hw/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 #include "hw.h"
  17 #include "pc.h"
  18 #include "pci.h"
  19 #include "msix.h"
  20 #include "kvm.h"
  21
  22 #include <sys/mman.h>
  23 #include <sys/types.h>
  24
  25 #define IVSHMEM_IOEVENTFD   0
  26 #define IVSHMEM_MSI     1
  27
  28 #define IVSHMEM_PEER    0
  29 #define IVSHMEM_MASTER  1
  30
  31 #define IVSHMEM_REG_BAR_SIZE 0x100
  32
  33 //#define DEBUG_IVSHMEM
  34 #ifdef DEBUG_IVSHMEM
  35 #define IVSHMEM_DPRINTF(fmt, ...)        \
  36     do {printf("IVSHMEM: " fmt, ## __VA_ARGS__); } while (0)
  37 #else
  38 #define IVSHMEM_DPRINTF(fmt, ...)
  39 #endif
  40
  41 typedef struct Peer {
  42     int nb_eventfds;
  43     int *eventfds;
  44 } Peer;
  45
  46 typedef struct EventfdEntry {
  47     PCIDevice *pdev;
  48     int vector;
  49 } EventfdEntry;
  50
  51 typedef struct IVShmemState {
  52     PCIDevice dev;
  53     uint32_t intrmask;
  54     uint32_t intrstatus;
  55     uint32_t doorbell;
  56
  57     CharDriverState **eventfd_chr;
  58     CharDriverState *server_chr;
  59     MemoryRegion ivshmem_mmio;
  60
  61     pcibus_t mmio_addr;
  62     /* We might need to register the BAR before we actually have the memory.
  63      * So prepare a container MemoryRegion for the BAR immediately and
  64      * add a subregion when we have the memory.
  65      */
  66     MemoryRegion bar;
  67     MemoryRegion ivshmem;
  68     MemoryRegion msix_bar;
  69     uint64_t ivshmem_size; /* size of shared memory region */
  70     int shm_fd; /* shared memory file descriptor */
  71
  72     Peer *peers;
  73     int nb_peers; /* how many guests we have space for */
  74     int max_peer; /* maximum numbered peer */
  75
  76     int vm_id;
  77     uint32_t vectors;
  78     uint32_t features;
  79     EventfdEntry *eventfd_table;
  80
  81     char * shmobj;
  82     char * sizearg;
  83     char * role;
  84     int role_val;   /* scalar to avoid multiple string comparisons */
  85 } IVShmemState;
  86
  87 /* registers for the Inter-VM shared memory device */
  88 enum ivshmem_registers {
  89     INTRMASK = 0,
  90     INTRSTATUS = 4,
  91     IVPOSITION = 8,
  92     DOORBELL = 12,
  93 };
  94
  95 static inline uint32_t ivshmem_has_feature(IVShmemState *ivs,
  96                                                     unsigned int feature) {
  97     return (ivs->features & (1 << feature));
  98 }
  99
 100 static inline bool is_power_of_two(uint64_t x) {
 101     return (x & (x - 1)) == 0;
 102 }
 103
 104 /* accessing registers - based on rtl8139 */
 105 static void ivshmem_update_irq(IVShmemState *s, int val)
 106 {
 107     int isr;
 108     isr = (s->intrstatus & s->intrmask) & 0xffffffff;
 109
 110     /* don't print ISR resets */
 111     if (isr) {
 112         IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
 113            isr ? 1 : 0, s->intrstatus, s->intrmask);
 114     }
 115
 116     qemu_set_irq(s->dev.irq[0], (isr != 0));
 117 }
 118
 119 static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
 120 {
 121     IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
 122
 123     s->intrmask = val;
 124
 125     ivshmem_update_irq(s, val);
 126 }
 127
 128 static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
 129 {
 130     uint32_t ret = s->intrmask;
 131
 132     IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
 133
 134     return ret;
 135 }
 136
 137 static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
 138 {
 139     IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
 140
 141     s->intrstatus = val;
 142
 143     ivshmem_update_irq(s, val);
 144     return;
 145 }
 146
 147 static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
 148 {
 149     uint32_t ret = s->intrstatus;
 150
 151     /* reading ISR clears all interrupts */
 152     s->intrstatus = 0;
 153
 154     ivshmem_update_irq(s, 0);
 155
 156     return ret;
 157 }
 158
 159 static void ivshmem_io_write(void *opaque, target_phys_addr_t addr,
 160                              uint64_t val, unsigned size)
 161 {
 162     IVShmemState *s = opaque;
 163
 164     uint64_t write_one = 1;
 165     uint16_t dest = val >> 16;
 166     uint16_t vector = val & 0xff;
 167
 168     addr &= 0xfc;
 169
 170     IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr);
 171     switch (addr)
 172     {
 173         case INTRMASK:
 174             ivshmem_IntrMask_write(s, val);
 175             break;
 176
 177         case INTRSTATUS:
 178             ivshmem_IntrStatus_write(s, val);
 179             break;
 180
 181         case DOORBELL:
 182             /* check that dest VM ID is reasonable */
 183             if (dest > s->max_peer) {
 184                 IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
 185                 break;
 186             }
 187
 188             /* check doorbell range */
 189             if (vector < s->peers[dest].nb_eventfds) {
 190                 IVSHMEM_DPRINTF("Writing %" PRId64 " to VM %d on vector %d\n",
 191                                                     write_one, dest, vector);
 192                 if (write(s->peers[dest].eventfds[vector],
 193                                                     &(write_one), 8) != 8) {
 194                     IVSHMEM_DPRINTF("error writing to eventfd\n");
 195                 }
 196             }
 197             break;
 198         default:
 199             IVSHMEM_DPRINTF("Invalid VM Doorbell VM %d\n", dest);
 200     }
 201 }
 202
 203 static uint64_t ivshmem_io_read(void *opaque, target_phys_addr_t addr,
 204                                 unsigned size)
 205 {
 206
 207     IVShmemState *s = opaque;
 208     uint32_t ret;
 209
 210     switch (addr)
 211     {
 212         case INTRMASK:
 213             ret = ivshmem_IntrMask_read(s);
 214             break;
 215
 216         case INTRSTATUS:
 217             ret = ivshmem_IntrStatus_read(s);
 218             break;
 219
 220         case IVPOSITION:
 221             /* return my VM ID if the memory is mapped */
 222             if (s->shm_fd > 0) {
 223                 ret = s->vm_id;
 224             } else {
 225                 ret = -1;
 226             }
 227             break;
 228
 229         default:
 230             IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr);
 231             ret = 0;
 232     }
 233
 234     return ret;
 235 }
 236
 237 static const MemoryRegionOps ivshmem_mmio_ops = {
 238     .read = ivshmem_io_read,
 239     .write = ivshmem_io_write,
 240     .endianness = DEVICE_NATIVE_ENDIAN,
 241     .impl = {
 242         .min_access_size = 4,
 243         .max_access_size = 4,
 244     },
 245 };
 246
 247 static void ivshmem_receive(void *opaque, const uint8_t *buf, int size)
 248 {
 249     IVShmemState *s = opaque;
 250
 251     ivshmem_IntrStatus_write(s, *buf);
 252
 253     IVSHMEM_DPRINTF("ivshmem_receive 0x%02x\n", *buf);
 254 }
 255
 256 static int ivshmem_can_receive(void * opaque)
 257 {
 258     return 8;
 259 }
 260
 261 static void ivshmem_event(void *opaque, int event)
 262 {
 263     IVSHMEM_DPRINTF("ivshmem_event %d\n", event);
 264 }
 265
 266 static void fake_irqfd(void *opaque, const uint8_t *buf, int size) {
 267
 268     EventfdEntry *entry = opaque;
 269     PCIDevice *pdev = entry->pdev;
 270
 271     IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, entry->vector);
 272     msix_notify(pdev, entry->vector);
 273 }
 274
 275 static CharDriverState* create_eventfd_chr_device(void * opaque, int eventfd,
 276                                                                     int vector)
 277 {
 278     /* create a event character device based on the passed eventfd */
 279     IVShmemState *s = opaque;
 280     CharDriverState * chr;
 281
 282     chr = qemu_chr_open_eventfd(eventfd);
 283
 284     if (chr == NULL) {
 285         fprintf(stderr, "creating eventfd for eventfd %d failed\n", eventfd);
 286         exit(-1);
 287     }
 288
 289     /* if MSI is supported we need multiple interrupts */
 290     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 291         s->eventfd_table[vector].pdev = &s->dev;
 292         s->eventfd_table[vector].vector = vector;
 293
 294         qemu_chr_add_handlers(chr, ivshmem_can_receive, fake_irqfd,
 295                       ivshmem_event, &s->eventfd_table[vector]);
 296     } else {
 297         qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive,
 298                       ivshmem_event, s);
 299     }
 300
 301     return chr;
 302
 303 }
 304
 305 static int check_shm_size(IVShmemState *s, int fd) {
 306     /* check that the guest isn't going to try and map more memory than the
 307      * the object has allocated return -1 to indicate error */
 308
 309     struct stat buf;
 310
 311     fstat(fd, &buf);
 312
 313     if (s->ivshmem_size > buf.st_size) {
 314         fprintf(stderr,
 315                 "IVSHMEM ERROR: Requested memory size greater"
 316                 " than shared object size (%" PRIu64 " > %" PRIu64")\n",
 317                 s->ivshmem_size, (uint64_t)buf.st_size);
 318         return -1;
 319     } else {
 320         return 0;
 321     }
 322 }
 323
 324 /* create the shared memory BAR when we are not using the server, so we can
 325  * create the BAR and map the memory immediately */
 326 static void create_shared_memory_BAR(IVShmemState *s, int fd) {
 327
 328     void * ptr;
 329
 330     s->shm_fd = fd;
 331
 332     ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
 333
 334     memory_region_init_ram_ptr(&s->ivshmem, &s->dev.qdev, "ivshmem.bar2",
 335                                s->ivshmem_size, ptr);
 336     memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
 337
 338     /* region for shared memory */
 339     pci_register_bar_region(&s->dev, 2, PCI_BASE_ADDRESS_SPACE_MEMORY, &s->bar);
 340 }
 341
 342 static void close_guest_eventfds(IVShmemState *s, int posn)
 343 {
 344     int i, guest_curr_max;
 345
 346     guest_curr_max = s->peers[posn].nb_eventfds;
 347
 348     for (i = 0; i < guest_curr_max; i++) {
 349         kvm_set_ioeventfd_mmio_long(s->peers[posn].eventfds[i],
 350                     s->mmio_addr + DOORBELL, (posn << 16) | i, 0);
 351         close(s->peers[posn].eventfds[i]);
 352     }
 353
 354     qemu_free(s->peers[posn].eventfds);
 355     s->peers[posn].nb_eventfds = 0;
 356 }
 357
 358 static void setup_ioeventfds(IVShmemState *s) {
 359
 360     int i, j;
 361
 362     for (i = 0; i <= s->max_peer; i++) {
 363         for (j = 0; j < s->peers[i].nb_eventfds; j++) {
 364             memory_region_add_eventfd(&s->ivshmem_mmio,
 365                                       DOORBELL,
 366                                       4,
 367                                       true,
 368                                       (i << 16) | j,
 369                                       s->peers[i].eventfds[j]);
 370         }
 371     }
 372 }
 373
 374 /* this function increase the dynamic storage need to store data about other
 375  * guests */
 376 static void increase_dynamic_storage(IVShmemState *s, int new_min_size) {
 377
 378     int j, old_nb_alloc;
 379
 380     old_nb_alloc = s->nb_peers;
 381
 382     while (new_min_size >= s->nb_peers)
 383         s->nb_peers = s->nb_peers * 2;
 384
 385     IVSHMEM_DPRINTF("bumping storage to %d guests\n", s->nb_peers);
 386     s->peers = qemu_realloc(s->peers, s->nb_peers * sizeof(Peer));
 387
 388     /* zero out new pointers */
 389     for (j = old_nb_alloc; j < s->nb_peers; j++) {
 390         s->peers[j].eventfds = NULL;
 391         s->peers[j].nb_eventfds = 0;
 392     }
 393 }
 394
 395 static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
 396 {
 397     IVShmemState *s = opaque;
 398     int incoming_fd, tmp_fd;
 399     int guest_max_eventfd;
 400     long incoming_posn;
 401
 402     memcpy(&incoming_posn, buf, sizeof(long));
 403     /* pick off s->server_chr->msgfd and store it, posn should accompany msg */
 404     tmp_fd = qemu_chr_get_msgfd(s->server_chr);
 405     IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd);
 406
 407     /* make sure we have enough space for this guest */
 408     if (incoming_posn >= s->nb_peers) {
 409         increase_dynamic_storage(s, incoming_posn);
 410     }
 411
 412     if (tmp_fd == -1) {
 413         /* if posn is positive and unseen before then this is our posn*/
 414         if ((incoming_posn >= 0) &&
 415                             (s->peers[incoming_posn].eventfds == NULL)) {
 416             /* receive our posn */
 417             s->vm_id = incoming_posn;
 418             return;
 419         } else {
 420             /* otherwise an fd == -1 means an existing guest has gone away */
 421             IVSHMEM_DPRINTF("posn %ld has gone away\n", incoming_posn);
 422             close_guest_eventfds(s, incoming_posn);
 423             return;
 424         }
 425     }
 426
 427     /* because of the implementation of get_msgfd, we need a dup */
 428     incoming_fd = dup(tmp_fd);
 429
 430     if (incoming_fd == -1) {
 431         fprintf(stderr, "could not allocate file descriptor %s\n",
 432                                                             strerror(errno));
 433         return;
 434     }
 435
 436     /* if the position is -1, then it's shared memory region fd */
 437     if (incoming_posn == -1) {
 438
 439         void * map_ptr;
 440
 441         s->max_peer = 0;
 442
 443         if (check_shm_size(s, incoming_fd) == -1) {
 444             exit(-1);
 445         }
 446
 447         /* mmap the region and map into the BAR2 */
 448         map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
 449                                                             incoming_fd, 0);
 450         memory_region_init_ram_ptr(&s->ivshmem, &s->dev.qdev,
 451                                    "ivshmem.bar2", s->ivshmem_size, map_ptr);
 452
 453         IVSHMEM_DPRINTF("guest h/w addr = %" PRIu64 ", size = %" PRIu64 "\n",
 454                          s->ivshmem_offset, s->ivshmem_size);
 455
 456         memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
 457
 458         /* only store the fd if it is successfully mapped */
 459         s->shm_fd = incoming_fd;
 460
 461         return;
 462     }
 463
 464     /* each guest has an array of eventfds, and we keep track of how many
 465      * guests for each VM */
 466     guest_max_eventfd = s->peers[incoming_posn].nb_eventfds;
 467
 468     if (guest_max_eventfd == 0) {
 469         /* one eventfd per MSI vector */
 470         s->peers[incoming_posn].eventfds = (int *) qemu_malloc(s->vectors *
 471                                                                 sizeof(int));
 472     }
 473
 474     /* this is an eventfd for a particular guest VM */
 475     IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn,
 476                                             guest_max_eventfd, incoming_fd);
 477     s->peers[incoming_posn].eventfds[guest_max_eventfd] = incoming_fd;
 478
 479     /* increment count for particular guest */
 480     s->peers[incoming_posn].nb_eventfds++;
 481
 482     /* keep track of the maximum VM ID */
 483     if (incoming_posn > s->max_peer) {
 484         s->max_peer = incoming_posn;
 485     }
 486
 487     if (incoming_posn == s->vm_id) {
 488         s->eventfd_chr[guest_max_eventfd] = create_eventfd_chr_device(s,
 489                    s->peers[s->vm_id].eventfds[guest_max_eventfd],
 490                    guest_max_eventfd);
 491     }
 492
 493     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 494         if (kvm_set_ioeventfd_mmio_long(incoming_fd, s->mmio_addr + DOORBELL,
 495                         (incoming_posn << 16) | guest_max_eventfd, 1) < 0) {
 496             fprintf(stderr, "ivshmem: ioeventfd not available\n");
 497         }
 498     }
 499
 500     return;
 501 }
 502
 503 static void ivshmem_reset(DeviceState *d)
 504 {
 505     IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
 506
 507     s->intrstatus = 0;
 508     return;
 509 }
 510
 511 static uint64_t ivshmem_get_size(IVShmemState * s) {
 512
 513     uint64_t value;
 514     char *ptr;
 515
 516     value = strtoull(s->sizearg, &ptr, 10);
 517     switch (*ptr) {
 518         case 0: case 'M': case 'm':
 519             value <<= 20;
 520             break;
 521         case 'G': case 'g':
 522             value <<= 30;
 523             break;
 524         default:
 525             fprintf(stderr, "qemu: invalid ram size: %s\n", s->sizearg);
 526             exit(1);
 527     }
 528
 529     /* BARs must be a power of 2 */
 530     if (!is_power_of_two(value)) {
 531         fprintf(stderr, "ivshmem: size must be power of 2\n");
 532         exit(1);
 533     }
 534
 535     return value;
 536 }
 537
 538 static void ivshmem_setup_msi(IVShmemState * s) {
 539
 540     int i;
 541
 542     /* allocate the MSI-X vectors */
 543
 544     memory_region_init(&s->msix_bar, "ivshmem-msix", 4096);
 545     if (!msix_init(&s->dev, s->vectors, &s->msix_bar, 1, 0)) {
 546         pci_register_bar_region(&s->dev, 1,
 547                                 PCI_BASE_ADDRESS_SPACE_MEMORY,
 548                                 &s->msix_bar);
 549         IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
 550     } else {
 551         IVSHMEM_DPRINTF("msix initialization failed\n");
 552         exit(1);
 553     }
 554
 555     /* 'activate' the vectors */
 556     for (i = 0; i < s->vectors; i++) {
 557         msix_vector_use(&s->dev, i);
 558     }
 559
 560     /* allocate Qemu char devices for receiving interrupts */
 561     s->eventfd_table = qemu_mallocz(s->vectors * sizeof(EventfdEntry));
 562 }
 563
 564 static void ivshmem_save(QEMUFile* f, void *opaque)
 565 {
 566     IVShmemState *proxy = opaque;
 567
 568     IVSHMEM_DPRINTF("ivshmem_save\n");
 569     pci_device_save(&proxy->dev, f);
 570
 571     if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) {
 572         msix_save(&proxy->dev, f);
 573     } else {
 574         qemu_put_be32(f, proxy->intrstatus);
 575         qemu_put_be32(f, proxy->intrmask);
 576     }
 577
 578 }
 579
 580 static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
 581 {
 582     IVSHMEM_DPRINTF("ivshmem_load\n");
 583
 584     IVShmemState *proxy = opaque;
 585     int ret, i;
 586
 587     if (version_id > 0) {
 588         return -EINVAL;
 589     }
 590
 591     if (proxy->role_val == IVSHMEM_PEER) {
 592         fprintf(stderr, "ivshmem: 'peer' devices are not migratable\n");
 593         return -EINVAL;
 594     }
 595
 596     ret = pci_device_load(&proxy->dev, f);
 597     if (ret) {
 598         return ret;
 599     }
 600
 601     if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) {
 602         msix_load(&proxy->dev, f);
 603         for (i = 0; i < proxy->vectors; i++) {
 604             msix_vector_use(&proxy->dev, i);
 605         }
 606     } else {
 607         proxy->intrstatus = qemu_get_be32(f);
 608         proxy->intrmask = qemu_get_be32(f);
 609     }
 610
 611     return 0;
 612 }
 613
 614 static int pci_ivshmem_init(PCIDevice *dev)
 615 {
 616     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
 617     uint8_t *pci_conf;
 618
 619     if (s->sizearg == NULL)
 620         s->ivshmem_size = 4 << 20; /* 4 MB default */
 621     else {
 622         s->ivshmem_size = ivshmem_get_size(s);
 623     }
 624
 625     register_savevm(&s->dev.qdev, "ivshmem", 0, 0, ivshmem_save, ivshmem_load,
 626                                                                         dev);
 627
 628     /* IRQFD requires MSI */
 629     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
 630         !ivshmem_has_feature(s, IVSHMEM_MSI)) {
 631         fprintf(stderr, "ivshmem: ioeventfd/irqfd requires MSI\n");
 632         exit(1);
 633     }
 634
 635     /* check that role is reasonable */
 636     if (s->role) {
 637         if (strncmp(s->role, "peer", 5) == 0) {
 638             s->role_val = IVSHMEM_PEER;
 639         } else if (strncmp(s->role, "master", 7) == 0) {
 640             s->role_val = IVSHMEM_MASTER;
 641         } else {
 642             fprintf(stderr, "ivshmem: 'role' must be 'peer' or 'master'\n");
 643             exit(1);
 644         }
 645     } else {
 646         s->role_val = IVSHMEM_MASTER; /* default */
 647     }
 648
 649     if (s->role_val == IVSHMEM_PEER) {
 650         register_device_unmigratable(&s->dev.qdev, "ivshmem", s);
 651     }
 652
 653     pci_conf = s->dev.config;
 654     pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
 655
 656     pci_config_set_interrupt_pin(pci_conf, 1);
 657
 658     s->shm_fd = 0;
 659
 660     memory_region_init_io(&s->ivshmem_mmio, &ivshmem_mmio_ops, s,
 661                           "ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
 662
 663     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 664         setup_ioeventfds(s);
 665     }
 666
 667     /* region for registers*/
 668     pci_register_bar_region(&s->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
 669                             &s->ivshmem_mmio);
 670
 671     memory_region_init(&s->bar, "ivshmem-bar2-container", s->ivshmem_size);
 672
 673     if ((s->server_chr != NULL) &&
 674                         (strncmp(s->server_chr->filename, "unix:", 5) == 0)) {
 675         /* if we get a UNIX socket as the parameter we will talk
 676          * to the ivshmem server to receive the memory region */
 677
 678         if (s->shmobj != NULL) {
 679             fprintf(stderr, "WARNING: do not specify both 'chardev' "
 680                                                 "and 'shm' with ivshmem\n");
 681         }
 682
 683         IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
 684                                                     s->server_chr->filename);
 685
 686         if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 687             ivshmem_setup_msi(s);
 688         }
 689
 690         /* we allocate enough space for 16 guests and grow as needed */
 691         s->nb_peers = 16;
 692         s->vm_id = -1;
 693
 694         /* allocate/initialize space for interrupt handling */
 695         s->peers = qemu_mallocz(s->nb_peers * sizeof(Peer));
 696
 697         pci_register_bar_region(&s->dev, 2,
 698                                 PCI_BASE_ADDRESS_SPACE_MEMORY, &s->ivshmem);
 699
 700         s->eventfd_chr = qemu_mallocz(s->vectors * sizeof(CharDriverState *));
 701
 702         qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read,
 703                      ivshmem_event, s);
 704     } else {
 705         /* just map the file immediately, we're not using a server */
 706         int fd;
 707
 708         if (s->shmobj == NULL) {
 709             fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
 710         }
 711
 712         IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);
 713
 714         /* try opening with O_EXCL and if it succeeds zero the memory
 715          * by truncating to 0 */
 716         if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL,
 717                         S_IRWXU|S_IRWXG|S_IRWXO)) > 0) {
 718            /* truncate file to length PCI device's memory */
 719             if (ftruncate(fd, s->ivshmem_size) != 0) {
 720                 fprintf(stderr, "ivshmem: could not truncate shared file\n");
 721             }
 722
 723         } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR,
 724                         S_IRWXU|S_IRWXG|S_IRWXO)) < 0) {
 725             fprintf(stderr, "ivshmem: could not open shared file\n");
 726             exit(-1);
 727
 728         }
 729
 730         if (check_shm_size(s, fd) == -1) {
 731             exit(-1);
 732         }
 733
 734         create_shared_memory_BAR(s, fd);
 735
 736     }
 737
 738     return 0;
 739 }
 740
 741 static int pci_ivshmem_uninit(PCIDevice *dev)
 742 {
 743     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
 744
 745     memory_region_destroy(&s->ivshmem_mmio);
 746     memory_region_del_subregion(&s->bar, &s->ivshmem);
 747     memory_region_destroy(&s->ivshmem);
 748     memory_region_destroy(&s->bar);
 749     unregister_savevm(&dev->qdev, "ivshmem", s);
 750
 751     return 0;
 752 }
 753
 754 static PCIDeviceInfo ivshmem_info = {
 755     .qdev.name  = "ivshmem",
 756     .qdev.size  = sizeof(IVShmemState),
 757     .qdev.reset = ivshmem_reset,
 758     .init       = pci_ivshmem_init,
 759     .exit       = pci_ivshmem_uninit,
 760     .vendor_id  = PCI_VENDOR_ID_REDHAT_QUMRANET,
 761     .device_id  = 0x1110,
 762     .class_id   = PCI_CLASS_MEMORY_RAM,
 763     .qdev.props = (Property[]) {
 764         DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
 765         DEFINE_PROP_STRING("size", IVShmemState, sizearg),
 766         DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
 767         DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD, false),
 768         DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true),
 769         DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
 770         DEFINE_PROP_STRING("role", IVShmemState, role),
 771         DEFINE_PROP_END_OF_LIST(),
 772     }
 773 };
 774
 775 static void ivshmem_register_devices(void)
 776 {
 777     pci_qdev_register(&ivshmem_info);
 778 }
 779
 780 device_init(ivshmem_register_devices)