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 #include "qemu/osdep.h"
  20 #include "qemu/units.h"
  21 #include "qapi/error.h"
  22 #include "qemu/cutils.h"
  23 #include "hw/hw.h"
  24 #include "hw/pci/pci.h"
  25 #include "hw/pci/msi.h"
  26 #include "hw/pci/msix.h"
  27 #include "sysemu/kvm.h"
  28 #include "migration/blocker.h"
  29 #include "qemu/error-report.h"
  30 #include "qemu/event_notifier.h"
  31 #include "qom/object_interfaces.h"
  32 #include "chardev/char-fe.h"
  33 #include "sysemu/hostmem.h"
  34 #include "sysemu/qtest.h"
  35 #include "qapi/visitor.h"
  36
  37 #include "hw/misc/ivshmem.h"
  38
  39 #define PCI_VENDOR_ID_IVSHMEM   PCI_VENDOR_ID_REDHAT_QUMRANET
  40 #define PCI_DEVICE_ID_IVSHMEM   0x1110
  41
  42 #define IVSHMEM_MAX_PEERS UINT16_MAX
  43 #define IVSHMEM_IOEVENTFD   0
  44 #define IVSHMEM_MSI     1
  45
  46 #define IVSHMEM_REG_BAR_SIZE 0x100
  47
  48 #define IVSHMEM_DEBUG 0
  49 #define IVSHMEM_DPRINTF(fmt, ...)                       \
  50     do {                                                \
  51         if (IVSHMEM_DEBUG) {                            \
  52             printf("IVSHMEM: " fmt, ## __VA_ARGS__);    \
  53         }                                               \
  54     } while (0)
  55
  56 #define TYPE_IVSHMEM_COMMON "ivshmem-common"
  57 #define IVSHMEM_COMMON(obj) \
  58     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM_COMMON)
  59
  60 #define TYPE_IVSHMEM_PLAIN "ivshmem-plain"
  61 #define IVSHMEM_PLAIN(obj) \
  62     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM_PLAIN)
  63
  64 #define TYPE_IVSHMEM_DOORBELL "ivshmem-doorbell"
  65 #define IVSHMEM_DOORBELL(obj) \
  66     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM_DOORBELL)
  67
  68 #define TYPE_IVSHMEM "ivshmem"
  69 #define IVSHMEM(obj) \
  70     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM)
  71
  72 typedef struct Peer {
  73     int nb_eventfds;
  74     EventNotifier *eventfds;
  75 } Peer;
  76
  77 typedef struct MSIVector {
  78     PCIDevice *pdev;
  79     int virq;
  80     bool unmasked;
  81 } MSIVector;
  82
  83 typedef struct IVShmemState {
  84     /*< private >*/
  85     PCIDevice parent_obj;
  86     /*< public >*/
  87
  88     uint32_t features;
  89
  90     /* exactly one of these two may be set */
  91     HostMemoryBackend *hostmem; /* with interrupts */
  92     CharBackend server_chr; /* without interrupts */
  93
  94     /* registers */
  95     uint32_t intrmask;
  96     uint32_t intrstatus;
  97     int vm_id;
  98
  99     /* BARs */
 100     MemoryRegion ivshmem_mmio;  /* BAR 0 (registers) */
 101     MemoryRegion *ivshmem_bar2; /* BAR 2 (shared memory) */
 102     MemoryRegion server_bar2;   /* used with server_chr */
 103
 104     /* interrupt support */
 105     Peer *peers;
 106     int nb_peers;               /* space in @peers[] */
 107     uint32_t vectors;
 108     MSIVector *msi_vectors;
 109     uint64_t msg_buf;           /* buffer for receiving server messages */
 110     int msg_buffered_bytes;     /* #bytes in @msg_buf */
 111
 112     /* migration stuff */
 113     OnOffAuto master;
 114     Error *migration_blocker;
 115
 116     /* legacy cruft */
 117     char *role;
 118     char *shmobj;
 119     char *sizearg;
 120     size_t legacy_size;
 121     uint32_t not_legacy_32bit;
 122 } IVShmemState;
 123
 124 /* registers for the Inter-VM shared memory device */
 125 enum ivshmem_registers {
 126     INTRMASK = 0,
 127     INTRSTATUS = 4,
 128     IVPOSITION = 8,
 129     DOORBELL = 12,
 130 };
 131
 132 static inline uint32_t ivshmem_has_feature(IVShmemState *ivs,
 133                                                     unsigned int feature) {
 134     return (ivs->features & (1 << feature));
 135 }
 136
 137 static inline bool ivshmem_is_master(IVShmemState *s)
 138 {
 139     assert(s->master != ON_OFF_AUTO_AUTO);
 140     return s->master == ON_OFF_AUTO_ON;
 141 }
 142
 143 static void ivshmem_update_irq(IVShmemState *s)
 144 {
 145     PCIDevice *d = PCI_DEVICE(s);
 146     uint32_t isr = s->intrstatus & s->intrmask;
 147
 148     /*
 149      * Do nothing unless the device actually uses INTx.  Here's how
 150      * the device variants signal interrupts, what they put in PCI
 151      * config space:
 152      * Device variant    Interrupt  Interrupt Pin  MSI-X cap.
 153      * ivshmem-plain         none            0         no
 154      * ivshmem-doorbell     MSI-X            1        yes(1)
 155      * ivshmem,msi=off       INTx            1         no
 156      * ivshmem,msi=on       MSI-X            1(2)     yes(1)
 157      * (1) if guest enabled MSI-X
 158      * (2) the device lies
 159      * Leads to the condition for doing nothing:
 160      */
 161     if (ivshmem_has_feature(s, IVSHMEM_MSI)
 162         || !d->config[PCI_INTERRUPT_PIN]) {
 163         return;
 164     }
 165
 166     /* don't print ISR resets */
 167     if (isr) {
 168         IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
 169                         isr ? 1 : 0, s->intrstatus, s->intrmask);
 170     }
 171
 172     pci_set_irq(d, isr != 0);
 173 }
 174
 175 static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
 176 {
 177     IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
 178
 179     s->intrmask = val;
 180     ivshmem_update_irq(s);
 181 }
 182
 183 static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
 184 {
 185     uint32_t ret = s->intrmask;
 186
 187     IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
 188     return ret;
 189 }
 190
 191 static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
 192 {
 193     IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
 194
 195     s->intrstatus = val;
 196     ivshmem_update_irq(s);
 197 }
 198
 199 static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
 200 {
 201     uint32_t ret = s->intrstatus;
 202
 203     /* reading ISR clears all interrupts */
 204     s->intrstatus = 0;
 205     ivshmem_update_irq(s);
 206     return ret;
 207 }
 208
 209 static void ivshmem_io_write(void *opaque, hwaddr addr,
 210                              uint64_t val, unsigned size)
 211 {
 212     IVShmemState *s = opaque;
 213
 214     uint16_t dest = val >> 16;
 215     uint16_t vector = val & 0xff;
 216
 217     addr &= 0xfc;
 218
 219     IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr);
 220     switch (addr)
 221     {
 222         case INTRMASK:
 223             ivshmem_IntrMask_write(s, val);
 224             break;
 225
 226         case INTRSTATUS:
 227             ivshmem_IntrStatus_write(s, val);
 228             break;
 229
 230         case DOORBELL:
 231             /* check that dest VM ID is reasonable */
 232             if (dest >= s->nb_peers) {
 233                 IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
 234                 break;
 235             }
 236
 237             /* check doorbell range */
 238             if (vector < s->peers[dest].nb_eventfds) {
 239                 IVSHMEM_DPRINTF("Notifying VM %d on vector %d\n", dest, vector);
 240                 event_notifier_set(&s->peers[dest].eventfds[vector]);
 241             } else {
 242                 IVSHMEM_DPRINTF("Invalid destination vector %d on VM %d\n",
 243                                 vector, dest);
 244             }
 245             break;
 246         default:
 247             IVSHMEM_DPRINTF("Unhandled write " TARGET_FMT_plx "\n", addr);
 248     }
 249 }
 250
 251 static uint64_t ivshmem_io_read(void *opaque, hwaddr addr,
 252                                 unsigned size)
 253 {
 254
 255     IVShmemState *s = opaque;
 256     uint32_t ret;
 257
 258     switch (addr)
 259     {
 260         case INTRMASK:
 261             ret = ivshmem_IntrMask_read(s);
 262             break;
 263
 264         case INTRSTATUS:
 265             ret = ivshmem_IntrStatus_read(s);
 266             break;
 267
 268         case IVPOSITION:
 269             ret = s->vm_id;
 270             break;
 271
 272         default:
 273             IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr);
 274             ret = 0;
 275     }
 276
 277     return ret;
 278 }
 279
 280 static const MemoryRegionOps ivshmem_mmio_ops = {
 281     .read = ivshmem_io_read,
 282     .write = ivshmem_io_write,
 283     .endianness = DEVICE_NATIVE_ENDIAN,
 284     .impl = {
 285         .min_access_size = 4,
 286         .max_access_size = 4,
 287     },
 288 };
 289
 290 static void ivshmem_vector_notify(void *opaque)
 291 {
 292     MSIVector *entry = opaque;
 293     PCIDevice *pdev = entry->pdev;
 294     IVShmemState *s = IVSHMEM_COMMON(pdev);
 295     int vector = entry - s->msi_vectors;
 296     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 297
 298     if (!event_notifier_test_and_clear(n)) {
 299         return;
 300     }
 301
 302     IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, vector);
 303     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 304         if (msix_enabled(pdev)) {
 305             msix_notify(pdev, vector);
 306         }
 307     } else {
 308         ivshmem_IntrStatus_write(s, 1);
 309     }
 310 }
 311
 312 static int ivshmem_vector_unmask(PCIDevice *dev, unsigned vector,
 313                                  MSIMessage msg)
 314 {
 315     IVShmemState *s = IVSHMEM_COMMON(dev);
 316     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 317     MSIVector *v = &s->msi_vectors[vector];
 318     int ret;
 319
 320     IVSHMEM_DPRINTF("vector unmask %p %d\n", dev, vector);
 321     if (!v->pdev) {
 322         error_report("ivshmem: vector %d route does not exist", vector);
 323         return -EINVAL;
 324     }
 325     assert(!v->unmasked);
 326
 327     ret = kvm_irqchip_update_msi_route(kvm_state, v->virq, msg, dev);
 328     if (ret < 0) {
 329         return ret;
 330     }
 331     kvm_irqchip_commit_routes(kvm_state);
 332
 333     ret = kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq);
 334     if (ret < 0) {
 335         return ret;
 336     }
 337     v->unmasked = true;
 338
 339     return 0;
 340 }
 341
 342 static void ivshmem_vector_mask(PCIDevice *dev, unsigned vector)
 343 {
 344     IVShmemState *s = IVSHMEM_COMMON(dev);
 345     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 346     MSIVector *v = &s->msi_vectors[vector];
 347     int ret;
 348
 349     IVSHMEM_DPRINTF("vector mask %p %d\n", dev, vector);
 350     if (!v->pdev) {
 351         error_report("ivshmem: vector %d route does not exist", vector);
 352         return;
 353     }
 354     assert(v->unmasked);
 355
 356     ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, v->virq);
 357     if (ret < 0) {
 358         error_report("remove_irqfd_notifier_gsi failed");
 359         return;
 360     }
 361     v->unmasked = false;
 362 }
 363
 364 static void ivshmem_vector_poll(PCIDevice *dev,
 365                                 unsigned int vector_start,
 366                                 unsigned int vector_end)
 367 {
 368     IVShmemState *s = IVSHMEM_COMMON(dev);
 369     unsigned int vector;
 370
 371     IVSHMEM_DPRINTF("vector poll %p %d-%d\n", dev, vector_start, vector_end);
 372
 373     vector_end = MIN(vector_end, s->vectors);
 374
 375     for (vector = vector_start; vector < vector_end; vector++) {
 376         EventNotifier *notifier = &s->peers[s->vm_id].eventfds[vector];
 377
 378         if (!msix_is_masked(dev, vector)) {
 379             continue;
 380         }
 381
 382         if (event_notifier_test_and_clear(notifier)) {
 383             msix_set_pending(dev, vector);
 384         }
 385     }
 386 }
 387
 388 static void watch_vector_notifier(IVShmemState *s, EventNotifier *n,
 389                                  int vector)
 390 {
 391     int eventfd = event_notifier_get_fd(n);
 392
 393     assert(!s->msi_vectors[vector].pdev);
 394     s->msi_vectors[vector].pdev = PCI_DEVICE(s);
 395
 396     qemu_set_fd_handler(eventfd, ivshmem_vector_notify,
 397                         NULL, &s->msi_vectors[vector]);
 398 }
 399
 400 static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i)
 401 {
 402     memory_region_add_eventfd(&s->ivshmem_mmio,
 403                               DOORBELL,
 404                               4,
 405                               true,
 406                               (posn << 16) | i,
 407                               &s->peers[posn].eventfds[i]);
 408 }
 409
 410 static void ivshmem_del_eventfd(IVShmemState *s, int posn, int i)
 411 {
 412     memory_region_del_eventfd(&s->ivshmem_mmio,
 413                               DOORBELL,
 414                               4,
 415                               true,
 416                               (posn << 16) | i,
 417                               &s->peers[posn].eventfds[i]);
 418 }
 419
 420 static void close_peer_eventfds(IVShmemState *s, int posn)
 421 {
 422     int i, n;
 423
 424     assert(posn >= 0 && posn < s->nb_peers);
 425     n = s->peers[posn].nb_eventfds;
 426
 427     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 428         memory_region_transaction_begin();
 429         for (i = 0; i < n; i++) {
 430             ivshmem_del_eventfd(s, posn, i);
 431         }
 432         memory_region_transaction_commit();
 433     }
 434
 435     for (i = 0; i < n; i++) {
 436         event_notifier_cleanup(&s->peers[posn].eventfds[i]);
 437     }
 438
 439     g_free(s->peers[posn].eventfds);
 440     s->peers[posn].nb_eventfds = 0;
 441 }
 442
 443 static void resize_peers(IVShmemState *s, int nb_peers)
 444 {
 445     int old_nb_peers = s->nb_peers;
 446     int i;
 447
 448     assert(nb_peers > old_nb_peers);
 449     IVSHMEM_DPRINTF("bumping storage to %d peers\n", nb_peers);
 450
 451     s->peers = g_realloc(s->peers, nb_peers * sizeof(Peer));
 452     s->nb_peers = nb_peers;
 453
 454     for (i = old_nb_peers; i < nb_peers; i++) {
 455         s->peers[i].eventfds = g_new0(EventNotifier, s->vectors);
 456         s->peers[i].nb_eventfds = 0;
 457     }
 458 }
 459
 460 static void ivshmem_add_kvm_msi_virq(IVShmemState *s, int vector,
 461                                      Error **errp)
 462 {
 463     PCIDevice *pdev = PCI_DEVICE(s);
 464     int ret;
 465
 466     IVSHMEM_DPRINTF("ivshmem_add_kvm_msi_virq vector:%d\n", vector);
 467     assert(!s->msi_vectors[vector].pdev);
 468
 469     ret = kvm_irqchip_add_msi_route(kvm_state, vector, pdev);
 470     if (ret < 0) {
 471         error_setg(errp, "kvm_irqchip_add_msi_route failed");
 472         return;
 473     }
 474
 475     s->msi_vectors[vector].virq = ret;
 476     s->msi_vectors[vector].pdev = pdev;
 477 }
 478
 479 static void setup_interrupt(IVShmemState *s, int vector, Error **errp)
 480 {
 481     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 482     bool with_irqfd = kvm_msi_via_irqfd_enabled() &&
 483         ivshmem_has_feature(s, IVSHMEM_MSI);
 484     PCIDevice *pdev = PCI_DEVICE(s);
 485     Error *err = NULL;
 486
 487     IVSHMEM_DPRINTF("setting up interrupt for vector: %d\n", vector);
 488
 489     if (!with_irqfd) {
 490         IVSHMEM_DPRINTF("with eventfd\n");
 491         watch_vector_notifier(s, n, vector);
 492     } else if (msix_enabled(pdev)) {
 493         IVSHMEM_DPRINTF("with irqfd\n");
 494         ivshmem_add_kvm_msi_virq(s, vector, &err);
 495         if (err) {
 496             error_propagate(errp, err);
 497             return;
 498         }
 499
 500         if (!msix_is_masked(pdev, vector)) {
 501             kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL,
 502                                                s->msi_vectors[vector].virq);
 503             /* TODO handle error */
 504         }
 505     } else {
 506         /* it will be delayed until msix is enabled, in write_config */
 507         IVSHMEM_DPRINTF("with irqfd, delayed until msix enabled\n");
 508     }
 509 }
 510
 511 static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
 512 {
 513     Error *local_err = NULL;
 514     struct stat buf;
 515     size_t size;
 516
 517     if (s->ivshmem_bar2) {
 518         error_setg(errp, "server sent unexpected shared memory message");
 519         close(fd);
 520         return;
 521     }
 522
 523     if (fstat(fd, &buf) < 0) {
 524         error_setg_errno(errp, errno,
 525             "can't determine size of shared memory sent by server");
 526         close(fd);
 527         return;
 528     }
 529
 530     size = buf.st_size;
 531
 532     /* Legacy cruft */
 533     if (s->legacy_size != SIZE_MAX) {
 534         if (size < s->legacy_size) {
 535             error_setg(errp, "server sent only %zd bytes of shared memory",
 536                        (size_t)buf.st_size);
 537             close(fd);
 538             return;
 539         }
 540         size = s->legacy_size;
 541     }
 542
 543     /* mmap the region and map into the BAR2 */
 544     memory_region_init_ram_from_fd(&s->server_bar2, OBJECT(s),
 545                                    "ivshmem.bar2", size, true, fd, &local_err);
 546     if (local_err) {
 547         error_propagate(errp, local_err);
 548         return;
 549     }
 550
 551     s->ivshmem_bar2 = &s->server_bar2;
 552 }
 553
 554 static void process_msg_disconnect(IVShmemState *s, uint16_t posn,
 555                                    Error **errp)
 556 {
 557     IVSHMEM_DPRINTF("posn %d has gone away\n", posn);
 558     if (posn >= s->nb_peers || posn == s->vm_id) {
 559         error_setg(errp, "invalid peer %d", posn);
 560         return;
 561     }
 562     close_peer_eventfds(s, posn);
 563 }
 564
 565 static void process_msg_connect(IVShmemState *s, uint16_t posn, int fd,
 566                                 Error **errp)
 567 {
 568     Peer *peer = &s->peers[posn];
 569     int vector;
 570
 571     /*
 572      * The N-th connect message for this peer comes with the file
 573      * descriptor for vector N-1.  Count messages to find the vector.
 574      */
 575     if (peer->nb_eventfds >= s->vectors) {
 576         error_setg(errp, "Too many eventfd received, device has %d vectors",
 577                    s->vectors);
 578         close(fd);
 579         return;
 580     }
 581     vector = peer->nb_eventfds++;
 582
 583     IVSHMEM_DPRINTF("eventfds[%d][%d] = %d\n", posn, vector, fd);
 584     event_notifier_init_fd(&peer->eventfds[vector], fd);
 585     fcntl_setfl(fd, O_NONBLOCK); /* msix/irqfd poll non block */
 586
 587     if (posn == s->vm_id) {
 588         setup_interrupt(s, vector, errp);
 589         /* TODO do we need to handle the error? */
 590     }
 591
 592     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 593         ivshmem_add_eventfd(s, posn, vector);
 594     }
 595 }
 596
 597 static void process_msg(IVShmemState *s, int64_t msg, int fd, Error **errp)
 598 {
 599     IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", msg, fd);
 600
 601     if (msg < -1 || msg > IVSHMEM_MAX_PEERS) {
 602         error_setg(errp, "server sent invalid message %" PRId64, msg);
 603         close(fd);
 604         return;
 605     }
 606
 607     if (msg == -1) {
 608         process_msg_shmem(s, fd, errp);
 609         return;
 610     }
 611
 612     if (msg >= s->nb_peers) {
 613         resize_peers(s, msg + 1);
 614     }
 615
 616     if (fd >= 0) {
 617         process_msg_connect(s, msg, fd, errp);
 618     } else {
 619         process_msg_disconnect(s, msg, errp);
 620     }
 621 }
 622
 623 static int ivshmem_can_receive(void *opaque)
 624 {
 625     IVShmemState *s = opaque;
 626
 627     assert(s->msg_buffered_bytes < sizeof(s->msg_buf));
 628     return sizeof(s->msg_buf) - s->msg_buffered_bytes;
 629 }
 630
 631 static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
 632 {
 633     IVShmemState *s = opaque;
 634     Error *err = NULL;
 635     int fd;
 636     int64_t msg;
 637
 638     assert(size >= 0 && s->msg_buffered_bytes + size <= sizeof(s->msg_buf));
 639     memcpy((unsigned char *)&s->msg_buf + s->msg_buffered_bytes, buf, size);
 640     s->msg_buffered_bytes += size;
 641     if (s->msg_buffered_bytes < sizeof(s->msg_buf)) {
 642         return;
 643     }
 644     msg = le64_to_cpu(s->msg_buf);
 645     s->msg_buffered_bytes = 0;
 646
 647     fd = qemu_chr_fe_get_msgfd(&s->server_chr);
 648
 649     process_msg(s, msg, fd, &err);
 650     if (err) {
 651         error_report_err(err);
 652     }
 653 }
 654
 655 static int64_t ivshmem_recv_msg(IVShmemState *s, int *pfd, Error **errp)
 656 {
 657     int64_t msg;
 658     int n, ret;
 659
 660     n = 0;
 661     do {
 662         ret = qemu_chr_fe_read_all(&s->server_chr, (uint8_t *)&msg + n,
 663                                    sizeof(msg) - n);
 664         if (ret < 0) {
 665             if (ret == -EINTR) {
 666                 continue;
 667             }
 668             error_setg_errno(errp, -ret, "read from server failed");
 669             return INT64_MIN;
 670         }
 671         n += ret;
 672     } while (n < sizeof(msg));
 673
 674     *pfd = qemu_chr_fe_get_msgfd(&s->server_chr);
 675     return le64_to_cpu(msg);
 676 }
 677
 678 static void ivshmem_recv_setup(IVShmemState *s, Error **errp)
 679 {
 680     Error *err = NULL;
 681     int64_t msg;
 682     int fd;
 683
 684     msg = ivshmem_recv_msg(s, &fd, &err);
 685     if (err) {
 686         error_propagate(errp, err);
 687         return;
 688     }
 689     if (msg != IVSHMEM_PROTOCOL_VERSION) {
 690         error_setg(errp, "server sent version %" PRId64 ", expecting %d",
 691                    msg, IVSHMEM_PROTOCOL_VERSION);
 692         return;
 693     }
 694     if (fd != -1) {
 695         error_setg(errp, "server sent invalid version message");
 696         return;
 697     }
 698
 699     /*
 700      * ivshmem-server sends the remaining initial messages in a fixed
 701      * order, but the device has always accepted them in any order.
 702      * Stay as compatible as practical, just in case people use
 703      * servers that behave differently.
 704      */
 705
 706     /*
 707      * ivshmem_device_spec.txt has always required the ID message
 708      * right here, and ivshmem-server has always complied.  However,
 709      * older versions of the device accepted it out of order, but
 710      * broke when an interrupt setup message arrived before it.
 711      */
 712     msg = ivshmem_recv_msg(s, &fd, &err);
 713     if (err) {
 714         error_propagate(errp, err);
 715         return;
 716     }
 717     if (fd != -1 || msg < 0 || msg > IVSHMEM_MAX_PEERS) {
 718         error_setg(errp, "server sent invalid ID message");
 719         return;
 720     }
 721     s->vm_id = msg;
 722
 723     /*
 724      * Receive more messages until we got shared memory.
 725      */
 726     do {
 727         msg = ivshmem_recv_msg(s, &fd, &err);
 728         if (err) {
 729             error_propagate(errp, err);
 730             return;
 731         }
 732         process_msg(s, msg, fd, &err);
 733         if (err) {
 734             error_propagate(errp, err);
 735             return;
 736         }
 737     } while (msg != -1);
 738
 739     /*
 740      * This function must either map the shared memory or fail.  The
 741      * loop above ensures that: it terminates normally only after it
 742      * successfully processed the server's shared memory message.
 743      * Assert that actually mapped the shared memory:
 744      */
 745     assert(s->ivshmem_bar2);
 746 }
 747
 748 /* Select the MSI-X vectors used by device.
 749  * ivshmem maps events to vectors statically, so
 750  * we just enable all vectors on init and after reset. */
 751 static void ivshmem_msix_vector_use(IVShmemState *s)
 752 {
 753     PCIDevice *d = PCI_DEVICE(s);
 754     int i;
 755
 756     for (i = 0; i < s->vectors; i++) {
 757         msix_vector_use(d, i);
 758     }
 759 }
 760
 761 static void ivshmem_disable_irqfd(IVShmemState *s);
 762
 763 static void ivshmem_reset(DeviceState *d)
 764 {
 765     IVShmemState *s = IVSHMEM_COMMON(d);
 766
 767     ivshmem_disable_irqfd(s);
 768
 769     s->intrstatus = 0;
 770     s->intrmask = 0;
 771     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 772         ivshmem_msix_vector_use(s);
 773     }
 774 }
 775
 776 static int ivshmem_setup_interrupts(IVShmemState *s, Error **errp)
 777 {
 778     /* allocate QEMU callback data for receiving interrupts */
 779     s->msi_vectors = g_malloc0(s->vectors * sizeof(MSIVector));
 780
 781     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 782         if (msix_init_exclusive_bar(PCI_DEVICE(s), s->vectors, 1, errp)) {
 783             return -1;
 784         }
 785
 786         IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
 787         ivshmem_msix_vector_use(s);
 788     }
 789
 790     return 0;
 791 }
 792
 793 static void ivshmem_remove_kvm_msi_virq(IVShmemState *s, int vector)
 794 {
 795     IVSHMEM_DPRINTF("ivshmem_remove_kvm_msi_virq vector:%d\n", vector);
 796
 797     if (s->msi_vectors[vector].pdev == NULL) {
 798         return;
 799     }
 800
 801     /* it was cleaned when masked in the frontend. */
 802     kvm_irqchip_release_virq(kvm_state, s->msi_vectors[vector].virq);
 803
 804     s->msi_vectors[vector].pdev = NULL;
 805 }
 806
 807 static void ivshmem_enable_irqfd(IVShmemState *s)
 808 {
 809     PCIDevice *pdev = PCI_DEVICE(s);
 810     int i;
 811
 812     for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
 813         Error *err = NULL;
 814
 815         ivshmem_add_kvm_msi_virq(s, i, &err);
 816         if (err) {
 817             error_report_err(err);
 818             goto undo;
 819         }
 820     }
 821
 822     if (msix_set_vector_notifiers(pdev,
 823                                   ivshmem_vector_unmask,
 824                                   ivshmem_vector_mask,
 825                                   ivshmem_vector_poll)) {
 826         error_report("ivshmem: msix_set_vector_notifiers failed");
 827         goto undo;
 828     }
 829     return;
 830
 831 undo:
 832     while (--i >= 0) {
 833         ivshmem_remove_kvm_msi_virq(s, i);
 834     }
 835 }
 836
 837 static void ivshmem_disable_irqfd(IVShmemState *s)
 838 {
 839     PCIDevice *pdev = PCI_DEVICE(s);
 840     int i;
 841
 842     if (!pdev->msix_vector_use_notifier) {
 843         return;
 844     }
 845
 846     msix_unset_vector_notifiers(pdev);
 847
 848     for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
 849         /*
 850          * MSI-X is already disabled here so msix_unset_vector_notifiers()
 851          * didn't call our release notifier.  Do it now to keep our masks and
 852          * unmasks balanced.
 853          */
 854         if (s->msi_vectors[i].unmasked) {
 855             ivshmem_vector_mask(pdev, i);
 856         }
 857         ivshmem_remove_kvm_msi_virq(s, i);
 858     }
 859
 860 }
 861
 862 static void ivshmem_write_config(PCIDevice *pdev, uint32_t address,
 863                                  uint32_t val, int len)
 864 {
 865     IVShmemState *s = IVSHMEM_COMMON(pdev);
 866     int is_enabled, was_enabled = msix_enabled(pdev);
 867
 868     pci_default_write_config(pdev, address, val, len);
 869     is_enabled = msix_enabled(pdev);
 870
 871     if (kvm_msi_via_irqfd_enabled()) {
 872         if (!was_enabled && is_enabled) {
 873             ivshmem_enable_irqfd(s);
 874         } else if (was_enabled && !is_enabled) {
 875             ivshmem_disable_irqfd(s);
 876         }
 877     }
 878 }
 879
 880 static void ivshmem_common_realize(PCIDevice *dev, Error **errp)
 881 {
 882     IVShmemState *s = IVSHMEM_COMMON(dev);
 883     Error *err = NULL;
 884     uint8_t *pci_conf;
 885     uint8_t attr = PCI_BASE_ADDRESS_SPACE_MEMORY |
 886         PCI_BASE_ADDRESS_MEM_PREFETCH;
 887     Error *local_err = NULL;
 888
 889     /* IRQFD requires MSI */
 890     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
 891         !ivshmem_has_feature(s, IVSHMEM_MSI)) {
 892         error_setg(errp, "ioeventfd/irqfd requires MSI");
 893         return;
 894     }
 895
 896     pci_conf = dev->config;
 897     pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
 898
 899     memory_region_init_io(&s->ivshmem_mmio, OBJECT(s), &ivshmem_mmio_ops, s,
 900                           "ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
 901
 902     /* region for registers*/
 903     pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
 904                      &s->ivshmem_mmio);
 905
 906     if (s->not_legacy_32bit) {
 907         attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;
 908     }
 909
 910     if (s->hostmem != NULL) {
 911         IVSHMEM_DPRINTF("using hostmem\n");
 912
 913         s->ivshmem_bar2 = host_memory_backend_get_memory(s->hostmem);
 914     } else {
 915         Chardev *chr = qemu_chr_fe_get_driver(&s->server_chr);
 916         assert(chr);
 917
 918         IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
 919                         chr->filename);
 920
 921         /* we allocate enough space for 16 peers and grow as needed */
 922         resize_peers(s, 16);
 923
 924         /*
 925          * Receive setup messages from server synchronously.
 926          * Older versions did it asynchronously, but that creates a
 927          * number of entertaining race conditions.
 928          */
 929         ivshmem_recv_setup(s, &err);
 930         if (err) {
 931             error_propagate(errp, err);
 932             return;
 933         }
 934
 935         if (s->master == ON_OFF_AUTO_ON && s->vm_id != 0) {
 936             error_setg(errp,
 937                        "master must connect to the server before any peers");
 938             return;
 939         }
 940
 941         qemu_chr_fe_set_handlers(&s->server_chr, ivshmem_can_receive,
 942                                  ivshmem_read, NULL, NULL, s, NULL, true);
 943
 944         if (ivshmem_setup_interrupts(s, errp) < 0) {
 945             error_prepend(errp, "Failed to initialize interrupts: ");
 946             return;
 947         }
 948     }
 949
 950     if (s->master == ON_OFF_AUTO_AUTO) {
 951         s->master = s->vm_id == 0 ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
 952     }
 953
 954     if (!ivshmem_is_master(s)) {
 955         error_setg(&s->migration_blocker,
 956                    "Migration is disabled when using feature 'peer mode' in device 'ivshmem'");
 957         migrate_add_blocker(s->migration_blocker, &local_err);
 958         if (local_err) {
 959             error_propagate(errp, local_err);
 960             error_free(s->migration_blocker);
 961             return;
 962         }
 963     }
 964
 965     vmstate_register_ram(s->ivshmem_bar2, DEVICE(s));
 966     pci_register_bar(PCI_DEVICE(s), 2, attr, s->ivshmem_bar2);
 967 }
 968
 969 static void ivshmem_exit(PCIDevice *dev)
 970 {
 971     IVShmemState *s = IVSHMEM_COMMON(dev);
 972     int i;
 973
 974     if (s->migration_blocker) {
 975         migrate_del_blocker(s->migration_blocker);
 976         error_free(s->migration_blocker);
 977     }
 978
 979     if (memory_region_is_mapped(s->ivshmem_bar2)) {
 980         if (!s->hostmem) {
 981             void *addr = memory_region_get_ram_ptr(s->ivshmem_bar2);
 982             int fd;
 983
 984             if (munmap(addr, memory_region_size(s->ivshmem_bar2) == -1)) {
 985                 error_report("Failed to munmap shared memory %s",
 986                              strerror(errno));
 987             }
 988
 989             fd = memory_region_get_fd(s->ivshmem_bar2);
 990             close(fd);
 991         }
 992
 993         vmstate_unregister_ram(s->ivshmem_bar2, DEVICE(dev));
 994     }
 995
 996     if (s->peers) {
 997         for (i = 0; i < s->nb_peers; i++) {
 998             close_peer_eventfds(s, i);
 999         }
1000         g_free(s->peers);
1001     }
1002
1003     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
1004         msix_uninit_exclusive_bar(dev);
1005     }
1006
1007     g_free(s->msi_vectors);
1008 }
1009
1010 static int ivshmem_pre_load(void *opaque)
1011 {
1012     IVShmemState *s = opaque;
1013
1014     if (!ivshmem_is_master(s)) {
1015         error_report("'peer' devices are not migratable");
1016         return -EINVAL;
1017     }
1018
1019     return 0;
1020 }
1021
1022 static int ivshmem_post_load(void *opaque, int version_id)
1023 {
1024     IVShmemState *s = opaque;
1025
1026     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
1027         ivshmem_msix_vector_use(s);
1028     }
1029     return 0;
1030 }
1031
1032 static void ivshmem_common_class_init(ObjectClass *klass, void *data)
1033 {
1034     DeviceClass *dc = DEVICE_CLASS(klass);
1035     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1036
1037     k->realize = ivshmem_common_realize;
1038     k->exit = ivshmem_exit;
1039     k->config_write = ivshmem_write_config;
1040     k->vendor_id = PCI_VENDOR_ID_IVSHMEM;
1041     k->device_id = PCI_DEVICE_ID_IVSHMEM;
1042     k->class_id = PCI_CLASS_MEMORY_RAM;
1043     k->revision = 1;
1044     dc->reset = ivshmem_reset;
1045     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
1046     dc->desc = "Inter-VM shared memory";
1047 }
1048
1049 static const TypeInfo ivshmem_common_info = {
1050     .name          = TYPE_IVSHMEM_COMMON,
1051     .parent        = TYPE_PCI_DEVICE,
1052     .instance_size = sizeof(IVShmemState),
1053     .abstract      = true,
1054     .class_init    = ivshmem_common_class_init,
1055     .interfaces = (InterfaceInfo[]) {
1056         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
1057         { },
1058     },
1059 };
1060
1061 static const VMStateDescription ivshmem_plain_vmsd = {
1062     .name = TYPE_IVSHMEM_PLAIN,
1063     .version_id = 0,
1064     .minimum_version_id = 0,
1065     .pre_load = ivshmem_pre_load,
1066     .post_load = ivshmem_post_load,
1067     .fields = (VMStateField[]) {
1068         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1069         VMSTATE_UINT32(intrstatus, IVShmemState),
1070         VMSTATE_UINT32(intrmask, IVShmemState),
1071         VMSTATE_END_OF_LIST()
1072     },
1073 };
1074
1075 static Property ivshmem_plain_properties[] = {
1076     DEFINE_PROP_ON_OFF_AUTO("master", IVShmemState, master, ON_OFF_AUTO_OFF),
1077     DEFINE_PROP_LINK("memdev", IVShmemState, hostmem, TYPE_MEMORY_BACKEND,
1078                      HostMemoryBackend *),
1079     DEFINE_PROP_END_OF_LIST(),
1080 };
1081
1082 static void ivshmem_plain_init(Object *obj)
1083 {
1084     IVShmemState *s = IVSHMEM_PLAIN(obj);
1085
1086     s->not_legacy_32bit = 1;
1087 }
1088
1089 static void ivshmem_plain_realize(PCIDevice *dev, Error **errp)
1090 {
1091     IVShmemState *s = IVSHMEM_COMMON(dev);
1092
1093     if (!s->hostmem) {
1094         error_setg(errp, "You must specify a 'memdev'");
1095         return;
1096     } else if (host_memory_backend_is_mapped(s->hostmem)) {
1097         char *path = object_get_canonical_path_component(OBJECT(s->hostmem));
1098         error_setg(errp, "can't use already busy memdev: %s", path);
1099         g_free(path);
1100         return;
1101     }
1102
1103     ivshmem_common_realize(dev, errp);
1104     host_memory_backend_set_mapped(s->hostmem, true);
1105 }
1106
1107 static void ivshmem_plain_exit(PCIDevice *pci_dev)
1108 {
1109     IVShmemState *s = IVSHMEM_COMMON(pci_dev);
1110
1111     host_memory_backend_set_mapped(s->hostmem, false);
1112 }
1113
1114 static void ivshmem_plain_class_init(ObjectClass *klass, void *data)
1115 {
1116     DeviceClass *dc = DEVICE_CLASS(klass);
1117     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1118
1119     k->realize = ivshmem_plain_realize;
1120     k->exit = ivshmem_plain_exit;
1121     dc->props = ivshmem_plain_properties;
1122     dc->vmsd = &ivshmem_plain_vmsd;
1123 }
1124
1125 static const TypeInfo ivshmem_plain_info = {
1126     .name          = TYPE_IVSHMEM_PLAIN,
1127     .parent        = TYPE_IVSHMEM_COMMON,
1128     .instance_size = sizeof(IVShmemState),
1129     .instance_init = ivshmem_plain_init,
1130     .class_init    = ivshmem_plain_class_init,
1131 };
1132
1133 static const VMStateDescription ivshmem_doorbell_vmsd = {
1134     .name = TYPE_IVSHMEM_DOORBELL,
1135     .version_id = 0,
1136     .minimum_version_id = 0,
1137     .pre_load = ivshmem_pre_load,
1138     .post_load = ivshmem_post_load,
1139     .fields = (VMStateField[]) {
1140         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1141         VMSTATE_MSIX(parent_obj, IVShmemState),
1142         VMSTATE_UINT32(intrstatus, IVShmemState),
1143         VMSTATE_UINT32(intrmask, IVShmemState),
1144         VMSTATE_END_OF_LIST()
1145     },
1146 };
1147
1148 static Property ivshmem_doorbell_properties[] = {
1149     DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
1150     DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
1151     DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD,
1152                     true),
1153     DEFINE_PROP_ON_OFF_AUTO("master", IVShmemState, master, ON_OFF_AUTO_OFF),
1154     DEFINE_PROP_END_OF_LIST(),
1155 };
1156
1157 static void ivshmem_doorbell_init(Object *obj)
1158 {
1159     IVShmemState *s = IVSHMEM_DOORBELL(obj);
1160
1161     s->features |= (1 << IVSHMEM_MSI);
1162     s->legacy_size = SIZE_MAX;  /* whatever the server sends */
1163     s->not_legacy_32bit = 1;
1164 }
1165
1166 static void ivshmem_doorbell_realize(PCIDevice *dev, Error **errp)
1167 {
1168     IVShmemState *s = IVSHMEM_COMMON(dev);
1169
1170     if (!qemu_chr_fe_backend_connected(&s->server_chr)) {
1171         error_setg(errp, "You must specify a 'chardev'");
1172         return;
1173     }
1174
1175     ivshmem_common_realize(dev, errp);
1176 }
1177
1178 static void ivshmem_doorbell_class_init(ObjectClass *klass, void *data)
1179 {
1180     DeviceClass *dc = DEVICE_CLASS(klass);
1181     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1182
1183     k->realize = ivshmem_doorbell_realize;
1184     dc->props = ivshmem_doorbell_properties;
1185     dc->vmsd = &ivshmem_doorbell_vmsd;
1186 }
1187
1188 static const TypeInfo ivshmem_doorbell_info = {
1189     .name          = TYPE_IVSHMEM_DOORBELL,
1190     .parent        = TYPE_IVSHMEM_COMMON,
1191     .instance_size = sizeof(IVShmemState),
1192     .instance_init = ivshmem_doorbell_init,
1193     .class_init    = ivshmem_doorbell_class_init,
1194 };
1195
1196 static int ivshmem_load_old(QEMUFile *f, void *opaque, int version_id)
1197 {
1198     IVShmemState *s = opaque;
1199     PCIDevice *pdev = PCI_DEVICE(s);
1200     int ret;
1201
1202     IVSHMEM_DPRINTF("ivshmem_load_old\n");
1203
1204     if (version_id != 0) {
1205         return -EINVAL;
1206     }
1207
1208     ret = ivshmem_pre_load(s);
1209     if (ret) {
1210         return ret;
1211     }
1212
1213     ret = pci_device_load(pdev, f);
1214     if (ret) {
1215         return ret;
1216     }
1217
1218     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
1219         msix_load(pdev, f);
1220         ivshmem_msix_vector_use(s);
1221     } else {
1222         s->intrstatus = qemu_get_be32(f);
1223         s->intrmask = qemu_get_be32(f);
1224     }
1225
1226     return 0;
1227 }
1228
1229 static bool test_msix(void *opaque, int version_id)
1230 {
1231     IVShmemState *s = opaque;
1232
1233     return ivshmem_has_feature(s, IVSHMEM_MSI);
1234 }
1235
1236 static bool test_no_msix(void *opaque, int version_id)
1237 {
1238     return !test_msix(opaque, version_id);
1239 }
1240
1241 static const VMStateDescription ivshmem_vmsd = {
1242     .name = "ivshmem",
1243     .version_id = 1,
1244     .minimum_version_id = 1,
1245     .pre_load = ivshmem_pre_load,
1246     .post_load = ivshmem_post_load,
1247     .fields = (VMStateField[]) {
1248         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1249
1250         VMSTATE_MSIX_TEST(parent_obj, IVShmemState, test_msix),
1251         VMSTATE_UINT32_TEST(intrstatus, IVShmemState, test_no_msix),
1252         VMSTATE_UINT32_TEST(intrmask, IVShmemState, test_no_msix),
1253
1254         VMSTATE_END_OF_LIST()
1255     },
1256     .load_state_old = ivshmem_load_old,
1257     .minimum_version_id_old = 0
1258 };
1259
1260 static Property ivshmem_properties[] = {
1261     DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
1262     DEFINE_PROP_STRING("size", IVShmemState, sizearg),
1263     DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
1264     DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD,
1265                     false),
1266     DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true),
1267     DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
1268     DEFINE_PROP_STRING("role", IVShmemState, role),
1269     DEFINE_PROP_UINT32("use64", IVShmemState, not_legacy_32bit, 1),
1270     DEFINE_PROP_END_OF_LIST(),
1271 };
1272
1273 static void desugar_shm(IVShmemState *s)
1274 {
1275     Object *obj;
1276     char *path;
1277
1278     obj = object_new("memory-backend-file");
1279     path = g_strdup_printf("/dev/shm/%s", s->shmobj);
1280     object_property_set_str(obj, path, "mem-path", &error_abort);
1281     g_free(path);
1282     object_property_set_int(obj, s->legacy_size, "size", &error_abort);
1283     object_property_set_bool(obj, true, "share", &error_abort);
1284     object_property_add_child(OBJECT(s), "internal-shm-backend", obj,
1285                               &error_abort);
1286     user_creatable_complete(obj, &error_abort);
1287     s->hostmem = MEMORY_BACKEND(obj);
1288 }
1289
1290 static void ivshmem_realize(PCIDevice *dev, Error **errp)
1291 {
1292     IVShmemState *s = IVSHMEM_COMMON(dev);
1293
1294     if (!qtest_enabled()) {
1295         error_report("ivshmem is deprecated, please use ivshmem-plain"
1296                      " or ivshmem-doorbell instead");
1297     }
1298
1299     if (qemu_chr_fe_backend_connected(&s->server_chr) + !!s->shmobj != 1) {
1300         error_setg(errp, "You must specify either 'shm' or 'chardev'");
1301         return;
1302     }
1303
1304     if (s->sizearg == NULL) {
1305         s->legacy_size = 4 * MiB; /* 4 MB default */
1306     } else {
1307         int ret;
1308         uint64_t size;
1309
1310         ret = qemu_strtosz_MiB(s->sizearg, NULL, &size);
1311         if (ret < 0 || (size_t)size != size || !is_power_of_2(size)) {
1312             error_setg(errp, "Invalid size %s", s->sizearg);
1313             return;
1314         }
1315         s->legacy_size = size;
1316     }
1317
1318     /* check that role is reasonable */
1319     if (s->role) {
1320         if (strncmp(s->role, "peer", 5) == 0) {
1321             s->master = ON_OFF_AUTO_OFF;
1322         } else if (strncmp(s->role, "master", 7) == 0) {
1323             s->master = ON_OFF_AUTO_ON;
1324         } else {
1325             error_setg(errp, "'role' must be 'peer' or 'master'");
1326             return;
1327         }
1328     } else {
1329         s->master = ON_OFF_AUTO_AUTO;
1330     }
1331
1332     if (s->shmobj) {
1333         desugar_shm(s);
1334     }
1335
1336     /*
1337      * Note: we don't use INTx with IVSHMEM_MSI at all, so this is a
1338      * bald-faced lie then.  But it's a backwards compatible lie.
1339      */
1340     pci_config_set_interrupt_pin(dev->config, 1);
1341
1342     ivshmem_common_realize(dev, errp);
1343 }
1344
1345 static void ivshmem_class_init(ObjectClass *klass, void *data)
1346 {
1347     DeviceClass *dc = DEVICE_CLASS(klass);
1348     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1349
1350     k->realize = ivshmem_realize;
1351     k->revision = 0;
1352     dc->desc = "Inter-VM shared memory (legacy)";
1353     dc->props = ivshmem_properties;
1354     dc->vmsd = &ivshmem_vmsd;
1355 }
1356
1357 static const TypeInfo ivshmem_info = {
1358     .name          = TYPE_IVSHMEM,
1359     .parent        = TYPE_IVSHMEM_COMMON,
1360     .instance_size = sizeof(IVShmemState),
1361     .class_init    = ivshmem_class_init,
1362 };
1363
1364 static void ivshmem_register_types(void)
1365 {
1366     type_register_static(&ivshmem_common_info);
1367     type_register_static(&ivshmem_plain_info);
1368     type_register_static(&ivshmem_doorbell_info);
1369     type_register_static(&ivshmem_info);
1370 }
1371
1372 type_init(ivshmem_register_types)