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