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 "hw/hw.h"
  21 #include "hw/i386/pc.h"
  22 #include "hw/pci/pci.h"
  23 #include "hw/pci/msi.h"
  24 #include "hw/pci/msix.h"
  25 #include "sysemu/kvm.h"
  26 #include "migration/migration.h"
  27 #include "qemu/error-report.h"
  28 #include "qemu/event_notifier.h"
  29 #include "qemu/fifo8.h"
  30 #include "sysemu/char.h"
  31 #include "sysemu/hostmem.h"
  32 #include "qapi/visitor.h"
  33 #include "exec/ram_addr.h"
  34
  35 #include "hw/misc/ivshmem.h"
  36
  37 #include <sys/mman.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 G_MAXUINT16
  43 #define IVSHMEM_IOEVENTFD   0
  44 #define IVSHMEM_MSI     1
  45
  46 #define IVSHMEM_PEER    0
  47 #define IVSHMEM_MASTER  1
  48
  49 #define IVSHMEM_REG_BAR_SIZE 0x100
  50
  51 //#define DEBUG_IVSHMEM
  52 #ifdef DEBUG_IVSHMEM
  53 #define IVSHMEM_DPRINTF(fmt, ...)        \
  54     do {printf("IVSHMEM: " fmt, ## __VA_ARGS__); } while (0)
  55 #else
  56 #define IVSHMEM_DPRINTF(fmt, ...)
  57 #endif
  58
  59 #define TYPE_IVSHMEM "ivshmem"
  60 #define IVSHMEM(obj) \
  61     OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM)
  62
  63 typedef struct Peer {
  64     int nb_eventfds;
  65     EventNotifier *eventfds;
  66 } Peer;
  67
  68 typedef struct MSIVector {
  69     PCIDevice *pdev;
  70     int virq;
  71 } MSIVector;
  72
  73 typedef struct IVShmemState {
  74     /*< private >*/
  75     PCIDevice parent_obj;
  76     /*< public >*/
  77
  78     HostMemoryBackend *hostmem;
  79     uint32_t intrmask;
  80     uint32_t intrstatus;
  81
  82     CharDriverState **eventfd_chr;
  83     CharDriverState *server_chr;
  84     Fifo8 incoming_fifo;
  85     MemoryRegion ivshmem_mmio;
  86
  87     /* We might need to register the BAR before we actually have the memory.
  88      * So prepare a container MemoryRegion for the BAR immediately and
  89      * add a subregion when we have the memory.
  90      */
  91     MemoryRegion bar;
  92     MemoryRegion ivshmem;
  93     uint64_t ivshmem_size; /* size of shared memory region */
  94     uint32_t ivshmem_64bit;
  95
  96     Peer *peers;
  97     int nb_peers; /* how many peers we have space for */
  98
  99     int vm_id;
 100     uint32_t vectors;
 101     uint32_t features;
 102     MSIVector *msi_vectors;
 103
 104     Error *migration_blocker;
 105
 106     char * shmobj;
 107     char * sizearg;
 108     char * role;
 109     int role_val;   /* scalar to avoid multiple string comparisons */
 110 } IVShmemState;
 111
 112 /* registers for the Inter-VM shared memory device */
 113 enum ivshmem_registers {
 114     INTRMASK = 0,
 115     INTRSTATUS = 4,
 116     IVPOSITION = 8,
 117     DOORBELL = 12,
 118 };
 119
 120 static inline uint32_t ivshmem_has_feature(IVShmemState *ivs,
 121                                                     unsigned int feature) {
 122     return (ivs->features & (1 << feature));
 123 }
 124
 125 /* accessing registers - based on rtl8139 */
 126 static void ivshmem_update_irq(IVShmemState *s)
 127 {
 128     PCIDevice *d = PCI_DEVICE(s);
 129     int isr;
 130     isr = (s->intrstatus & s->intrmask) & 0xffffffff;
 131
 132     /* don't print ISR resets */
 133     if (isr) {
 134         IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
 135                         isr ? 1 : 0, s->intrstatus, s->intrmask);
 136     }
 137
 138     pci_set_irq(d, (isr != 0));
 139 }
 140
 141 static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
 142 {
 143     IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
 144
 145     s->intrmask = val;
 146
 147     ivshmem_update_irq(s);
 148 }
 149
 150 static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
 151 {
 152     uint32_t ret = s->intrmask;
 153
 154     IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
 155
 156     return ret;
 157 }
 158
 159 static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
 160 {
 161     IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
 162
 163     s->intrstatus = val;
 164
 165     ivshmem_update_irq(s);
 166 }
 167
 168 static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
 169 {
 170     uint32_t ret = s->intrstatus;
 171
 172     /* reading ISR clears all interrupts */
 173     s->intrstatus = 0;
 174
 175     ivshmem_update_irq(s);
 176
 177     return ret;
 178 }
 179
 180 static void ivshmem_io_write(void *opaque, hwaddr addr,
 181                              uint64_t val, unsigned size)
 182 {
 183     IVShmemState *s = opaque;
 184
 185     uint16_t dest = val >> 16;
 186     uint16_t vector = val & 0xff;
 187
 188     addr &= 0xfc;
 189
 190     IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr);
 191     switch (addr)
 192     {
 193         case INTRMASK:
 194             ivshmem_IntrMask_write(s, val);
 195             break;
 196
 197         case INTRSTATUS:
 198             ivshmem_IntrStatus_write(s, val);
 199             break;
 200
 201         case DOORBELL:
 202             /* check that dest VM ID is reasonable */
 203             if (dest >= s->nb_peers) {
 204                 IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
 205                 break;
 206             }
 207
 208             /* check doorbell range */
 209             if (vector < s->peers[dest].nb_eventfds) {
 210                 IVSHMEM_DPRINTF("Notifying VM %d on vector %d\n", dest, vector);
 211                 event_notifier_set(&s->peers[dest].eventfds[vector]);
 212             } else {
 213                 IVSHMEM_DPRINTF("Invalid destination vector %d on VM %d\n",
 214                                 vector, dest);
 215             }
 216             break;
 217         default:
 218             IVSHMEM_DPRINTF("Unhandled write " TARGET_FMT_plx "\n", addr);
 219     }
 220 }
 221
 222 static uint64_t ivshmem_io_read(void *opaque, hwaddr addr,
 223                                 unsigned size)
 224 {
 225
 226     IVShmemState *s = opaque;
 227     uint32_t ret;
 228
 229     switch (addr)
 230     {
 231         case INTRMASK:
 232             ret = ivshmem_IntrMask_read(s);
 233             break;
 234
 235         case INTRSTATUS:
 236             ret = ivshmem_IntrStatus_read(s);
 237             break;
 238
 239         case IVPOSITION:
 240             /* return my VM ID if the memory is mapped */
 241             if (memory_region_is_mapped(&s->ivshmem)) {
 242                 ret = s->vm_id;
 243             } else {
 244                 ret = -1;
 245             }
 246             break;
 247
 248         default:
 249             IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr);
 250             ret = 0;
 251     }
 252
 253     return ret;
 254 }
 255
 256 static const MemoryRegionOps ivshmem_mmio_ops = {
 257     .read = ivshmem_io_read,
 258     .write = ivshmem_io_write,
 259     .endianness = DEVICE_NATIVE_ENDIAN,
 260     .impl = {
 261         .min_access_size = 4,
 262         .max_access_size = 4,
 263     },
 264 };
 265
 266 static void ivshmem_receive(void *opaque, const uint8_t *buf, int size)
 267 {
 268     IVShmemState *s = opaque;
 269
 270     IVSHMEM_DPRINTF("ivshmem_receive 0x%02x size: %d\n", *buf, size);
 271
 272     ivshmem_IntrStatus_write(s, *buf);
 273 }
 274
 275 static int ivshmem_can_receive(void * opaque)
 276 {
 277     return sizeof(int64_t);
 278 }
 279
 280 static void ivshmem_event(void *opaque, int event)
 281 {
 282     IVSHMEM_DPRINTF("ivshmem_event %d\n", event);
 283 }
 284
 285 static void fake_irqfd(void *opaque, const uint8_t *buf, int size) {
 286
 287     MSIVector *entry = opaque;
 288     PCIDevice *pdev = entry->pdev;
 289     IVShmemState *s = IVSHMEM(pdev);
 290     int vector = entry - s->msi_vectors;
 291
 292     IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, vector);
 293     msix_notify(pdev, vector);
 294 }
 295
 296 static int ivshmem_vector_unmask(PCIDevice *dev, unsigned vector,
 297                                  MSIMessage msg)
 298 {
 299     IVShmemState *s = IVSHMEM(dev);
 300     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 301     MSIVector *v = &s->msi_vectors[vector];
 302     int ret;
 303
 304     IVSHMEM_DPRINTF("vector unmask %p %d\n", dev, vector);
 305
 306     ret = kvm_irqchip_update_msi_route(kvm_state, v->virq, msg, dev);
 307     if (ret < 0) {
 308         return ret;
 309     }
 310
 311     return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq);
 312 }
 313
 314 static void ivshmem_vector_mask(PCIDevice *dev, unsigned vector)
 315 {
 316     IVShmemState *s = IVSHMEM(dev);
 317     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 318     int ret;
 319
 320     IVSHMEM_DPRINTF("vector mask %p %d\n", dev, vector);
 321
 322     ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n,
 323                                                 s->msi_vectors[vector].virq);
 324     if (ret != 0) {
 325         error_report("remove_irqfd_notifier_gsi failed");
 326     }
 327 }
 328
 329 static void ivshmem_vector_poll(PCIDevice *dev,
 330                                 unsigned int vector_start,
 331                                 unsigned int vector_end)
 332 {
 333     IVShmemState *s = IVSHMEM(dev);
 334     unsigned int vector;
 335
 336     IVSHMEM_DPRINTF("vector poll %p %d-%d\n", dev, vector_start, vector_end);
 337
 338     vector_end = MIN(vector_end, s->vectors);
 339
 340     for (vector = vector_start; vector < vector_end; vector++) {
 341         EventNotifier *notifier = &s->peers[s->vm_id].eventfds[vector];
 342
 343         if (!msix_is_masked(dev, vector)) {
 344             continue;
 345         }
 346
 347         if (event_notifier_test_and_clear(notifier)) {
 348             msix_set_pending(dev, vector);
 349         }
 350     }
 351 }
 352
 353 static CharDriverState* create_eventfd_chr_device(void * opaque, EventNotifier *n,
 354                                                   int vector)
 355 {
 356     /* create a event character device based on the passed eventfd */
 357     IVShmemState *s = opaque;
 358     PCIDevice *pdev = PCI_DEVICE(s);
 359     int eventfd = event_notifier_get_fd(n);
 360     CharDriverState *chr;
 361
 362     s->msi_vectors[vector].pdev = pdev;
 363
 364     chr = qemu_chr_open_eventfd(eventfd);
 365
 366     if (chr == NULL) {
 367         error_report("creating chardriver for eventfd %d failed", eventfd);
 368         return NULL;
 369     }
 370     qemu_chr_fe_claim_no_fail(chr);
 371
 372     /* if MSI is supported we need multiple interrupts */
 373     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 374         s->msi_vectors[vector].pdev = PCI_DEVICE(s);
 375
 376         qemu_chr_add_handlers(chr, ivshmem_can_receive, fake_irqfd,
 377                       ivshmem_event, &s->msi_vectors[vector]);
 378     } else {
 379         qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive,
 380                       ivshmem_event, s);
 381     }
 382
 383     return chr;
 384
 385 }
 386
 387 static int check_shm_size(IVShmemState *s, int fd, Error **errp)
 388 {
 389     /* check that the guest isn't going to try and map more memory than the
 390      * the object has allocated return -1 to indicate error */
 391
 392     struct stat buf;
 393
 394     if (fstat(fd, &buf) < 0) {
 395         error_setg(errp, "exiting: fstat on fd %d failed: %s",
 396                    fd, strerror(errno));
 397         return -1;
 398     }
 399
 400     if (s->ivshmem_size > buf.st_size) {
 401         error_setg(errp, "Requested memory size greater"
 402                    " than shared object size (%" PRIu64 " > %" PRIu64")",
 403                    s->ivshmem_size, (uint64_t)buf.st_size);
 404         return -1;
 405     } else {
 406         return 0;
 407     }
 408 }
 409
 410 /* create the shared memory BAR when we are not using the server, so we can
 411  * create the BAR and map the memory immediately */
 412 static int create_shared_memory_BAR(IVShmemState *s, int fd, uint8_t attr,
 413                                     Error **errp)
 414 {
 415     void * ptr;
 416
 417     ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
 418     if (ptr == MAP_FAILED) {
 419         error_setg_errno(errp, errno, "Failed to mmap shared memory");
 420         return -1;
 421     }
 422
 423     memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), "ivshmem.bar2",
 424                                s->ivshmem_size, ptr);
 425     qemu_set_ram_fd(s->ivshmem.ram_addr, fd);
 426     vmstate_register_ram(&s->ivshmem, DEVICE(s));
 427     memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
 428
 429     /* region for shared memory */
 430     pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar);
 431
 432     return 0;
 433 }
 434
 435 static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i)
 436 {
 437     memory_region_add_eventfd(&s->ivshmem_mmio,
 438                               DOORBELL,
 439                               4,
 440                               true,
 441                               (posn << 16) | i,
 442                               &s->peers[posn].eventfds[i]);
 443 }
 444
 445 static void ivshmem_del_eventfd(IVShmemState *s, int posn, int i)
 446 {
 447     memory_region_del_eventfd(&s->ivshmem_mmio,
 448                               DOORBELL,
 449                               4,
 450                               true,
 451                               (posn << 16) | i,
 452                               &s->peers[posn].eventfds[i]);
 453 }
 454
 455 static void close_peer_eventfds(IVShmemState *s, int posn)
 456 {
 457     int i, n;
 458
 459     if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 460         return;
 461     }
 462     if (posn < 0 || posn >= s->nb_peers) {
 463         error_report("invalid peer %d", posn);
 464         return;
 465     }
 466
 467     n = s->peers[posn].nb_eventfds;
 468
 469     memory_region_transaction_begin();
 470     for (i = 0; i < n; i++) {
 471         ivshmem_del_eventfd(s, posn, i);
 472     }
 473     memory_region_transaction_commit();
 474     for (i = 0; i < n; i++) {
 475         event_notifier_cleanup(&s->peers[posn].eventfds[i]);
 476     }
 477
 478     g_free(s->peers[posn].eventfds);
 479     s->peers[posn].nb_eventfds = 0;
 480 }
 481
 482 /* this function increase the dynamic storage need to store data about other
 483  * peers */
 484 static int resize_peers(IVShmemState *s, int new_min_size)
 485 {
 486
 487     int j, old_size;
 488
 489     /* limit number of max peers */
 490     if (new_min_size <= 0 || new_min_size > IVSHMEM_MAX_PEERS) {
 491         return -1;
 492     }
 493     if (new_min_size <= s->nb_peers) {
 494         return 0;
 495     }
 496
 497     old_size = s->nb_peers;
 498     s->nb_peers = new_min_size;
 499
 500     IVSHMEM_DPRINTF("bumping storage to %d peers\n", s->nb_peers);
 501
 502     s->peers = g_realloc(s->peers, s->nb_peers * sizeof(Peer));
 503
 504     for (j = old_size; j < s->nb_peers; j++) {
 505         s->peers[j].eventfds = g_new0(EventNotifier, s->vectors);
 506         s->peers[j].nb_eventfds = 0;
 507     }
 508
 509     return 0;
 510 }
 511
 512 static bool fifo_update_and_get(IVShmemState *s, const uint8_t *buf, int size,
 513                                 void *data, size_t len)
 514 {
 515     const uint8_t *p;
 516     uint32_t num;
 517
 518     assert(len <= sizeof(int64_t)); /* limitation of the fifo */
 519     if (fifo8_is_empty(&s->incoming_fifo) && size == len) {
 520         memcpy(data, buf, size);
 521         return true;
 522     }
 523
 524     IVSHMEM_DPRINTF("short read of %d bytes\n", size);
 525
 526     num = MIN(size, sizeof(int64_t) - fifo8_num_used(&s->incoming_fifo));
 527     fifo8_push_all(&s->incoming_fifo, buf, num);
 528
 529     if (fifo8_num_used(&s->incoming_fifo) < len) {
 530         assert(num == 0);
 531         return false;
 532     }
 533
 534     size -= num;
 535     buf += num;
 536     p = fifo8_pop_buf(&s->incoming_fifo, len, &num);
 537     assert(num == len);
 538
 539     memcpy(data, p, len);
 540
 541     if (size > 0) {
 542         fifo8_push_all(&s->incoming_fifo, buf, size);
 543     }
 544
 545     return true;
 546 }
 547
 548 static bool fifo_update_and_get_i64(IVShmemState *s,
 549                                     const uint8_t *buf, int size, int64_t *i64)
 550 {
 551     if (fifo_update_and_get(s, buf, size, i64, sizeof(*i64))) {
 552         *i64 = GINT64_FROM_LE(*i64);
 553         return true;
 554     }
 555
 556     return false;
 557 }
 558
 559 static int ivshmem_add_kvm_msi_virq(IVShmemState *s, int vector)
 560 {
 561     PCIDevice *pdev = PCI_DEVICE(s);
 562     MSIMessage msg = msix_get_message(pdev, vector);
 563     int ret;
 564
 565     IVSHMEM_DPRINTF("ivshmem_add_kvm_msi_virq vector:%d\n", vector);
 566
 567     if (s->msi_vectors[vector].pdev != NULL) {
 568         return 0;
 569     }
 570
 571     ret = kvm_irqchip_add_msi_route(kvm_state, msg, pdev);
 572     if (ret < 0) {
 573         error_report("ivshmem: kvm_irqchip_add_msi_route failed");
 574         return -1;
 575     }
 576
 577     s->msi_vectors[vector].virq = ret;
 578     s->msi_vectors[vector].pdev = pdev;
 579
 580     return 0;
 581 }
 582
 583 static void setup_interrupt(IVShmemState *s, int vector)
 584 {
 585     EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
 586     bool with_irqfd = kvm_msi_via_irqfd_enabled() &&
 587         ivshmem_has_feature(s, IVSHMEM_MSI);
 588     PCIDevice *pdev = PCI_DEVICE(s);
 589
 590     IVSHMEM_DPRINTF("setting up interrupt for vector: %d\n", vector);
 591
 592     if (!with_irqfd) {
 593         IVSHMEM_DPRINTF("with eventfd");
 594         s->eventfd_chr[vector] = create_eventfd_chr_device(s, n, vector);
 595     } else if (msix_enabled(pdev)) {
 596         IVSHMEM_DPRINTF("with irqfd");
 597         if (ivshmem_add_kvm_msi_virq(s, vector) < 0) {
 598             return;
 599         }
 600
 601         if (!msix_is_masked(pdev, vector)) {
 602             kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL,
 603                                                s->msi_vectors[vector].virq);
 604         }
 605     } else {
 606         /* it will be delayed until msix is enabled, in write_config */
 607         IVSHMEM_DPRINTF("with irqfd, delayed until msix enabled");
 608     }
 609 }
 610
 611 static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
 612 {
 613     IVShmemState *s = opaque;
 614     int incoming_fd;
 615     int new_eventfd;
 616     int64_t incoming_posn;
 617     Error *err = NULL;
 618     Peer *peer;
 619
 620     if (!fifo_update_and_get_i64(s, buf, size, &incoming_posn)) {
 621         return;
 622     }
 623
 624     if (incoming_posn < -1) {
 625         IVSHMEM_DPRINTF("invalid incoming_posn %" PRId64 "\n", incoming_posn);
 626         return;
 627     }
 628
 629     /* pick off s->server_chr->msgfd and store it, posn should accompany msg */
 630     incoming_fd = qemu_chr_fe_get_msgfd(s->server_chr);
 631     IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n",
 632                     incoming_posn, incoming_fd);
 633
 634     /* make sure we have enough space for this peer */
 635     if (incoming_posn >= s->nb_peers) {
 636         if (resize_peers(s, incoming_posn + 1) < 0) {
 637             error_report("failed to resize peers array");
 638             if (incoming_fd != -1) {
 639                 close(incoming_fd);
 640             }
 641             return;
 642         }
 643     }
 644
 645     peer = &s->peers[incoming_posn];
 646
 647     if (incoming_fd == -1) {
 648         /* if posn is positive and unseen before then this is our posn*/
 649         if (incoming_posn >= 0 && s->vm_id == -1) {
 650             /* receive our posn */
 651             s->vm_id = incoming_posn;
 652         } else {
 653             /* otherwise an fd == -1 means an existing peer has gone away */
 654             IVSHMEM_DPRINTF("posn %" PRId64 " has gone away\n", incoming_posn);
 655             close_peer_eventfds(s, incoming_posn);
 656         }
 657         return;
 658     }
 659
 660     /* if the position is -1, then it's shared memory region fd */
 661     if (incoming_posn == -1) {
 662         void * map_ptr;
 663
 664         if (memory_region_is_mapped(&s->ivshmem)) {
 665             error_report("shm already initialized");
 666             close(incoming_fd);
 667             return;
 668         }
 669
 670         if (check_shm_size(s, incoming_fd, &err) == -1) {
 671             error_report_err(err);
 672             close(incoming_fd);
 673             return;
 674         }
 675
 676         /* mmap the region and map into the BAR2 */
 677         map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
 678                                                             incoming_fd, 0);
 679         if (map_ptr == MAP_FAILED) {
 680             error_report("Failed to mmap shared memory %s", strerror(errno));
 681             close(incoming_fd);
 682             return;
 683         }
 684         memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s),
 685                                    "ivshmem.bar2", s->ivshmem_size, map_ptr);
 686         qemu_set_ram_fd(s->ivshmem.ram_addr, incoming_fd);
 687         vmstate_register_ram(&s->ivshmem, DEVICE(s));
 688
 689         IVSHMEM_DPRINTF("guest h/w addr = %p, size = %" PRIu64 "\n",
 690                         map_ptr, s->ivshmem_size);
 691
 692         memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
 693
 694         return;
 695     }
 696
 697     /* each peer has an associated array of eventfds, and we keep
 698      * track of how many eventfds received so far */
 699     /* get a new eventfd: */
 700     if (peer->nb_eventfds >= s->vectors) {
 701         error_report("Too many eventfd received, device has %d vectors",
 702                      s->vectors);
 703         close(incoming_fd);
 704         return;
 705     }
 706
 707     new_eventfd = peer->nb_eventfds++;
 708
 709     /* this is an eventfd for a particular peer VM */
 710     IVSHMEM_DPRINTF("eventfds[%" PRId64 "][%d] = %d\n", incoming_posn,
 711                     new_eventfd, incoming_fd);
 712     event_notifier_init_fd(&peer->eventfds[new_eventfd], incoming_fd);
 713     fcntl_setfl(incoming_fd, O_NONBLOCK); /* msix/irqfd poll non block */
 714
 715     if (incoming_posn == s->vm_id) {
 716         setup_interrupt(s, new_eventfd);
 717     }
 718
 719     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 720         ivshmem_add_eventfd(s, incoming_posn, new_eventfd);
 721     }
 722 }
 723
 724 static void ivshmem_check_version(void *opaque, const uint8_t * buf, int size)
 725 {
 726     IVShmemState *s = opaque;
 727     int tmp;
 728     int64_t version;
 729
 730     if (!fifo_update_and_get_i64(s, buf, size, &version)) {
 731         return;
 732     }
 733
 734     tmp = qemu_chr_fe_get_msgfd(s->server_chr);
 735     if (tmp != -1 || version != IVSHMEM_PROTOCOL_VERSION) {
 736         fprintf(stderr, "incompatible version, you are connecting to a ivshmem-"
 737                 "server using a different protocol please check your setup\n");
 738         qemu_chr_delete(s->server_chr);
 739         s->server_chr = NULL;
 740         return;
 741     }
 742
 743     IVSHMEM_DPRINTF("version check ok, switch to real chardev handler\n");
 744     qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read,
 745                           ivshmem_event, s);
 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_use_msix(IVShmemState * s)
 752 {
 753     PCIDevice *d = PCI_DEVICE(s);
 754     int i;
 755
 756     IVSHMEM_DPRINTF("%s, msix present: %d\n", __func__, msix_present(d));
 757     if (!msix_present(d)) {
 758         return;
 759     }
 760
 761     for (i = 0; i < s->vectors; i++) {
 762         msix_vector_use(d, i);
 763     }
 764 }
 765
 766 static void ivshmem_reset(DeviceState *d)
 767 {
 768     IVShmemState *s = IVSHMEM(d);
 769
 770     s->intrstatus = 0;
 771     s->intrmask = 0;
 772     ivshmem_use_msix(s);
 773 }
 774
 775 static int ivshmem_setup_msi(IVShmemState * s)
 776 {
 777     if (msix_init_exclusive_bar(PCI_DEVICE(s), s->vectors, 1)) {
 778         return -1;
 779     }
 780
 781     IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
 782
 783     /* allocate QEMU char devices for receiving interrupts */
 784     s->msi_vectors = g_malloc0(s->vectors * sizeof(MSIVector));
 785
 786     ivshmem_use_msix(s);
 787     return 0;
 788 }
 789
 790 static void ivshmem_enable_irqfd(IVShmemState *s)
 791 {
 792     PCIDevice *pdev = PCI_DEVICE(s);
 793     int i;
 794
 795     for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
 796         ivshmem_add_kvm_msi_virq(s, i);
 797     }
 798
 799     if (msix_set_vector_notifiers(pdev,
 800                                   ivshmem_vector_unmask,
 801                                   ivshmem_vector_mask,
 802                                   ivshmem_vector_poll)) {
 803         error_report("ivshmem: msix_set_vector_notifiers failed");
 804     }
 805 }
 806
 807 static void ivshmem_remove_kvm_msi_virq(IVShmemState *s, int vector)
 808 {
 809     IVSHMEM_DPRINTF("ivshmem_remove_kvm_msi_virq vector:%d\n", vector);
 810
 811     if (s->msi_vectors[vector].pdev == NULL) {
 812         return;
 813     }
 814
 815     /* it was cleaned when masked in the frontend. */
 816     kvm_irqchip_release_virq(kvm_state, s->msi_vectors[vector].virq);
 817
 818     s->msi_vectors[vector].pdev = NULL;
 819 }
 820
 821 static void ivshmem_disable_irqfd(IVShmemState *s)
 822 {
 823     PCIDevice *pdev = PCI_DEVICE(s);
 824     int i;
 825
 826     for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
 827         ivshmem_remove_kvm_msi_virq(s, i);
 828     }
 829
 830     msix_unset_vector_notifiers(pdev);
 831 }
 832
 833 static void ivshmem_write_config(PCIDevice *pdev, uint32_t address,
 834                                  uint32_t val, int len)
 835 {
 836     IVShmemState *s = IVSHMEM(pdev);
 837     int is_enabled, was_enabled = msix_enabled(pdev);
 838
 839     pci_default_write_config(pdev, address, val, len);
 840     is_enabled = msix_enabled(pdev);
 841
 842     if (kvm_msi_via_irqfd_enabled() && s->vm_id != -1) {
 843         if (!was_enabled && is_enabled) {
 844             ivshmem_enable_irqfd(s);
 845         } else if (was_enabled && !is_enabled) {
 846             ivshmem_disable_irqfd(s);
 847         }
 848     }
 849 }
 850
 851 static void pci_ivshmem_realize(PCIDevice *dev, Error **errp)
 852 {
 853     IVShmemState *s = IVSHMEM(dev);
 854     uint8_t *pci_conf;
 855     uint8_t attr = PCI_BASE_ADDRESS_SPACE_MEMORY |
 856         PCI_BASE_ADDRESS_MEM_PREFETCH;
 857
 858     if (!!s->server_chr + !!s->shmobj + !!s->hostmem != 1) {
 859         error_setg(errp,
 860                    "You must specify either 'shm', 'chardev' or 'x-memdev'");
 861         return;
 862     }
 863
 864     if (s->hostmem) {
 865         MemoryRegion *mr;
 866
 867         if (s->sizearg) {
 868             g_warning("size argument ignored with hostmem");
 869         }
 870
 871         mr = host_memory_backend_get_memory(s->hostmem, errp);
 872         s->ivshmem_size = memory_region_size(mr);
 873     } else if (s->sizearg == NULL) {
 874         s->ivshmem_size = 4 << 20; /* 4 MB default */
 875     } else {
 876         char *end;
 877         int64_t size = qemu_strtosz(s->sizearg, &end);
 878         if (size < 0 || *end != '\0' || !is_power_of_2(size)) {
 879             error_setg(errp, "Invalid size %s", s->sizearg);
 880             return;
 881         }
 882         s->ivshmem_size = size;
 883     }
 884
 885     fifo8_create(&s->incoming_fifo, sizeof(int64_t));
 886
 887     /* IRQFD requires MSI */
 888     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
 889         !ivshmem_has_feature(s, IVSHMEM_MSI)) {
 890         error_setg(errp, "ioeventfd/irqfd requires MSI");
 891         return;
 892     }
 893
 894     /* check that role is reasonable */
 895     if (s->role) {
 896         if (strncmp(s->role, "peer", 5) == 0) {
 897             s->role_val = IVSHMEM_PEER;
 898         } else if (strncmp(s->role, "master", 7) == 0) {
 899             s->role_val = IVSHMEM_MASTER;
 900         } else {
 901             error_setg(errp, "'role' must be 'peer' or 'master'");
 902             return;
 903         }
 904     } else {
 905         s->role_val = IVSHMEM_MASTER; /* default */
 906     }
 907
 908     if (s->role_val == IVSHMEM_PEER) {
 909         error_setg(&s->migration_blocker,
 910                    "Migration is disabled when using feature 'peer mode' in device 'ivshmem'");
 911         migrate_add_blocker(s->migration_blocker);
 912     }
 913
 914     pci_conf = dev->config;
 915     pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
 916
 917     pci_config_set_interrupt_pin(pci_conf, 1);
 918
 919     memory_region_init_io(&s->ivshmem_mmio, OBJECT(s), &ivshmem_mmio_ops, s,
 920                           "ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
 921
 922     /* region for registers*/
 923     pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
 924                      &s->ivshmem_mmio);
 925
 926     memory_region_init(&s->bar, OBJECT(s), "ivshmem-bar2-container", s->ivshmem_size);
 927     if (s->ivshmem_64bit) {
 928         attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;
 929     }
 930
 931     if (s->hostmem != NULL) {
 932         MemoryRegion *mr;
 933
 934         IVSHMEM_DPRINTF("using hostmem\n");
 935
 936         mr = host_memory_backend_get_memory(MEMORY_BACKEND(s->hostmem), errp);
 937         vmstate_register_ram(mr, DEVICE(s));
 938         memory_region_add_subregion(&s->bar, 0, mr);
 939         pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar);
 940     } else if (s->server_chr != NULL) {
 941         /* FIXME do not rely on what chr drivers put into filename */
 942         if (strncmp(s->server_chr->filename, "unix:", 5)) {
 943             error_setg(errp, "chardev is not a unix client socket");
 944             return;
 945         }
 946
 947         /* if we get a UNIX socket as the parameter we will talk
 948          * to the ivshmem server to receive the memory region */
 949
 950         IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
 951                         s->server_chr->filename);
 952
 953         if (ivshmem_has_feature(s, IVSHMEM_MSI) &&
 954             ivshmem_setup_msi(s)) {
 955             error_setg(errp, "msix initialization failed");
 956             return;
 957         }
 958
 959         /* we allocate enough space for 16 peers and grow as needed */
 960         resize_peers(s, 16);
 961         s->vm_id = -1;
 962
 963         pci_register_bar(dev, 2, attr, &s->bar);
 964
 965         s->eventfd_chr = g_malloc0(s->vectors * sizeof(CharDriverState *));
 966
 967         qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive,
 968                               ivshmem_check_version, ivshmem_event, s);
 969     } else {
 970         /* just map the file immediately, we're not using a server */
 971         int fd;
 972
 973         IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);
 974
 975         /* try opening with O_EXCL and if it succeeds zero the memory
 976          * by truncating to 0 */
 977         if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL,
 978                         S_IRWXU|S_IRWXG|S_IRWXO)) > 0) {
 979            /* truncate file to length PCI device's memory */
 980             if (ftruncate(fd, s->ivshmem_size) != 0) {
 981                 error_report("could not truncate shared file");
 982             }
 983
 984         } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR,
 985                         S_IRWXU|S_IRWXG|S_IRWXO)) < 0) {
 986             error_setg(errp, "could not open shared file");
 987             return;
 988         }
 989
 990         if (check_shm_size(s, fd, errp) == -1) {
 991             return;
 992         }
 993
 994         create_shared_memory_BAR(s, fd, attr, errp);
 995     }
 996 }
 997
 998 static void pci_ivshmem_exit(PCIDevice *dev)
 999 {
1000     IVShmemState *s = IVSHMEM(dev);
1001     int i;
1002
1003     fifo8_destroy(&s->incoming_fifo);
1004
1005     if (s->migration_blocker) {
1006         migrate_del_blocker(s->migration_blocker);
1007         error_free(s->migration_blocker);
1008     }
1009
1010     if (memory_region_is_mapped(&s->ivshmem)) {
1011         if (!s->hostmem) {
1012             void *addr = memory_region_get_ram_ptr(&s->ivshmem);
1013             int fd;
1014
1015             if (munmap(addr, s->ivshmem_size) == -1) {
1016                 error_report("Failed to munmap shared memory %s",
1017                              strerror(errno));
1018             }
1019
1020             if ((fd = qemu_get_ram_fd(s->ivshmem.ram_addr)) != -1)
1021                 close(fd);
1022         }
1023
1024         vmstate_unregister_ram(&s->ivshmem, DEVICE(dev));
1025         memory_region_del_subregion(&s->bar, &s->ivshmem);
1026     }
1027
1028     if (s->eventfd_chr) {
1029         for (i = 0; i < s->vectors; i++) {
1030             if (s->eventfd_chr[i]) {
1031                 qemu_chr_free(s->eventfd_chr[i]);
1032             }
1033         }
1034         g_free(s->eventfd_chr);
1035     }
1036
1037     if (s->peers) {
1038         for (i = 0; i < s->nb_peers; i++) {
1039             close_peer_eventfds(s, i);
1040         }
1041         g_free(s->peers);
1042     }
1043
1044     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
1045         msix_uninit_exclusive_bar(dev);
1046     }
1047
1048     g_free(s->msi_vectors);
1049 }
1050
1051 static bool test_msix(void *opaque, int version_id)
1052 {
1053     IVShmemState *s = opaque;
1054
1055     return ivshmem_has_feature(s, IVSHMEM_MSI);
1056 }
1057
1058 static bool test_no_msix(void *opaque, int version_id)
1059 {
1060     return !test_msix(opaque, version_id);
1061 }
1062
1063 static int ivshmem_pre_load(void *opaque)
1064 {
1065     IVShmemState *s = opaque;
1066
1067     if (s->role_val == IVSHMEM_PEER) {
1068         error_report("'peer' devices are not migratable");
1069         return -EINVAL;
1070     }
1071
1072     return 0;
1073 }
1074
1075 static int ivshmem_post_load(void *opaque, int version_id)
1076 {
1077     IVShmemState *s = opaque;
1078
1079     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
1080         ivshmem_use_msix(s);
1081     }
1082
1083     return 0;
1084 }
1085
1086 static int ivshmem_load_old(QEMUFile *f, void *opaque, int version_id)
1087 {
1088     IVShmemState *s = opaque;
1089     PCIDevice *pdev = PCI_DEVICE(s);
1090     int ret;
1091
1092     IVSHMEM_DPRINTF("ivshmem_load_old\n");
1093
1094     if (version_id != 0) {
1095         return -EINVAL;
1096     }
1097
1098     if (s->role_val == IVSHMEM_PEER) {
1099         error_report("'peer' devices are not migratable");
1100         return -EINVAL;
1101     }
1102
1103     ret = pci_device_load(pdev, f);
1104     if (ret) {
1105         return ret;
1106     }
1107
1108     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
1109         msix_load(pdev, f);
1110         ivshmem_use_msix(s);
1111     } else {
1112         s->intrstatus = qemu_get_be32(f);
1113         s->intrmask = qemu_get_be32(f);
1114     }
1115
1116     return 0;
1117 }
1118
1119 static const VMStateDescription ivshmem_vmsd = {
1120     .name = "ivshmem",
1121     .version_id = 1,
1122     .minimum_version_id = 1,
1123     .pre_load = ivshmem_pre_load,
1124     .post_load = ivshmem_post_load,
1125     .fields = (VMStateField[]) {
1126         VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
1127
1128         VMSTATE_MSIX_TEST(parent_obj, IVShmemState, test_msix),
1129         VMSTATE_UINT32_TEST(intrstatus, IVShmemState, test_no_msix),
1130         VMSTATE_UINT32_TEST(intrmask, IVShmemState, test_no_msix),
1131
1132         VMSTATE_END_OF_LIST()
1133     },
1134     .load_state_old = ivshmem_load_old,
1135     .minimum_version_id_old = 0
1136 };
1137
1138 static Property ivshmem_properties[] = {
1139     DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
1140     DEFINE_PROP_STRING("size", IVShmemState, sizearg),
1141     DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
1142     DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD, false),
1143     DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true),
1144     DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
1145     DEFINE_PROP_STRING("role", IVShmemState, role),
1146     DEFINE_PROP_UINT32("use64", IVShmemState, ivshmem_64bit, 1),
1147     DEFINE_PROP_END_OF_LIST(),
1148 };
1149
1150 static void ivshmem_class_init(ObjectClass *klass, void *data)
1151 {
1152     DeviceClass *dc = DEVICE_CLASS(klass);
1153     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
1154
1155     k->realize = pci_ivshmem_realize;
1156     k->exit = pci_ivshmem_exit;
1157     k->config_write = ivshmem_write_config;
1158     k->vendor_id = PCI_VENDOR_ID_IVSHMEM;
1159     k->device_id = PCI_DEVICE_ID_IVSHMEM;
1160     k->class_id = PCI_CLASS_MEMORY_RAM;
1161     dc->reset = ivshmem_reset;
1162     dc->props = ivshmem_properties;
1163     dc->vmsd = &ivshmem_vmsd;
1164     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
1165     dc->desc = "Inter-VM shared memory";
1166 }
1167
1168 static void ivshmem_check_memdev_is_busy(Object *obj, const char *name,
1169                                          Object *val, Error **errp)
1170 {
1171     MemoryRegion *mr;
1172
1173     mr = host_memory_backend_get_memory(MEMORY_BACKEND(val), errp);
1174     if (memory_region_is_mapped(mr)) {
1175         char *path = object_get_canonical_path_component(val);
1176         error_setg(errp, "can't use already busy memdev: %s", path);
1177         g_free(path);
1178     } else {
1179         qdev_prop_allow_set_link_before_realize(obj, name, val, errp);
1180     }
1181 }
1182
1183 static void ivshmem_init(Object *obj)
1184 {
1185     IVShmemState *s = IVSHMEM(obj);
1186
1187     object_property_add_link(obj, "x-memdev", TYPE_MEMORY_BACKEND,
1188                              (Object **)&s->hostmem,
1189                              ivshmem_check_memdev_is_busy,
1190                              OBJ_PROP_LINK_UNREF_ON_RELEASE,
1191                              &error_abort);
1192 }
1193
1194 static const TypeInfo ivshmem_info = {
1195     .name          = TYPE_IVSHMEM,
1196     .parent        = TYPE_PCI_DEVICE,
1197     .instance_size = sizeof(IVShmemState),
1198     .instance_init = ivshmem_init,
1199     .class_init    = ivshmem_class_init,
1200 };
1201
1202 static void ivshmem_register_types(void)
1203 {
1204     type_register_static(&ivshmem_info);
1205 }
1206
1207 type_init(ivshmem_register_types)