hw/pci/msix.c

   1 /*
   2  * MSI-X device support
   3  *
   4  * This module includes support for MSI-X in pci devices.
   5  *
   6  * Author: Michael S. Tsirkin <mst@redhat.com>
   7  *
   8  *  Copyright (c) 2009, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2.  See
  11  * the COPYING file in the top-level directory.
  12  *
  13  * Contributions after 2012-01-13 are licensed under the terms of the
  14  * GNU GPL, version 2 or (at your option) any later version.
  15  */
  16
  17 #include "qemu/osdep.h"
  18 #include "hw/hw.h"
  19 #include "hw/pci/msi.h"
  20 #include "hw/pci/msix.h"
  21 #include "hw/pci/pci.h"
  22 #include "hw/xen/xen.h"
  23 #include "qemu/range.h"
  24 #include "qapi/error.h"
  25 #include "trace.h"
  26
  27 #define MSIX_CAP_LENGTH 12
  28
  29 /* MSI enable bit and maskall bit are in byte 1 in FLAGS register */
  30 #define MSIX_CONTROL_OFFSET (PCI_MSIX_FLAGS + 1)
  31 #define MSIX_ENABLE_MASK (PCI_MSIX_FLAGS_ENABLE >> 8)
  32 #define MSIX_MASKALL_MASK (PCI_MSIX_FLAGS_MASKALL >> 8)
  33
  34 MSIMessage msix_get_message(PCIDevice *dev, unsigned vector)
  35 {
  36     uint8_t *table_entry = dev->msix_table + vector * PCI_MSIX_ENTRY_SIZE;
  37     MSIMessage msg;
  38
  39     msg.address = pci_get_quad(table_entry + PCI_MSIX_ENTRY_LOWER_ADDR);
  40     msg.data = pci_get_long(table_entry + PCI_MSIX_ENTRY_DATA);
  41     return msg;
  42 }
  43
  44 /*
  45  * Special API for POWER to configure the vectors through
  46  * a side channel. Should never be used by devices.
  47  */
  48 void msix_set_message(PCIDevice *dev, int vector, struct MSIMessage msg)
  49 {
  50     uint8_t *table_entry = dev->msix_table + vector * PCI_MSIX_ENTRY_SIZE;
  51
  52     pci_set_quad(table_entry + PCI_MSIX_ENTRY_LOWER_ADDR, msg.address);
  53     pci_set_long(table_entry + PCI_MSIX_ENTRY_DATA, msg.data);
  54     table_entry[PCI_MSIX_ENTRY_VECTOR_CTRL] &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
  55 }
  56
  57 static uint8_t msix_pending_mask(int vector)
  58 {
  59     return 1 << (vector % 8);
  60 }
  61
  62 static uint8_t *msix_pending_byte(PCIDevice *dev, int vector)
  63 {
  64     return dev->msix_pba + vector / 8;
  65 }
  66
  67 static int msix_is_pending(PCIDevice *dev, int vector)
  68 {
  69     return *msix_pending_byte(dev, vector) & msix_pending_mask(vector);
  70 }
  71
  72 void msix_set_pending(PCIDevice *dev, unsigned int vector)
  73 {
  74     *msix_pending_byte(dev, vector) |= msix_pending_mask(vector);
  75 }
  76
  77 void msix_clr_pending(PCIDevice *dev, int vector)
  78 {
  79     *msix_pending_byte(dev, vector) &= ~msix_pending_mask(vector);
  80 }
  81
  82 static bool msix_vector_masked(PCIDevice *dev, unsigned int vector, bool fmask)
  83 {
  84     unsigned offset = vector * PCI_MSIX_ENTRY_SIZE;
  85     uint8_t *data = &dev->msix_table[offset + PCI_MSIX_ENTRY_DATA];
  86     /* MSIs on Xen can be remapped into pirqs. In those cases, masking
  87      * and unmasking go through the PV evtchn path. */
  88     if (xen_enabled() && xen_is_pirq_msi(pci_get_long(data))) {
  89         return false;
  90     }
  91     return fmask || dev->msix_table[offset + PCI_MSIX_ENTRY_VECTOR_CTRL] &
  92         PCI_MSIX_ENTRY_CTRL_MASKBIT;
  93 }
  94
  95 bool msix_is_masked(PCIDevice *dev, unsigned int vector)
  96 {
  97     return msix_vector_masked(dev, vector, dev->msix_function_masked);
  98 }
  99
 100 static void msix_fire_vector_notifier(PCIDevice *dev,
 101                                       unsigned int vector, bool is_masked)
 102 {
 103     MSIMessage msg;
 104     int ret;
 105
 106     if (!dev->msix_vector_use_notifier) {
 107         return;
 108     }
 109     if (is_masked) {
 110         dev->msix_vector_release_notifier(dev, vector);
 111     } else {
 112         msg = msix_get_message(dev, vector);
 113         ret = dev->msix_vector_use_notifier(dev, vector, msg);
 114         assert(ret >= 0);
 115     }
 116 }
 117
 118 static void msix_handle_mask_update(PCIDevice *dev, int vector, bool was_masked)
 119 {
 120     bool is_masked = msix_is_masked(dev, vector);
 121
 122     if (is_masked == was_masked) {
 123         return;
 124     }
 125
 126     msix_fire_vector_notifier(dev, vector, is_masked);
 127
 128     if (!is_masked && msix_is_pending(dev, vector)) {
 129         msix_clr_pending(dev, vector);
 130         msix_notify(dev, vector);
 131     }
 132 }
 133
 134 static bool msix_masked(PCIDevice *dev)
 135 {
 136     return dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] & MSIX_MASKALL_MASK;
 137 }
 138
 139 static void msix_update_function_masked(PCIDevice *dev)
 140 {
 141     dev->msix_function_masked = !msix_enabled(dev) || msix_masked(dev);
 142 }
 143
 144 /* Handle MSI-X capability config write. */
 145 void msix_write_config(PCIDevice *dev, uint32_t addr,
 146                        uint32_t val, int len)
 147 {
 148     unsigned enable_pos = dev->msix_cap + MSIX_CONTROL_OFFSET;
 149     int vector;
 150     bool was_masked;
 151
 152     if (!msix_present(dev) || !range_covers_byte(addr, len, enable_pos)) {
 153         return;
 154     }
 155
 156     trace_msix_write_config(dev->name, msix_enabled(dev), msix_masked(dev));
 157
 158     was_masked = dev->msix_function_masked;
 159     msix_update_function_masked(dev);
 160
 161     if (!msix_enabled(dev)) {
 162         return;
 163     }
 164
 165     pci_device_deassert_intx(dev);
 166
 167     if (dev->msix_function_masked == was_masked) {
 168         return;
 169     }
 170
 171     for (vector = 0; vector < dev->msix_entries_nr; ++vector) {
 172         msix_handle_mask_update(dev, vector,
 173                                 msix_vector_masked(dev, vector, was_masked));
 174     }
 175 }
 176
 177 static uint64_t msix_table_mmio_read(void *opaque, hwaddr addr,
 178                                      unsigned size)
 179 {
 180     PCIDevice *dev = opaque;
 181
 182     return pci_get_long(dev->msix_table + addr);
 183 }
 184
 185 static void msix_table_mmio_write(void *opaque, hwaddr addr,
 186                                   uint64_t val, unsigned size)
 187 {
 188     PCIDevice *dev = opaque;
 189     int vector = addr / PCI_MSIX_ENTRY_SIZE;
 190     bool was_masked;
 191
 192     was_masked = msix_is_masked(dev, vector);
 193     pci_set_long(dev->msix_table + addr, val);
 194     msix_handle_mask_update(dev, vector, was_masked);
 195 }
 196
 197 static const MemoryRegionOps msix_table_mmio_ops = {
 198     .read = msix_table_mmio_read,
 199     .write = msix_table_mmio_write,
 200     .endianness = DEVICE_LITTLE_ENDIAN,
 201     .valid = {
 202         .min_access_size = 4,
 203         .max_access_size = 4,
 204     },
 205 };
 206
 207 static uint64_t msix_pba_mmio_read(void *opaque, hwaddr addr,
 208                                    unsigned size)
 209 {
 210     PCIDevice *dev = opaque;
 211     if (dev->msix_vector_poll_notifier) {
 212         unsigned vector_start = addr * 8;
 213         unsigned vector_end = MIN(addr + size * 8, dev->msix_entries_nr);
 214         dev->msix_vector_poll_notifier(dev, vector_start, vector_end);
 215     }
 216
 217     return pci_get_long(dev->msix_pba + addr);
 218 }
 219
 220 static void msix_pba_mmio_write(void *opaque, hwaddr addr,
 221                                 uint64_t val, unsigned size)
 222 {
 223 }
 224
 225 static const MemoryRegionOps msix_pba_mmio_ops = {
 226     .read = msix_pba_mmio_read,
 227     .write = msix_pba_mmio_write,
 228     .endianness = DEVICE_LITTLE_ENDIAN,
 229     .valid = {
 230         .min_access_size = 4,
 231         .max_access_size = 4,
 232     },
 233 };
 234
 235 static void msix_mask_all(struct PCIDevice *dev, unsigned nentries)
 236 {
 237     int vector;
 238
 239     for (vector = 0; vector < nentries; ++vector) {
 240         unsigned offset =
 241             vector * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL;
 242         bool was_masked = msix_is_masked(dev, vector);
 243
 244         dev->msix_table[offset] |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
 245         msix_handle_mask_update(dev, vector, was_masked);
 246     }
 247 }
 248
 249 /*
 250  * Make PCI device @dev MSI-X capable
 251  * @nentries is the max number of MSI-X vectors that the device support.
 252  * @table_bar is the MemoryRegion that MSI-X table structure resides.
 253  * @table_bar_nr is number of base address register corresponding to @table_bar.
 254  * @table_offset indicates the offset that the MSI-X table structure starts with
 255  * in @table_bar.
 256  * @pba_bar is the MemoryRegion that the Pending Bit Array structure resides.
 257  * @pba_bar_nr is number of base address register corresponding to @pba_bar.
 258  * @pba_offset indicates the offset that the Pending Bit Array structure
 259  * starts with in @pba_bar.
 260  * Non-zero @cap_pos puts capability MSI-X at that offset in PCI config space.
 261  * @errp is for returning errors.
 262  *
 263  * Return 0 on success; set @errp and return -errno on error:
 264  * -ENOTSUP means lacking msi support for a msi-capable platform.
 265  * -EINVAL means capability overlap, happens when @cap_pos is non-zero,
 266  * also means a programming error, except device assignment, which can check
 267  * if a real HW is broken.
 268  */
 269 int msix_init(struct PCIDevice *dev, unsigned short nentries,
 270               MemoryRegion *table_bar, uint8_t table_bar_nr,
 271               unsigned table_offset, MemoryRegion *pba_bar,
 272               uint8_t pba_bar_nr, unsigned pba_offset, uint8_t cap_pos,
 273               Error **errp)
 274 {
 275     int cap;
 276     unsigned table_size, pba_size;
 277     uint8_t *config;
 278
 279     /* Nothing to do if MSI is not supported by interrupt controller */
 280     if (!msi_nonbroken) {
 281         error_setg(errp, "MSI-X is not supported by interrupt controller");
 282         return -ENOTSUP;
 283     }
 284
 285     if (nentries < 1 || nentries > PCI_MSIX_FLAGS_QSIZE + 1) {
 286         error_setg(errp, "The number of MSI-X vectors is invalid");
 287         return -EINVAL;
 288     }
 289
 290     table_size = nentries * PCI_MSIX_ENTRY_SIZE;
 291     pba_size = QEMU_ALIGN_UP(nentries, 64) / 8;
 292
 293     /* Sanity test: table & pba don't overlap, fit within BARs, min aligned */
 294     if ((table_bar_nr == pba_bar_nr &&
 295          ranges_overlap(table_offset, table_size, pba_offset, pba_size)) ||
 296         table_offset + table_size > memory_region_size(table_bar) ||
 297         pba_offset + pba_size > memory_region_size(pba_bar) ||
 298         (table_offset | pba_offset) & PCI_MSIX_FLAGS_BIRMASK) {
 299         error_setg(errp, "table & pba overlap, or they don't fit in BARs,"
 300                    " or don't align");
 301         return -EINVAL;
 302     }
 303
 304     cap = pci_add_capability(dev, PCI_CAP_ID_MSIX,
 305                               cap_pos, MSIX_CAP_LENGTH, errp);
 306     if (cap < 0) {
 307         return cap;
 308     }
 309
 310     dev->msix_cap = cap;
 311     dev->cap_present |= QEMU_PCI_CAP_MSIX;
 312     config = dev->config + cap;
 313
 314     pci_set_word(config + PCI_MSIX_FLAGS, nentries - 1);
 315     dev->msix_entries_nr = nentries;
 316     dev->msix_function_masked = true;
 317
 318     pci_set_long(config + PCI_MSIX_TABLE, table_offset | table_bar_nr);
 319     pci_set_long(config + PCI_MSIX_PBA, pba_offset | pba_bar_nr);
 320
 321     /* Make flags bit writable. */
 322     dev->wmask[cap + MSIX_CONTROL_OFFSET] |= MSIX_ENABLE_MASK |
 323                                              MSIX_MASKALL_MASK;
 324
 325     dev->msix_table = g_malloc0(table_size);
 326     dev->msix_pba = g_malloc0(pba_size);
 327     dev->msix_entry_used = g_malloc0(nentries * sizeof *dev->msix_entry_used);
 328
 329     msix_mask_all(dev, nentries);
 330
 331     memory_region_init_io(&dev->msix_table_mmio, OBJECT(dev), &msix_table_mmio_ops, dev,
 332                           "msix-table", table_size);
 333     memory_region_add_subregion(table_bar, table_offset, &dev->msix_table_mmio);
 334     memory_region_init_io(&dev->msix_pba_mmio, OBJECT(dev), &msix_pba_mmio_ops, dev,
 335                           "msix-pba", pba_size);
 336     memory_region_add_subregion(pba_bar, pba_offset, &dev->msix_pba_mmio);
 337
 338     return 0;
 339 }
 340
 341 int msix_init_exclusive_bar(PCIDevice *dev, unsigned short nentries,
 342                             uint8_t bar_nr, Error **errp)
 343 {
 344     int ret;
 345     char *name;
 346     uint32_t bar_size = 4096;
 347     uint32_t bar_pba_offset = bar_size / 2;
 348     uint32_t bar_pba_size = (nentries / 8 + 1) * 8;
 349
 350     /*
 351      * Migration compatibility dictates that this remains a 4k
 352      * BAR with the vector table in the lower half and PBA in
 353      * the upper half for nentries which is lower or equal to 128.
 354      * No need to care about using more than 65 entries for legacy
 355      * machine types who has at most 64 queues.
 356      */
 357     if (nentries * PCI_MSIX_ENTRY_SIZE > bar_pba_offset) {
 358         bar_pba_offset = nentries * PCI_MSIX_ENTRY_SIZE;
 359     }
 360
 361     if (bar_pba_offset + bar_pba_size > 4096) {
 362         bar_size = bar_pba_offset + bar_pba_size;
 363     }
 364
 365     bar_size = pow2ceil(bar_size);
 366
 367     name = g_strdup_printf("%s-msix", dev->name);
 368     memory_region_init(&dev->msix_exclusive_bar, OBJECT(dev), name, bar_size);
 369     g_free(name);
 370
 371     ret = msix_init(dev, nentries, &dev->msix_exclusive_bar, bar_nr,
 372                     0, &dev->msix_exclusive_bar,
 373                     bar_nr, bar_pba_offset,
 374                     0, errp);
 375     if (ret) {
 376         return ret;
 377     }
 378
 379     pci_register_bar(dev, bar_nr, PCI_BASE_ADDRESS_SPACE_MEMORY,
 380                      &dev->msix_exclusive_bar);
 381
 382     return 0;
 383 }
 384
 385 static void msix_free_irq_entries(PCIDevice *dev)
 386 {
 387     int vector;
 388
 389     for (vector = 0; vector < dev->msix_entries_nr; ++vector) {
 390         dev->msix_entry_used[vector] = 0;
 391         msix_clr_pending(dev, vector);
 392     }
 393 }
 394
 395 static void msix_clear_all_vectors(PCIDevice *dev)
 396 {
 397     int vector;
 398
 399     for (vector = 0; vector < dev->msix_entries_nr; ++vector) {
 400         msix_clr_pending(dev, vector);
 401     }
 402 }
 403
 404 /* Clean up resources for the device. */
 405 void msix_uninit(PCIDevice *dev, MemoryRegion *table_bar, MemoryRegion *pba_bar)
 406 {
 407     if (!msix_present(dev)) {
 408         return;
 409     }
 410     pci_del_capability(dev, PCI_CAP_ID_MSIX, MSIX_CAP_LENGTH);
 411     dev->msix_cap = 0;
 412     msix_free_irq_entries(dev);
 413     dev->msix_entries_nr = 0;
 414     memory_region_del_subregion(pba_bar, &dev->msix_pba_mmio);
 415     g_free(dev->msix_pba);
 416     dev->msix_pba = NULL;
 417     memory_region_del_subregion(table_bar, &dev->msix_table_mmio);
 418     g_free(dev->msix_table);
 419     dev->msix_table = NULL;
 420     g_free(dev->msix_entry_used);
 421     dev->msix_entry_used = NULL;
 422     dev->cap_present &= ~QEMU_PCI_CAP_MSIX;
 423 }
 424
 425 void msix_uninit_exclusive_bar(PCIDevice *dev)
 426 {
 427     if (msix_present(dev)) {
 428         msix_uninit(dev, &dev->msix_exclusive_bar, &dev->msix_exclusive_bar);
 429     }
 430 }
 431
 432 void msix_save(PCIDevice *dev, QEMUFile *f)
 433 {
 434     unsigned n = dev->msix_entries_nr;
 435
 436     if (!msix_present(dev)) {
 437         return;
 438     }
 439
 440     qemu_put_buffer(f, dev->msix_table, n * PCI_MSIX_ENTRY_SIZE);
 441     qemu_put_buffer(f, dev->msix_pba, DIV_ROUND_UP(n, 8));
 442 }
 443
 444 /* Should be called after restoring the config space. */
 445 void msix_load(PCIDevice *dev, QEMUFile *f)
 446 {
 447     unsigned n = dev->msix_entries_nr;
 448     unsigned int vector;
 449
 450     if (!msix_present(dev)) {
 451         return;
 452     }
 453
 454     msix_clear_all_vectors(dev);
 455     qemu_get_buffer(f, dev->msix_table, n * PCI_MSIX_ENTRY_SIZE);
 456     qemu_get_buffer(f, dev->msix_pba, DIV_ROUND_UP(n, 8));
 457     msix_update_function_masked(dev);
 458
 459     for (vector = 0; vector < n; vector++) {
 460         msix_handle_mask_update(dev, vector, true);
 461     }
 462 }
 463
 464 /* Does device support MSI-X? */
 465 int msix_present(PCIDevice *dev)
 466 {
 467     return dev->cap_present & QEMU_PCI_CAP_MSIX;
 468 }
 469
 470 /* Is MSI-X enabled? */
 471 int msix_enabled(PCIDevice *dev)
 472 {
 473     return (dev->cap_present & QEMU_PCI_CAP_MSIX) &&
 474         (dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &
 475          MSIX_ENABLE_MASK);
 476 }
 477
 478 /* Send an MSI-X message */
 479 void msix_notify(PCIDevice *dev, unsigned vector)
 480 {
 481     MSIMessage msg;
 482
 483     if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector]) {
 484         return;
 485     }
 486
 487     if (msix_is_masked(dev, vector)) {
 488         msix_set_pending(dev, vector);
 489         return;
 490     }
 491
 492     msg = msix_get_message(dev, vector);
 493
 494     msi_send_message(dev, msg);
 495 }
 496
 497 void msix_reset(PCIDevice *dev)
 498 {
 499     if (!msix_present(dev)) {
 500         return;
 501     }
 502     msix_clear_all_vectors(dev);
 503     dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &=
 504             ~dev->wmask[dev->msix_cap + MSIX_CONTROL_OFFSET];
 505     memset(dev->msix_table, 0, dev->msix_entries_nr * PCI_MSIX_ENTRY_SIZE);
 506     memset(dev->msix_pba, 0, QEMU_ALIGN_UP(dev->msix_entries_nr, 64) / 8);
 507     msix_mask_all(dev, dev->msix_entries_nr);
 508 }
 509
 510 /* PCI spec suggests that devices make it possible for software to configure
 511  * less vectors than supported by the device, but does not specify a standard
 512  * mechanism for devices to do so.
 513  *
 514  * We support this by asking devices to declare vectors software is going to
 515  * actually use, and checking this on the notification path. Devices that
 516  * don't want to follow the spec suggestion can declare all vectors as used. */
 517
 518 /* Mark vector as used. */
 519 int msix_vector_use(PCIDevice *dev, unsigned vector)
 520 {
 521     if (vector >= dev->msix_entries_nr) {
 522         return -EINVAL;
 523     }
 524
 525     dev->msix_entry_used[vector]++;
 526     return 0;
 527 }
 528
 529 /* Mark vector as unused. */
 530 void msix_vector_unuse(PCIDevice *dev, unsigned vector)
 531 {
 532     if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector]) {
 533         return;
 534     }
 535     if (--dev->msix_entry_used[vector]) {
 536         return;
 537     }
 538     msix_clr_pending(dev, vector);
 539 }
 540
 541 void msix_unuse_all_vectors(PCIDevice *dev)
 542 {
 543     if (!msix_present(dev)) {
 544         return;
 545     }
 546     msix_free_irq_entries(dev);
 547 }
 548
 549 unsigned int msix_nr_vectors_allocated(const PCIDevice *dev)
 550 {
 551     return dev->msix_entries_nr;
 552 }
 553
 554 static int msix_set_notifier_for_vector(PCIDevice *dev, unsigned int vector)
 555 {
 556     MSIMessage msg;
 557
 558     if (msix_is_masked(dev, vector)) {
 559         return 0;
 560     }
 561     msg = msix_get_message(dev, vector);
 562     return dev->msix_vector_use_notifier(dev, vector, msg);
 563 }
 564
 565 static void msix_unset_notifier_for_vector(PCIDevice *dev, unsigned int vector)
 566 {
 567     if (msix_is_masked(dev, vector)) {
 568         return;
 569     }
 570     dev->msix_vector_release_notifier(dev, vector);
 571 }
 572
 573 int msix_set_vector_notifiers(PCIDevice *dev,
 574                               MSIVectorUseNotifier use_notifier,
 575                               MSIVectorReleaseNotifier release_notifier,
 576                               MSIVectorPollNotifier poll_notifier)
 577 {
 578     int vector, ret;
 579
 580     assert(use_notifier && release_notifier);
 581
 582     dev->msix_vector_use_notifier = use_notifier;
 583     dev->msix_vector_release_notifier = release_notifier;
 584     dev->msix_vector_poll_notifier = poll_notifier;
 585
 586     if ((dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &
 587         (MSIX_ENABLE_MASK | MSIX_MASKALL_MASK)) == MSIX_ENABLE_MASK) {
 588         for (vector = 0; vector < dev->msix_entries_nr; vector++) {
 589             ret = msix_set_notifier_for_vector(dev, vector);
 590             if (ret < 0) {
 591                 goto undo;
 592             }
 593         }
 594     }
 595     if (dev->msix_vector_poll_notifier) {
 596         dev->msix_vector_poll_notifier(dev, 0, dev->msix_entries_nr);
 597     }
 598     return 0;
 599
 600 undo:
 601     while (--vector >= 0) {
 602         msix_unset_notifier_for_vector(dev, vector);
 603     }
 604     dev->msix_vector_use_notifier = NULL;
 605     dev->msix_vector_release_notifier = NULL;
 606     return ret;
 607 }
 608
 609 void msix_unset_vector_notifiers(PCIDevice *dev)
 610 {
 611     int vector;
 612
 613     assert(dev->msix_vector_use_notifier &&
 614            dev->msix_vector_release_notifier);
 615
 616     if ((dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &
 617         (MSIX_ENABLE_MASK | MSIX_MASKALL_MASK)) == MSIX_ENABLE_MASK) {
 618         for (vector = 0; vector < dev->msix_entries_nr; vector++) {
 619             msix_unset_notifier_for_vector(dev, vector);
 620         }
 621     }
 622     dev->msix_vector_use_notifier = NULL;
 623     dev->msix_vector_release_notifier = NULL;
 624     dev->msix_vector_poll_notifier = NULL;
 625 }
 626
 627 static int put_msix_state(QEMUFile *f, void *pv, size_t size,
 628                           const VMStateField *field, QJSON *vmdesc)
 629 {
 630     msix_save(pv, f);
 631
 632     return 0;
 633 }
 634
 635 static int get_msix_state(QEMUFile *f, void *pv, size_t size,
 636                           const VMStateField *field)
 637 {
 638     msix_load(pv, f);
 639     return 0;
 640 }
 641
 642 static VMStateInfo vmstate_info_msix = {
 643     .name = "msix state",
 644     .get  = get_msix_state,
 645     .put  = put_msix_state,
 646 };
 647
 648 const VMStateDescription vmstate_msix = {
 649     .name = "msix",
 650     .fields = (VMStateField[]) {
 651         {
 652             .name         = "msix",
 653             .version_id   = 0,
 654             .field_exists = NULL,
 655             .size         = 0,   /* ouch */
 656             .info         = &vmstate_info_msix,
 657             .flags        = VMS_SINGLE,
 658             .offset       = 0,
 659         },
 660         VMSTATE_END_OF_LIST()
 661     }
 662 };