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 "sysbus.h"
  25 #include "trace.h"
  26 #include "virtio-serial.h"
  27
  28 /* The virtio-serial bus on top of which the ports will ride as devices */
  29 struct VirtIOSerialBus {
  30     BusState qbus;
  31
  32     /* This is the parent device that provides the bus for ports. */
  33     VirtIOSerial *vser;
  34
  35     /* The maximum number of ports that can ride on top of this bus */
  36     uint32_t max_nr_ports;
  37 };
  38
  39 typedef struct VirtIOSerialPostLoad {
  40     QEMUTimer *timer;
  41     uint32_t nr_active_ports;
  42     struct {
  43         VirtIOSerialPort *port;
  44         uint8_t host_connected;
  45     } *connected;
  46 } VirtIOSerialPostLoad;
  47
  48 struct VirtIOSerial {
  49     VirtIODevice vdev;
  50
  51     VirtQueue *c_ivq, *c_ovq;
  52     /* Arrays of ivqs and ovqs: one per port */
  53     VirtQueue **ivqs, **ovqs;
  54
  55     VirtIOSerialBus bus;
  56
  57     DeviceState *qdev;
  58
  59     QTAILQ_HEAD(, VirtIOSerialPort) ports;
  60
  61     /* bitmap for identifying active ports */
  62     uint32_t *ports_map;
  63
  64     struct virtio_console_config config;
  65
  66     struct VirtIOSerialPostLoad *post_load;
  67 };
  68
  69 static VirtIOSerialPort *find_port_by_id(VirtIOSerial *vser, uint32_t id)
  70 {
  71     VirtIOSerialPort *port;
  72
  73     if (id == VIRTIO_CONSOLE_BAD_ID) {
  74         return NULL;
  75     }
  76
  77     QTAILQ_FOREACH(port, &vser->ports, next) {
  78         if (port->id == id)
  79             return port;
  80     }
  81     return NULL;
  82 }
  83
  84 static VirtIOSerialPort *find_port_by_vq(VirtIOSerial *vser, VirtQueue *vq)
  85 {
  86     VirtIOSerialPort *port;
  87
  88     QTAILQ_FOREACH(port, &vser->ports, next) {
  89         if (port->ivq == vq || port->ovq == vq)
  90             return port;
  91     }
  92     return NULL;
  93 }
  94
  95 static bool use_multiport(VirtIOSerial *vser)
  96 {
  97     return vser->vdev.guest_features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
  98 }
  99
 100 static size_t write_to_port(VirtIOSerialPort *port,
 101                             const uint8_t *buf, size_t size)
 102 {
 103     VirtQueueElement elem;
 104     VirtQueue *vq;
 105     size_t offset;
 106
 107     vq = port->ivq;
 108     if (!virtio_queue_ready(vq)) {
 109         return 0;
 110     }
 111
 112     offset = 0;
 113     while (offset < size) {
 114         size_t len;
 115
 116         if (!virtqueue_pop(vq, &elem)) {
 117             break;
 118         }
 119
 120         len = iov_from_buf(elem.in_sg, elem.in_num, 0,
 121                            buf + offset, size - offset);
 122         offset += len;
 123
 124         virtqueue_push(vq, &elem, len);
 125     }
 126
 127     virtio_notify(&port->vser->vdev, vq);
 128     return offset;
 129 }
 130
 131 static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
 132 {
 133     VirtQueueElement elem;
 134
 135     if (!virtio_queue_ready(vq)) {
 136         return;
 137     }
 138     while (virtqueue_pop(vq, &elem)) {
 139         virtqueue_push(vq, &elem, 0);
 140     }
 141     virtio_notify(vdev, vq);
 142 }
 143
 144 static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
 145                                  VirtIODevice *vdev)
 146 {
 147     VirtIOSerialPortClass *vsc;
 148
 149     assert(port);
 150     assert(virtio_queue_ready(vq));
 151
 152     vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 153
 154     while (!port->throttled) {
 155         unsigned int i;
 156
 157         /* Pop an elem only if we haven't left off a previous one mid-way */
 158         if (!port->elem.out_num) {
 159             if (!virtqueue_pop(vq, &port->elem)) {
 160                 break;
 161             }
 162             port->iov_idx = 0;
 163             port->iov_offset = 0;
 164         }
 165
 166         for (i = port->iov_idx; i < port->elem.out_num; i++) {
 167             size_t buf_size;
 168             ssize_t ret;
 169
 170             buf_size = port->elem.out_sg[i].iov_len - port->iov_offset;
 171             ret = vsc->have_data(port,
 172                                   port->elem.out_sg[i].iov_base
 173                                   + port->iov_offset,
 174                                   buf_size);
 175             if (ret < 0 && ret != -EAGAIN) {
 176                 /* We don't handle any other type of errors here */
 177                 abort();
 178             }
 179             if (ret == -EAGAIN || (ret >= 0 && ret < buf_size)) {
 180                 /*
 181                  * this is a temporary check until chardevs can signal to
 182                  * frontends that they are writable again. This prevents
 183                  * the console from going into throttled mode (forever)
 184                  * if virtio-console is connected to a pty without a
 185                  * listener. Otherwise the guest spins forever.
 186                  * We can revert this if
 187                  * 1: chardevs can notify frondends
 188                  * 2: the guest driver does not spin in these cases
 189                  */
 190                 if (!vsc->is_console) {
 191                     virtio_serial_throttle_port(port, true);
 192                 }
 193                 port->iov_idx = i;
 194                 if (ret > 0) {
 195                     port->iov_offset += ret;
 196                 }
 197                 break;
 198             }
 199             port->iov_offset = 0;
 200         }
 201         if (port->throttled) {
 202             break;
 203         }
 204         virtqueue_push(vq, &port->elem, 0);
 205         port->elem.out_num = 0;
 206     }
 207     virtio_notify(vdev, vq);
 208 }
 209
 210 static void flush_queued_data(VirtIOSerialPort *port)
 211 {
 212     assert(port);
 213
 214     if (!virtio_queue_ready(port->ovq)) {
 215         return;
 216     }
 217     do_flush_queued_data(port, port->ovq, &port->vser->vdev);
 218 }
 219
 220 static size_t send_control_msg(VirtIOSerial *vser, void *buf, size_t len)
 221 {
 222     VirtQueueElement elem;
 223     VirtQueue *vq;
 224
 225     vq = vser->c_ivq;
 226     if (!virtio_queue_ready(vq)) {
 227         return 0;
 228     }
 229     if (!virtqueue_pop(vq, &elem)) {
 230         return 0;
 231     }
 232
 233     memcpy(elem.in_sg[0].iov_base, buf, len);
 234
 235     virtqueue_push(vq, &elem, len);
 236     virtio_notify(&vser->vdev, vq);
 237     return len;
 238 }
 239
 240 static size_t send_control_event(VirtIOSerial *vser, uint32_t port_id,
 241                                  uint16_t event, uint16_t value)
 242 {
 243     struct virtio_console_control cpkt;
 244
 245     stl_p(&cpkt.id, port_id);
 246     stw_p(&cpkt.event, event);
 247     stw_p(&cpkt.value, value);
 248
 249     trace_virtio_serial_send_control_event(port_id, event, value);
 250     return send_control_msg(vser, &cpkt, sizeof(cpkt));
 251 }
 252
 253 /* Functions for use inside qemu to open and read from/write to ports */
 254 int virtio_serial_open(VirtIOSerialPort *port)
 255 {
 256     /* Don't allow opening an already-open port */
 257     if (port->host_connected) {
 258         return 0;
 259     }
 260     /* Send port open notification to the guest */
 261     port->host_connected = true;
 262     send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
 263
 264     return 0;
 265 }
 266
 267 int virtio_serial_close(VirtIOSerialPort *port)
 268 {
 269     port->host_connected = false;
 270     /*
 271      * If there's any data the guest sent which the app didn't
 272      * consume, reset the throttling flag and discard the data.
 273      */
 274     port->throttled = false;
 275     discard_vq_data(port->ovq, &port->vser->vdev);
 276
 277     send_control_event(port->vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 0);
 278
 279     return 0;
 280 }
 281
 282 /* Individual ports/apps call this function to write to the guest. */
 283 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 284                             size_t size)
 285 {
 286     if (!port || !port->host_connected || !port->guest_connected) {
 287         return 0;
 288     }
 289     return write_to_port(port, buf, size);
 290 }
 291
 292 /*
 293  * Readiness of the guest to accept data on a port.
 294  * Returns max. data the guest can receive
 295  */
 296 size_t virtio_serial_guest_ready(VirtIOSerialPort *port)
 297 {
 298     VirtQueue *vq = port->ivq;
 299     unsigned int bytes;
 300
 301     if (!virtio_queue_ready(vq) ||
 302         !(port->vser->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK) ||
 303         virtio_queue_empty(vq)) {
 304         return 0;
 305     }
 306     if (use_multiport(port->vser) && !port->guest_connected) {
 307         return 0;
 308     }
 309     virtqueue_get_avail_bytes(vq, &bytes, NULL, 4096, 0);
 310     return bytes;
 311 }
 312
 313 static void flush_queued_data_bh(void *opaque)
 314 {
 315     VirtIOSerialPort *port = opaque;
 316
 317     flush_queued_data(port);
 318 }
 319
 320 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
 321 {
 322     if (!port) {
 323         return;
 324     }
 325
 326     trace_virtio_serial_throttle_port(port->id, throttle);
 327     port->throttled = throttle;
 328     if (throttle) {
 329         return;
 330     }
 331     qemu_bh_schedule(port->bh);
 332 }
 333
 334 /* Guest wants to notify us of some event */
 335 static void handle_control_message(VirtIOSerial *vser, void *buf, size_t len)
 336 {
 337     struct VirtIOSerialPort *port;
 338     VirtIOSerialPortClass *vsc;
 339     struct virtio_console_control cpkt, *gcpkt;
 340     uint8_t *buffer;
 341     size_t buffer_len;
 342
 343     gcpkt = buf;
 344
 345     if (len < sizeof(cpkt)) {
 346         /* The guest sent an invalid control packet */
 347         return;
 348     }
 349
 350     cpkt.event = lduw_p(&gcpkt->event);
 351     cpkt.value = lduw_p(&gcpkt->value);
 352
 353     trace_virtio_serial_handle_control_message(cpkt.event, cpkt.value);
 354
 355     if (cpkt.event == VIRTIO_CONSOLE_DEVICE_READY) {
 356         if (!cpkt.value) {
 357             error_report("virtio-serial-bus: Guest failure in adding device %s",
 358                          vser->bus.qbus.name);
 359             return;
 360         }
 361         /*
 362          * The device is up, we can now tell the device about all the
 363          * ports we have here.
 364          */
 365         QTAILQ_FOREACH(port, &vser->ports, next) {
 366             send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_ADD, 1);
 367         }
 368         return;
 369     }
 370
 371     port = find_port_by_id(vser, ldl_p(&gcpkt->id));
 372     if (!port) {
 373         error_report("virtio-serial-bus: Unexpected port id %u for device %s",
 374                      ldl_p(&gcpkt->id), vser->bus.qbus.name);
 375         return;
 376     }
 377
 378     trace_virtio_serial_handle_control_message_port(port->id);
 379
 380     vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 381
 382     switch(cpkt.event) {
 383     case VIRTIO_CONSOLE_PORT_READY:
 384         if (!cpkt.value) {
 385             error_report("virtio-serial-bus: Guest failure in adding port %u for device %s",
 386                          port->id, vser->bus.qbus.name);
 387             break;
 388         }
 389         /*
 390          * Now that we know the guest asked for the port name, we're
 391          * sure the guest has initialised whatever state is necessary
 392          * for this port. Now's a good time to let the guest know if
 393          * this port is a console port so that the guest can hook it
 394          * up to hvc.
 395          */
 396         if (vsc->is_console) {
 397             send_control_event(vser, port->id, VIRTIO_CONSOLE_CONSOLE_PORT, 1);
 398         }
 399
 400         if (port->name) {
 401             stl_p(&cpkt.id, port->id);
 402             stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME);
 403             stw_p(&cpkt.value, 1);
 404
 405             buffer_len = sizeof(cpkt) + strlen(port->name) + 1;
 406             buffer = g_malloc(buffer_len);
 407
 408             memcpy(buffer, &cpkt, sizeof(cpkt));
 409             memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));
 410             buffer[buffer_len - 1] = 0;
 411
 412             send_control_msg(vser, buffer, buffer_len);
 413             g_free(buffer);
 414         }
 415
 416         if (port->host_connected) {
 417             send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_OPEN, 1);
 418         }
 419
 420         /*
 421          * When the guest has asked us for this information it means
 422          * the guest is all setup and has its virtqueues
 423          * initialised. If some app is interested in knowing about
 424          * this event, let it know.
 425          */
 426         if (vsc->guest_ready) {
 427             vsc->guest_ready(port);
 428         }
 429         break;
 430
 431     case VIRTIO_CONSOLE_PORT_OPEN:
 432         port->guest_connected = cpkt.value;
 433         if (cpkt.value && vsc->guest_open) {
 434             /* Send the guest opened notification if an app is interested */
 435             vsc->guest_open(port);
 436         }
 437
 438         if (!cpkt.value && vsc->guest_close) {
 439             /* Send the guest closed notification if an app is interested */
 440             vsc->guest_close(port);
 441         }
 442         break;
 443     }
 444 }
 445
 446 static void control_in(VirtIODevice *vdev, VirtQueue *vq)
 447 {
 448 }
 449
 450 static void control_out(VirtIODevice *vdev, VirtQueue *vq)
 451 {
 452     VirtQueueElement elem;
 453     VirtIOSerial *vser;
 454     uint8_t *buf;
 455     size_t len;
 456
 457     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 458
 459     len = 0;
 460     buf = NULL;
 461     while (virtqueue_pop(vq, &elem)) {
 462         size_t cur_len;
 463
 464         cur_len = iov_size(elem.out_sg, elem.out_num);
 465         /*
 466          * Allocate a new buf only if we didn't have one previously or
 467          * if the size of the buf differs
 468          */
 469         if (cur_len > len) {
 470             g_free(buf);
 471
 472             buf = g_malloc(cur_len);
 473             len = cur_len;
 474         }
 475         iov_to_buf(elem.out_sg, elem.out_num, 0, buf, cur_len);
 476
 477         handle_control_message(vser, buf, cur_len);
 478         virtqueue_push(vq, &elem, 0);
 479     }
 480     g_free(buf);
 481     virtio_notify(vdev, vq);
 482 }
 483
 484 /* Guest wrote something to some port. */
 485 static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
 486 {
 487     VirtIOSerial *vser;
 488     VirtIOSerialPort *port;
 489
 490     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 491     port = find_port_by_vq(vser, vq);
 492
 493     if (!port || !port->host_connected) {
 494         discard_vq_data(vq, vdev);
 495         return;
 496     }
 497
 498     if (!port->throttled) {
 499         do_flush_queued_data(port, vq, vdev);
 500         return;
 501     }
 502 }
 503
 504 static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
 505 {
 506 }
 507
 508 static uint32_t get_features(VirtIODevice *vdev, uint32_t features)
 509 {
 510     VirtIOSerial *vser;
 511
 512     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 513
 514     if (vser->bus.max_nr_ports > 1) {
 515         features |= (1 << VIRTIO_CONSOLE_F_MULTIPORT);
 516     }
 517     return features;
 518 }
 519
 520 /* Guest requested config info */
 521 static void get_config(VirtIODevice *vdev, uint8_t *config_data)
 522 {
 523     VirtIOSerial *vser;
 524
 525     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 526     memcpy(config_data, &vser->config, sizeof(struct virtio_console_config));
 527 }
 528
 529 static void set_config(VirtIODevice *vdev, const uint8_t *config_data)
 530 {
 531     struct virtio_console_config config;
 532
 533     memcpy(&config, config_data, sizeof(config));
 534 }
 535
 536 static void guest_reset(VirtIOSerial *vser)
 537 {
 538     VirtIOSerialPort *port;
 539     VirtIOSerialPortClass *vsc;
 540
 541     QTAILQ_FOREACH(port, &vser->ports, next) {
 542         vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 543         if (port->guest_connected) {
 544             port->guest_connected = false;
 545
 546             if (vsc->guest_close)
 547                 vsc->guest_close(port);
 548         }
 549     }
 550 }
 551
 552 static void set_status(VirtIODevice *vdev, uint8_t status)
 553 {
 554     VirtIOSerial *vser;
 555     VirtIOSerialPort *port;
 556
 557     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 558     port = find_port_by_id(vser, 0);
 559
 560     if (port && !use_multiport(port->vser)
 561         && (status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 562         /*
 563          * Non-multiport guests won't be able to tell us guest
 564          * open/close status.  Such guests can only have a port at id
 565          * 0, so set guest_connected for such ports as soon as guest
 566          * is up.
 567          */
 568         port->guest_connected = true;
 569     }
 570     if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) {
 571         guest_reset(vser);
 572     }
 573 }
 574
 575 static void vser_reset(VirtIODevice *vdev)
 576 {
 577     VirtIOSerial *vser;
 578
 579     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 580     guest_reset(vser);
 581 }
 582
 583 static void virtio_serial_save(QEMUFile *f, void *opaque)
 584 {
 585     VirtIOSerial *s = opaque;
 586     VirtIOSerialPort *port;
 587     uint32_t nr_active_ports;
 588     unsigned int i, max_nr_ports;
 589
 590     /* The virtio device */
 591     virtio_save(&s->vdev, f);
 592
 593     /* The config space */
 594     qemu_put_be16s(f, &s->config.cols);
 595     qemu_put_be16s(f, &s->config.rows);
 596
 597     qemu_put_be32s(f, &s->config.max_nr_ports);
 598
 599     /* The ports map */
 600     max_nr_ports = tswap32(s->config.max_nr_ports);
 601     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 602         qemu_put_be32s(f, &s->ports_map[i]);
 603     }
 604
 605     /* Ports */
 606
 607     nr_active_ports = 0;
 608     QTAILQ_FOREACH(port, &s->ports, next) {
 609         nr_active_ports++;
 610     }
 611
 612     qemu_put_be32s(f, &nr_active_ports);
 613
 614     /*
 615      * Items in struct VirtIOSerialPort.
 616      */
 617     QTAILQ_FOREACH(port, &s->ports, next) {
 618         uint32_t elem_popped;
 619
 620         qemu_put_be32s(f, &port->id);
 621         qemu_put_byte(f, port->guest_connected);
 622         qemu_put_byte(f, port->host_connected);
 623
 624         elem_popped = 0;
 625         if (port->elem.out_num) {
 626             elem_popped = 1;
 627         }
 628         qemu_put_be32s(f, &elem_popped);
 629         if (elem_popped) {
 630             qemu_put_be32s(f, &port->iov_idx);
 631             qemu_put_be64s(f, &port->iov_offset);
 632
 633             qemu_put_buffer(f, (unsigned char *)&port->elem,
 634                             sizeof(port->elem));
 635         }
 636     }
 637 }
 638
 639 static void virtio_serial_post_load_timer_cb(void *opaque)
 640 {
 641     uint32_t i;
 642     VirtIOSerial *s = opaque;
 643     VirtIOSerialPort *port;
 644     uint8_t host_connected;
 645
 646     if (!s->post_load) {
 647         return;
 648     }
 649     for (i = 0 ; i < s->post_load->nr_active_ports; ++i) {
 650         port = s->post_load->connected[i].port;
 651         host_connected = s->post_load->connected[i].host_connected;
 652         if (host_connected != port->host_connected) {
 653             /*
 654              * We have to let the guest know of the host connection
 655              * status change
 656              */
 657             send_control_event(s, port->id, VIRTIO_CONSOLE_PORT_OPEN,
 658                                port->host_connected);
 659         }
 660     }
 661     g_free(s->post_load->connected);
 662     qemu_free_timer(s->post_load->timer);
 663     g_free(s->post_load);
 664     s->post_load = NULL;
 665 }
 666
 667 static int fetch_active_ports_list(QEMUFile *f, int version_id,
 668                                    VirtIOSerial *s, uint32_t nr_active_ports)
 669 {
 670     uint32_t i;
 671
 672     s->post_load = g_malloc0(sizeof(*s->post_load));
 673     s->post_load->nr_active_ports = nr_active_ports;
 674     s->post_load->connected =
 675         g_malloc0(sizeof(*s->post_load->connected) * nr_active_ports);
 676
 677     s->post_load->timer = qemu_new_timer_ns(vm_clock,
 678                                             virtio_serial_post_load_timer_cb,
 679                                             s);
 680
 681     /* Items in struct VirtIOSerialPort */
 682     for (i = 0; i < nr_active_ports; i++) {
 683         VirtIOSerialPort *port;
 684         uint32_t id;
 685
 686         id = qemu_get_be32(f);
 687         port = find_port_by_id(s, id);
 688         if (!port) {
 689             return -EINVAL;
 690         }
 691
 692         port->guest_connected = qemu_get_byte(f);
 693         s->post_load->connected[i].port = port;
 694         s->post_load->connected[i].host_connected = qemu_get_byte(f);
 695
 696         if (version_id > 2) {
 697             uint32_t elem_popped;
 698
 699             qemu_get_be32s(f, &elem_popped);
 700             if (elem_popped) {
 701                 qemu_get_be32s(f, &port->iov_idx);
 702                 qemu_get_be64s(f, &port->iov_offset);
 703
 704                 qemu_get_buffer(f, (unsigned char *)&port->elem,
 705                                 sizeof(port->elem));
 706                 virtqueue_map_sg(port->elem.in_sg, port->elem.in_addr,
 707                                  port->elem.in_num, 1);
 708                 virtqueue_map_sg(port->elem.out_sg, port->elem.out_addr,
 709                                  port->elem.out_num, 1);
 710
 711                 /*
 712                  *  Port was throttled on source machine.  Let's
 713                  *  unthrottle it here so data starts flowing again.
 714                  */
 715                 virtio_serial_throttle_port(port, false);
 716             }
 717         }
 718     }
 719     qemu_mod_timer(s->post_load->timer, 1);
 720     return 0;
 721 }
 722
 723 static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
 724 {
 725     VirtIOSerial *s = opaque;
 726     uint32_t max_nr_ports, nr_active_ports, ports_map;
 727     unsigned int i;
 728     int ret;
 729
 730     if (version_id > 3) {
 731         return -EINVAL;
 732     }
 733
 734     /* The virtio device */
 735     ret = virtio_load(&s->vdev, f);
 736     if (ret) {
 737         return ret;
 738     }
 739
 740     if (version_id < 2) {
 741         return 0;
 742     }
 743
 744     /* The config space */
 745     qemu_get_be16s(f, &s->config.cols);
 746     qemu_get_be16s(f, &s->config.rows);
 747
 748     qemu_get_be32s(f, &max_nr_ports);
 749     tswap32s(&max_nr_ports);
 750     if (max_nr_ports > tswap32(s->config.max_nr_ports)) {
 751         /* Source could have had more ports than us. Fail migration. */
 752         return -EINVAL;
 753     }
 754
 755     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 756         qemu_get_be32s(f, &ports_map);
 757
 758         if (ports_map != s->ports_map[i]) {
 759             /*
 760              * Ports active on source and destination don't
 761              * match. Fail migration.
 762              */
 763             return -EINVAL;
 764         }
 765     }
 766
 767     qemu_get_be32s(f, &nr_active_ports);
 768
 769     if (nr_active_ports) {
 770         ret = fetch_active_ports_list(f, version_id, s, nr_active_ports);
 771         if (ret) {
 772             return ret;
 773         }
 774     }
 775     return 0;
 776 }
 777
 778 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent);
 779
 780 static Property virtser_props[] = {
 781     DEFINE_PROP_UINT32("nr", VirtIOSerialPort, id, VIRTIO_CONSOLE_BAD_ID),
 782     DEFINE_PROP_STRING("name", VirtIOSerialPort, name),
 783     DEFINE_PROP_END_OF_LIST()
 784 };
 785
 786 #define TYPE_VIRTIO_SERIAL_BUS "virtio-serial-bus"
 787 #define VIRTIO_SERIAL_BUS(obj) \
 788       OBJECT_CHECK(VirtIOSerialBus, (obj), TYPE_VIRTIO_SERIAL_BUS)
 789
 790 static void virtser_bus_class_init(ObjectClass *klass, void *data)
 791 {
 792     BusClass *k = BUS_CLASS(klass);
 793     k->print_dev = virtser_bus_dev_print;
 794 }
 795
 796 static const TypeInfo virtser_bus_info = {
 797     .name = TYPE_VIRTIO_SERIAL_BUS,
 798     .parent = TYPE_BUS,
 799     .instance_size = sizeof(VirtIOSerialBus),
 800     .class_init = virtser_bus_class_init,
 801 };
 802
 803 static void virtser_bus_dev_print(Monitor *mon, DeviceState *qdev, int indent)
 804 {
 805     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 806
 807     monitor_printf(mon, "%*sport %d, guest %s, host %s, throttle %s\n",
 808                    indent, "", port->id,
 809                    port->guest_connected ? "on" : "off",
 810                    port->host_connected ? "on" : "off",
 811                    port->throttled ? "on" : "off");
 812 }
 813
 814 /* This function is only used if a port id is not provided by the user */
 815 static uint32_t find_free_port_id(VirtIOSerial *vser)
 816 {
 817     unsigned int i, max_nr_ports;
 818
 819     max_nr_ports = tswap32(vser->config.max_nr_ports);
 820     for (i = 0; i < (max_nr_ports + 31) / 32; i++) {
 821         uint32_t map, bit;
 822
 823         map = vser->ports_map[i];
 824         bit = ffs(~map);
 825         if (bit) {
 826             return (bit - 1) + i * 32;
 827         }
 828     }
 829     return VIRTIO_CONSOLE_BAD_ID;
 830 }
 831
 832 static void mark_port_added(VirtIOSerial *vser, uint32_t port_id)
 833 {
 834     unsigned int i;
 835
 836     i = port_id / 32;
 837     vser->ports_map[i] |= 1U << (port_id % 32);
 838 }
 839
 840 static void add_port(VirtIOSerial *vser, uint32_t port_id)
 841 {
 842     mark_port_added(vser, port_id);
 843     send_control_event(vser, port_id, VIRTIO_CONSOLE_PORT_ADD, 1);
 844 }
 845
 846 static void remove_port(VirtIOSerial *vser, uint32_t port_id)
 847 {
 848     VirtIOSerialPort *port;
 849     unsigned int i;
 850
 851     i = port_id / 32;
 852     vser->ports_map[i] &= ~(1U << (port_id % 32));
 853
 854     port = find_port_by_id(vser, port_id);
 855     /*
 856      * This function is only called from qdev's unplug callback; if we
 857      * get a NULL port here, we're in trouble.
 858      */
 859     assert(port);
 860
 861     /* Flush out any unconsumed buffers first */
 862     discard_vq_data(port->ovq, &port->vser->vdev);
 863
 864     send_control_event(vser, port->id, VIRTIO_CONSOLE_PORT_REMOVE, 1);
 865 }
 866
 867 static int virtser_port_qdev_init(DeviceState *qdev)
 868 {
 869     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 870     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 871     VirtIOSerialBus *bus = DO_UPCAST(VirtIOSerialBus, qbus, qdev->parent_bus);
 872     int ret, max_nr_ports;
 873     bool plugging_port0;
 874
 875     port->vser = bus->vser;
 876     port->bh = qemu_bh_new(flush_queued_data_bh, port);
 877
 878     assert(vsc->have_data);
 879
 880     /*
 881      * Is the first console port we're seeing? If so, put it up at
 882      * location 0. This is done for backward compatibility (old
 883      * kernel, new qemu).
 884      */
 885     plugging_port0 = vsc->is_console && !find_port_by_id(port->vser, 0);
 886
 887     if (find_port_by_id(port->vser, port->id)) {
 888         error_report("virtio-serial-bus: A port already exists at id %u",
 889                      port->id);
 890         return -1;
 891     }
 892
 893     if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 894         if (plugging_port0) {
 895             port->id = 0;
 896         } else {
 897             port->id = find_free_port_id(port->vser);
 898             if (port->id == VIRTIO_CONSOLE_BAD_ID) {
 899                 error_report("virtio-serial-bus: Maximum port limit for this device reached");
 900                 return -1;
 901             }
 902         }
 903     }
 904
 905     max_nr_ports = tswap32(port->vser->config.max_nr_ports);
 906     if (port->id >= max_nr_ports) {
 907         error_report("virtio-serial-bus: Out-of-range port id specified, max. allowed: %u",
 908                      max_nr_ports - 1);
 909         return -1;
 910     }
 911
 912     ret = vsc->init(port);
 913     if (ret) {
 914         return ret;
 915     }
 916
 917     port->elem.out_num = 0;
 918
 919     QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
 920     port->ivq = port->vser->ivqs[port->id];
 921     port->ovq = port->vser->ovqs[port->id];
 922
 923     add_port(port->vser, port->id);
 924
 925     /* Send an update to the guest about this new port added */
 926     virtio_notify_config(&port->vser->vdev);
 927
 928     return ret;
 929 }
 930
 931 static int virtser_port_qdev_exit(DeviceState *qdev)
 932 {
 933     VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, qdev);
 934     VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
 935     VirtIOSerial *vser = port->vser;
 936
 937     qemu_bh_delete(port->bh);
 938     remove_port(port->vser, port->id);
 939
 940     QTAILQ_REMOVE(&vser->ports, port, next);
 941
 942     if (vsc->exit) {
 943         vsc->exit(port);
 944     }
 945     return 0;
 946 }
 947
 948 VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *conf)
 949 {
 950     VirtIOSerial *vser;
 951     VirtIODevice *vdev;
 952     uint32_t i, max_supported_ports;
 953
 954     if (!conf->max_virtserial_ports)
 955         return NULL;
 956
 957     /* Each port takes 2 queues, and one pair is for the control queue */
 958     max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
 959
 960     if (conf->max_virtserial_ports > max_supported_ports) {
 961         error_report("maximum ports supported: %u", max_supported_ports);
 962         return NULL;
 963     }
 964
 965     vdev = virtio_common_init("virtio-serial", VIRTIO_ID_CONSOLE,
 966                               sizeof(struct virtio_console_config),
 967                               sizeof(VirtIOSerial));
 968
 969     vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
 970
 971     /* Spawn a new virtio-serial bus on which the ports will ride as devices */
 972     qbus_create_inplace(&vser->bus.qbus, TYPE_VIRTIO_SERIAL_BUS, dev, NULL);
 973     vser->bus.qbus.allow_hotplug = 1;
 974     vser->bus.vser = vser;
 975     QTAILQ_INIT(&vser->ports);
 976
 977     vser->bus.max_nr_ports = conf->max_virtserial_ports;
 978     vser->ivqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
 979     vser->ovqs = g_malloc(conf->max_virtserial_ports * sizeof(VirtQueue *));
 980
 981     /* Add a queue for host to guest transfers for port 0 (backward compat) */
 982     vser->ivqs[0] = virtio_add_queue(vdev, 128, handle_input);
 983     /* Add a queue for guest to host transfers for port 0 (backward compat) */
 984     vser->ovqs[0] = virtio_add_queue(vdev, 128, handle_output);
 985
 986     /* TODO: host to guest notifications can get dropped
 987      * if the queue fills up. Implement queueing in host,
 988      * this might also make it possible to reduce the control
 989      * queue size: as guest preposts buffers there,
 990      * this will save 4Kbyte of guest memory per entry. */
 991
 992     /* control queue: host to guest */
 993     vser->c_ivq = virtio_add_queue(vdev, 32, control_in);
 994     /* control queue: guest to host */
 995     vser->c_ovq = virtio_add_queue(vdev, 32, control_out);
 996
 997     for (i = 1; i < vser->bus.max_nr_ports; i++) {
 998         /* Add a per-port queue for host to guest transfers */
 999         vser->ivqs[i] = virtio_add_queue(vdev, 128, handle_input);
1000         /* Add a per-per queue for guest to host transfers */
1001         vser->ovqs[i] = virtio_add_queue(vdev, 128, handle_output);
1002     }
1003
1004     vser->config.max_nr_ports = tswap32(conf->max_virtserial_ports);
1005     vser->ports_map = g_malloc0(((conf->max_virtserial_ports + 31) / 32)
1006         * sizeof(vser->ports_map[0]));
1007     /*
1008      * Reserve location 0 for a console port for backward compat
1009      * (old kernel, new qemu)
1010      */
1011     mark_port_added(vser, 0);
1012
1013     vser->vdev.get_features = get_features;
1014     vser->vdev.get_config = get_config;
1015     vser->vdev.set_config = set_config;
1016     vser->vdev.set_status = set_status;
1017     vser->vdev.reset = vser_reset;
1018
1019     vser->qdev = dev;
1020
1021     vser->post_load = NULL;
1022
1023     /*
1024      * Register for the savevm section with the virtio-console name
1025      * to preserve backward compat
1026      */
1027     register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
1028                     virtio_serial_load, vser);
1029
1030     return vdev;
1031 }
1032
1033 void virtio_serial_exit(VirtIODevice *vdev)
1034 {
1035     VirtIOSerial *vser = DO_UPCAST(VirtIOSerial, vdev, vdev);
1036
1037     unregister_savevm(vser->qdev, "virtio-console", vser);
1038
1039     g_free(vser->ivqs);
1040     g_free(vser->ovqs);
1041     g_free(vser->ports_map);
1042     if (vser->post_load) {
1043         g_free(vser->post_load->connected);
1044         qemu_del_timer(vser->post_load->timer);
1045         qemu_free_timer(vser->post_load->timer);
1046         g_free(vser->post_load);
1047     }
1048     virtio_cleanup(vdev);
1049 }
1050
1051 static void virtio_serial_port_class_init(ObjectClass *klass, void *data)
1052 {
1053     DeviceClass *k = DEVICE_CLASS(klass);
1054     k->init = virtser_port_qdev_init;
1055     k->bus_type = TYPE_VIRTIO_SERIAL_BUS;
1056     k->exit = virtser_port_qdev_exit;
1057     k->unplug = qdev_simple_unplug_cb;
1058     k->props = virtser_props;
1059 }
1060
1061 static TypeInfo virtio_serial_port_type_info = {
1062     .name = TYPE_VIRTIO_SERIAL_PORT,
1063     .parent = TYPE_DEVICE,
1064     .instance_size = sizeof(VirtIOSerialPort),
1065     .abstract = true,
1066     .class_size = sizeof(VirtIOSerialPortClass),
1067     .class_init = virtio_serial_port_class_init,
1068 };
1069
1070 static void virtio_serial_register_types(void)
1071 {
1072     type_register_static(&virtser_bus_info);
1073     type_register_static(&virtio_serial_port_type_info);
1074 }
1075
1076 type_init(virtio_serial_register_types)