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_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     }
 255 }
 256
 257 static void raw_parse_flags(int flags, bool use_aio, int *access_flags,
 258                             DWORD *overlapped)
 259 {
 260     assert(access_flags != NULL);
 261     assert(overlapped != NULL);
 262
 263     if (flags & BDRV_O_RDWR) {
 264         *access_flags = GENERIC_READ | GENERIC_WRITE;
 265     } else {
 266         *access_flags = GENERIC_READ;
 267     }
 268
 269     *overlapped = FILE_ATTRIBUTE_NORMAL;
 270     if (use_aio) {
 271         *overlapped |= FILE_FLAG_OVERLAPPED;
 272     }
 273     if (flags & BDRV_O_NOCACHE) {
 274         *overlapped |= FILE_FLAG_NO_BUFFERING;
 275     }
 276 }
 277
 278 static void raw_parse_filename(const char *filename, QDict *options,
 279                                Error **errp)
 280 {
 281     bdrv_parse_filename_strip_prefix(filename, "file:", options);
 282 }
 283
 284 static QemuOptsList raw_runtime_opts = {
 285     .name = "raw",
 286     .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
 287     .desc = {
 288         {
 289             .name = "filename",
 290             .type = QEMU_OPT_STRING,
 291             .help = "File name of the image",
 292         },
 293         {
 294             .name = "aio",
 295             .type = QEMU_OPT_STRING,
 296             .help = "host AIO implementation (threads, native)",
 297         },
 298         { /* end of list */ }
 299     },
 300 };
 301
 302 static bool get_aio_option(QemuOpts *opts, int flags, Error **errp)
 303 {
 304     BlockdevAioOptions aio, aio_default;
 305
 306     aio_default = (flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE
 307                                               : BLOCKDEV_AIO_OPTIONS_THREADS;
 308     aio = qapi_enum_parse(&BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
 309                           aio_default, errp);
 310
 311     switch (aio) {
 312     case BLOCKDEV_AIO_OPTIONS_NATIVE:
 313         return true;
 314     case BLOCKDEV_AIO_OPTIONS_THREADS:
 315         return false;
 316     default:
 317         error_setg(errp, "Invalid AIO option");
 318     }
 319     return false;
 320 }
 321
 322 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
 323                     Error **errp)
 324 {
 325     BDRVRawState *s = bs->opaque;
 326     int access_flags;
 327     DWORD overlapped;
 328     QemuOpts *opts;
 329     Error *local_err = NULL;
 330     const char *filename;
 331     bool use_aio;
 332     int ret;
 333
 334     s->type = FTYPE_FILE;
 335
 336     opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
 337     qemu_opts_absorb_qdict(opts, options, &local_err);
 338     if (local_err) {
 339         error_propagate(errp, local_err);
 340         ret = -EINVAL;
 341         goto fail;
 342     }
 343
 344     if (qdict_get_try_bool(options, "locking", false)) {
 345         error_setg(errp, "locking=on is not supported on Windows");
 346         ret = -EINVAL;
 347         goto fail;
 348     }
 349
 350     filename = qemu_opt_get(opts, "filename");
 351
 352     use_aio = get_aio_option(opts, flags, &local_err);
 353     if (local_err) {
 354         error_propagate(errp, local_err);
 355         ret = -EINVAL;
 356         goto fail;
 357     }
 358
 359     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
 360
 361     if (filename[0] && filename[1] == ':') {
 362         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
 363     } else if (filename[0] == '\\' && filename[1] == '\\') {
 364         s->drive_path[0] = 0;
 365     } else {
 366         /* Relative path.  */
 367         char buf[MAX_PATH];
 368         GetCurrentDirectory(MAX_PATH, buf);
 369         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
 370     }
 371
 372     s->hfile = CreateFile(filename, access_flags,
 373                           FILE_SHARE_READ, NULL,
 374                           OPEN_EXISTING, overlapped, NULL);
 375     if (s->hfile == INVALID_HANDLE_VALUE) {
 376         int err = GetLastError();
 377
 378         error_setg_win32(errp, err, "Could not open '%s'", filename);
 379         if (err == ERROR_ACCESS_DENIED) {
 380             ret = -EACCES;
 381         } else {
 382             ret = -EINVAL;
 383         }
 384         goto fail;
 385     }
 386
 387     if (use_aio) {
 388         s->aio = win32_aio_init();
 389         if (s->aio == NULL) {
 390             CloseHandle(s->hfile);
 391             error_setg(errp, "Could not initialize AIO");
 392             ret = -EINVAL;
 393             goto fail;
 394         }
 395
 396         ret = win32_aio_attach(s->aio, s->hfile);
 397         if (ret < 0) {
 398             win32_aio_cleanup(s->aio);
 399             CloseHandle(s->hfile);
 400             error_setg_errno(errp, -ret, "Could not enable AIO");
 401             goto fail;
 402         }
 403
 404         win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
 405     }
 406
 407     ret = 0;
 408 fail:
 409     qemu_opts_del(opts);
 410     return ret;
 411 }
 412
 413 static BlockAIOCB *raw_aio_readv(BlockDriverState *bs,
 414                          int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 415                          BlockCompletionFunc *cb, void *opaque)
 416 {
 417     BDRVRawState *s = bs->opaque;
 418     if (s->aio) {
 419         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
 420                                 nb_sectors, cb, opaque, QEMU_AIO_READ);
 421     } else {
 422         return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
 423                            nb_sectors << BDRV_SECTOR_BITS,
 424                            cb, opaque, QEMU_AIO_READ);
 425     }
 426 }
 427
 428 static BlockAIOCB *raw_aio_writev(BlockDriverState *bs,
 429                           int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 430                           BlockCompletionFunc *cb, void *opaque)
 431 {
 432     BDRVRawState *s = bs->opaque;
 433     if (s->aio) {
 434         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
 435                                 nb_sectors, cb, opaque, QEMU_AIO_WRITE);
 436     } else {
 437         return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
 438                            nb_sectors << BDRV_SECTOR_BITS,
 439                            cb, opaque, QEMU_AIO_WRITE);
 440     }
 441 }
 442
 443 static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
 444                          BlockCompletionFunc *cb, void *opaque)
 445 {
 446     BDRVRawState *s = bs->opaque;
 447     return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
 448 }
 449
 450 static void raw_close(BlockDriverState *bs)
 451 {
 452     BDRVRawState *s = bs->opaque;
 453
 454     if (s->aio) {
 455         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 456         win32_aio_cleanup(s->aio);
 457         s->aio = NULL;
 458     }
 459
 460     CloseHandle(s->hfile);
 461     if (bs->open_flags & BDRV_O_TEMPORARY) {
 462         unlink(bs->filename);
 463     }
 464 }
 465
 466 static int raw_truncate(BlockDriverState *bs, int64_t offset,
 467                         PreallocMode prealloc, Error **errp)
 468 {
 469     BDRVRawState *s = bs->opaque;
 470     LONG low, high;
 471     DWORD dwPtrLow;
 472
 473     if (prealloc != PREALLOC_MODE_OFF) {
 474         error_setg(errp, "Unsupported preallocation mode '%s'",
 475                    PreallocMode_str(prealloc));
 476         return -ENOTSUP;
 477     }
 478
 479     low = offset;
 480     high = offset >> 32;
 481
 482     /*
 483      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
 484      * and GetLastError doesn't return NO_ERROR.
 485      */
 486     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
 487     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 488         error_setg_win32(errp, GetLastError(), "SetFilePointer error");
 489         return -EIO;
 490     }
 491     if (SetEndOfFile(s->hfile) == 0) {
 492         error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
 493         return -EIO;
 494     }
 495     return 0;
 496 }
 497
 498 static int64_t raw_getlength(BlockDriverState *bs)
 499 {
 500     BDRVRawState *s = bs->opaque;
 501     LARGE_INTEGER l;
 502     ULARGE_INTEGER available, total, total_free;
 503     DISK_GEOMETRY_EX dg;
 504     DWORD count;
 505     BOOL status;
 506
 507     switch(s->type) {
 508     case FTYPE_FILE:
 509         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
 510         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
 511             return -EIO;
 512         break;
 513     case FTYPE_CD:
 514         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
 515             return -EIO;
 516         l.QuadPart = total.QuadPart;
 517         break;
 518     case FTYPE_HARDDISK:
 519         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 520                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 521         if (status != 0) {
 522             l = dg.DiskSize;
 523         }
 524         break;
 525     default:
 526         return -EIO;
 527     }
 528     return l.QuadPart;
 529 }
 530
 531 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
 532 {
 533     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
 534                                               DWORD * high);
 535     get_compressed_t get_compressed;
 536     struct _stati64 st;
 537     const char *filename = bs->filename;
 538     /* WinNT support GetCompressedFileSize to determine allocate size */
 539     get_compressed =
 540         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
 541                                             "GetCompressedFileSizeA");
 542     if (get_compressed) {
 543         DWORD high, low;
 544         low = get_compressed(filename, &high);
 545         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
 546             return (((int64_t) high) << 32) + low;
 547         }
 548     }
 549
 550     if (_stati64(filename, &st) < 0) {
 551         return -1;
 552     }
 553     return st.st_size;
 554 }
 555
 556 static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
 557 {
 558     int fd;
 559     int64_t total_size = 0;
 560
 561     strstart(filename, "file:", &filename);
 562
 563     /* Read out options */
 564     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 565                           BDRV_SECTOR_SIZE);
 566
 567     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
 568                    0644);
 569     if (fd < 0) {
 570         error_setg_errno(errp, errno, "Could not create file");
 571         return -EIO;
 572     }
 573     set_sparse(fd);
 574     ftruncate(fd, total_size);
 575     qemu_close(fd);
 576     return 0;
 577 }
 578
 579
 580 static QemuOptsList raw_create_opts = {
 581     .name = "raw-create-opts",
 582     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
 583     .desc = {
 584         {
 585             .name = BLOCK_OPT_SIZE,
 586             .type = QEMU_OPT_SIZE,
 587             .help = "Virtual disk size"
 588         },
 589         { /* end of list */ }
 590     }
 591 };
 592
 593 BlockDriver bdrv_file = {
 594     .format_name        = "file",
 595     .protocol_name      = "file",
 596     .instance_size      = sizeof(BDRVRawState),
 597     .bdrv_needs_filename = true,
 598     .bdrv_parse_filename = raw_parse_filename,
 599     .bdrv_file_open     = raw_open,
 600     .bdrv_refresh_limits = raw_probe_alignment,
 601     .bdrv_close         = raw_close,
 602     .bdrv_create        = raw_create,
 603     .bdrv_has_zero_init = bdrv_has_zero_init_1,
 604
 605     .bdrv_aio_readv     = raw_aio_readv,
 606     .bdrv_aio_writev    = raw_aio_writev,
 607     .bdrv_aio_flush     = raw_aio_flush,
 608
 609     .bdrv_truncate      = raw_truncate,
 610     .bdrv_getlength     = raw_getlength,
 611     .bdrv_get_allocated_file_size
 612                         = raw_get_allocated_file_size,
 613
 614     .create_opts        = &raw_create_opts,
 615 };
 616
 617 /***********************************************/
 618 /* host device */
 619
 620 static int find_cdrom(char *cdrom_name, int cdrom_name_size)
 621 {
 622     char drives[256], *pdrv = drives;
 623     UINT type;
 624
 625     memset(drives, 0, sizeof(drives));
 626     GetLogicalDriveStrings(sizeof(drives), drives);
 627     while(pdrv[0] != '\0') {
 628         type = GetDriveType(pdrv);
 629         switch(type) {
 630         case DRIVE_CDROM:
 631             snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
 632             return 0;
 633             break;
 634         }
 635         pdrv += lstrlen(pdrv) + 1;
 636     }
 637     return -1;
 638 }
 639
 640 static int find_device_type(BlockDriverState *bs, const char *filename)
 641 {
 642     BDRVRawState *s = bs->opaque;
 643     UINT type;
 644     const char *p;
 645
 646     if (strstart(filename, "\\\\.\\", &p) ||
 647         strstart(filename, "//./", &p)) {
 648         if (stristart(p, "PhysicalDrive", NULL))
 649             return FTYPE_HARDDISK;
 650         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
 651         type = GetDriveType(s->drive_path);
 652         switch (type) {
 653         case DRIVE_REMOVABLE:
 654         case DRIVE_FIXED:
 655             return FTYPE_HARDDISK;
 656         case DRIVE_CDROM:
 657             return FTYPE_CD;
 658         default:
 659             return FTYPE_FILE;
 660         }
 661     } else {
 662         return FTYPE_FILE;
 663     }
 664 }
 665
 666 static int hdev_probe_device(const char *filename)
 667 {
 668     if (strstart(filename, "/dev/cdrom", NULL))
 669         return 100;
 670     if (is_windows_drive(filename))
 671         return 100;
 672     return 0;
 673 }
 674
 675 static void hdev_parse_filename(const char *filename, QDict *options,
 676                                 Error **errp)
 677 {
 678     bdrv_parse_filename_strip_prefix(filename, "host_device:", options);
 679 }
 680
 681 static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
 682                      Error **errp)
 683 {
 684     BDRVRawState *s = bs->opaque;
 685     int access_flags, create_flags;
 686     int ret = 0;
 687     DWORD overlapped;
 688     char device_name[64];
 689
 690     Error *local_err = NULL;
 691     const char *filename;
 692     bool use_aio;
 693
 694     QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
 695                                       &error_abort);
 696     qemu_opts_absorb_qdict(opts, options, &local_err);
 697     if (local_err) {
 698         error_propagate(errp, local_err);
 699         ret = -EINVAL;
 700         goto done;
 701     }
 702
 703     filename = qemu_opt_get(opts, "filename");
 704
 705     use_aio = get_aio_option(opts, flags, &local_err);
 706     if (!local_err && use_aio) {
 707         error_setg(&local_err, "AIO is not supported on Windows host devices");
 708     }
 709     if (local_err) {
 710         error_propagate(errp, local_err);
 711         ret = -EINVAL;
 712         goto done;
 713     }
 714
 715     if (strstart(filename, "/dev/cdrom", NULL)) {
 716         if (find_cdrom(device_name, sizeof(device_name)) < 0) {
 717             error_setg(errp, "Could not open CD-ROM drive");
 718             ret = -ENOENT;
 719             goto done;
 720         }
 721         filename = device_name;
 722     } else {
 723         /* transform drive letters into device name */
 724         if (((filename[0] >= 'a' && filename[0] <= 'z') ||
 725              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 726             filename[1] == ':' && filename[2] == '\0') {
 727             snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
 728             filename = device_name;
 729         }
 730     }
 731     s->type = find_device_type(bs, filename);
 732
 733     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
 734
 735     create_flags = OPEN_EXISTING;
 736
 737     s->hfile = CreateFile(filename, access_flags,
 738                           FILE_SHARE_READ, NULL,
 739                           create_flags, overlapped, NULL);
 740     if (s->hfile == INVALID_HANDLE_VALUE) {
 741         int err = GetLastError();
 742
 743         if (err == ERROR_ACCESS_DENIED) {
 744             ret = -EACCES;
 745         } else {
 746             ret = -EINVAL;
 747         }
 748         error_setg_errno(errp, -ret, "Could not open device");
 749         goto done;
 750     }
 751
 752 done:
 753     qemu_opts_del(opts);
 754     return ret;
 755 }
 756
 757 static BlockDriver bdrv_host_device = {
 758     .format_name        = "host_device",
 759     .protocol_name      = "host_device",
 760     .instance_size      = sizeof(BDRVRawState),
 761     .bdrv_needs_filename = true,
 762     .bdrv_parse_filename = hdev_parse_filename,
 763     .bdrv_probe_device  = hdev_probe_device,
 764     .bdrv_file_open     = hdev_open,
 765     .bdrv_close         = raw_close,
 766
 767     .bdrv_aio_readv     = raw_aio_readv,
 768     .bdrv_aio_writev    = raw_aio_writev,
 769     .bdrv_aio_flush     = raw_aio_flush,
 770
 771     .bdrv_detach_aio_context = raw_detach_aio_context,
 772     .bdrv_attach_aio_context = raw_attach_aio_context,
 773
 774     .bdrv_getlength      = raw_getlength,
 775     .has_variable_length = true,
 776
 777     .bdrv_get_allocated_file_size
 778                         = raw_get_allocated_file_size,
 779 };
 780
 781 static void bdrv_file_init(void)
 782 {
 783     bdrv_register(&bdrv_file);
 784     bdrv_register(&bdrv_host_device);
 785 }
 786
 787 block_init(bdrv_file_init);