hw/misc/ivshmem.c

   1 /*
   2  * Inter-VM Shared Memory PCI device.
   3  *
   4  * Author:
   5  *      Cam Macdonell <[email protected]>
   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 "qapi/error.h"
  21 #include "qemu/cutils.h"
  22 #include "hw/hw.h"
  23 #include "hw/i386/pc.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/migration.h"
  29 #include "qemu/error-report.h"
  30 #include "qemu/event_notifier.h"
  31 #include "qom/object_interfaces.h"
  32 #include "sysemu/char.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 #include <sys/mman.h>
  40
  41 #define PCI_VENDOR_ID_IVSHMEM   PCI_VENDOR_ID_REDHAT_QUMRANET
  42 #define PCI_DEVICE_ID_IVSHMEM   0x1110
  43
  44 #define IVSHMEM_MAX_PEERS UINT16_MAX
  45 #define IVSHMEM_IOEVENTFD   0
  46 #define IVSHMEM_MSI     1
  47
  48 #define IVSHMEM_REG_BAR_SIZE 0x100
  49
  50 #define IVSHMEM_DEBUG 0
  51 #define IVSHMEM_DPRINTF(fmt, ...)                       \
  52     do {                                                \
  53         if (IVSHMEM_DEBUG) {                            \
  54             printf("IVSHMEM: " fmt, ## __VA_ARGS__);    \
  55         }                                               \
  56     } while (0)
  57
  58 #define TYPE_IVSHMEM_COMMON "ivshmem-common"
  59 #define IVSHMEM_COMMON(obj) \
  60     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM_COMMON)
  61
  62 #define TYPE_IVSHMEM_PLAIN "ivshmem-plain"
  63 #define IVSHMEM_PLAIN(obj) \
  64     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM_PLAIN)
  65
  66 #define TYPE_IVSHMEM_DOORBELL "ivshmem-doorbell"
  67 #define IVSHMEM_DOORBELL(obj) \
  68     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM_DOORBELL)
  69
  70 #define TYPE_IVSHMEM "ivshmem"
  71 #define IVSHMEM(obj) \
  72     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM)
  73
  74 typedef struct Peer {
  75     int nb_eventfds;
  76     EventNotifier *eventfds;
  77 } Peer;
  78
  79 typedef struct MSIVector {
  80     PCIDevice *pdev;
  81     int virq;
  82 } MSIVector;
  83
  84 typedef struct IVShmemState {
  85     /*< private >*/
  86     PCIDevice parent_obj;
  87     /*< public >*/
  88
  89     uint32_t features;
  90
  91     /* exactly one of these two may be set */
  92     HostMemoryBackend *hostmem; /* with interrupts */
  93     CharDriverState *server_chr; /* without interrupts */
  94
  95     /* registers */
  96     uint32_t intrmask;
  97     uint32_t intrstatus;
  98     int vm_id;
  99
 100     /* BARs */
 101     MemoryRegion ivshmem_mmio;  /* BAR 0 (registers) */
 102     MemoryRegion *ivshmem_bar2; /* BAR 2 (shared memory) */
 103     MemoryRegion server_bar2;   /* used with server_chr */
 104
 105     /* interrupt support */
 106     Peer *peers;
 107     int nb_peers;               /* space in @peers[] */
 108     uint32_t vectors;
 109     MSIVector *msi_vectors;
 110     uint64_t msg_buf;           /* buffer for receiving server messages */
 111     int msg_buffered_bytes;     /* #bytes in @msg_buf */
 112
 113     /* migration stuff */
 114     OnOffAuto master;
 115     Error *migration_blocker;
 116
 117     /* legacy cruft */
 118     char *role;
 119     char *shmobj;
 120     char *sizearg;
 121     size_t legacy_size;
 122     uint32_t not_legacy_32bit;
 123 } IVShmemState;
 124
 125 /* registers for the Inter-VM shared memory device */
 126 enum ivshmem_registers {
 127     INTRMASK = 0,
 128     INTRSTATUS = 4,
 129     IVPOSITION = 8,
 130     DOORBELL = 12,
 131 };
 132
 133 static inline uint32_t ivshmem_has_feature(IVShmemState *ivs,
 134                                                     unsigned int feature) {
 135     return (ivs->features & (1 << feature));
 136 }
 137
 138 static inline bool ivshmem_is_master(IVShmemState *s)
 139 {
 140     assert(s->master != ON_OFF_AUTO_AUTO);
 141     return s->master == ON_OFF_AUTO_ON;
 142 }
 143
 144 static void ivshmem_update_irq(IVShmemState *s)
 145 {
 146     PCIDevice *d = PCI_DEVICE(s);
 147     uint32_t isr = s->intrstatus & s->intrmask;
 148
 149     /*
 150      * Do nothing unless the device actually uses INTx.  Here's how
 151      * the device variants signal interrupts, what they put in PCI
 152      * config space:
 153      * Device variant    Interrupt  Interrupt Pin  MSI-X cap.
 154      * ivshmem-plain         none            0         no
 155      * ivshmem-doorbell     MSI-X            1        yes(1)
 156      * ivshmem,msi=off       INTx            1         no
 157      * ivshmem,msi=on       MSI-X            1(2)     yes(1)
 158      * (1) if guest enabled MSI-X
 159      * (2) the device lies
 160      * Leads to the condition for doing nothing:
 161      */
 162     if (ivshmem_has_feature(s, IVSHMEM_MSI)
 163         || !d->config[PCI_INTERRUPT_PIN]) {
 164         return;
 165     }
 166
 167     /* don't print ISR resets */
 168     if (isr) {
 169         IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
 170                         isr ? 1 : 0, s->intrstatus, s->intrmask);
 171     }
 172
 173     pci_set_irq(d, isr != 0);
 174 }
 175
 176 static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
 177 {
 178     IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
 179
 180     s->intrmask = val;
 181     ivshmem_update_irq(s);
 182 }
 183
 184 static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
 185 {
 186     uint32_t ret = s->intrmask;
 187
 188     IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
 189     return ret;
 190 }
 191
 192 static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
 193 {
 194     IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
 195
 196     s->intrstatus = val;
 197     ivshmem_update_irq(s);
 198 }
 199
 200 static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
 201 {
 202     uint32_t ret = s->intrstatus;
 203
 204     /* reading ISR clears all interrupts */
 205     s->intrstatus = 0;
 206     ivshmem_update_irq(s);
 207     return ret;
 208 }
 209
 210 static void ivshmem_io_write(void *opaque, hwaddr addr,
 211                              uint64_t val, unsigned size)
 212 {
 213     IVShmemState *s = opaque;
 214
 215     uint16_t dest = val >> 16;
 216     uint16_t vector = val & 0xff;
 217
 218     addr &= 0xfc;
 219
 220     IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr);
 221     switch (addr)
 222     {
 223         case INTRMASK:
 224             ivshmem_IntrMask_write(s, val);
 225             break;
 226
 227         case INTRSTATUS:
 228             ivshmem_IntrStatus_write(s, val);
 229             break;
 230
 231         case DOORBELL:
 232             /* check that dest VM ID is reasonable */
 233             if (dest >= s->nb_peers) {
 234                 IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
 235                 break;
 236             }
 237
 238             /* check doorbell range */
 239             if (vector < s->peers[dest].nb_eventfds) {
 240                 IVSHMEM_DPRINTF("Notifying VM %d on vector %d\n", dest, vector);
 241                 event_notifier_set(&s->peers[dest].eventfds[vector]);
 242             } else {
 243                 IVSHMEM_DPRINTF("Invalid destination vector %d on VM %d\n",
 244                                 vector, dest);
 245             }
 246             break;
 247         default:
 248             IVSHMEM_DPRINTF("Unhandled write " TARGET_FMT_plx "\n", addr);
 249     }
 250 }
 251
 252 static uint64_t ivshmem_io_read(void *opaque, hwaddr addr,
 253                                 unsigned size)
 254 {
 255
 256     IVShmemState *s = opaque;
 257     uint32_t ret;
 258
 259     switch (addr)
 260     {
 261         case INTRMASK:
 262             ret = ivshmem_IntrMask_read(s);
 263             break;
 264
 265         case INTRSTATUS:
 266             ret = ivshmem_IntrStatus_read(s);
 267             break;
 268
 269         case IVPOSITION:
 270             ret = s->vm_id;
 271             break;
 272
 273         default:
 274             IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr);
 275             ret = 0;
 276     }
 277
 278     return ret;
 279 }
 280
 281 static const MemoryRegionOps ivshmem_mmio_ops = {
 282     .read = ivshmem_io_read,
 283     .write = ivshmem_io_write,
 284     .endianness = DEVICE_NATIVE_ENDIAN,
 285     .impl = {
 286         .min_access_size = 4,
 287         .max_access_size = 4,
 288     },
 289 };
 290
 291 static void ivshmem_vector_notify(void *opaque)
 292 {
 293     MSIVector *entry = opaque;
 294     PCIDevice *pdev = entry->pdev;
 295     IVShmemState *s = IVSHMEM_COMMON(pdev);
 296     int vector = entry - s->msi_vectors;
 297     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 298
 299     if (!event_notifier_test_and_clear(n)) {
 300         return;
 301     }
 302
 303     IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, vector);
 304     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 305         if (msix_enabled(pdev)) {
 306             msix_notify(pdev, vector);
 307         }
 308     } else {
 309         ivshmem_IntrStatus_write(s, 1);
 310     }
 311 }
 312
 313 static int ivshmem_vector_unmask(PCIDevice *dev, unsigned vector,
 314                                  MSIMessage msg)
 315 {
 316     IVShmemState *s = IVSHMEM_COMMON(dev);
 317     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 318     MSIVector *v = &s->msi_vectors[vector];
 319     int ret;
 320
 321     IVSHMEM_DPRINTF("vector unmask %p %d\n", dev, vector);
 322
 323     ret = kvm_irqchip_update_msi_route(kvm_state, v->virq, msg, dev);
 324     if (ret < 0) {
 325         return ret;
 326     }
 327
 328     return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq);
 329 }
 330
 331 static void ivshmem_vector_mask(PCIDevice *dev, unsigned vector)
 332 {
 333     IVShmemState *s = IVSHMEM_COMMON(dev);
 334     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 335     int ret;
 336
 337     IVSHMEM_DPRINTF("vector mask %p %d\n", dev, vector);
 338
 339     ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n,
 340                                                 s->msi_vectors[vector].virq);
 341     if (ret != 0) {
 342         error_report("remove_irqfd_notifier_gsi failed");
 343     }
 344 }
 345
 346 static void ivshmem_vector_poll(PCIDevice *dev,
 347                                 unsigned int vector_start,
 348                                 unsigned int vector_end)
 349 {
 350     IVShmemState *s = IVSHMEM_COMMON(dev);
 351     unsigned int vector;
 352
 353     IVSHMEM_DPRINTF("vector poll %p %d-%d\n", dev, vector_start, vector_end);
 354
 355     vector_end = MIN(vector_end, s->vectors);
 356
 357     for (vector = vector_start; vector < vector_end; vector++) {
 358         EventNotifier *notifier = &s->peers[s->vm_id].eventfds[vector];
 359
 360         if (!msix_is_masked(dev, vector)) {
 361             continue;
 362         }
 363
 364         if (event_notifier_test_and_clear(notifier)) {
 365             msix_set_pending(dev, vector);
 366         }
 367     }
 368 }
 369
 370 static void watch_vector_notifier(IVShmemState *s, EventNotifier *n,
 371                                  int vector)
 372 {
 373     int eventfd = event_notifier_get_fd(n);
 374
 375     assert(!s->msi_vectors[vector].pdev);
 376     s->msi_vectors[vector].pdev = PCI_DEVICE(s);
 377
 378     qemu_set_fd_handler(eventfd, ivshmem_vector_notify,
 379                         NULL, &s->msi_vectors[vector]);
 380 }
 381
 382 static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i)
 383 {
 384     memory_region_add_eventfd(&s->ivshmem_mmio,
 385                               DOORBELL,
 386                               4,
 387                               true,
 388                               (posn << 16) | i,
 389                               &s->peers[posn].eventfds[i]);
 390 }
 391
 392 static void ivshmem_del_eventfd(IVShmemState *s, int posn, int i)
 393 {
 394     memory_region_del_eventfd(&s->ivshmem_mmio,
 395                               DOORBELL,
 396                               4,
 397                               true,
 398                               (posn << 16) | i,
 399                               &s->peers[posn].eventfds[i]);
 400 }
 401
 402 static void close_peer_eventfds(IVShmemState *s, int posn)
 403 {
 404     int i, n;
 405
 406     assert(posn >= 0 && posn < s->nb_peers);
 407     n = s->peers[posn].nb_eventfds;
 408
 409     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 410         memory_region_transaction_begin();
 411         for (i = 0; i < n; i++) {
 412             ivshmem_del_eventfd(s, posn, i);
 413         }
 414         memory_region_transaction_commit();
 415     }
 416
 417     for (i = 0; i < n; i++) {
 418         event_notifier_cleanup(&s->peers[posn].eventfds[i]);
 419     }
 420
 421     g_free(s->peers[posn].eventfds);
 422     s->peers[posn].nb_eventfds = 0;
 423 }
 424
 425 static void resize_peers(IVShmemState *s, int nb_peers)
 426 {
 427     int old_nb_peers = s->nb_peers;
 428     int i;
 429
 430     assert(nb_peers > old_nb_peers);
 431     IVSHMEM_DPRINTF("bumping storage to %d peers\n", nb_peers);
 432
 433     s->peers = g_realloc(s->peers, nb_peers * sizeof(Peer));
 434     s->nb_peers = nb_peers;
 435
 436     for (i = old_nb_peers; i < nb_peers; i++) {
 437         s->peers[i].eventfds = g_new0(EventNotifier, s->vectors);
 438         s->peers[i].nb_eventfds = 0;
 439     }
 440 }
 441
 442 static void ivshmem_add_kvm_msi_virq(IVShmemState *s, int vector,
 443                                      Error **errp)
 444 {
 445     PCIDevice *pdev = PCI_DEVICE(s);
 446     MSIMessage msg = msix_get_message(pdev, vector);
 447     int ret;
 448
 449     IVSHMEM_DPRINTF("ivshmem_add_kvm_msi_virq vector:%d\n", vector);
 450     assert(!s->msi_vectors[vector].pdev);
 451
 452     ret = kvm_irqchip_add_msi_route(kvm_state, msg, pdev);
 453     if (ret < 0) {
 454         error_setg(errp, "kvm_irqchip_add_msi_route failed");
 455         return;
 456     }
 457
 458     s->msi_vectors[vector].virq = ret;
 459     s->msi_vectors[vector].pdev = pdev;
 460 }
 461
 462 static void setup_interrupt(IVShmemState *s, int vector, Error **errp)
 463 {
 464     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 465     bool with_irqfd = kvm_msi_via_irqfd_enabled() &&
 466         ivshmem_has_feature(s, IVSHMEM_MSI);
 467     PCIDevice *pdev = PCI_DEVICE(s);
 468     Error *err = NULL;
 469
 470     IVSHMEM_DPRINTF("setting up interrupt for vector: %d\n", vector);
 471
 472     if (!with_irqfd) {
 473         IVSHMEM_DPRINTF("with eventfd\n");
 474         watch_vector_notifier(s, n, vector);
 475     } else if (msix_enabled(pdev)) {
 476         IVSHMEM_DPRINTF("with irqfd\n");
 477         ivshmem_add_kvm_msi_virq(s, vector, &err);
 478         if (err) {
 479             error_propagate(errp, err);
 480             return;
 481         }
 482
 483         if (!msix_is_masked(pdev, vector)) {
 484             kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL,
 485                                                s->msi_vectors[vector].virq);
 486             /* TODO handle error */
 487         }
 488     } else {
 489         /* it will be delayed until msix is enabled, in write_config */
 490         IVSHMEM_DPRINTF("with irqfd, delayed until msix enabled\n");
 491     }
 492 }
 493
 494 static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
 495 {
 496     struct stat buf;
 497     size_t size;
 498     void *ptr;
 499
 500     if (s->ivshmem_bar2) {
 501         error_setg(errp, "server sent unexpected shared memory message");
 502         close(fd);
 503         return;
 504     }
 505
 506     if (fstat(fd, &buf) < 0) {
 507         error_setg_errno(errp, errno,
 508             "can't determine size of shared memory sent by server");
 509         close(fd);
 510         return;
 511     }
 512
 513     size = buf.st_size;
 514
 515     /* Legacy cruft */
 516     if (s->legacy_size != SIZE_MAX) {
 517         if (size < s->legacy_size) {
 518             error_setg(errp, "server sent only %zd bytes of shared memory",
 519                        (size_t)buf.st_size);
 520             close(fd);
 521             return;
 522         }
 523         size = s->legacy_size;
 524     }
 525
 526     /* mmap the region and map into the BAR2 */
 527     ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 528     if (ptr == MAP_FAILED) {
 529         error_setg_errno(errp, errno, "Failed to mmap shared memory");
 530         close(fd);
 531         return;
 532     }
 533     memory_region_init_ram_ptr(&s->server_bar2, OBJECT(s),
 534                                "ivshmem.bar2", size, ptr);
 535     memory_region_set_fd(&s->server_bar2, fd);
 536     s->ivshmem_bar2 = &s->server_bar2;
 537 }
 538
 539 static void process_msg_disconnect(IVShmemState *s, uint16_t posn,
 540                                    Error **errp)
 541 {
 542     IVSHMEM_DPRINTF("posn %d has gone away\n", posn);
 543     if (posn >= s->nb_peers || posn == s->vm_id) {
 544         error_setg(errp, "invalid peer %d", posn);
 545         return;
 546     }
 547     close_peer_eventfds(s, posn);
 548 }
 549
 550 static void process_msg_connect(IVShmemState *s, uint16_t posn, int fd,
 551                                 Error **errp)
 552 {
 553     Peer *peer = &s->peers[posn];
 554     int vector;
 555
 556     /*
 557      * The N-th connect message for this peer comes with the file
 558      * descriptor for vector N-1.  Count messages to find the vector.
 559      */
 560     if (peer->nb_eventfds >= s->vectors) {
 561         error_setg(errp, "Too many eventfd received, device has %d vectors",
 562                    s->vectors);
 563         close(fd);
 564         return;
 565     }
 566     vector = peer->nb_eventfds++;
 567
 568     IVSHMEM_DPRINTF("eventfds[%d][%d] = %d\n", posn, vector, fd);
 569     event_notifier_init_fd(&peer->eventfds[vector], fd);
 570     fcntl_setfl(fd, O_NONBLOCK); /* msix/irqfd poll non block */
 571
 572     if (posn == s->vm_id) {
 573         setup_interrupt(s, vector, errp);
 574         /* TODO do we need to handle the error? */
 575     }
 576
 577     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 578         ivshmem_add_eventfd(s, posn, vector);
 579     }
 580 }
 581
 582 static void process_msg(IVShmemState *s, int64_t msg, int fd, Error **errp)
 583 {
 584     IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", msg, fd);
 585
 586     if (msg < -1 || msg > IVSHMEM_MAX_PEERS) {
 587         error_setg(errp, "server sent invalid message %" PRId64, msg);
 588         close(fd);
 589         return;
 590     }
 591
 592     if (msg == -1) {
 593         process_msg_shmem(s, fd, errp);
 594         return;
 595     }
 596
 597     if (msg >= s->nb_peers) {
 598         resize_peers(s, msg + 1);
 599     }
 600
 601     if (fd >= 0) {
 602         process_msg_connect(s, msg, fd, errp);
 603     } else {
 604         process_msg_disconnect(s, msg, errp);
 605     }
 606 }
 607
 608 static int ivshmem_can_receive(void *opaque)
 609 {
 610     IVShmemState *s = opaque;
 611
 612     assert(s->msg_buffered_bytes < sizeof(s->msg_buf));
 613     return sizeof(s->msg_buf) - s->msg_buffered_bytes;
 614 }
 615
 616 static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
 617 {
 618     IVShmemState *s = opaque;
 619     Error *err = NULL;
 620     int fd;
 621     int64_t msg;
 622
 623     assert(size >= 0 && s->msg_buffered_bytes + size <= sizeof(s->msg_buf));
 624     memcpy((unsigned char *)&s->msg_buf + s->msg_buffered_bytes, buf, size);
 625     s->msg_buffered_bytes += size;
 626     if (s->msg_buffered_bytes < sizeof(s->msg_buf)) {
 627         return;
 628     }
 629     msg = le64_to_cpu(s->msg_buf);
 630     s->msg_buffered_bytes = 0;
 631
 632     fd = qemu_chr_fe_get_msgfd(s->server_chr);
 633     IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", msg, fd);
 634
 635     process_msg(s, msg, fd, &err);
 636     if (err) {
 637         error_report_err(err);
 638     }
 639 }
 640
 641 static int64_t ivshmem_recv_msg(IVShmemState *s, int *pfd, Error **errp)
 642 {
 643     int64_t msg;
 644     int n, ret;
 645
 646     n = 0;
 647     do {
 648         ret = qemu_chr_fe_read_all(s->server_chr, (uint8_t *)&msg + n,
 649                                  sizeof(msg) - n);
 650         if (ret < 0 && ret != -EINTR) {
 651             error_setg_errno(errp, -ret, "read from server failed");
 652             return INT64_MIN;
 653         }
 654         n += ret;
 655     } while (n < sizeof(msg));
 656
 657     *pfd = qemu_chr_fe_get_msgfd(s->server_chr);
 658     return msg;
 659 }
 660
 661 static void ivshmem_recv_setup(IVShmemState *s, Error **errp)
 662 {
 663     Error *err = NULL;
 664     int64_t msg;
 665     int fd;
 666
 667     msg = ivshmem_recv_msg(s, &fd, &err);
 668     if (err) {
 669         error_propagate(errp, err);
 670         return;
 671     }
 672     if (msg != IVSHMEM_PROTOCOL_VERSION) {
 673         error_setg(errp, "server sent version %" PRId64 ", expecting %d",
 674                    msg, IVSHMEM_PROTOCOL_VERSION);
 675         return;
 676     }
 677     if (fd != -1) {
 678         error_setg(errp, "server sent invalid version message");
 679         return;
 680     }
 681
 682     /*
 683      * ivshmem-server sends the remaining initial messages in a fixed
 684      * order, but the device has always accepted them in any order.
 685      * Stay as compatible as practical, just in case people use
 686      * servers that behave differently.
 687      */
 688
 689     /*
 690      * ivshmem_device_spec.txt has always required the ID message
 691      * right here, and ivshmem-server has always complied.  However,
 692      * older versions of the device accepted it out of order, but
 693      * broke when an interrupt setup message arrived before it.
 694      */
 695     msg = ivshmem_recv_msg(s, &fd, &err);
 696     if (err) {
 697         error_propagate(errp, err);
 698         return;
 699     }
 700     if (fd != -1 || msg < 0 || msg > IVSHMEM_MAX_PEERS) {
 701         error_setg(errp, "server sent invalid ID message");
 702         return;
 703     }
 704     s->vm_id = msg;
 705
 706     /*
 707      * Receive more messages until we got shared memory.
 708      */
 709     do {
 710         msg = ivshmem_recv_msg(s, &fd, &err);
 711         if (err) {
 712             error_propagate(errp, err);
 713             return;
 714         }
 715         process_msg(s, msg, fd, &err);
 716         if (err) {
 717             error_propagate(errp, err);
 718             return;
 719         }
 720     } while (msg != -1);
 721
 722     /*
 723      * This function must either map the shared memory or fail.  The
 724      * loop above ensures that: it terminates normally only after it
 725      * successfully processed the server's shared memory message.
 726      * Assert that actually mapped the shared memory:
 727      */
 728     assert(s->ivshmem_bar2);
 729 }
 730
 731 /* Select the MSI-X vectors used by device.
 732  * ivshmem maps events to vectors statically, so
 733  * we just enable all vectors on init and after reset. */
 734 static void ivshmem_msix_vector_use(IVShmemState *s)
 735 {
 736     PCIDevice *d = PCI_DEVICE(s);
 737     int i;
 738
 739     for (i = 0; i < s->vectors; i++) {
 740         msix_vector_use(d, i);
 741     }
 742 }
 743
 744 static void ivshmem_reset(DeviceState *d)
 745 {
 746     IVShmemState *s = IVSHMEM_COMMON(d);
 747
 748     s->intrstatus = 0;
 749     s->intrmask = 0;
 750     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 751         ivshmem_msix_vector_use(s);
 752     }
 753 }
 754
 755 static int ivshmem_setup_interrupts(IVShmemState *s)
 756 {
 757     /* allocate QEMU callback data for receiving interrupts */
 758     s->msi_vectors = g_malloc0(s->vectors * sizeof(MSIVector));
 759
 760     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 761         if (msix_init_exclusive_bar(PCI_DEVICE(s), s->vectors, 1)) {
 762             return -1;
 763         }
 764
 765         IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
 766         ivshmem_msix_vector_use(s);
 767     }
 768
 769     return 0;
 770 }
 771
 772 static void ivshmem_enable_irqfd(IVShmemState *s)
 773 {
 774     PCIDevice *pdev = PCI_DEVICE(s);
 775     int i;
 776
 777     for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
 778         Error *err = NULL;
 779
 780         ivshmem_add_kvm_msi_virq(s, i, &err);
 781         if (err) {
 782             error_report_err(err);
 783             /* TODO do we need to handle the error? */
 784         }
 785     }
 786
 787     if (msix_set_vector_notifiers(pdev,
 788                                   ivshmem_vector_unmask,
 789                                   ivshmem_vector_mask,
 790                                   ivshmem_vector_poll)) {
 791         error_report("ivshmem: msix_set_vector_notifiers failed");
 792     }
 793 }
 794
 795 static void ivshmem_remove_kvm_msi_virq(IVShmemState *s, int vector)
 796 {
 797     IVSHMEM_DPRINTF("ivshmem_remove_kvm_msi_virq vector:%d\n", vector);
 798
 799     if (s->msi_vectors[vector].pdev == NULL) {
 800         return;
 801     }
 802
 803     /* it was cleaned when masked in the frontend. */
 804     kvm_irqchip_release_virq(kvm_state, s->msi_vectors[vector].virq);
 805
 806     s->msi_vectors[vector].pdev = NULL;
 807 }
 808
 809 static void ivshmem_disable_irqfd(IVShmemState *s)
 810 {
 811     PCIDevice *pdev = PCI_DEVICE(s);
 812     int i;
 813
 814     for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
 815         ivshmem_remove_kvm_msi_virq(s, i);
 816     }
 817
 818     msix_unset_vector_notifiers(pdev);
 819 }
 820
 821 static void ivshmem_write_config(PCIDevice *pdev, uint32_t address,
 822                                  uint32_t val, int len)
 823 {
 824     IVShmemState *s = IVSHMEM_COMMON(pdev);
 825     int is_enabled, was_enabled = msix_enabled(pdev);
 826
 827     pci_default_write_config(pdev, address, val, len);
 828     is_enabled = msix_enabled(pdev);
 829
 830     if (kvm_msi_via_irqfd_enabled()) {
 831         if (!was_enabled && is_enabled) {
 832             ivshmem_enable_irqfd(s);
 833         } else if (was_enabled && !is_enabled) {
 834             ivshmem_disable_irqfd(s);
 835         }
 836     }
 837 }
 838
 839 static void ivshmem_common_realize(PCIDevice *dev, Error **errp)
 840 {
 841     IVShmemState *s = IVSHMEM_COMMON(dev);
 842     Error *err = NULL;
 843     uint8_t *pci_conf;
 844     uint8_t attr = PCI_BASE_ADDRESS_SPACE_MEMORY |
 845         PCI_BASE_ADDRESS_MEM_PREFETCH;
 846
 847     /* IRQFD requires MSI */
 848     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
 849         !ivshmem_has_feature(s, IVSHMEM_MSI)) {
 850         error_setg(errp, "ioeventfd/irqfd requires MSI");
 851         return;
 852     }
 853
 854     pci_conf = dev->config;
 855     pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
 856
 857     memory_region_init_io(&s->ivshmem_mmio, OBJECT(s), &ivshmem_mmio_ops, s,
 858                           "ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
 859
 860     /* region for registers*/
 861     pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
 862                      &s->ivshmem_mmio);
 863
 864     if (!s->not_legacy_32bit) {
 865         attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;
 866     }
 867
 868     if (s->hostmem != NULL) {
 869         IVSHMEM_DPRINTF("using hostmem\n");
 870
 871         s->ivshmem_bar2 = host_memory_backend_get_memory(s->hostmem,
 872                                                          &error_abort);
 873     } else {
 874         assert(s->server_chr);
 875
 876         IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
 877                         s->server_chr->filename);
 878
 879         /* we allocate enough space for 16 peers and grow as needed */
 880         resize_peers(s, 16);
 881
 882         /*
 883          * Receive setup messages from server synchronously.
 884          * Older versions did it asynchronously, but that creates a
 885          * number of entertaining race conditions.
 886          */
 887         ivshmem_recv_setup(s, &err);
 888         if (err) {
 889             error_propagate(errp, err);
 890             return;
 891         }
 892
 893         if (s->master == ON_OFF_AUTO_ON && s->vm_id != 0) {
 894             error_setg(errp,
 895                        "master must connect to the server before any peers");
 896             return;
 897         }
 898
 899         qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive,
 900                               ivshmem_read, NULL, s);
 901
 902         if (ivshmem_setup_interrupts(s) < 0) {
 903             error_setg(errp, "failed to initialize interrupts");
 904             return;
 905         }
 906     }
 907
 908     vmstate_register_ram(s->ivshmem_bar2, DEVICE(s));
 909     pci_register_bar(PCI_DEVICE(s), 2, attr, s->ivshmem_bar2);
 910
 911     if (s->master == ON_OFF_AUTO_AUTO) {
 912         s->master = s->vm_id == 0 ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
 913     }
 914
 915     if (!ivshmem_is_master(s)) {
 916         error_setg(&s->migration_blocker,
 917                    "Migration is disabled when using feature 'peer mode' in device 'ivshmem'");
 918         migrate_add_blocker(s->migration_blocker);
 919     }
 920 }
 921
 922 static void ivshmem_exit(PCIDevice *dev)
 923 {
 924     IVShmemState *s = IVSHMEM_COMMON(dev);
 925     int i;
 926
 927     if (s->migration_blocker) {
 928         migrate_del_blocker(s->migration_blocker);
 929         error_free(s->migration_blocker);
 930     }
 931
 932     if (memory_region_is_mapped(s->ivshmem_bar2)) {
 933         if (!s->hostmem) {
 934             void *addr = memory_region_get_ram_ptr(s->ivshmem_bar2);
 935             int fd;
 936
 937             if (munmap(addr, memory_region_size(s->ivshmem_bar2) == -1)) {
 938                 error_report("Failed to munmap shared memory %s",
 939                              strerror(errno));
 940             }
 941
 942             fd = memory_region_get_fd(s->ivshmem_bar2);
 943             close(fd);
 944         }
 945
 946         vmstate_unregister_ram(s->ivshmem_bar2, DEVICE(dev));
 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 };
1009
1010 static void ivshmem_check_memdev_is_busy(Object *obj, const char *name,
1011                                          Object *val, Error **errp)
1012 {
1013     MemoryRegion *mr;
1014
1015     mr = host_memory_backend_get_memory(MEMORY_BACKEND(val), &error_abort);
1016     if (memory_region_is_mapped(mr)) {
1017         char *path = object_get_canonical_path_component(val);
1018         error_setg(errp, "can't use already busy memdev: %s", path);
1019         g_free(path);
1020     } else {
1021         qdev_prop_allow_set_link_before_realize(obj, name, val, errp);
1022     }
1023 }
1024
1025 static const VMStateDescription ivshmem_plain_vmsd = {
1026     .name = TYPE_IVSHMEM_PLAIN,
1027     .version_id = 0,
1028     .minimum_version_id = 0,
1029     .pre_load = ivshmem_pre_load,
1030     .post_load = ivshmem_post_load,
1031     .fields = (VMStateField[]) {
1032         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1033         VMSTATE_UINT32(intrstatus, IVShmemState),
1034         VMSTATE_UINT32(intrmask, IVShmemState),
1035         VMSTATE_END_OF_LIST()
1036     },
1037 };
1038
1039 static Property ivshmem_plain_properties[] = {
1040     DEFINE_PROP_ON_OFF_AUTO("master", IVShmemState, master, ON_OFF_AUTO_OFF),
1041     DEFINE_PROP_END_OF_LIST(),
1042 };
1043
1044 static void ivshmem_plain_init(Object *obj)
1045 {
1046     IVShmemState *s = IVSHMEM_PLAIN(obj);
1047
1048     object_property_add_link(obj, "memdev", TYPE_MEMORY_BACKEND,
1049                              (Object **)&s->hostmem,
1050                              ivshmem_check_memdev_is_busy,
1051                              OBJ_PROP_LINK_UNREF_ON_RELEASE,
1052                              &error_abort);
1053 }
1054
1055 static void ivshmem_plain_realize(PCIDevice *dev, Error **errp)
1056 {
1057     IVShmemState *s = IVSHMEM_COMMON(dev);
1058
1059     if (!s->hostmem) {
1060         error_setg(errp, "You must specify a 'memdev'");
1061         return;
1062     }
1063
1064     ivshmem_common_realize(dev, errp);
1065 }
1066
1067 static void ivshmem_plain_class_init(ObjectClass *klass, void *data)
1068 {
1069     DeviceClass *dc = DEVICE_CLASS(klass);
1070     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1071
1072     k->realize = ivshmem_plain_realize;
1073     dc->props = ivshmem_plain_properties;
1074     dc->vmsd = &ivshmem_plain_vmsd;
1075 }
1076
1077 static const TypeInfo ivshmem_plain_info = {
1078     .name          = TYPE_IVSHMEM_PLAIN,
1079     .parent        = TYPE_IVSHMEM_COMMON,
1080     .instance_size = sizeof(IVShmemState),
1081     .instance_init = ivshmem_plain_init,
1082     .class_init    = ivshmem_plain_class_init,
1083 };
1084
1085 static const VMStateDescription ivshmem_doorbell_vmsd = {
1086     .name = TYPE_IVSHMEM_DOORBELL,
1087     .version_id = 0,
1088     .minimum_version_id = 0,
1089     .pre_load = ivshmem_pre_load,
1090     .post_load = ivshmem_post_load,
1091     .fields = (VMStateField[]) {
1092         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1093         VMSTATE_MSIX(parent_obj, IVShmemState),
1094         VMSTATE_UINT32(intrstatus, IVShmemState),
1095         VMSTATE_UINT32(intrmask, IVShmemState),
1096         VMSTATE_END_OF_LIST()
1097     },
1098 };
1099
1100 static Property ivshmem_doorbell_properties[] = {
1101     DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
1102     DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
1103     DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD,
1104                     true),
1105     DEFINE_PROP_ON_OFF_AUTO("master", IVShmemState, master, ON_OFF_AUTO_OFF),
1106     DEFINE_PROP_END_OF_LIST(),
1107 };
1108
1109 static void ivshmem_doorbell_init(Object *obj)
1110 {
1111     IVShmemState *s = IVSHMEM_DOORBELL(obj);
1112
1113     s->features |= (1 << IVSHMEM_MSI);
1114     s->legacy_size = SIZE_MAX;  /* whatever the server sends */
1115 }
1116
1117 static void ivshmem_doorbell_realize(PCIDevice *dev, Error **errp)
1118 {
1119     IVShmemState *s = IVSHMEM_COMMON(dev);
1120
1121     if (!s->server_chr) {
1122         error_setg(errp, "You must specify a 'chardev'");
1123         return;
1124     }
1125
1126     ivshmem_common_realize(dev, errp);
1127 }
1128
1129 static void ivshmem_doorbell_class_init(ObjectClass *klass, void *data)
1130 {
1131     DeviceClass *dc = DEVICE_CLASS(klass);
1132     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1133
1134     k->realize = ivshmem_doorbell_realize;
1135     dc->props = ivshmem_doorbell_properties;
1136     dc->vmsd = &ivshmem_doorbell_vmsd;
1137 }
1138
1139 static const TypeInfo ivshmem_doorbell_info = {
1140     .name          = TYPE_IVSHMEM_DOORBELL,
1141     .parent        = TYPE_IVSHMEM_COMMON,
1142     .instance_size = sizeof(IVShmemState),
1143     .instance_init = ivshmem_doorbell_init,
1144     .class_init    = ivshmem_doorbell_class_init,
1145 };
1146
1147 static int ivshmem_load_old(QEMUFile *f, void *opaque, int version_id)
1148 {
1149     IVShmemState *s = opaque;
1150     PCIDevice *pdev = PCI_DEVICE(s);
1151     int ret;
1152
1153     IVSHMEM_DPRINTF("ivshmem_load_old\n");
1154
1155     if (version_id != 0) {
1156         return -EINVAL;
1157     }
1158
1159     ret = ivshmem_pre_load(s);
1160     if (ret) {
1161         return ret;
1162     }
1163
1164     ret = pci_device_load(pdev, f);
1165     if (ret) {
1166         return ret;
1167     }
1168
1169     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
1170         msix_load(pdev, f);
1171         ivshmem_msix_vector_use(s);
1172     } else {
1173         s->intrstatus = qemu_get_be32(f);
1174         s->intrmask = qemu_get_be32(f);
1175     }
1176
1177     return 0;
1178 }
1179
1180 static bool test_msix(void *opaque, int version_id)
1181 {
1182     IVShmemState *s = opaque;
1183
1184     return ivshmem_has_feature(s, IVSHMEM_MSI);
1185 }
1186
1187 static bool test_no_msix(void *opaque, int version_id)
1188 {
1189     return !test_msix(opaque, version_id);
1190 }
1191
1192 static const VMStateDescription ivshmem_vmsd = {
1193     .name = "ivshmem",
1194     .version_id = 1,
1195     .minimum_version_id = 1,
1196     .pre_load = ivshmem_pre_load,
1197     .post_load = ivshmem_post_load,
1198     .fields = (VMStateField[]) {
1199         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1200
1201         VMSTATE_MSIX_TEST(parent_obj, IVShmemState, test_msix),
1202         VMSTATE_UINT32_TEST(intrstatus, IVShmemState, test_no_msix),
1203         VMSTATE_UINT32_TEST(intrmask, IVShmemState, test_no_msix),
1204
1205         VMSTATE_END_OF_LIST()
1206     },
1207     .load_state_old = ivshmem_load_old,
1208     .minimum_version_id_old = 0
1209 };
1210
1211 static Property ivshmem_properties[] = {
1212     DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
1213     DEFINE_PROP_STRING("size", IVShmemState, sizearg),
1214     DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
1215     DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD,
1216                     false),
1217     DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true),
1218     DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
1219     DEFINE_PROP_STRING("role", IVShmemState, role),
1220     DEFINE_PROP_UINT32("use64", IVShmemState, not_legacy_32bit, 1),
1221     DEFINE_PROP_END_OF_LIST(),
1222 };
1223
1224 static void desugar_shm(IVShmemState *s)
1225 {
1226     Object *obj;
1227     char *path;
1228
1229     obj = object_new("memory-backend-file");
1230     path = g_strdup_printf("/dev/shm/%s", s->shmobj);
1231     object_property_set_str(obj, path, "mem-path", &error_abort);
1232     g_free(path);
1233     object_property_set_int(obj, s->legacy_size, "size", &error_abort);
1234     object_property_set_bool(obj, true, "share", &error_abort);
1235     object_property_add_child(OBJECT(s), "internal-shm-backend", obj,
1236                               &error_abort);
1237     user_creatable_complete(obj, &error_abort);
1238     s->hostmem = MEMORY_BACKEND(obj);
1239 }
1240
1241 static void ivshmem_realize(PCIDevice *dev, Error **errp)
1242 {
1243     IVShmemState *s = IVSHMEM_COMMON(dev);
1244
1245     if (!qtest_enabled()) {
1246         error_report("ivshmem is deprecated, please use ivshmem-plain"
1247                      " or ivshmem-doorbell instead");
1248     }
1249
1250     if (!!s->server_chr + !!s->shmobj != 1) {
1251         error_setg(errp, "You must specify either 'shm' or 'chardev'");
1252         return;
1253     }
1254
1255     if (s->sizearg == NULL) {
1256         s->legacy_size = 4 << 20; /* 4 MB default */
1257     } else {
1258         char *end;
1259         int64_t size = qemu_strtosz(s->sizearg, &end);
1260         if (size < 0 || (size_t)size != size || *end != '\0'
1261             || !is_power_of_2(size)) {
1262             error_setg(errp, "Invalid size %s", s->sizearg);
1263             return;
1264         }
1265         s->legacy_size = size;
1266     }
1267
1268     /* check that role is reasonable */
1269     if (s->role) {
1270         if (strncmp(s->role, "peer", 5) == 0) {
1271             s->master = ON_OFF_AUTO_OFF;
1272         } else if (strncmp(s->role, "master", 7) == 0) {
1273             s->master = ON_OFF_AUTO_ON;
1274         } else {
1275             error_setg(errp, "'role' must be 'peer' or 'master'");
1276             return;
1277         }
1278     } else {
1279         s->master = ON_OFF_AUTO_AUTO;
1280     }
1281
1282     if (s->shmobj) {
1283         desugar_shm(s);
1284     }
1285
1286     /*
1287      * Note: we don't use INTx with IVSHMEM_MSI at all, so this is a
1288      * bald-faced lie then.  But it's a backwards compatible lie.
1289      */
1290     pci_config_set_interrupt_pin(dev->config, 1);
1291
1292     ivshmem_common_realize(dev, errp);
1293 }
1294
1295 static void ivshmem_class_init(ObjectClass *klass, void *data)
1296 {
1297     DeviceClass *dc = DEVICE_CLASS(klass);
1298     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1299
1300     k->realize = ivshmem_realize;
1301     k->revision = 0;
1302     dc->desc = "Inter-VM shared memory (legacy)";
1303     dc->props = ivshmem_properties;
1304     dc->vmsd = &ivshmem_vmsd;
1305 }
1306
1307 static const TypeInfo ivshmem_info = {
1308     .name          = TYPE_IVSHMEM,
1309     .parent        = TYPE_IVSHMEM_COMMON,
1310     .instance_size = sizeof(IVShmemState),
1311     .class_init    = ivshmem_class_init,
1312 };
1313
1314 static void ivshmem_register_types(void)
1315 {
1316     type_register_static(&ivshmem_common_info);
1317     type_register_static(&ivshmem_plain_info);
1318     type_register_static(&ivshmem_doorbell_info);
1319     type_register_static(&ivshmem_info);
1320 }
1321
1322 type_init(ivshmem_register_types)