we didn't have one previously or
 406          * if the size of the buf differs
 407          */
 408         if (cur_len > len) {
 409             g_free(buf);
 410
 411             buf = g_malloc(cur_len);
 412             len = cur_len;
 413         }
 414         iov_to_buf(elem.out_sg, elem.out_num, 0, buf, cur_len);
 415
 416         handle_control_message(vser, buf, cur_len);
 417         virtqueue_push(vq, &elem, 0);
 418     }
 419     g_free(buf);
 420     virtio_notify(vdev, vq);
 421 }
 422
 423 /* Guest wrote something to some port. */
 424 static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
 425 {
 426     VirtIOSerial *vser;
 427     VirtIOSerialPort *port;
 428
 429     vser = VIRTIO_SERIAL(vdev);
 430     port = find_port_by_vq(vser, vq);
 431
 432     if (!port || !port->host_connected) {
 433         discard_vq_data(vq, vdev);
 434         return;
 435     }
 436
 437     if (!port->throttled) {
 438         do_flush_queued_data(port, vq, vdev);
 439         return;
 440     }
 441 }
 442
 443 static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
 444 {
 445 }
 446
 447 static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
 448 {
 449     VirtIOSerial *vser;
 450
 451     vser = VIRTIO_SERIAL(vdev);
 452
 453     if (vser->bus.max_nr_ports > 1) {
 454         features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
 455     }
 456     return features;
 457 }
 458
 459 /* Guest requested config info */
 460 static void get_config(VirtIODevice *vdev, uint8_t *config_data)
 461 {
 462     VirtIOSerial *vser;
 463
 464     vser = VIRTIO_SERIAL(vdev);
 465     memcpy(config_data, &vser->config, sizeof(struct virtio_console_config));
 466 }
 467
 468 static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
 469 {
 470     struct virtio_console_config config;
 471
 472     memcpy(&config, config_data, sizeof(config));
 473 }
 474
 475 static void guest_reset(VirtIOSerial *vser)
 476 {
 477     VirtIOSerialPort *port;
 478     VirtIOSerialPortClass *vsc;
 479
 480     QTAILQ_FOREACH(port, &vser->ports, next) {
 481         vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 482         if (port->guest_connected) {
 483             port->guest_connected = false;
 484             if (vsc->set_guest_connected) {
 485                 vsc->set_guest_connected(port, false);
 486             }
 487         }
 488     }
 489 }
 490
 491 static void set_status(VirtIODevice *vdev, uint8_t status)
 492 {
 493     VirtIOSerial *vser;
 494     VirtIOSerialPort *port;
 495
 496     vser = VIRTIO_SERIAL(vdev);
 497     port = find_port_by_id(vser, 0);
 498
 499     if (port && !use_multiport(port->vser)
 500         && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 501         /*
 502          * Non-multiport guests won't be able to tell us guest
 503          * open/close status.  Such guests can only have a port at id
 504          * 0, so set guest_connected for such ports as soon as guest
 505          * is up.
 506          */
 507         port->guest_connected = true;
 508     }
 509     if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 510         guest_reset(vser);
 511     }
 512 }
 513
 514 static void vser_reset(VirtIODevice *vdev)
 515 {
 516     VirtIOSerial *vser;
 517
 518     vser = VIRTIO_SERIAL(vdev);
 519     guest_reset(vser);
 520 }
 521
 522 static void virtio_serial_save(QEMUFile *f, void *opaque)
 523 {
 524     VirtIOSerial *s = VIRTIO_SERIAL(opaque);
 525     VirtIOSerialPort *port;
 526     uint32_t nr_active_ports;
 527     unsigned int i, max_nr_ports;
 528
 529     /* The virtio device */
 530     virtio_save(VIRTIO_DEVICE(s), f);
 531
 532     /* The config space */
 533     qemu_put_be16s(f, &s->config.cols);
 534     qemu_put_be16s(f, &s->config.rows);
 535
 536     qemu_put_be32s(f, &s->config.max_nr_ports);
 537
 538     /* The ports map */
 539     max_nr_ports = tswap32(s->config.max_nr_ports);
 540     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 541         qemu_put_be32s(f, &s->ports_map[i]);
 542     }
 543
 544     /* Ports */
 545
 546     nr_active_ports = 0;
 547     QTAILQ_FOREACH(port, &s->ports, next) {
 548         nr_active_ports++;
 549     }
 550
 551     qemu_put_be32s(f, &nr_active_ports);
 552
 553     /*
 554      * Items in struct VirtIOSerialPort.
 555      */
 556     QTAILQ_FOREACH(port, &s->ports, next) {
 557         uint32_t elem_popped;
 558
 559         qemu_put_be32s(f, &port->id);
 560         qemu_put_byte(f, port->guest_connected);
 561         qemu_put_byte(f, port->host_connected);
 562
 563         elem_popped = 0;
 564         if (port->elem.out_num) {
 565             elem_popped = 1;
 566         }
 567         qemu_put_be32s(f, &elem_popped);
 568         if (elem_popped) {
 569             qemu_put_be32s(f, &port->iov_idx);
 570             qemu_put_be64s(f, &port->iov_offset);
 571
 572             qemu_put_buffer(f, (unsigned char *)&port->elem,
 573                             sizeof(port->elem));
 574         }
 575     }
 576 }
 577
 578 static void virtio_serial_post_load_timer_cb(void *opaque)
 579 {
 580     uint32_t i;
 581     VirtIOSerial *s = VIRTIO_SERIAL(opaque);
 582     VirtIOSerialPort *port;
 583     uint8_t host_connected;
 584     VirtIOSerialPortClass *vsc;
 585
 586     if (!s->post_load) {
 587         return;
 588     }
 589     for (i = 0 ; i < s->post_load->nr_active_ports; ++i) {
 590         port = s->post_load->connected[i].port;
 591         host_connected = s->post_load->connected[i].host_connected;
 592         if (host_connected != port->host_connected) {
 593             /*
 594              * We have to let the guest know of the host connection
 595              * status change
 596              */
 597             send_control_event(s, port->id, VIRTIO_CONSOLE_PORT_OPEN,
 598                                port->host_connected);
 599         }
 600         vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 601         if (vsc->set_guest_connected) {
 602             vsc->set_guest_connected(port, port->guest_connected);
 603         }
 604     }
 605     g_free(s->post_load->connected);
 606     timer_free(s->post_load->timer);
 607     g_free(s->post_load);
 608     s->post_load = NULL;
 609 }
 610
 611 static int fetch_active_ports_list(QEMUFile *f, int version_id,
 612                                    VirtIOSerial *s, uint32_t nr_active_ports)
 613 {
 614     uint32_t i;
 615
 616     s->post_load = g_malloc0(sizeof(*s->post_load));
 617     s->post_load->nr_active_ports = nr_active_ports;
 618     s->post_load->connected =
 619         g_malloc0(sizeof(*s->post_load->connected) * nr_active_ports);
 620
 621     s->post_load->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
 622                                             virtio_serial_post_load_timer_cb,
 623                                             s);
 624
 625     /* Items in struct VirtIOSerialPort */
 626     for (i = 0; i < nr_active_ports; i++) {
 627         VirtIOSerialPort *port;
 628         uint32_t id;
 629
 630         id = qemu_get_be32(f);
 631         port = find_port_by_id(s, id);
 632         if (!port) {
 633             return -EINVAL;
 634         }
 635
 636         port->guest_connected = qemu_get_byte(f);
 637         s->post_load->connected[i].port = port;
 638         s->post_load->connected[i].host_connected = qemu_get_byte(f);
 639
 640         if (version_id > 2) {
 641             uint32_t elem_popped;
 642
 643             qemu_get_be32s(f, &elem_popped);
 644             if (elem_popped) {
 645                 qemu_get_be32s(f, &port->iov_idx);
 646                 qemu_get_be64s(f, &port->iov_offset);
 647
 648                 qemu_get_buffer(f, (unsigned char *)&port->elem,
 649                                 sizeof(port->elem));
 650                 virtqueue_map_sg(port->elem.in_sg, port->elem.in_addr,
 651                                  port->elem.in_num, 1);
 652                 virtqueue_map_sg(port->elem.out_sg, port->elem.out_addr,
 653                                  port->elem.out_num, 1);
 654
 655                 /*
 656                  *  Port was throttled on source machine.  Let's
 657                  *  unthrottle it here so data starts flowing again.
 658                  */
 659                 virtio_serial_throttle_port(port, false);
 660             }
 661         }
 662     }
 663     timer_mod(s->post_load->timer, 1);
 664     return 0;
 665 }
 666
 667 static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
 668 {
 669     VirtIOSerial *s = VIRTIO_SERIAL(opaque);
 670     uint32_t max_nr_ports, nr_active_ports, ports_map;
 671     unsigned int i;
 672     int ret;
 673
 674     if (version_id > 3) {
 675         return -EINVAL;
 676     }
 677
 678     /* The virtio device */
 679     ret = virtio_load(VIRTIO_DEVICE(s), f);
 680     if (ret) {
 681         return ret;
 682     }
 683
 684     if (version_id < 2) {
 685         return 0;
 686     }
 687
 688     /* The config space */
 689     qemu_get_be16s(f, &s->config.cols);
 690     qemu_get_be16s(f, &s->config.rows);
 691
 692     qemu_get_be32s(f, &max_nr_ports);
 693     tswap32s(&max_nr_ports);
 694     if (max_nr_ports > tswap32(s->config.max_nr_ports)) {
 695         /* Source could have had more ports than us. Fail migration. */
 696         return -EINVAL;
 697     }
 698
 699     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 700         qemu_get_be32s(f, &ports_map);
 701
 702         if (ports_map != s->ports_map[i]) {
 703             /*
 704              * Ports active on source and destination don't
 705              * match. Fail migration.
 706              */
 707             return -EINVAL;
 708         }
 709     }
 710
 711     qemu_get_be32s(f, &nr_active_ports);
 712
 713     if (nr_active_ports) {
 714         ret = fetch_active_ports_list(f, version_id, s, nr_active_ports);
 715         if (ret) {
 716             return ret;
 717         }
 718     }
 719     return 0;
 720 }
 721
 722 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
 723
 724 static Property virtser_props[] = {
 725     DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
 726     DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
 727     DEFINE_PROP_END_OF_LIST()
 728 };
 729
 730 #define TYPE_VIRTIO_SERIAL_BUS "virtio-serial-bus"
 731 #define VIRTIO_SERIAL_BUS(obj) \
 732       OBJECT_CHECK(VirtIOSerialBus, (obj), TYPE_VIRTIO_SERIAL_BUS)
 733
 734 static void virtser_bus_class_init(ObjectClass *klass, void *data)
 735 {
 736     BusClass *k = BUS_CLASS(klass);
 737     k->print_dev = virtser_bus_dev_print;
 738 }
 739
 740 static const TypeInfo virtser_bus_info = {
 741     .name = TYPE_VIRTIO_SERIAL_BUS,
 742     .parent = TYPE_BUS,
 743     .instance_size = sizeof(VirtIOSerialBus),
 744     .class_init = virtser_bus_class_init,
 745 };
 746
 747 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
 748 {
 749     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 750
 751     monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
 752                    indent, "", port->id,
 753                    port->guest_connected ? "on" : "off",
 754                    port->host_connected ? "on" : "off",
 755                    port->throttled ? "on" : "off");
 756 }
 757
 758 /* This function is only used if a port id is not provided by the user */
 759 static uint32_t find_free_port_id(VirtIOSerial *vser)
 760 {
 761     unsigned int i, max_nr_ports;
 762
 763     max_nr_ports = tswap32(vser->config.max_nr_ports);
 764     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 765         uint32_t map, bit;
 766
 767         map = vser->ports_map[i];
 768         bit = ffs(~map);
 769         if (bit) {
 770             return (bit - 1) + i * 32;
 771         }
 772     }
 773     return VIRTIO_CONSOLE_BAD_ID;
 774 }
 775
 776 static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
 777 {
 778     unsigned int i;
 779
 780     i = port_id / 32;
 781     vser->ports_map[i] |= 1U << (port_id % 32);
 782 }
 783
 784 static void add_port(VirtIOSerial *vser, uint32_t port_id)
 785 {
 786     mark_port_added(vser, port_id);
 787     send_control_event(vser, port_id, VIRTIO_CONSOLE_PORT_ADD, 1);
 788 }
 789
 790 static void remove_port(VirtIOSerial *vser, uint32_t port_id)
 791 {
 792     VirtIOSerialPort *port;
 793     unsigned int i;
 794
 795     i = port_id / 32;
 796     vser->ports_map[i] &= ~(1U << (port_id % 32));
 797
 798     port = find_port_by_id(vser, port_id);
 799     /*
 800      * This function is only called from qdev's unplug callback; if we
 801      * get a NULL port here, we're in trouble.
 802      */
 803     assert(port);
 804
 805     /* Flush out any unconsumed buffers first */
 806     discard_vq_data(port->ovq, VIRTIO_DEVICE(port->vser));
 807
 808     send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_REMOVE, 1);
 809 }
 810
 811 static void virtser_port_device_realize(DeviceState *dev, Error **errp)
 812 {
 813     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
 814     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 815     VirtIOSerialBus *bus = VIRTIO_SERIAL_BUS(qdev_get_parent_bus(dev));
 816     int max_nr_ports;
 817     bool plugging_port0;
 818     Error *err = NULL;
 819
 820     port->vser = bus->vser;
 821     port->bh = qemu_bh_new(flush_queued_data_bh, port);
 822
 823     assert(vsc->have_data);
 824
 825     /*
 826      * Is the first console port we're seeing? If so, put it up at
 827      * location 0. This is done for backward compatibility (old
 828      * kernel, new qemu).
 829      */
 830     plugging_port0 = vsc->is_console && !find_port_by_id(port->vser, 0);
 831
 832     if (find_port_by_id(port->vser, port->id)) {
 833         error_setg(errp, "virtio-serial-bus: A port already exists at id %u",
 834                    port->id);
 835         return;
 836     }
 837
 838     if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 839         if (plugging_port0) {
 840             port->id = 0;
 841         } else {
 842             port->id = find_free_port_id(port->vser);
 843             if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 844                 error_setg(errp, "virtio-serial-bus: Maximum port limit for "
 845                                  "this device reached");
 846                 return;
 847             }
 848         }
 849     }
 850
 851     max_nr_ports = tswap32(port->vser->config.max_nr_ports);
 852     if (port->id >= max_nr_ports) {
 853         error_setg(errp, "virtio-serial-bus: Out-of-range port id specified, "
 854                          "max. allowed: %u", max_nr_ports - 1);
 855         return;
 856     }
 857
 858     vsc->realize(dev, &err);
 859     if (err != NULL) {
 860         error_propagate(errp, err);
 861         return;
 862     }
 863
 864     port->elem.out_num = 0;
 865
 866     QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
 867     port->ivq = port->vser->ivqs[port->id];
 868     port->ovq = port->vser->ovqs[port->id];
 869
 870     add_port(port->vser, port->id);
 871
 872     /* Send an update to the guest about this new port added */
 873     virtio_notify_config(VIRTIO_DEVICE(port->vser));
 874 }
 875
 876 static void virtser_port_device_unrealize(DeviceState *dev, Error **errp)
 877 {
 878     VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev);
 879     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(dev);
 880     VirtIOSerial *vser = port->vser;
 881
 882     qemu_bh_delete(port->bh);
 883     remove_port(port->vser, port->id);
 884
 885     QTAILQ_REMOVE(&vser->ports, port, next);
 886
 887     if (vsc->unrealize) {
 888         vsc->unrealize(dev, errp);
 889     }
 890 }
 891
 892 static void virtio_serial_device_realize(DeviceState *dev, Error **errp)
 893 {
 894     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 895     VirtIOSerial *vser = VIRTIO_SERIAL(dev);
 896     BusState *bus;
 897     uint32_t i, max_supported_ports;
 898
 899     if (!vser->serial.max_virtserial_ports) {
 900         error_setg(errp, "Maximum number of serial ports not specified");
 901         return;
 902     }
 903
 904     /* Each port takes 2 queues, and one pair is for the control queue */
 905     max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
 906
 907     if (vser->serial.max_virtserial_ports > max_supported_ports) {
 908         error_setg(errp, "maximum ports supported: %u", max_supported_ports);
 909         return;
 910     }
 911
 912     virtio_init(vdev, "virtio-serial", VIRTIO_ID_CONSOLE,
 913                 sizeof(struct virtio_console_config));
 914
 915     /* Spawn a new virtio-serial bus on which the ports will ride as devices */
 916     qbus_create_inplace(&vser->bus, sizeof(vser->bus), TYPE_VIRTIO_SERIAL_BUS,
 917                         dev, vdev->bus_name);
 918     bus = BUS(&vser->bus);
 919     bus->allow_hotplug = 1;
 920     vser->bus.vser = vser;
 921     QTAILQ_INIT(&vser->ports);
 922
 923     vser->bus.max_nr_ports = vser->serial.max_virtserial_ports;
 924     vser->ivqs = g_malloc(vser->serial.max_virtserial_ports
 925                           * sizeof(VirtQueue *));
 926     vser->ovqs = g_malloc(vser->serial.max_virtserial_ports
 927                           * sizeof(VirtQueue *));
 928
 929     /* Add a queue for host to guest transfers for port 0 (backward compat) */
 930     vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
 931     /* Add a queue for guest to host transfers for port 0 (backward compat) */
 932     vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
 933
 934     /* TODO: host to guest notifications can get dropped
 935      * if the queue fills up. Implement queueing in host,
 936      * this might also make it possible to reduce the control
 937      * queue size: as guest preposts buffers there,
 938      * this will save 4Kbyte of guest memory per entry. */
 939
 940     /* control queue: host to guest */
 941     vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
 942     /* control queue: guest to host */
 943     vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
 944
 945     for (i = 1; i < vser->bus.max_nr_ports; i++) {
 946         /* Add a per-port queue for host to guest transfers */
 947         vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
 948         /* Add a per-per queue for guest to host transfers */
 949         vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
 950     }
 951
 952     vser->config.max_nr_ports = tswap32(vser->serial.max_virtserial_ports);
 953     vser->ports_map = g_malloc0(((vser->serial.max_virtserial_ports + 31) / 32)
 954         * sizeof(vser->ports_map[0]));
 955     /*
 956      * Reserve location 0 for a console port for backward compat
 957      * (old kernel, new qemu)
 958      */
 959     mark_port_added(vser, 0);
 960
 961     vser->post_load = NULL;
 962
 963     /*
 964      * Register for the savevm section with the virtio-console name
 965      * to preserve backward compat
 966      */
 967     register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
 968                     virtio_serial_load, vser);
 969 }
 970
 971 static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
 972 {
 973     DeviceClass *k = DEVICE_CLASS(klass);
 974
 975     set_bit(DEVICE_CATEGORY_INPUT, k->categories);
 976     k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
 977     k->realize = virtser_port_device_realize;
 978     k->unrealize = virtser_port_device_unrealize;
 979     k->unplug = qdev_simple_unplug_cb;
 980     k->props = virtser_props;
 981 }
 982
 983 static const TypeInfo virtio_serial_port_type_info = {
 984     .name = TYPE_VIRTIO_SERIAL_PORT,
 985     .parent = TYPE_DEVICE,
 986     .instance_size = sizeof(VirtIOSerialPort),
 987     .abstract = true,
 988     .class_size = sizeof(VirtIOSerialPortClass),
 989     .class_init = virtio_serial_port_class_init,
 990 };
 991
 992 static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp)
 993 {
 994     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
 995     VirtIOSerial *vser = VIRTIO_SERIAL(dev);
 996
 997     unregister_savevm(dev, "virtio-console", vser);
 998
 999     g_free(vser->ivqs);
1000     g_free(vser->ovqs);
1001     g_free(vser->ports_map);
1002     if (vser->post_load) {
1003         g_free(vser->post_load->connected);
1004         timer_del(vser->post_load->timer);
1005         timer_free(vser->post_load->timer);
1006         g_free(vser->post_load);
1007     }
1008     virtio_cleanup(vdev);
1009 }
1010
1011 static Property virtio_serial_properties[] = {
1012     DEFINE_VIRTIO_SERIAL_PROPERTIES(VirtIOSerial, serial),
1013     DEFINE_PROP_END_OF_LIST(),
1014 };
1015
1016 static void virtio_serial_class_init(ObjectClass *klass, void *data)
1017 {
1018     DeviceClass *dc = DEVICE_CLASS(klass);
1019     VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
1020
1021     dc->props = virtio_serial_properties;
1022     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
1023     vdc->realize = virtio_serial_device_realize;
1024     vdc->unrealize = virtio_serial_device_unrealize;
1025     vdc->get_features = get_features;
1026     vdc->get_config = get_config;
1027     vdc->set_config = set_config;
1028     vdc->set_status = set_status;
1029     vdc->reset = vser_reset;
1030 }
1031
1032 static const TypeInfo virtio_device_info = {
1033     .name = TYPE_VIRTIO_SERIAL,
1034     .parent = TYPE_VIRTIO_DEVICE,
1035     .instance_size = sizeof(VirtIOSerial),
1036     .class_init = virtio_serial_class_init,
1037 };
1038
1039 static void virtio_serial_register_types(void)
1040 {
1041     type_register_static(&virtser_bus_info);
1042     type_register_static(&virtio_serial_port_type_info);
1043     type_register_static(&virtio_device_info);
1044 }
1045
1046 type_init(virtio_serial_register_types)