hw/misc/ivshmem.c

   1 /*
   2  * Inter-VM Shared Memory PCI device.
   3  *
   4  * Author:
   5  *      Cam Macdonell <cam@cs.ualberta.ca>
   6  *
   7  * Based On: cirrus_vga.c
   8  *          Copyright (c) 2004 Fabrice Bellard
   9  *          Copyright (c) 2004 Makoto Suzuki (suzu)
  10  *
  11  *      and rtl8139.c
  12  *          Copyright (c) 2006 Igor Kovalenko
  13  *
  14  * This code is licensed under the GNU GPL v2.
  15  *
  16  * Contributions after 2012-01-13 are licensed under the terms of the
  17  * GNU GPL, version 2 or (at your option) any later version.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "qemu/units.h"
  22 #include "qapi/error.h"
  23 #include "qemu/cutils.h"
  24 #include "hw/pci/pci.h"
  25 #include "hw/qdev-properties.h"
  26 #include "hw/qdev-properties-system.h"
  27 #include "hw/pci/msi.h"
  28 #include "hw/pci/msix.h"
  29 #include "sysemu/kvm.h"
  30 #include "migration/blocker.h"
  31 #include "migration/vmstate.h"
  32 #include "qemu/error-report.h"
  33 #include "qemu/event_notifier.h"
  34 #include "qemu/module.h"
  35 #include "qom/object_interfaces.h"
  36 #include "chardev/char-fe.h"
  37 #include "sysemu/hostmem.h"
  38 #include "qapi/visitor.h"
  39
  40 #include "hw/misc/ivshmem.h"
  41 #include "qom/object.h"
  42
  43 #define PCI_VENDOR_ID_IVSHMEM   PCI_VENDOR_ID_REDHAT_QUMRANET
  44 #define PCI_DEVICE_ID_IVSHMEM   0x1110
  45
  46 #define IVSHMEM_MAX_PEERS UINT16_MAX
  47 #define IVSHMEM_IOEVENTFD   0
  48 #define IVSHMEM_MSI     1
  49
  50 #define IVSHMEM_REG_BAR_SIZE 0x100
  51
  52 #define IVSHMEM_DEBUG 0
  53 #define IVSHMEM_DPRINTF(fmt, ...)                       \
  54     do {                                                \
  55         if (IVSHMEM_DEBUG) {                            \
  56             printf("IVSHMEM: " fmt, ## __VA_ARGS__);    \
  57         }                                               \
  58     } while (0)
  59
  60 #define TYPE_IVSHMEM_COMMON "ivshmem-common"
  61 typedef struct IVShmemState IVShmemState;
  62 DECLARE_INSTANCE_CHECKER(IVShmemState, IVSHMEM_COMMON,
  63                          TYPE_IVSHMEM_COMMON)
  64
  65 #define TYPE_IVSHMEM_PLAIN "ivshmem-plain"
  66 DECLARE_INSTANCE_CHECKER(IVShmemState, IVSHMEM_PLAIN,
  67                          TYPE_IVSHMEM_PLAIN)
  68
  69 #define TYPE_IVSHMEM_DOORBELL "ivshmem-doorbell"
  70 DECLARE_INSTANCE_CHECKER(IVShmemState, IVSHMEM_DOORBELL,
  71                          TYPE_IVSHMEM_DOORBELL)
  72
  73 #define TYPE_IVSHMEM "ivshmem"
  74 DECLARE_INSTANCE_CHECKER(IVShmemState, IVSHMEM,
  75                          TYPE_IVSHMEM)
  76
  77 typedef struct Peer {
  78     int nb_eventfds;
  79     EventNotifier *eventfds;
  80 } Peer;
  81
  82 typedef struct MSIVector {
  83     PCIDevice *pdev;
  84     int virq;
  85     bool unmasked;
  86 } MSIVector;
  87
  88 struct IVShmemState {
  89     /*< private >*/
  90     PCIDevice parent_obj;
  91     /*< public >*/
  92
  93     uint32_t features;
  94
  95     /* exactly one of these two may be set */
  96     HostMemoryBackend *hostmem; /* with interrupts */
  97     CharBackend server_chr; /* without interrupts */
  98
  99     /* registers */
 100     uint32_t intrmask;
 101     uint32_t intrstatus;
 102     int vm_id;
 103
 104     /* BARs */
 105     MemoryRegion ivshmem_mmio;  /* BAR 0 (registers) */
 106     MemoryRegion *ivshmem_bar2; /* BAR 2 (shared memory) */
 107     MemoryRegion server_bar2;   /* used with server_chr */
 108
 109     /* interrupt support */
 110     Peer *peers;
 111     int nb_peers;               /* space in @peers[] */
 112     uint32_t vectors;
 113     MSIVector *msi_vectors;
 114     uint64_t msg_buf;           /* buffer for receiving server messages */
 115     int msg_buffered_bytes;     /* #bytes in @msg_buf */
 116
 117     /* migration stuff */
 118     OnOffAuto master;
 119     Error *migration_blocker;
 120 };
 121
 122 /* registers for the Inter-VM shared memory device */
 123 enum ivshmem_registers {
 124     INTRMASK = 0,
 125     INTRSTATUS = 4,
 126     IVPOSITION = 8,
 127     DOORBELL = 12,
 128 };
 129
 130 static inline uint32_t ivshmem_has_feature(IVShmemState *ivs,
 131                                                     unsigned int feature) {
 132     return (ivs->features & (1 << feature));
 133 }
 134
 135 static inline bool ivshmem_is_master(IVShmemState *s)
 136 {
 137     assert(s->master != ON_OFF_AUTO_AUTO);
 138     return s->master == ON_OFF_AUTO_ON;
 139 }
 140
 141 static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
 142 {
 143     IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
 144
 145     s->intrmask = val;
 146 }
 147
 148 static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
 149 {
 150     uint32_t ret = s->intrmask;
 151
 152     IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
 153     return ret;
 154 }
 155
 156 static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
 157 {
 158     IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
 159
 160     s->intrstatus = val;
 161 }
 162
 163 static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
 164 {
 165     uint32_t ret = s->intrstatus;
 166
 167     /* reading ISR clears all interrupts */
 168     s->intrstatus = 0;
 169     return ret;
 170 }
 171
 172 static void ivshmem_io_write(void *opaque, hwaddr addr,
 173                              uint64_t val, unsigned size)
 174 {
 175     IVShmemState *s = opaque;
 176
 177     uint16_t dest = val >> 16;
 178     uint16_t vector = val & 0xff;
 179
 180     addr &= 0xfc;
 181
 182     IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr);
 183     switch (addr)
 184     {
 185         case INTRMASK:
 186             ivshmem_IntrMask_write(s, val);
 187             break;
 188
 189         case INTRSTATUS:
 190             ivshmem_IntrStatus_write(s, val);
 191             break;
 192
 193         case DOORBELL:
 194             /* check that dest VM ID is reasonable */
 195             if (dest >= s->nb_peers) {
 196                 IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
 197                 break;
 198             }
 199
 200             /* check doorbell range */
 201             if (vector < s->peers[dest].nb_eventfds) {
 202                 IVSHMEM_DPRINTF("Notifying VM %d on vector %d\n", dest, vector);
 203                 event_notifier_set(&s->peers[dest].eventfds[vector]);
 204             } else {
 205                 IVSHMEM_DPRINTF("Invalid destination vector %d on VM %d\n",
 206                                 vector, dest);
 207             }
 208             break;
 209         default:
 210             IVSHMEM_DPRINTF("Unhandled write " TARGET_FMT_plx "\n", addr);
 211     }
 212 }
 213
 214 static uint64_t ivshmem_io_read(void *opaque, hwaddr addr,
 215                                 unsigned size)
 216 {
 217
 218     IVShmemState *s = opaque;
 219     uint32_t ret;
 220
 221     switch (addr)
 222     {
 223         case INTRMASK:
 224             ret = ivshmem_IntrMask_read(s);
 225             break;
 226
 227         case INTRSTATUS:
 228             ret = ivshmem_IntrStatus_read(s);
 229             break;
 230
 231         case IVPOSITION:
 232             ret = s->vm_id;
 233             break;
 234
 235         default:
 236             IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr);
 237             ret = 0;
 238     }
 239
 240     return ret;
 241 }
 242
 243 static const MemoryRegionOps ivshmem_mmio_ops = {
 244     .read = ivshmem_io_read,
 245     .write = ivshmem_io_write,
 246     .endianness = DEVICE_NATIVE_ENDIAN,
 247     .impl = {
 248         .min_access_size = 4,
 249         .max_access_size = 4,
 250     },
 251 };
 252
 253 static void ivshmem_vector_notify(void *opaque)
 254 {
 255     MSIVector *entry = opaque;
 256     PCIDevice *pdev = entry->pdev;
 257     IVShmemState *s = IVSHMEM_COMMON(pdev);
 258     int vector = entry - s->msi_vectors;
 259     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 260
 261     if (!event_notifier_test_and_clear(n)) {
 262         return;
 263     }
 264
 265     IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, vector);
 266     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 267         if (msix_enabled(pdev)) {
 268             msix_notify(pdev, vector);
 269         }
 270     } else {
 271         ivshmem_IntrStatus_write(s, 1);
 272     }
 273 }
 274
 275 static int ivshmem_vector_unmask(PCIDevice *dev, unsigned vector,
 276                                  MSIMessage msg)
 277 {
 278     IVShmemState *s = IVSHMEM_COMMON(dev);
 279     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 280     MSIVector *v = &s->msi_vectors[vector];
 281     int ret;
 282
 283     IVSHMEM_DPRINTF("vector unmask %p %d\n", dev, vector);
 284     if (!v->pdev) {
 285         error_report("ivshmem: vector %d route does not exist", vector);
 286         return -EINVAL;
 287     }
 288     assert(!v->unmasked);
 289
 290     ret = kvm_irqchip_update_msi_route(kvm_state, v->virq, msg, dev);
 291     if (ret < 0) {
 292         return ret;
 293     }
 294     kvm_irqchip_commit_routes(kvm_state);
 295
 296     ret = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq);
 297     if (ret < 0) {
 298         return ret;
 299     }
 300     v->unmasked = true;
 301
 302     return 0;
 303 }
 304
 305 static void ivshmem_vector_mask(PCIDevice *dev, unsigned vector)
 306 {
 307     IVShmemState *s = IVSHMEM_COMMON(dev);
 308     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 309     MSIVector *v = &s->msi_vectors[vector];
 310     int ret;
 311
 312     IVSHMEM_DPRINTF("vector mask %p %d\n", dev, vector);
 313     if (!v->pdev) {
 314         error_report("ivshmem: vector %d route does not exist", vector);
 315         return;
 316     }
 317     assert(v->unmasked);
 318
 319     ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, v->virq);
 320     if (ret < 0) {
 321         error_report("remove_irqfd_notifier_gsi failed");
 322         return;
 323     }
 324     v->unmasked = false;
 325 }
 326
 327 static void ivshmem_vector_poll(PCIDevice *dev,
 328                                 unsigned int vector_start,
 329                                 unsigned int vector_end)
 330 {
 331     IVShmemState *s = IVSHMEM_COMMON(dev);
 332     unsigned int vector;
 333
 334     IVSHMEM_DPRINTF("vector poll %p %d-%d\n", dev, vector_start, vector_end);
 335
 336     vector_end = MIN(vector_end, s->vectors);
 337
 338     for (vector = vector_start; vector < vector_end; vector++) {
 339         EventNotifier *notifier = &s->peers[s->vm_id].eventfds[vector];
 340
 341         if (!msix_is_masked(dev, vector)) {
 342             continue;
 343         }
 344
 345         if (event_notifier_test_and_clear(notifier)) {
 346             msix_set_pending(dev, vector);
 347         }
 348     }
 349 }
 350
 351 static void watch_vector_notifier(IVShmemState *s, EventNotifier *n,
 352                                  int vector)
 353 {
 354     int eventfd = event_notifier_get_fd(n);
 355
 356     assert(!s->msi_vectors[vector].pdev);
 357     s->msi_vectors[vector].pdev = PCI_DEVICE(s);
 358
 359     qemu_set_fd_handler(eventfd, ivshmem_vector_notify,
 360                         NULL, &s->msi_vectors[vector]);
 361 }
 362
 363 static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i)
 364 {
 365     memory_region_add_eventfd(&s->ivshmem_mmio,
 366                               DOORBELL,
 367                               4,
 368                               true,
 369                               (posn << 16) | i,
 370                               &s->peers[posn].eventfds[i]);
 371 }
 372
 373 static void ivshmem_del_eventfd(IVShmemState *s, int posn, int i)
 374 {
 375     memory_region_del_eventfd(&s->ivshmem_mmio,
 376                               DOORBELL,
 377                               4,
 378                               true,
 379                               (posn << 16) | i,
 380                               &s->peers[posn].eventfds[i]);
 381 }
 382
 383 static void close_peer_eventfds(IVShmemState *s, int posn)
 384 {
 385     int i, n;
 386
 387     assert(posn >= 0 && posn < s->nb_peers);
 388     n = s->peers[posn].nb_eventfds;
 389
 390     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 391         memory_region_transaction_begin();
 392         for (i = 0; i < n; i++) {
 393             ivshmem_del_eventfd(s, posn, i);
 394         }
 395         memory_region_transaction_commit();
 396     }
 397
 398     for (i = 0; i < n; i++) {
 399         event_notifier_cleanup(&s->peers[posn].eventfds[i]);
 400     }
 401
 402     g_free(s->peers[posn].eventfds);
 403     s->peers[posn].nb_eventfds = 0;
 404 }
 405
 406 static void resize_peers(IVShmemState *s, int nb_peers)
 407 {
 408     int old_nb_peers = s->nb_peers;
 409     int i;
 410
 411     assert(nb_peers > old_nb_peers);
 412     IVSHMEM_DPRINTF("bumping storage to %d peers\n", nb_peers);
 413
 414     s->peers = g_realloc(s->peers, nb_peers * sizeof(Peer));
 415     s->nb_peers = nb_peers;
 416
 417     for (i = old_nb_peers; i < nb_peers; i++) {
 418         s->peers[i].eventfds = g_new0(EventNotifier, s->vectors);
 419         s->peers[i].nb_eventfds = 0;
 420     }
 421 }
 422
 423 static void ivshmem_add_kvm_msi_virq(IVShmemState *s, int vector,
 424                                      Error **errp)
 425 {
 426     PCIDevice *pdev = PCI_DEVICE(s);
 427     int ret;
 428
 429     IVSHMEM_DPRINTF("ivshmem_add_kvm_msi_virq vector:%d\n", vector);
 430     assert(!s->msi_vectors[vector].pdev);
 431
 432     ret = kvm_irqchip_add_msi_route(kvm_state, vector, pdev);
 433     if (ret < 0) {
 434         error_setg(errp, "kvm_irqchip_add_msi_route failed");
 435         return;
 436     }
 437
 438     s->msi_vectors[vector].virq = ret;
 439     s->msi_vectors[vector].pdev = pdev;
 440 }
 441
 442 static void setup_interrupt(IVShmemState *s, int vector, Error **errp)
 443 {
 444     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 445     bool with_irqfd = kvm_msi_via_irqfd_enabled() &&
 446         ivshmem_has_feature(s, IVSHMEM_MSI);
 447     PCIDevice *pdev = PCI_DEVICE(s);
 448     Error *err = NULL;
 449
 450     IVSHMEM_DPRINTF("setting up interrupt for vector: %d\n", vector);
 451
 452     if (!with_irqfd) {
 453         IVSHMEM_DPRINTF("with eventfd\n");
 454         watch_vector_notifier(s, n, vector);
 455     } else if (msix_enabled(pdev)) {
 456         IVSHMEM_DPRINTF("with irqfd\n");
 457         ivshmem_add_kvm_msi_virq(s, vector, &err);
 458         if (err) {
 459             error_propagate(errp, err);
 460             return;
 461         }
 462
 463         if (!msix_is_masked(pdev, vector)) {
 464             kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL,
 465                                                s->msi_vectors[vector].virq);
 466             /* TODO handle error */
 467         }
 468     } else {
 469         /* it will be delayed until msix is enabled, in write_config */
 470         IVSHMEM_DPRINTF("with irqfd, delayed until msix enabled\n");
 471     }
 472 }
 473
 474 static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
 475 {
 476     Error *local_err = NULL;
 477     struct stat buf;
 478     size_t size;
 479
 480     if (s->ivshmem_bar2) {
 481         error_setg(errp, "server sent unexpected shared memory message");
 482         close(fd);
 483         return;
 484     }
 485
 486     if (fstat(fd, &buf) < 0) {
 487         error_setg_errno(errp, errno,
 488             "can't determine size of shared memory sent by server");
 489         close(fd);
 490         return;
 491     }
 492
 493     size = buf.st_size;
 494
 495     /* mmap the region and map into the BAR2 */
 496     memory_region_init_ram_from_fd(&s->server_bar2, OBJECT(s),
 497                                    "ivshmem.bar2", size, true, fd, 0,
 498                                    &local_err);
 499     if (local_err) {
 500         error_propagate(errp, local_err);
 501         return;
 502     }
 503
 504     s->ivshmem_bar2 = &s->server_bar2;
 505 }
 506
 507 static void process_msg_disconnect(IVShmemState *s, uint16_t posn,
 508                                    Error **errp)
 509 {
 510     IVSHMEM_DPRINTF("posn %d has gone away\n", posn);
 511     if (posn >= s->nb_peers || posn == s->vm_id) {
 512         error_setg(errp, "invalid peer %d", posn);
 513         return;
 514     }
 515     close_peer_eventfds(s, posn);
 516 }
 517
 518 static void process_msg_connect(IVShmemState *s, uint16_t posn, int fd,
 519                                 Error **errp)
 520 {
 521     Peer *peer = &s->peers[posn];
 522     int vector;
 523
 524     /*
 525      * The N-th connect message for this peer comes with the file
 526      * descriptor for vector N-1.  Count messages to find the vector.
 527      */
 528     if (peer->nb_eventfds >= s->vectors) {
 529         error_setg(errp, "Too many eventfd received, device has %d vectors",
 530                    s->vectors);
 531         close(fd);
 532         return;
 533     }
 534     vector = peer->nb_eventfds++;
 535
 536     IVSHMEM_DPRINTF("eventfds[%d][%d] = %d\n", posn, vector, fd);
 537     event_notifier_init_fd(&peer->eventfds[vector], fd);
 538     fcntl_setfl(fd, O_NONBLOCK); /* msix/irqfd poll non block */
 539
 540     if (posn == s->vm_id) {
 541         setup_interrupt(s, vector, errp);
 542         /* TODO do we need to handle the error? */
 543     }
 544
 545     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 546         ivshmem_add_eventfd(s, posn, vector);
 547     }
 548 }
 549
 550 static void process_msg(IVShmemState *s, int64_t msg, int fd, Error **errp)
 551 {
 552     IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", msg, fd);
 553
 554     if (msg < -1 || msg > IVSHMEM_MAX_PEERS) {
 555         error_setg(errp, "server sent invalid message %" PRId64, msg);
 556         close(fd);
 557         return;
 558     }
 559
 560     if (msg == -1) {
 561         process_msg_shmem(s, fd, errp);
 562         return;
 563     }
 564
 565     if (msg >= s->nb_peers) {
 566         resize_peers(s, msg + 1);
 567     }
 568
 569     if (fd >= 0) {
 570         process_msg_connect(s, msg, fd, errp);
 571     } else {
 572         process_msg_disconnect(s, msg, errp);
 573     }
 574 }
 575
 576 static int ivshmem_can_receive(void *opaque)
 577 {
 578     IVShmemState *s = opaque;
 579
 580     assert(s->msg_buffered_bytes < sizeof(s->msg_buf));
 581     return sizeof(s->msg_buf) - s->msg_buffered_bytes;
 582 }
 583
 584 static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
 585 {
 586     IVShmemState *s = opaque;
 587     Error *err = NULL;
 588     int fd;
 589     int64_t msg;
 590
 591     assert(size >= 0 && s->msg_buffered_bytes + size <= sizeof(s->msg_buf));
 592     memcpy((unsigned char *)&s->msg_buf + s->msg_buffered_bytes, buf, size);
 593     s->msg_buffered_bytes += size;
 594     if (s->msg_buffered_bytes < sizeof(s->msg_buf)) {
 595         return;
 596     }
 597     msg = le64_to_cpu(s->msg_buf);
 598     s->msg_buffered_bytes = 0;
 599
 600     fd = qemu_chr_fe_get_msgfd(&s->server_chr);
 601
 602     process_msg(s, msg, fd, &err);
 603     if (err) {
 604         error_report_err(err);
 605     }
 606 }
 607
 608 static int64_t ivshmem_recv_msg(IVShmemState *s, int *pfd, Error **errp)
 609 {
 610     int64_t msg;
 611     int n, ret;
 612
 613     n = 0;
 614     do {
 615         ret = qemu_chr_fe_read_all(&s->server_chr, (uint8_t *)&msg + n,
 616                                    sizeof(msg) - n);
 617         if (ret < 0) {
 618             if (ret == -EINTR) {
 619                 continue;
 620             }
 621             error_setg_errno(errp, -ret, "read from server failed");
 622             return INT64_MIN;
 623         }
 624         n += ret;
 625     } while (n < sizeof(msg));
 626
 627     *pfd = qemu_chr_fe_get_msgfd(&s->server_chr);
 628     return le64_to_cpu(msg);
 629 }
 630
 631 static void ivshmem_recv_setup(IVShmemState *s, Error **errp)
 632 {
 633     Error *err = NULL;
 634     int64_t msg;
 635     int fd;
 636
 637     msg = ivshmem_recv_msg(s, &fd, &err);
 638     if (err) {
 639         error_propagate(errp, err);
 640         return;
 641     }
 642     if (msg != IVSHMEM_PROTOCOL_VERSION) {
 643         error_setg(errp, "server sent version %" PRId64 ", expecting %d",
 644                    msg, IVSHMEM_PROTOCOL_VERSION);
 645         return;
 646     }
 647     if (fd != -1) {
 648         error_setg(errp, "server sent invalid version message");
 649         return;
 650     }
 651
 652     /*
 653      * ivshmem-server sends the remaining initial messages in a fixed
 654      * order, but the device has always accepted them in any order.
 655      * Stay as compatible as practical, just in case people use
 656      * servers that behave differently.
 657      */
 658
 659     /*
 660      * ivshmem_device_spec.txt has always required the ID message
 661      * right here, and ivshmem-server has always complied.  However,
 662      * older versions of the device accepted it out of order, but
 663      * broke when an interrupt setup message arrived before it.
 664      */
 665     msg = ivshmem_recv_msg(s, &fd, &err);
 666     if (err) {
 667         error_propagate(errp, err);
 668         return;
 669     }
 670     if (fd != -1 || msg < 0 || msg > IVSHMEM_MAX_PEERS) {
 671         error_setg(errp, "server sent invalid ID message");
 672         return;
 673     }
 674     s->vm_id = msg;
 675
 676     /*
 677      * Receive more messages until we got shared memory.
 678      */
 679     do {
 680         msg = ivshmem_recv_msg(s, &fd, &err);
 681         if (err) {
 682             error_propagate(errp, err);
 683             return;
 684         }
 685         process_msg(s, msg, fd, &err);
 686         if (err) {
 687             error_propagate(errp, err);
 688             return;
 689         }
 690     } while (msg != -1);
 691
 692     /*
 693      * This function must either map the shared memory or fail.  The
 694      * loop above ensures that: it terminates normally only after it
 695      * successfully processed the server's shared memory message.
 696      * Assert that actually mapped the shared memory:
 697      */
 698     assert(s->ivshmem_bar2);
 699 }
 700
 701 /* Select the MSI-X vectors used by device.
 702  * ivshmem maps events to vectors statically, so
 703  * we just enable all vectors on init and after reset. */
 704 static void ivshmem_msix_vector_use(IVShmemState *s)
 705 {
 706     PCIDevice *d = PCI_DEVICE(s);
 707     int i;
 708
 709     for (i = 0; i < s->vectors; i++) {
 710         msix_vector_use(d, i);
 711     }
 712 }
 713
 714 static void ivshmem_disable_irqfd(IVShmemState *s);
 715
 716 static void ivshmem_reset(DeviceState *d)
 717 {
 718     IVShmemState *s = IVSHMEM_COMMON(d);
 719
 720     ivshmem_disable_irqfd(s);
 721
 722     s->intrstatus = 0;
 723     s->intrmask = 0;
 724     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 725         ivshmem_msix_vector_use(s);
 726     }
 727 }
 728
 729 static int ivshmem_setup_interrupts(IVShmemState *s, Error **errp)
 730 {
 731     /* allocate QEMU callback data for receiving interrupts */
 732     s->msi_vectors = g_malloc0(s->vectors * sizeof(MSIVector));
 733
 734     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 735         if (msix_init_exclusive_bar(PCI_DEVICE(s), s->vectors, 1, errp)) {
 736             return -1;
 737         }
 738
 739         IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
 740         ivshmem_msix_vector_use(s);
 741     }
 742
 743     return 0;
 744 }
 745
 746 static void ivshmem_remove_kvm_msi_virq(IVShmemState *s, int vector)
 747 {
 748     IVSHMEM_DPRINTF("ivshmem_remove_kvm_msi_virq vector:%d\n", vector);
 749
 750     if (s->msi_vectors[vector].pdev == NULL) {
 751         return;
 752     }
 753
 754     /* it was cleaned when masked in the frontend. */
 755     kvm_irqchip_release_virq(kvm_state, s->msi_vectors[vector].virq);
 756
 757     s->msi_vectors[vector].pdev = NULL;
 758 }
 759
 760 static void ivshmem_enable_irqfd(IVShmemState *s)
 761 {
 762     PCIDevice *pdev = PCI_DEVICE(s);
 763     int i;
 764
 765     for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
 766         Error *err = NULL;
 767
 768         ivshmem_add_kvm_msi_virq(s, i, &err);
 769         if (err) {
 770             error_report_err(err);
 771             goto undo;
 772         }
 773     }
 774
 775     if (msix_set_vector_notifiers(pdev,
 776                                   ivshmem_vector_unmask,
 777                                   ivshmem_vector_mask,
 778                                   ivshmem_vector_poll)) {
 779         error_report("ivshmem: msix_set_vector_notifiers failed");
 780         goto undo;
 781     }
 782     return;
 783
 784 undo:
 785     while (--i >= 0) {
 786         ivshmem_remove_kvm_msi_virq(s, i);
 787     }
 788 }
 789
 790 static void ivshmem_disable_irqfd(IVShmemState *s)
 791 {
 792     PCIDevice *pdev = PCI_DEVICE(s);
 793     int i;
 794
 795     if (!pdev->msix_vector_use_notifier) {
 796         return;
 797     }
 798
 799     msix_unset_vector_notifiers(pdev);
 800
 801     for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
 802         /*
 803          * MSI-X is already disabled here so msix_unset_vector_notifiers()
 804          * didn't call our release notifier.  Do it now to keep our masks and
 805          * unmasks balanced.
 806          */
 807         if (s->msi_vectors[i].unmasked) {
 808             ivshmem_vector_mask(pdev, i);
 809         }
 810         ivshmem_remove_kvm_msi_virq(s, i);
 811     }
 812
 813 }
 814
 815 static void ivshmem_write_config(PCIDevice *pdev, uint32_t address,
 816                                  uint32_t val, int len)
 817 {
 818     IVShmemState *s = IVSHMEM_COMMON(pdev);
 819     int is_enabled, was_enabled = msix_enabled(pdev);
 820
 821     pci_default_write_config(pdev, address, val, len);
 822     is_enabled = msix_enabled(pdev);
 823
 824     if (kvm_msi_via_irqfd_enabled()) {
 825         if (!was_enabled && is_enabled) {
 826             ivshmem_enable_irqfd(s);
 827         } else if (was_enabled && !is_enabled) {
 828             ivshmem_disable_irqfd(s);
 829         }
 830     }
 831 }
 832
 833 static void ivshmem_common_realize(PCIDevice *dev, Error **errp)
 834 {
 835     IVShmemState *s = IVSHMEM_COMMON(dev);
 836     Error *err = NULL;
 837     uint8_t *pci_conf;
 838
 839     /* IRQFD requires MSI */
 840     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
 841         !ivshmem_has_feature(s, IVSHMEM_MSI)) {
 842         error_setg(errp, "ioeventfd/irqfd requires MSI");
 843         return;
 844     }
 845
 846     pci_conf = dev->config;
 847     pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
 848
 849     memory_region_init_io(&s->ivshmem_mmio, OBJECT(s), &ivshmem_mmio_ops, s,
 850                           "ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
 851
 852     /* region for registers*/
 853     pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
 854                      &s->ivshmem_mmio);
 855
 856     if (s->hostmem != NULL) {
 857         IVSHMEM_DPRINTF("using hostmem\n");
 858
 859         s->ivshmem_bar2 = host_memory_backend_get_memory(s->hostmem);
 860         host_memory_backend_set_mapped(s->hostmem, true);
 861     } else {
 862         Chardev *chr = qemu_chr_fe_get_driver(&s->server_chr);
 863         assert(chr);
 864
 865         IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
 866                         chr->filename);
 867
 868         /* we allocate enough space for 16 peers and grow as needed */
 869         resize_peers(s, 16);
 870
 871         /*
 872          * Receive setup messages from server synchronously.
 873          * Older versions did it asynchronously, but that creates a
 874          * number of entertaining race conditions.
 875          */
 876         ivshmem_recv_setup(s, &err);
 877         if (err) {
 878             error_propagate(errp, err);
 879             return;
 880         }
 881
 882         if (s->master == ON_OFF_AUTO_ON && s->vm_id != 0) {
 883             error_setg(errp,
 884                        "master must connect to the server before any peers");
 885             return;
 886         }
 887
 888         qemu_chr_fe_set_handlers(&s->server_chr, ivshmem_can_receive,
 889                                  ivshmem_read, NULL, NULL, s, NULL, true);
 890
 891         if (ivshmem_setup_interrupts(s, errp) < 0) {
 892             error_prepend(errp, "Failed to initialize interrupts: ");
 893             return;
 894         }
 895     }
 896
 897     if (s->master == ON_OFF_AUTO_AUTO) {
 898         s->master = s->vm_id == 0 ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
 899     }
 900
 901     if (!ivshmem_is_master(s)) {
 902         error_setg(&s->migration_blocker,
 903                    "Migration is disabled when using feature 'peer mode' in device 'ivshmem'");
 904         if (migrate_add_blocker(s->migration_blocker, errp) < 0) {
 905             error_free(s->migration_blocker);
 906             return;
 907         }
 908     }
 909
 910     vmstate_register_ram(s->ivshmem_bar2, DEVICE(s));
 911     pci_register_bar(PCI_DEVICE(s), 2,
 912                      PCI_BASE_ADDRESS_SPACE_MEMORY |
 913                      PCI_BASE_ADDRESS_MEM_PREFETCH |
 914                      PCI_BASE_ADDRESS_MEM_TYPE_64,
 915                      s->ivshmem_bar2);
 916 }
 917
 918 static void ivshmem_exit(PCIDevice *dev)
 919 {
 920     IVShmemState *s = IVSHMEM_COMMON(dev);
 921     int i;
 922
 923     if (s->migration_blocker) {
 924         migrate_del_blocker(s->migration_blocker);
 925         error_free(s->migration_blocker);
 926     }
 927
 928     if (memory_region_is_mapped(s->ivshmem_bar2)) {
 929         if (!s->hostmem) {
 930             void *addr = memory_region_get_ram_ptr(s->ivshmem_bar2);
 931             int fd;
 932
 933             if (munmap(addr, memory_region_size(s->ivshmem_bar2) == -1)) {
 934                 error_report("Failed to munmap shared memory %s",
 935                              strerror(errno));
 936             }
 937
 938             fd = memory_region_get_fd(s->ivshmem_bar2);
 939             close(fd);
 940         }
 941
 942         vmstate_unregister_ram(s->ivshmem_bar2, DEVICE(dev));
 943     }
 944
 945     if (s->hostmem) {
 946         host_memory_backend_set_mapped(s->hostmem, false);
 947     }
 948
 949     if (s->peers) {
 950         for (i = 0; i < s->nb_peers; i++) {
 951             close_peer_eventfds(s, i);
 952         }
 953         g_free(s->peers);
 954     }
 955
 956     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 957         msix_uninit_exclusive_bar(dev);
 958     }
 959
 960     g_free(s->msi_vectors);
 961 }
 962
 963 static int ivshmem_pre_load(void *opaque)
 964 {
 965     IVShmemState *s = opaque;
 966
 967     if (!ivshmem_is_master(s)) {
 968         error_report("'peer' devices are not migratable");
 969         return -EINVAL;
 970     }
 971
 972     return 0;
 973 }
 974
 975 static int ivshmem_post_load(void *opaque, int version_id)
 976 {
 977     IVShmemState *s = opaque;
 978
 979     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 980         ivshmem_msix_vector_use(s);
 981     }
 982     return 0;
 983 }
 984
 985 static void ivshmem_common_class_init(ObjectClass *klass, void *data)
 986 {
 987     DeviceClass *dc = DEVICE_CLASS(klass);
 988     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 989
 990     k->realize = ivshmem_common_realize;
 991     k->exit = ivshmem_exit;
 992     k->config_write = ivshmem_write_config;
 993     k->vendor_id = PCI_VENDOR_ID_IVSHMEM;
 994     k->device_id = PCI_DEVICE_ID_IVSHMEM;
 995     k->class_id = PCI_CLASS_MEMORY_RAM;
 996     k->revision = 1;
 997     dc->reset = ivshmem_reset;
 998     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 999     dc->desc = "Inter-VM shared memory";
1000 }
1001
1002 static const TypeInfo ivshmem_common_info = {
1003     .name          = TYPE_IVSHMEM_COMMON,
1004     .parent        = TYPE_PCI_DEVICE,
1005     .instance_size = sizeof(IVShmemState),
1006     .abstract      = true,
1007     .class_init    = ivshmem_common_class_init,
1008     .interfaces = (InterfaceInfo[]) {
1009         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
1010         { },
1011     },
1012 };
1013
1014 static const VMStateDescription ivshmem_plain_vmsd = {
1015     .name = TYPE_IVSHMEM_PLAIN,
1016     .version_id = 0,
1017     .minimum_version_id = 0,
1018     .pre_load = ivshmem_pre_load,
1019     .post_load = ivshmem_post_load,
1020     .fields = (VMStateField[]) {
1021         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1022         VMSTATE_UINT32(intrstatus, IVShmemState),
1023         VMSTATE_UINT32(intrmask, IVShmemState),
1024         VMSTATE_END_OF_LIST()
1025     },
1026 };
1027
1028 static Property ivshmem_plain_properties[] = {
1029     DEFINE_PROP_ON_OFF_AUTO("master", IVShmemState, master, ON_OFF_AUTO_OFF),
1030     DEFINE_PROP_LINK("memdev", IVShmemState, hostmem, TYPE_MEMORY_BACKEND,
1031                      HostMemoryBackend *),
1032     DEFINE_PROP_END_OF_LIST(),
1033 };
1034
1035 static void ivshmem_plain_realize(PCIDevice *dev, Error **errp)
1036 {
1037     IVShmemState *s = IVSHMEM_COMMON(dev);
1038
1039     if (!s->hostmem) {
1040         error_setg(errp, "You must specify a 'memdev'");
1041         return;
1042     } else if (host_memory_backend_is_mapped(s->hostmem)) {
1043         error_setg(errp, "can't use already busy memdev: %s",
1044                    object_get_canonical_path_component(OBJECT(s->hostmem)));
1045         return;
1046     }
1047
1048     ivshmem_common_realize(dev, errp);
1049 }
1050
1051 static void ivshmem_plain_class_init(ObjectClass *klass, void *data)
1052 {
1053     DeviceClass *dc = DEVICE_CLASS(klass);
1054     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1055
1056     k->realize = ivshmem_plain_realize;
1057     device_class_set_props(dc, ivshmem_plain_properties);
1058     dc->vmsd = &ivshmem_plain_vmsd;
1059 }
1060
1061 static const TypeInfo ivshmem_plain_info = {
1062     .name          = TYPE_IVSHMEM_PLAIN,
1063     .parent        = TYPE_IVSHMEM_COMMON,
1064     .instance_size = sizeof(IVShmemState),
1065     .class_init    = ivshmem_plain_class_init,
1066 };
1067
1068 static const VMStateDescription ivshmem_doorbell_vmsd = {
1069     .name = TYPE_IVSHMEM_DOORBELL,
1070     .version_id = 0,
1071     .minimum_version_id = 0,
1072     .pre_load = ivshmem_pre_load,
1073     .post_load = ivshmem_post_load,
1074     .fields = (VMStateField[]) {
1075         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1076         VMSTATE_MSIX(parent_obj, IVShmemState),
1077         VMSTATE_UINT32(intrstatus, IVShmemState),
1078         VMSTATE_UINT32(intrmask, IVShmemState),
1079         VMSTATE_END_OF_LIST()
1080     },
1081 };
1082
1083 static Property ivshmem_doorbell_properties[] = {
1084     DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
1085     DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
1086     DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD,
1087                     true),
1088     DEFINE_PROP_ON_OFF_AUTO("master", IVShmemState, master, ON_OFF_AUTO_OFF),
1089     DEFINE_PROP_END_OF_LIST(),
1090 };
1091
1092 static void ivshmem_doorbell_init(Object *obj)
1093 {
1094     IVShmemState *s = IVSHMEM_DOORBELL(obj);
1095
1096     s->features |= (1 << IVSHMEM_MSI);
1097 }
1098
1099 static void ivshmem_doorbell_realize(PCIDevice *dev, Error **errp)
1100 {
1101     IVShmemState *s = IVSHMEM_COMMON(dev);
1102
1103     if (!qemu_chr_fe_backend_connected(&s->server_chr)) {
1104         error_setg(errp, "You must specify a 'chardev'");
1105         return;
1106     }
1107
1108     ivshmem_common_realize(dev, errp);
1109 }
1110
1111 static void ivshmem_doorbell_class_init(ObjectClass *klass, void *data)
1112 {
1113     DeviceClass *dc = DEVICE_CLASS(klass);
1114     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1115
1116     k->realize = ivshmem_doorbell_realize;
1117     device_class_set_props(dc, ivshmem_doorbell_properties);
1118     dc->vmsd = &ivshmem_doorbell_vmsd;
1119 }
1120
1121 static const TypeInfo ivshmem_doorbell_info = {
1122     .name          = TYPE_IVSHMEM_DOORBELL,
1123     .parent        = TYPE_IVSHMEM_COMMON,
1124     .instance_size = sizeof(IVShmemState),
1125     .instance_init = ivshmem_doorbell_init,
1126     .class_init    = ivshmem_doorbell_class_init,
1127 };
1128
1129 static void ivshmem_register_types(void)
1130 {
1131     type_register_static(&ivshmem_common_info);
1132     type_register_static(&ivshmem_plain_info);
1133     type_register_static(&ivshmem_doorbell_info);
1134 }
1135
1136 type_init(ivshmem_register_types)