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     int ivshmem_mmio_io_addr;
  60
  61     pcibus_t mmio_addr;
  62     pcibus_t shm_pci_addr;
  63     uint64_t ivshmem_offset;
  64     uint64_t ivshmem_size; /* size of shared memory region */
  65     int shm_fd; /* shared memory file descriptor */
  66
  67     Peer *peers;
  68     int nb_peers; /* how many guests we have space for */
  69     int max_peer; /* maximum numbered peer */
  70
  71     int vm_id;
  72     uint32_t vectors;
  73     uint32_t features;
  74     EventfdEntry *eventfd_table;
  75
  76     char * shmobj;
  77     char * sizearg;
  78     char * role;
  79     int role_val;   /* scalar to avoid multiple string comparisons */
  80 } IVShmemState;
  81
  82 /* registers for the Inter-VM shared memory device */
  83 enum ivshmem_registers {
  84     INTRMASK = 0,
  85     INTRSTATUS = 4,
  86     IVPOSITION = 8,
  87     DOORBELL = 12,
  88 };
  89
  90 static inline uint32_t ivshmem_has_feature(IVShmemState *ivs,
  91                                                     unsigned int feature) {
  92     return (ivs->features & (1 << feature));
  93 }
  94
  95 static inline bool is_power_of_two(uint64_t x) {
  96     return (x & (x - 1)) == 0;
  97 }
  98
  99 static void ivshmem_map(PCIDevice *pci_dev, int region_num,
 100                     pcibus_t addr, pcibus_t size, int type)
 101 {
 102     IVShmemState *s = DO_UPCAST(IVShmemState, dev, pci_dev);
 103
 104     s->shm_pci_addr = addr;
 105
 106     if (s->ivshmem_offset > 0) {
 107         cpu_register_physical_memory(s->shm_pci_addr, s->ivshmem_size,
 108                                                             s->ivshmem_offset);
 109     }
 110
 111     IVSHMEM_DPRINTF("guest pci addr = %" FMT_PCIBUS ", guest h/w addr = %"
 112         PRIu64 ", size = %" FMT_PCIBUS "\n", addr, s->ivshmem_offset, size);
 113
 114 }
 115
 116 /* accessing registers - based on rtl8139 */
 117 static void ivshmem_update_irq(IVShmemState *s, int val)
 118 {
 119     int isr;
 120     isr = (s->intrstatus & s->intrmask) & 0xffffffff;
 121
 122     /* don't print ISR resets */
 123     if (isr) {
 124         IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
 125            isr ? 1 : 0, s->intrstatus, s->intrmask);
 126     }
 127
 128     qemu_set_irq(s->dev.irq[0], (isr != 0));
 129 }
 130
 131 static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
 132 {
 133     IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
 134
 135     s->intrmask = val;
 136
 137     ivshmem_update_irq(s, val);
 138 }
 139
 140 static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
 141 {
 142     uint32_t ret = s->intrmask;
 143
 144     IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
 145
 146     return ret;
 147 }
 148
 149 static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
 150 {
 151     IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
 152
 153     s->intrstatus = val;
 154
 155     ivshmem_update_irq(s, val);
 156     return;
 157 }
 158
 159 static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
 160 {
 161     uint32_t ret = s->intrstatus;
 162
 163     /* reading ISR clears all interrupts */
 164     s->intrstatus = 0;
 165
 166     ivshmem_update_irq(s, 0);
 167
 168     return ret;
 169 }
 170
 171 static void ivshmem_io_writew(void *opaque, target_phys_addr_t addr,
 172                                                             uint32_t val)
 173 {
 174
 175     IVSHMEM_DPRINTF("We shouldn't be writing words\n");
 176 }
 177
 178 static void ivshmem_io_writel(void *opaque, target_phys_addr_t addr,
 179                                                             uint32_t val)
 180 {
 181     IVShmemState *s = opaque;
 182
 183     uint64_t write_one = 1;
 184     uint16_t dest = val >> 16;
 185     uint16_t vector = val & 0xff;
 186
 187     addr &= 0xfc;
 188
 189     IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr);
 190     switch (addr)
 191     {
 192         case INTRMASK:
 193             ivshmem_IntrMask_write(s, val);
 194             break;
 195
 196         case INTRSTATUS:
 197             ivshmem_IntrStatus_write(s, val);
 198             break;
 199
 200         case DOORBELL:
 201             /* check that dest VM ID is reasonable */
 202             if (dest > s->max_peer) {
 203                 IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
 204                 break;
 205             }
 206
 207             /* check doorbell range */
 208             if (vector < s->peers[dest].nb_eventfds) {
 209                 IVSHMEM_DPRINTF("Writing %" PRId64 " to VM %d on vector %d\n",
 210                                                     write_one, dest, vector);
 211                 if (write(s->peers[dest].eventfds[vector],
 212                                                     &(write_one), 8) != 8) {
 213                     IVSHMEM_DPRINTF("error writing to eventfd\n");
 214                 }
 215             }
 216             break;
 217         default:
 218             IVSHMEM_DPRINTF("Invalid VM Doorbell VM %d\n", dest);
 219     }
 220 }
 221
 222 static void ivshmem_io_writeb(void *opaque, target_phys_addr_t addr,
 223                                                                 uint32_t val)
 224 {
 225     IVSHMEM_DPRINTF("We shouldn't be writing bytes\n");
 226 }
 227
 228 static uint32_t ivshmem_io_readw(void *opaque, target_phys_addr_t addr)
 229 {
 230
 231     IVSHMEM_DPRINTF("We shouldn't be reading words\n");
 232     return 0;
 233 }
 234
 235 static uint32_t ivshmem_io_readl(void *opaque, target_phys_addr_t addr)
 236 {
 237
 238     IVShmemState *s = opaque;
 239     uint32_t ret;
 240
 241     switch (addr)
 242     {
 243         case INTRMASK:
 244             ret = ivshmem_IntrMask_read(s);
 245             break;
 246
 247         case INTRSTATUS:
 248             ret = ivshmem_IntrStatus_read(s);
 249             break;
 250
 251         case IVPOSITION:
 252             /* return my VM ID if the memory is mapped */
 253             if (s->shm_fd > 0) {
 254                 ret = s->vm_id;
 255             } else {
 256                 ret = -1;
 257             }
 258             break;
 259
 260         default:
 261             IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr);
 262             ret = 0;
 263     }
 264
 265     return ret;
 266 }
 267
 268 static uint32_t ivshmem_io_readb(void *opaque, target_phys_addr_t addr)
 269 {
 270     IVSHMEM_DPRINTF("We shouldn't be reading bytes\n");
 271
 272     return 0;
 273 }
 274
 275 static CPUReadMemoryFunc * const ivshmem_mmio_read[3] = {
 276     ivshmem_io_readb,
 277     ivshmem_io_readw,
 278     ivshmem_io_readl,
 279 };
 280
 281 static CPUWriteMemoryFunc * const ivshmem_mmio_write[3] = {
 282     ivshmem_io_writeb,
 283     ivshmem_io_writew,
 284     ivshmem_io_writel,
 285 };
 286
 287 static void ivshmem_receive(void *opaque, const uint8_t *buf, int size)
 288 {
 289     IVShmemState *s = opaque;
 290
 291     ivshmem_IntrStatus_write(s, *buf);
 292
 293     IVSHMEM_DPRINTF("ivshmem_receive 0x%02x\n", *buf);
 294 }
 295
 296 static int ivshmem_can_receive(void * opaque)
 297 {
 298     return 8;
 299 }
 300
 301 static void ivshmem_event(void *opaque, int event)
 302 {
 303     IVSHMEM_DPRINTF("ivshmem_event %d\n", event);
 304 }
 305
 306 static void fake_irqfd(void *opaque, const uint8_t *buf, int size) {
 307
 308     EventfdEntry *entry = opaque;
 309     PCIDevice *pdev = entry->pdev;
 310
 311     IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, entry->vector);
 312     msix_notify(pdev, entry->vector);
 313 }
 314
 315 static CharDriverState* create_eventfd_chr_device(void * opaque, int eventfd,
 316                                                                     int vector)
 317 {
 318     /* create a event character device based on the passed eventfd */
 319     IVShmemState *s = opaque;
 320     CharDriverState * chr;
 321
 322     chr = qemu_chr_open_eventfd(eventfd);
 323
 324     if (chr == NULL) {
 325         fprintf(stderr, "creating eventfd for eventfd %d failed\n", eventfd);
 326         exit(-1);
 327     }
 328
 329     /* if MSI is supported we need multiple interrupts */
 330     if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 331         s->eventfd_table[vector].pdev = &s->dev;
 332         s->eventfd_table[vector].vector = vector;
 333
 334         qemu_chr_add_handlers(chr, ivshmem_can_receive, fake_irqfd,
 335                       ivshmem_event, &s->eventfd_table[vector]);
 336     } else {
 337         qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive,
 338                       ivshmem_event, s);
 339     }
 340
 341     return chr;
 342
 343 }
 344
 345 static int check_shm_size(IVShmemState *s, int fd) {
 346     /* check that the guest isn't going to try and map more memory than the
 347      * the object has allocated return -1 to indicate error */
 348
 349     struct stat buf;
 350
 351     fstat(fd, &buf);
 352
 353     if (s->ivshmem_size > buf.st_size) {
 354         fprintf(stderr,
 355                 "IVSHMEM ERROR: Requested memory size greater"
 356                 " than shared object size (%" PRIu64 " > %" PRIu64")\n",
 357                 s->ivshmem_size, (uint64_t)buf.st_size);
 358         return -1;
 359     } else {
 360         return 0;
 361     }
 362 }
 363
 364 /* create the shared memory BAR when we are not using the server, so we can
 365  * create the BAR and map the memory immediately */
 366 static void create_shared_memory_BAR(IVShmemState *s, int fd) {
 367
 368     void * ptr;
 369
 370     s->shm_fd = fd;
 371
 372     ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
 373
 374     s->ivshmem_offset = qemu_ram_alloc_from_ptr(&s->dev.qdev, "ivshmem.bar2",
 375                                                         s->ivshmem_size, ptr);
 376
 377     /* region for shared memory */
 378     pci_register_bar(&s->dev, 2, s->ivshmem_size,
 379                                 PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_map);
 380 }
 381
 382 static void close_guest_eventfds(IVShmemState *s, int posn)
 383 {
 384     int i, guest_curr_max;
 385
 386     guest_curr_max = s->peers[posn].nb_eventfds;
 387
 388     for (i = 0; i < guest_curr_max; i++) {
 389         kvm_set_ioeventfd_mmio_long(s->peers[posn].eventfds[i],
 390                     s->mmio_addr + DOORBELL, (posn << 16) | i, 0);
 391         close(s->peers[posn].eventfds[i]);
 392     }
 393
 394     qemu_free(s->peers[posn].eventfds);
 395     s->peers[posn].nb_eventfds = 0;
 396 }
 397
 398 static void setup_ioeventfds(IVShmemState *s) {
 399
 400     int i, j;
 401
 402     for (i = 0; i <= s->max_peer; i++) {
 403         for (j = 0; j < s->peers[i].nb_eventfds; j++) {
 404             kvm_set_ioeventfd_mmio_long(s->peers[i].eventfds[j],
 405                     s->mmio_addr + DOORBELL, (i << 16) | j, 1);
 406         }
 407     }
 408 }
 409
 410 /* this function increase the dynamic storage need to store data about other
 411  * guests */
 412 static void increase_dynamic_storage(IVShmemState *s, int new_min_size) {
 413
 414     int j, old_nb_alloc;
 415
 416     old_nb_alloc = s->nb_peers;
 417
 418     while (new_min_size >= s->nb_peers)
 419         s->nb_peers = s->nb_peers * 2;
 420
 421     IVSHMEM_DPRINTF("bumping storage to %d guests\n", s->nb_peers);
 422     s->peers = qemu_realloc(s->peers, s->nb_peers * sizeof(Peer));
 423
 424     /* zero out new pointers */
 425     for (j = old_nb_alloc; j < s->nb_peers; j++) {
 426         s->peers[j].eventfds = NULL;
 427         s->peers[j].nb_eventfds = 0;
 428     }
 429 }
 430
 431 static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
 432 {
 433     IVShmemState *s = opaque;
 434     int incoming_fd, tmp_fd;
 435     int guest_max_eventfd;
 436     long incoming_posn;
 437
 438     memcpy(&incoming_posn, buf, sizeof(long));
 439     /* pick off s->server_chr->msgfd and store it, posn should accompany msg */
 440     tmp_fd = qemu_chr_get_msgfd(s->server_chr);
 441     IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd);
 442
 443     /* make sure we have enough space for this guest */
 444     if (incoming_posn >= s->nb_peers) {
 445         increase_dynamic_storage(s, incoming_posn);
 446     }
 447
 448     if (tmp_fd == -1) {
 449         /* if posn is positive and unseen before then this is our posn*/
 450         if ((incoming_posn >= 0) &&
 451                             (s->peers[incoming_posn].eventfds == NULL)) {
 452             /* receive our posn */
 453             s->vm_id = incoming_posn;
 454             return;
 455         } else {
 456             /* otherwise an fd == -1 means an existing guest has gone away */
 457             IVSHMEM_DPRINTF("posn %ld has gone away\n", incoming_posn);
 458             close_guest_eventfds(s, incoming_posn);
 459             return;
 460         }
 461     }
 462
 463     /* because of the implementation of get_msgfd, we need a dup */
 464     incoming_fd = dup(tmp_fd);
 465
 466     if (incoming_fd == -1) {
 467         fprintf(stderr, "could not allocate file descriptor %s\n",
 468                                                             strerror(errno));
 469         return;
 470     }
 471
 472     /* if the position is -1, then it's shared memory region fd */
 473     if (incoming_posn == -1) {
 474
 475         void * map_ptr;
 476
 477         s->max_peer = 0;
 478
 479         if (check_shm_size(s, incoming_fd) == -1) {
 480             exit(-1);
 481         }
 482
 483         /* mmap the region and map into the BAR2 */
 484         map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
 485                                                             incoming_fd, 0);
 486         s->ivshmem_offset = qemu_ram_alloc_from_ptr(&s->dev.qdev,
 487                                     "ivshmem.bar2", s->ivshmem_size, map_ptr);
 488
 489         IVSHMEM_DPRINTF("guest pci addr = %" FMT_PCIBUS ", guest h/w addr = %"
 490                          PRIu64 ", size = %" PRIu64 "\n", s->shm_pci_addr,
 491                          s->ivshmem_offset, s->ivshmem_size);
 492
 493         if (s->shm_pci_addr > 0) {
 494             /* map memory into BAR2 */
 495             cpu_register_physical_memory(s->shm_pci_addr, s->ivshmem_size,
 496                                                             s->ivshmem_offset);
 497         }
 498
 499         /* only store the fd if it is successfully mapped */
 500         s->shm_fd = incoming_fd;
 501
 502         return;
 503     }
 504
 505     /* each guest has an array of eventfds, and we keep track of how many
 506      * guests for each VM */
 507     guest_max_eventfd = s->peers[incoming_posn].nb_eventfds;
 508
 509     if (guest_max_eventfd == 0) {
 510         /* one eventfd per MSI vector */
 511         s->peers[incoming_posn].eventfds = (int *) qemu_malloc(s->vectors *
 512                                                                 sizeof(int));
 513     }
 514
 515     /* this is an eventfd for a particular guest VM */
 516     IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn,
 517                                             guest_max_eventfd, incoming_fd);
 518     s->peers[incoming_posn].eventfds[guest_max_eventfd] = incoming_fd;
 519
 520     /* increment count for particular guest */
 521     s->peers[incoming_posn].nb_eventfds++;
 522
 523     /* keep track of the maximum VM ID */
 524     if (incoming_posn > s->max_peer) {
 525         s->max_peer = incoming_posn;
 526     }
 527
 528     if (incoming_posn == s->vm_id) {
 529         s->eventfd_chr[guest_max_eventfd] = create_eventfd_chr_device(s,
 530                    s->peers[s->vm_id].eventfds[guest_max_eventfd],
 531                    guest_max_eventfd);
 532     }
 533
 534     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 535         if (kvm_set_ioeventfd_mmio_long(incoming_fd, s->mmio_addr + DOORBELL,
 536                         (incoming_posn << 16) | guest_max_eventfd, 1) < 0) {
 537             fprintf(stderr, "ivshmem: ioeventfd not available\n");
 538         }
 539     }
 540
 541     return;
 542 }
 543
 544 static void ivshmem_reset(DeviceState *d)
 545 {
 546     IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
 547
 548     s->intrstatus = 0;
 549     return;
 550 }
 551
 552 static void ivshmem_mmio_map(PCIDevice *pci_dev, int region_num,
 553                        pcibus_t addr, pcibus_t size, int type)
 554 {
 555     IVShmemState *s = DO_UPCAST(IVShmemState, dev, pci_dev);
 556
 557     s->mmio_addr = addr;
 558     cpu_register_physical_memory(addr + 0, IVSHMEM_REG_BAR_SIZE,
 559                                                 s->ivshmem_mmio_io_addr);
 560
 561     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
 562         setup_ioeventfds(s);
 563     }
 564 }
 565
 566 static uint64_t ivshmem_get_size(IVShmemState * s) {
 567
 568     uint64_t value;
 569     char *ptr;
 570
 571     value = strtoull(s->sizearg, &ptr, 10);
 572     switch (*ptr) {
 573         case 0: case 'M': case 'm':
 574             value <<= 20;
 575             break;
 576         case 'G': case 'g':
 577             value <<= 30;
 578             break;
 579         default:
 580             fprintf(stderr, "qemu: invalid ram size: %s\n", s->sizearg);
 581             exit(1);
 582     }
 583
 584     /* BARs must be a power of 2 */
 585     if (!is_power_of_two(value)) {
 586         fprintf(stderr, "ivshmem: size must be power of 2\n");
 587         exit(1);
 588     }
 589
 590     return value;
 591 }
 592
 593 static void ivshmem_setup_msi(IVShmemState * s) {
 594
 595     int i;
 596
 597     /* allocate the MSI-X vectors */
 598
 599     if (!msix_init(&s->dev, s->vectors, 1, 0)) {
 600         pci_register_bar(&s->dev, 1,
 601                          msix_bar_size(&s->dev),
 602                          PCI_BASE_ADDRESS_SPACE_MEMORY,
 603                          msix_mmio_map);
 604         IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
 605     } else {
 606         IVSHMEM_DPRINTF("msix initialization failed\n");
 607         exit(1);
 608     }
 609
 610     /* 'activate' the vectors */
 611     for (i = 0; i < s->vectors; i++) {
 612         msix_vector_use(&s->dev, i);
 613     }
 614
 615     /* allocate Qemu char devices for receiving interrupts */
 616     s->eventfd_table = qemu_mallocz(s->vectors * sizeof(EventfdEntry));
 617 }
 618
 619 static void ivshmem_save(QEMUFile* f, void *opaque)
 620 {
 621     IVShmemState *proxy = opaque;
 622
 623     IVSHMEM_DPRINTF("ivshmem_save\n");
 624     pci_device_save(&proxy->dev, f);
 625
 626     if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) {
 627         msix_save(&proxy->dev, f);
 628     } else {
 629         qemu_put_be32(f, proxy->intrstatus);
 630         qemu_put_be32(f, proxy->intrmask);
 631     }
 632
 633 }
 634
 635 static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
 636 {
 637     IVSHMEM_DPRINTF("ivshmem_load\n");
 638
 639     IVShmemState *proxy = opaque;
 640     int ret, i;
 641
 642     if (version_id > 0) {
 643         return -EINVAL;
 644     }
 645
 646     if (proxy->role_val == IVSHMEM_PEER) {
 647         fprintf(stderr, "ivshmem: 'peer' devices are not migratable\n");
 648         return -EINVAL;
 649     }
 650
 651     ret = pci_device_load(&proxy->dev, f);
 652     if (ret) {
 653         return ret;
 654     }
 655
 656     if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) {
 657         msix_load(&proxy->dev, f);
 658         for (i = 0; i < proxy->vectors; i++) {
 659             msix_vector_use(&proxy->dev, i);
 660         }
 661     } else {
 662         proxy->intrstatus = qemu_get_be32(f);
 663         proxy->intrmask = qemu_get_be32(f);
 664     }
 665
 666     return 0;
 667 }
 668
 669 static int pci_ivshmem_init(PCIDevice *dev)
 670 {
 671     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
 672     uint8_t *pci_conf;
 673
 674     if (s->sizearg == NULL)
 675         s->ivshmem_size = 4 << 20; /* 4 MB default */
 676     else {
 677         s->ivshmem_size = ivshmem_get_size(s);
 678     }
 679
 680     register_savevm(&s->dev.qdev, "ivshmem", 0, 0, ivshmem_save, ivshmem_load,
 681                                                                         dev);
 682
 683     /* IRQFD requires MSI */
 684     if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
 685         !ivshmem_has_feature(s, IVSHMEM_MSI)) {
 686         fprintf(stderr, "ivshmem: ioeventfd/irqfd requires MSI\n");
 687         exit(1);
 688     }
 689
 690     /* check that role is reasonable */
 691     if (s->role) {
 692         if (strncmp(s->role, "peer", 5) == 0) {
 693             s->role_val = IVSHMEM_PEER;
 694         } else if (strncmp(s->role, "master", 7) == 0) {
 695             s->role_val = IVSHMEM_MASTER;
 696         } else {
 697             fprintf(stderr, "ivshmem: 'role' must be 'peer' or 'master'\n");
 698             exit(1);
 699         }
 700     } else {
 701         s->role_val = IVSHMEM_MASTER; /* default */
 702     }
 703
 704     if (s->role_val == IVSHMEM_PEER) {
 705         register_device_unmigratable(&s->dev.qdev, "ivshmem", s);
 706     }
 707
 708     pci_conf = s->dev.config;
 709     pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_REDHAT_QUMRANET);
 710     pci_conf[0x02] = 0x10;
 711     pci_conf[0x03] = 0x11;
 712     pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
 713     pci_config_set_class(pci_conf, PCI_CLASS_MEMORY_RAM);
 714     pci_conf[PCI_HEADER_TYPE] = PCI_HEADER_TYPE_NORMAL;
 715
 716     pci_config_set_interrupt_pin(pci_conf, 1);
 717
 718     s->shm_pci_addr = 0;
 719     s->ivshmem_offset = 0;
 720     s->shm_fd = 0;
 721
 722     s->ivshmem_mmio_io_addr = cpu_register_io_memory(ivshmem_mmio_read,
 723                                     ivshmem_mmio_write, s);
 724     /* region for registers*/
 725     pci_register_bar(&s->dev, 0, IVSHMEM_REG_BAR_SIZE,
 726                            PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_mmio_map);
 727
 728     if ((s->server_chr != NULL) &&
 729                         (strncmp(s->server_chr->filename, "unix:", 5) == 0)) {
 730         /* if we get a UNIX socket as the parameter we will talk
 731          * to the ivshmem server to receive the memory region */
 732
 733         if (s->shmobj != NULL) {
 734             fprintf(stderr, "WARNING: do not specify both 'chardev' "
 735                                                 "and 'shm' with ivshmem\n");
 736         }
 737
 738         IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
 739                                                     s->server_chr->filename);
 740
 741         if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
 742             ivshmem_setup_msi(s);
 743         }
 744
 745         /* we allocate enough space for 16 guests and grow as needed */
 746         s->nb_peers = 16;
 747         s->vm_id = -1;
 748
 749         /* allocate/initialize space for interrupt handling */
 750         s->peers = qemu_mallocz(s->nb_peers * sizeof(Peer));
 751
 752         pci_register_bar(&s->dev, 2, s->ivshmem_size,
 753                                 PCI_BASE_ADDRESS_SPACE_MEMORY, ivshmem_map);
 754
 755         s->eventfd_chr = qemu_mallocz(s->vectors * sizeof(CharDriverState *));
 756
 757         qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read,
 758                      ivshmem_event, s);
 759     } else {
 760         /* just map the file immediately, we're not using a server */
 761         int fd;
 762
 763         if (s->shmobj == NULL) {
 764             fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
 765         }
 766
 767         IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);
 768
 769         /* try opening with O_EXCL and if it succeeds zero the memory
 770          * by truncating to 0 */
 771         if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL,
 772                         S_IRWXU|S_IRWXG|S_IRWXO)) > 0) {
 773            /* truncate file to length PCI device's memory */
 774             if (ftruncate(fd, s->ivshmem_size) != 0) {
 775                 fprintf(stderr, "ivshmem: could not truncate shared file\n");
 776             }
 777
 778         } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR,
 779                         S_IRWXU|S_IRWXG|S_IRWXO)) < 0) {
 780             fprintf(stderr, "ivshmem: could not open shared file\n");
 781             exit(-1);
 782
 783         }
 784
 785         if (check_shm_size(s, fd) == -1) {
 786             exit(-1);
 787         }
 788
 789         create_shared_memory_BAR(s, fd);
 790
 791     }
 792
 793     return 0;
 794 }
 795
 796 static int pci_ivshmem_uninit(PCIDevice *dev)
 797 {
 798     IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
 799
 800     cpu_unregister_io_memory(s->ivshmem_mmio_io_addr);
 801     unregister_savevm(&dev->qdev, "ivshmem", s);
 802
 803     return 0;
 804 }
 805
 806 static PCIDeviceInfo ivshmem_info = {
 807     .qdev.name  = "ivshmem",
 808     .qdev.size  = sizeof(IVShmemState),
 809     .qdev.reset = ivshmem_reset,
 810     .init       = pci_ivshmem_init,
 811     .exit       = pci_ivshmem_uninit,
 812     .qdev.props = (Property[]) {
 813         DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
 814         DEFINE_PROP_STRING("size", IVShmemState, sizearg),
 815         DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
 816         DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD, false),
 817         DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true),
 818         DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
 819         DEFINE_PROP_STRING("role", IVShmemState, role),
 820         DEFINE_PROP_END_OF_LIST(),
 821     }
 822 };
 823
 824 static void ivshmem_register_devices(void)
 825 {
 826     pci_qdev_register(&ivshmem_info);
 827 }
 828
 829 device_init(ivshmem_register_devices)