block/file-win32.c

   1 /*
   2  * Block driver for RAW files (win32)
   3  *
   4  * Copyright (c) 2006 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "qemu/osdep.h"
  26 #include "qapi/error.h"
  27 #include "qemu/cutils.h"
  28 #include "block/block_int.h"
  29 #include "qemu/module.h"
  30 #include "qemu/option.h"
  31 #include "block/raw-aio.h"
  32 #include "trace.h"
  33 #include "block/thread-pool.h"
  34 #include "qemu/iov.h"
  35 #include "qapi/qmp/qdict.h"
  36 #include "qapi/qmp/qstring.h"
  37 #include <windows.h>
  38 #include <winioctl.h>
  39
  40 #define FTYPE_FILE 0
  41 #define FTYPE_CD     1
  42 #define FTYPE_HARDDISK 2
  43
  44 typedef struct RawWin32AIOData {
  45     BlockDriverState *bs;
  46     HANDLE hfile;
  47     struct iovec *aio_iov;
  48     int aio_niov;
  49     size_t aio_nbytes;
  50     off64_t aio_offset;
  51     int aio_type;
  52 } RawWin32AIOData;
  53
  54 typedef struct BDRVRawState {
  55     HANDLE hfile;
  56     int type;
  57     char drive_path[16]; /* format: "d:\" */
  58     QEMUWin32AIOState *aio;
  59 } BDRVRawState;
  60
  61 /*
  62  * Read/writes the data to/from a given linear buffer.
  63  *
  64  * Returns the number of bytes handles or -errno in case of an error. Short
  65  * reads are only returned if the end of the file is reached.
  66  */
  67 static size_t handle_aiocb_rw(RawWin32AIOData *aiocb)
  68 {
  69     size_t offset = 0;
  70     int i;
  71
  72     for (i = 0; i < aiocb->aio_niov; i++) {
  73         OVERLAPPED ov;
  74         DWORD ret, ret_count, len;
  75
  76         memset(&ov, 0, sizeof(ov));
  77         ov.Offset = (aiocb->aio_offset + offset);
  78         ov.OffsetHigh = (aiocb->aio_offset + offset) >> 32;
  79         len = aiocb->aio_iov[i].iov_len;
  80         if (aiocb->aio_type & QEMU_AIO_WRITE) {
  81             ret = WriteFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
  82                             len, &ret_count, &ov);
  83         } else {
  84             ret = ReadFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
  85                            len, &ret_count, &ov);
  86         }
  87         if (!ret) {
  88             ret_count = 0;
  89         }
  90         if (ret_count != len) {
  91             offset += ret_count;
  92             break;
  93         }
  94         offset += len;
  95     }
  96
  97     return offset;
  98 }
  99
 100 static int aio_worker(void *arg)
 101 {
 102     RawWin32AIOData *aiocb = arg;
 103     ssize_t ret = 0;
 104     size_t count;
 105
 106     switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
 107     case QEMU_AIO_READ:
 108         count = handle_aiocb_rw(aiocb);
 109         if (count < aiocb->aio_nbytes) {
 110             /* A short read means that we have reached EOF. Pad the buffer
 111              * with zeros for bytes after EOF. */
 112             iov_memset(aiocb->aio_iov, aiocb->aio_niov, count,
 113                       0, aiocb->aio_nbytes - count);
 114
 115             count = aiocb->aio_nbytes;
 116         }
 117         if (count == aiocb->aio_nbytes) {
 118             ret = 0;
 119         } else {
 120             ret = -EINVAL;
 121         }
 122         break;
 123     case QEMU_AIO_WRITE:
 124         count = handle_aiocb_rw(aiocb);
 125         if (count == aiocb->aio_nbytes) {
 126             ret = 0;
 127         } else {
 128             ret = -EINVAL;
 129         }
 130         break;
 131     case QEMU_AIO_FLUSH:
 132         if (!FlushFileBuffers(aiocb->hfile)) {
 133             return -EIO;
 134         }
 135         break;
 136     default:
 137         fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
 138         ret = -EINVAL;
 139         break;
 140     }
 141
 142     g_free(aiocb);
 143     return ret;
 144 }
 145
 146 static BlockAIOCB *paio_submit(BlockDriverState *bs, HANDLE hfile,
 147         int64_t offset, QEMUIOVector *qiov, int count,
 148         BlockCompletionFunc *cb, void *opaque, int type)
 149 {
 150     RawWin32AIOData *acb = g_new(RawWin32AIOData, 1);
 151     ThreadPool *pool;
 152
 153     acb->bs = bs;
 154     acb->hfile = hfile;
 155     acb->aio_type = type;
 156
 157     if (qiov) {
 158         acb->aio_iov = qiov->iov;
 159         acb->aio_niov = qiov->niov;
 160         assert(qiov->size == count);
 161     }
 162     acb->aio_nbytes = count;
 163     acb->aio_offset = offset;
 164
 165     trace_file_paio_submit(acb, opaque, offset, count, type);
 166     pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
 167     return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
 168 }
 169
 170 int qemu_ftruncate64(int fd, int64_t length)
 171 {
 172     LARGE_INTEGER li;
 173     DWORD dw;
 174     LONG high;
 175     HANDLE h;
 176     BOOL res;
 177
 178     if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
 179         return -1;
 180
 181     h = (HANDLE)_get_osfhandle(fd);
 182
 183     /* get current position, ftruncate do not change position */
 184     li.HighPart = 0;
 185     li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
 186     if (li.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 187         return -1;
 188     }
 189
 190     high = length >> 32;
 191     dw = SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN);
 192     if (dw == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 193         return -1;
 194     }
 195     res = SetEndOfFile(h);
 196
 197     /* back to old position */
 198     SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
 199     return res ? 0 : -1;
 200 }
 201
 202 static int set_sparse(int fd)
 203 {
 204     DWORD returned;
 205     return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
 206                                  NULL, 0, NULL, 0, &returned, NULL);
 207 }
 208
 209 static void raw_detach_aio_context(BlockDriverState *bs)
 210 {
 211     BDRVRawState *s = bs->opaque;
 212
 213     if (s->aio) {
 214         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 215     }
 216 }
 217
 218 static void raw_attach_aio_context(BlockDriverState *bs,
 219                                    AioContext *new_context)
 220 {
 221     BDRVRawState *s = bs->opaque;
 222
 223     if (s->aio) {
 224         win32_aio_attach_aio_context(s->aio, new_context);
 225     }
 226 }
 227
 228 static void raw_probe_alignment(BlockDriverState *bs, Error **errp)
 229 {
 230     BDRVRawState *s = bs->opaque;
 231     DWORD sectorsPerCluster, freeClusters, totalClusters, count;
 232     DISK_GEOMETRY_EX dg;
 233     BOOL status;
 234
 235     if (s->type == FTYPE_CD) {
 236         bs->bl.request_alignment = 2048;
 237         return;
 238     }
 239     if (s->type == FTYPE_HARDDISK) {
 240         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 241                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 242         if (status != 0) {
 243             bs->bl.request_alignment = dg.Geometry.BytesPerSector;
 244             return;
 245         }
 246         /* try GetDiskFreeSpace too */
 247     }
 248
 249     if (s->drive_path[0]) {
 250         GetDiskFreeSpace(s->drive_path, &sectorsPerCluster,
 251                          &dg.Geometry.BytesPerSector,
 252                          &freeClusters, &totalClusters);
 253         bs->bl.request_alignment = dg.Geometry.BytesPerSector;
 254         return;
 255     }
 256
 257     /* XXX Does Windows support AIO on less than 512-byte alignment? */
 258     bs->bl.request_alignment = 512;
 259 }
 260
 261 static void raw_parse_flags(int flags, bool use_aio, int *access_flags,
 262                             DWORD *overlapped)
 263 {
 264     assert(access_flags != NULL);
 265     assert(overlapped != NULL);
 266
 267     if (flags & BDRV_O_RDWR) {
 268         *access_flags = GENERIC_READ | GENERIC_WRITE;
 269     } else {
 270         *access_flags = GENERIC_READ;
 271     }
 272
 273     *overlapped = FILE_ATTRIBUTE_NORMAL;
 274     if (use_aio) {
 275         *overlapped |= FILE_FLAG_OVERLAPPED;
 276     }
 277     if (flags & BDRV_O_NOCACHE) {
 278         *overlapped |= FILE_FLAG_NO_BUFFERING;
 279     }
 280 }
 281
 282 static void raw_parse_filename(const char *filename, QDict *options,
 283                                Error **errp)
 284 {
 285     bdrv_parse_filename_strip_prefix(filename, "file:", options);
 286 }
 287
 288 static QemuOptsList raw_runtime_opts = {
 289     .name = "raw",
 290     .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
 291     .desc = {
 292         {
 293             .name = "filename",
 294             .type = QEMU_OPT_STRING,
 295             .help = "File name of the image",
 296         },
 297         {
 298             .name = "aio",
 299             .type = QEMU_OPT_STRING,
 300             .help = "host AIO implementation (threads, native)",
 301         },
 302         {
 303             .name = "locking",
 304             .type = QEMU_OPT_STRING,
 305             .help = "file locking mode (on/off/auto, default: auto)",
 306         },
 307         { /* end of list */ }
 308     },
 309 };
 310
 311 static bool get_aio_option(QemuOpts *opts, int flags, Error **errp)
 312 {
 313     BlockdevAioOptions aio, aio_default;
 314
 315     aio_default = (flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE
 316                                               : BLOCKDEV_AIO_OPTIONS_THREADS;
 317     aio = qapi_enum_parse(&BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
 318                           aio_default, errp);
 319
 320     switch (aio) {
 321     case BLOCKDEV_AIO_OPTIONS_NATIVE:
 322         return true;
 323     case BLOCKDEV_AIO_OPTIONS_THREADS:
 324         return false;
 325     default:
 326         error_setg(errp, "Invalid AIO option");
 327     }
 328     return false;
 329 }
 330
 331 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
 332                     Error **errp)
 333 {
 334     BDRVRawState *s = bs->opaque;
 335     int access_flags;
 336     DWORD overlapped;
 337     QemuOpts *opts;
 338     Error *local_err = NULL;
 339     const char *filename;
 340     bool use_aio;
 341     OnOffAuto locking;
 342     int ret;
 343
 344     s->type = FTYPE_FILE;
 345
 346     opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
 347     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 348         ret = -EINVAL;
 349         goto fail;
 350     }
 351
 352     locking = qapi_enum_parse(&OnOffAuto_lookup,
 353                               qemu_opt_get(opts, "locking"),
 354                               ON_OFF_AUTO_AUTO, &local_err);
 355     if (local_err) {
 356         error_propagate(errp, local_err);
 357         ret = -EINVAL;
 358         goto fail;
 359     }
 360     switch (locking) {
 361     case ON_OFF_AUTO_ON:
 362         error_setg(errp, "locking=on is not supported on Windows");
 363         ret = -EINVAL;
 364         goto fail;
 365     case ON_OFF_AUTO_OFF:
 366     case ON_OFF_AUTO_AUTO:
 367         break;
 368     default:
 369         g_assert_not_reached();
 370     }
 371
 372     filename = qemu_opt_get(opts, "filename");
 373
 374     use_aio = get_aio_option(opts, flags, &local_err);
 375     if (local_err) {
 376         error_propagate(errp, local_err);
 377         ret = -EINVAL;
 378         goto fail;
 379     }
 380
 381     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
 382
 383     if (filename[0] && filename[1] == ':') {
 384         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
 385     } else if (filename[0] == '\\' && filename[1] == '\\') {
 386         s->drive_path[0] = 0;
 387     } else {
 388         /* Relative path.  */
 389         char buf[MAX_PATH];
 390         GetCurrentDirectory(MAX_PATH, buf);
 391         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
 392     }
 393
 394     s->hfile = CreateFile(filename, access_flags,
 395                           FILE_SHARE_READ, NULL,
 396                           OPEN_EXISTING, overlapped, NULL);
 397     if (s->hfile == INVALID_HANDLE_VALUE) {
 398         int err = GetLastError();
 399
 400         error_setg_win32(errp, err, "Could not open '%s'", filename);
 401         if (err == ERROR_ACCESS_DENIED) {
 402             ret = -EACCES;
 403         } else {
 404             ret = -EINVAL;
 405         }
 406         goto fail;
 407     }
 408
 409     if (use_aio) {
 410         s->aio = win32_aio_init();
 411         if (s->aio == NULL) {
 412             CloseHandle(s->hfile);
 413             error_setg(errp, "Could not initialize AIO");
 414             ret = -EINVAL;
 415             goto fail;
 416         }
 417
 418         ret = win32_aio_attach(s->aio, s->hfile);
 419         if (ret < 0) {
 420             win32_aio_cleanup(s->aio);
 421             CloseHandle(s->hfile);
 422             error_setg_errno(errp, -ret, "Could not enable AIO");
 423             goto fail;
 424         }
 425
 426         win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
 427     }
 428
 429     /* When extending regular files, we get zeros from the OS */
 430     bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
 431
 432     ret = 0;
 433 fail:
 434     qemu_opts_del(opts);
 435     return ret;
 436 }
 437
 438 static BlockAIOCB *raw_aio_preadv(BlockDriverState *bs,
 439                                   uint64_t offset, uint64_t bytes,
 440                                   QEMUIOVector *qiov, int flags,
 441                                   BlockCompletionFunc *cb, void *opaque)
 442 {
 443     BDRVRawState *s = bs->opaque;
 444     if (s->aio) {
 445         return win32_aio_submit(bs, s->aio, s->hfile, offset, bytes, qiov,
 446                                 cb, opaque, QEMU_AIO_READ);
 447     } else {
 448         return paio_submit(bs, s->hfile, offset, qiov, bytes,
 449                            cb, opaque, QEMU_AIO_READ);
 450     }
 451 }
 452
 453 static BlockAIOCB *raw_aio_pwritev(BlockDriverState *bs,
 454                                    uint64_t offset, uint64_t bytes,
 455                                    QEMUIOVector *qiov, int flags,
 456                                    BlockCompletionFunc *cb, void *opaque)
 457 {
 458     BDRVRawState *s = bs->opaque;
 459     if (s->aio) {
 460         return win32_aio_submit(bs, s->aio, s->hfile, offset, bytes, qiov,
 461                                 cb, opaque, QEMU_AIO_WRITE);
 462     } else {
 463         return paio_submit(bs, s->hfile, offset, qiov, bytes,
 464                            cb, opaque, QEMU_AIO_WRITE);
 465     }
 466 }
 467
 468 static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
 469                          BlockCompletionFunc *cb, void *opaque)
 470 {
 471     BDRVRawState *s = bs->opaque;
 472     return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
 473 }
 474
 475 static void raw_close(BlockDriverState *bs)
 476 {
 477     BDRVRawState *s = bs->opaque;
 478
 479     if (s->aio) {
 480         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 481         win32_aio_cleanup(s->aio);
 482         s->aio = NULL;
 483     }
 484
 485     CloseHandle(s->hfile);
 486     if (bs->open_flags & BDRV_O_TEMPORARY) {
 487         unlink(bs->filename);
 488     }
 489 }
 490
 491 static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset,
 492                                         bool exact, PreallocMode prealloc,
 493                                         BdrvRequestFlags flags, Error **errp)
 494 {
 495     BDRVRawState *s = bs->opaque;
 496     LONG low, high;
 497     DWORD dwPtrLow;
 498
 499     if (prealloc != PREALLOC_MODE_OFF) {
 500         error_setg(errp, "Unsupported preallocation mode '%s'",
 501                    PreallocMode_str(prealloc));
 502         return -ENOTSUP;
 503     }
 504
 505     low = offset;
 506     high = offset >> 32;
 507
 508     /*
 509      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
 510      * and GetLastError doesn't return NO_ERROR.
 511      */
 512     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
 513     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 514         error_setg_win32(errp, GetLastError(), "SetFilePointer error");
 515         return -EIO;
 516     }
 517     if (SetEndOfFile(s->hfile) == 0) {
 518         error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
 519         return -EIO;
 520     }
 521     return 0;
 522 }
 523
 524 static int64_t raw_getlength(BlockDriverState *bs)
 525 {
 526     BDRVRawState *s = bs->opaque;
 527     LARGE_INTEGER l;
 528     ULARGE_INTEGER available, total, total_free;
 529     DISK_GEOMETRY_EX dg;
 530     DWORD count;
 531     BOOL status;
 532
 533     switch(s->type) {
 534     case FTYPE_FILE:
 535         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
 536         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
 537             return -EIO;
 538         break;
 539     case FTYPE_CD:
 540         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
 541             return -EIO;
 542         l.QuadPart = total.QuadPart;
 543         break;
 544     case FTYPE_HARDDISK:
 545         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 546                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 547         if (status != 0) {
 548             l = dg.DiskSize;
 549         }
 550         break;
 551     default:
 552         return -EIO;
 553     }
 554     return l.QuadPart;
 555 }
 556
 557 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
 558 {
 559     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
 560                                               DWORD * high);
 561     get_compressed_t get_compressed;
 562     struct _stati64 st;
 563     const char *filename = bs->filename;
 564     /* WinNT support GetCompressedFileSize to determine allocate size */
 565     get_compressed =
 566         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
 567                                             "GetCompressedFileSizeA");
 568     if (get_compressed) {
 569         DWORD high, low;
 570         low = get_compressed(filename, &high);
 571         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
 572             return (((int64_t) high) << 32) + low;
 573         }
 574     }
 575
 576     if (_stati64(filename, &st) < 0) {
 577         return -1;
 578     }
 579     return st.st_size;
 580 }
 581
 582 static int raw_co_create(BlockdevCreateOptions *options, Error **errp)
 583 {
 584     BlockdevCreateOptionsFile *file_opts;
 585     int fd;
 586
 587     assert(options->driver == BLOCKDEV_DRIVER_FILE);
 588     file_opts = &options->u.file;
 589
 590     if (file_opts->has_preallocation) {
 591         error_setg(errp, "Preallocation is not supported on Windows");
 592         return -EINVAL;
 593     }
 594     if (file_opts->has_nocow) {
 595         error_setg(errp, "nocow is not supported on Windows");
 596         return -EINVAL;
 597     }
 598
 599     fd = qemu_create(file_opts->filename, O_WRONLY | O_TRUNC | O_BINARY,
 600                      0644, errp);
 601     if (fd < 0) {
 602         return -EIO;
 603     }
 604     set_sparse(fd);
 605     ftruncate(fd, file_opts->size);
 606     qemu_close(fd);
 607
 608     return 0;
 609 }
 610
 611 static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
 612                                            const char *filename,
 613                                            QemuOpts *opts,
 614                                            Error **errp)
 615 {
 616     BlockdevCreateOptions options;
 617     int64_t total_size = 0;
 618
 619     strstart(filename, "file:", &filename);
 620
 621     /* Read out options */
 622     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 623                           BDRV_SECTOR_SIZE);
 624
 625     options = (BlockdevCreateOptions) {
 626         .driver     = BLOCKDEV_DRIVER_FILE,
 627         .u.file     = {
 628             .filename           = (char *) filename,
 629             .size               = total_size,
 630             .has_preallocation  = false,
 631             .has_nocow          = false,
 632         },
 633     };
 634     return raw_co_create(&options, errp);
 635 }
 636
 637 static QemuOptsList raw_create_opts = {
 638     .name = "raw-create-opts",
 639     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
 640     .desc = {
 641         {
 642             .name = BLOCK_OPT_SIZE,
 643             .type = QEMU_OPT_SIZE,
 644             .help = "Virtual disk size"
 645         },
 646         { /* end of list */ }
 647     }
 648 };
 649
 650 BlockDriver bdrv_file = {
 651     .format_name        = "file",
 652     .protocol_name      = "file",
 653     .instance_size      = sizeof(BDRVRawState),
 654     .bdrv_needs_filename = true,
 655     .bdrv_parse_filename = raw_parse_filename,
 656     .bdrv_file_open     = raw_open,
 657     .bdrv_refresh_limits = raw_probe_alignment,
 658     .bdrv_close         = raw_close,
 659     .bdrv_co_create_opts = raw_co_create_opts,
 660     .bdrv_has_zero_init = bdrv_has_zero_init_1,
 661
 662     .bdrv_aio_preadv    = raw_aio_preadv,
 663     .bdrv_aio_pwritev   = raw_aio_pwritev,
 664     .bdrv_aio_flush     = raw_aio_flush,
 665
 666     .bdrv_co_truncate   = raw_co_truncate,
 667     .bdrv_getlength     = raw_getlength,
 668     .bdrv_get_allocated_file_size
 669                         = raw_get_allocated_file_size,
 670
 671     .create_opts        = &raw_create_opts,
 672 };
 673
 674 /***********************************************/
 675 /* host device */
 676
 677 static int find_cdrom(char *cdrom_name, int cdrom_name_size)
 678 {
 679     char drives[256], *pdrv = drives;
 680     UINT type;
 681
 682     memset(drives, 0, sizeof(drives));
 683     GetLogicalDriveStrings(sizeof(drives), drives);
 684     while(pdrv[0] != '\0') {
 685         type = GetDriveType(pdrv);
 686         switch(type) {
 687         case DRIVE_CDROM:
 688             snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
 689             return 0;
 690             break;
 691         }
 692         pdrv += lstrlen(pdrv) + 1;
 693     }
 694     return -1;
 695 }
 696
 697 static int find_device_type(BlockDriverState *bs, const char *filename)
 698 {
 699     BDRVRawState *s = bs->opaque;
 700     UINT type;
 701     const char *p;
 702
 703     if (strstart(filename, "\\\\.\\", &p) ||
 704         strstart(filename, "//./", &p)) {
 705         if (stristart(p, "PhysicalDrive", NULL))
 706             return FTYPE_HARDDISK;
 707         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
 708         type = GetDriveType(s->drive_path);
 709         switch (type) {
 710         case DRIVE_REMOVABLE:
 711         case DRIVE_FIXED:
 712             return FTYPE_HARDDISK;
 713         case DRIVE_CDROM:
 714             return FTYPE_CD;
 715         default:
 716             return FTYPE_FILE;
 717         }
 718     } else {
 719         return FTYPE_FILE;
 720     }
 721 }
 722
 723 static int hdev_probe_device(const char *filename)
 724 {
 725     if (strstart(filename, "/dev/cdrom", NULL))
 726         return 100;
 727     if (is_windows_drive(filename))
 728         return 100;
 729     return 0;
 730 }
 731
 732 static void hdev_parse_filename(const char *filename, QDict *options,
 733                                 Error **errp)
 734 {
 735     bdrv_parse_filename_strip_prefix(filename, "host_device:", options);
 736 }
 737
 738 static void hdev_refresh_limits(BlockDriverState *bs, Error **errp)
 739 {
 740     /* XXX Does Windows support AIO on less than 512-byte alignment? */
 741     bs->bl.request_alignment = 512;
 742 }
 743
 744 static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
 745                      Error **errp)
 746 {
 747     BDRVRawState *s = bs->opaque;
 748     int access_flags, create_flags;
 749     int ret = 0;
 750     DWORD overlapped;
 751     char device_name[64];
 752
 753     Error *local_err = NULL;
 754     const char *filename;
 755     bool use_aio;
 756
 757     QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
 758                                       &error_abort);
 759     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 760         ret = -EINVAL;
 761         goto done;
 762     }
 763
 764     filename = qemu_opt_get(opts, "filename");
 765
 766     use_aio = get_aio_option(opts, flags, &local_err);
 767     if (!local_err && use_aio) {
 768         error_setg(&local_err, "AIO is not supported on Windows host devices");
 769     }
 770     if (local_err) {
 771         error_propagate(errp, local_err);
 772         ret = -EINVAL;
 773         goto done;
 774     }
 775
 776     if (strstart(filename, "/dev/cdrom", NULL)) {
 777         if (find_cdrom(device_name, sizeof(device_name)) < 0) {
 778             error_setg(errp, "Could not open CD-ROM drive");
 779             ret = -ENOENT;
 780             goto done;
 781         }
 782         filename = device_name;
 783     } else {
 784         /* transform drive letters into device name */
 785         if (((filename[0] >= 'a' && filename[0] <= 'z') ||
 786              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 787             filename[1] == ':' && filename[2] == '\0') {
 788             snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
 789             filename = device_name;
 790         }
 791     }
 792     s->type = find_device_type(bs, filename);
 793
 794     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
 795
 796     create_flags = OPEN_EXISTING;
 797
 798     s->hfile = CreateFile(filename, access_flags,
 799                           FILE_SHARE_READ, NULL,
 800                           create_flags, overlapped, NULL);
 801     if (s->hfile == INVALID_HANDLE_VALUE) {
 802         int err = GetLastError();
 803
 804         if (err == ERROR_ACCESS_DENIED) {
 805             ret = -EACCES;
 806         } else {
 807             ret = -EINVAL;
 808         }
 809         error_setg_errno(errp, -ret, "Could not open device");
 810         goto done;
 811     }
 812
 813 done:
 814     qemu_opts_del(opts);
 815     return ret;
 816 }
 817
 818 static BlockDriver bdrv_host_device = {
 819     .format_name        = "host_device",
 820     .protocol_name      = "host_device",
 821     .instance_size      = sizeof(BDRVRawState),
 822     .bdrv_needs_filename = true,
 823     .bdrv_parse_filename = hdev_parse_filename,
 824     .bdrv_probe_device  = hdev_probe_device,
 825     .bdrv_file_open     = hdev_open,
 826     .bdrv_close         = raw_close,
 827     .bdrv_refresh_limits = hdev_refresh_limits,
 828
 829     .bdrv_aio_preadv    = raw_aio_preadv,
 830     .bdrv_aio_pwritev   = raw_aio_pwritev,
 831     .bdrv_aio_flush     = raw_aio_flush,
 832
 833     .bdrv_detach_aio_context = raw_detach_aio_context,
 834     .bdrv_attach_aio_context = raw_attach_aio_context,
 835
 836     .bdrv_getlength      = raw_getlength,
 837     .has_variable_length = true,
 838
 839     .bdrv_get_allocated_file_size
 840                         = raw_get_allocated_file_size,
 841 };
 842
 843 static void bdrv_file_init(void)
 844 {
 845     bdrv_register(&bdrv_file);
 846     bdrv_register(&bdrv_host_device);
 847 }
 848
 849 block_init(bdrv_file_init);