block/raw-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 "qemu/timer.h"
  28 #include "block/block_int.h"
  29 #include "qemu/module.h"
  30 #include "raw-aio.h"
  31 #include "trace.h"
  32 #include "block/thread-pool.h"
  33 #include "qemu/iov.h"
  34 #include "qapi/qmp/qstring.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 sector_num, QEMUIOVector *qiov, int nb_sectors,
 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     }
 159     acb->aio_nbytes = nb_sectors * 512;
 160     acb->aio_offset = sector_num * 512;
 161
 162     trace_paio_submit(acb, opaque, sector_num, nb_sectors, type);
 163     pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
 164     return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
 165 }
 166
 167 int qemu_ftruncate64(int fd, int64_t length)
 168 {
 169     LARGE_INTEGER li;
 170     DWORD dw;
 171     LONG high;
 172     HANDLE h;
 173     BOOL res;
 174
 175     if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
 176         return -1;
 177
 178     h = (HANDLE)_get_osfhandle(fd);
 179
 180     /* get current position, ftruncate do not change position */
 181     li.HighPart = 0;
 182     li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
 183     if (li.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 184         return -1;
 185     }
 186
 187     high = length >> 32;
 188     dw = SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN);
 189     if (dw == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 190         return -1;
 191     }
 192     res = SetEndOfFile(h);
 193
 194     /* back to old position */
 195     SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
 196     return res ? 0 : -1;
 197 }
 198
 199 static int set_sparse(int fd)
 200 {
 201     DWORD returned;
 202     return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
 203                                  NULL, 0, NULL, 0, &returned, NULL);
 204 }
 205
 206 static void raw_detach_aio_context(BlockDriverState *bs)
 207 {
 208     BDRVRawState *s = bs->opaque;
 209
 210     if (s->aio) {
 211         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 212     }
 213 }
 214
 215 static void raw_attach_aio_context(BlockDriverState *bs,
 216                                    AioContext *new_context)
 217 {
 218     BDRVRawState *s = bs->opaque;
 219
 220     if (s->aio) {
 221         win32_aio_attach_aio_context(s->aio, new_context);
 222     }
 223 }
 224
 225 static void raw_probe_alignment(BlockDriverState *bs)
 226 {
 227     BDRVRawState *s = bs->opaque;
 228     DWORD sectorsPerCluster, freeClusters, totalClusters, count;
 229     DISK_GEOMETRY_EX dg;
 230     BOOL status;
 231
 232     if (s->type == FTYPE_CD) {
 233         bs->request_alignment = 2048;
 234         return;
 235     }
 236     if (s->type == FTYPE_HARDDISK) {
 237         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 238                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 239         if (status != 0) {
 240             bs->request_alignment = dg.Geometry.BytesPerSector;
 241             return;
 242         }
 243         /* try GetDiskFreeSpace too */
 244     }
 245
 246     if (s->drive_path[0]) {
 247         GetDiskFreeSpace(s->drive_path, &sectorsPerCluster,
 248                          &dg.Geometry.BytesPerSector,
 249                          &freeClusters, &totalClusters);
 250         bs->request_alignment = dg.Geometry.BytesPerSector;
 251     }
 252 }
 253
 254 static void raw_parse_flags(int flags, int *access_flags, DWORD *overlapped)
 255 {
 256     assert(access_flags != NULL);
 257     assert(overlapped != NULL);
 258
 259     if (flags & BDRV_O_RDWR) {
 260         *access_flags = GENERIC_READ | GENERIC_WRITE;
 261     } else {
 262         *access_flags = GENERIC_READ;
 263     }
 264
 265     *overlapped = FILE_ATTRIBUTE_NORMAL;
 266     if (flags & BDRV_O_NATIVE_AIO) {
 267         *overlapped |= FILE_FLAG_OVERLAPPED;
 268     }
 269     if (flags & BDRV_O_NOCACHE) {
 270         *overlapped |= FILE_FLAG_NO_BUFFERING;
 271     }
 272 }
 273
 274 static void raw_parse_filename(const char *filename, QDict *options,
 275                                Error **errp)
 276 {
 277     /* The filename does not have to be prefixed by the protocol name, since
 278      * "file" is the default protocol; therefore, the return value of this
 279      * function call can be ignored. */
 280     strstart(filename, "file:", &filename);
 281
 282     qdict_put_obj(options, "filename", QOBJECT(qstring_from_str(filename)));
 283 }
 284
 285 static QemuOptsList raw_runtime_opts = {
 286     .name = "raw",
 287     .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
 288     .desc = {
 289         {
 290             .name = "filename",
 291             .type = QEMU_OPT_STRING,
 292             .help = "File name of the image",
 293         },
 294         { /* end of list */ }
 295     },
 296 };
 297
 298 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
 299                     Error **errp)
 300 {
 301     BDRVRawState *s = bs->opaque;
 302     int access_flags;
 303     DWORD overlapped;
 304     QemuOpts *opts;
 305     Error *local_err = NULL;
 306     const char *filename;
 307     int ret;
 308
 309     s->type = FTYPE_FILE;
 310
 311     opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
 312     qemu_opts_absorb_qdict(opts, options, &local_err);
 313     if (local_err) {
 314         error_propagate(errp, local_err);
 315         ret = -EINVAL;
 316         goto fail;
 317     }
 318
 319     filename = qemu_opt_get(opts, "filename");
 320
 321     raw_parse_flags(flags, &access_flags, &overlapped);
 322
 323     if (filename[0] && filename[1] == ':') {
 324         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
 325     } else if (filename[0] == '\\' && filename[1] == '\\') {
 326         s->drive_path[0] = 0;
 327     } else {
 328         /* Relative path.  */
 329         char buf[MAX_PATH];
 330         GetCurrentDirectory(MAX_PATH, buf);
 331         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
 332     }
 333
 334     s->hfile = CreateFile(filename, access_flags,
 335                           FILE_SHARE_READ, NULL,
 336                           OPEN_EXISTING, overlapped, NULL);
 337     if (s->hfile == INVALID_HANDLE_VALUE) {
 338         int err = GetLastError();
 339
 340         if (err == ERROR_ACCESS_DENIED) {
 341             ret = -EACCES;
 342         } else {
 343             ret = -EINVAL;
 344         }
 345         goto fail;
 346     }
 347
 348     if (flags & BDRV_O_NATIVE_AIO) {
 349         s->aio = win32_aio_init();
 350         if (s->aio == NULL) {
 351             CloseHandle(s->hfile);
 352             error_setg(errp, "Could not initialize AIO");
 353             ret = -EINVAL;
 354             goto fail;
 355         }
 356
 357         ret = win32_aio_attach(s->aio, s->hfile);
 358         if (ret < 0) {
 359             win32_aio_cleanup(s->aio);
 360             CloseHandle(s->hfile);
 361             error_setg_errno(errp, -ret, "Could not enable AIO");
 362             goto fail;
 363         }
 364
 365         win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
 366     }
 367
 368     raw_probe_alignment(bs);
 369     ret = 0;
 370 fail:
 371     qemu_opts_del(opts);
 372     return ret;
 373 }
 374
 375 static BlockAIOCB *raw_aio_readv(BlockDriverState *bs,
 376                          int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 377                          BlockCompletionFunc *cb, void *opaque)
 378 {
 379     BDRVRawState *s = bs->opaque;
 380     if (s->aio) {
 381         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
 382                                 nb_sectors, cb, opaque, QEMU_AIO_READ);
 383     } else {
 384         return paio_submit(bs, s->hfile, sector_num, qiov, nb_sectors,
 385                            cb, opaque, QEMU_AIO_READ);
 386     }
 387 }
 388
 389 static BlockAIOCB *raw_aio_writev(BlockDriverState *bs,
 390                           int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 391                           BlockCompletionFunc *cb, void *opaque)
 392 {
 393     BDRVRawState *s = bs->opaque;
 394     if (s->aio) {
 395         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
 396                                 nb_sectors, cb, opaque, QEMU_AIO_WRITE);
 397     } else {
 398         return paio_submit(bs, s->hfile, sector_num, qiov, nb_sectors,
 399                            cb, opaque, QEMU_AIO_WRITE);
 400     }
 401 }
 402
 403 static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
 404                          BlockCompletionFunc *cb, void *opaque)
 405 {
 406     BDRVRawState *s = bs->opaque;
 407     return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
 408 }
 409
 410 static void raw_close(BlockDriverState *bs)
 411 {
 412     BDRVRawState *s = bs->opaque;
 413
 414     if (s->aio) {
 415         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 416         win32_aio_cleanup(s->aio);
 417         s->aio = NULL;
 418     }
 419
 420     CloseHandle(s->hfile);
 421     if (bs->open_flags & BDRV_O_TEMPORARY) {
 422         unlink(bs->filename);
 423     }
 424 }
 425
 426 static int raw_truncate(BlockDriverState *bs, int64_t offset)
 427 {
 428     BDRVRawState *s = bs->opaque;
 429     LONG low, high;
 430     DWORD dwPtrLow;
 431
 432     low = offset;
 433     high = offset >> 32;
 434
 435     /*
 436      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
 437      * and GetLastError doesn't return NO_ERROR.
 438      */
 439     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
 440     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 441         fprintf(stderr, "SetFilePointer error: %lu\n", GetLastError());
 442         return -EIO;
 443     }
 444     if (SetEndOfFile(s->hfile) == 0) {
 445         fprintf(stderr, "SetEndOfFile error: %lu\n", GetLastError());
 446         return -EIO;
 447     }
 448     return 0;
 449 }
 450
 451 static int64_t raw_getlength(BlockDriverState *bs)
 452 {
 453     BDRVRawState *s = bs->opaque;
 454     LARGE_INTEGER l;
 455     ULARGE_INTEGER available, total, total_free;
 456     DISK_GEOMETRY_EX dg;
 457     DWORD count;
 458     BOOL status;
 459
 460     switch(s->type) {
 461     case FTYPE_FILE:
 462         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
 463         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
 464             return -EIO;
 465         break;
 466     case FTYPE_CD:
 467         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
 468             return -EIO;
 469         l.QuadPart = total.QuadPart;
 470         break;
 471     case FTYPE_HARDDISK:
 472         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 473                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 474         if (status != 0) {
 475             l = dg.DiskSize;
 476         }
 477         break;
 478     default:
 479         return -EIO;
 480     }
 481     return l.QuadPart;
 482 }
 483
 484 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
 485 {
 486     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
 487                                               DWORD * high);
 488     get_compressed_t get_compressed;
 489     struct _stati64 st;
 490     const char *filename = bs->filename;
 491     /* WinNT support GetCompressedFileSize to determine allocate size */
 492     get_compressed =
 493         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
 494                                             "GetCompressedFileSizeA");
 495     if (get_compressed) {
 496         DWORD high, low;
 497         low = get_compressed(filename, &high);
 498         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
 499             return (((int64_t) high) << 32) + low;
 500         }
 501     }
 502
 503     if (_stati64(filename, &st) < 0) {
 504         return -1;
 505     }
 506     return st.st_size;
 507 }
 508
 509 static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
 510 {
 511     int fd;
 512     int64_t total_size = 0;
 513
 514     strstart(filename, "file:", &filename);
 515
 516     /* Read out options */
 517     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 518                           BDRV_SECTOR_SIZE);
 519
 520     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
 521                    0644);
 522     if (fd < 0) {
 523         error_setg_errno(errp, errno, "Could not create file");
 524         return -EIO;
 525     }
 526     set_sparse(fd);
 527     ftruncate(fd, total_size);
 528     qemu_close(fd);
 529     return 0;
 530 }
 531
 532
 533 static QemuOptsList raw_create_opts = {
 534     .name = "raw-create-opts",
 535     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
 536     .desc = {
 537         {
 538             .name = BLOCK_OPT_SIZE,
 539             .type = QEMU_OPT_SIZE,
 540             .help = "Virtual disk size"
 541         },
 542         { /* end of list */ }
 543     }
 544 };
 545
 546 BlockDriver bdrv_file = {
 547     .format_name        = "file",
 548     .protocol_name      = "file",
 549     .instance_size      = sizeof(BDRVRawState),
 550     .bdrv_needs_filename = true,
 551     .bdrv_parse_filename = raw_parse_filename,
 552     .bdrv_file_open     = raw_open,
 553     .bdrv_close         = raw_close,
 554     .bdrv_create        = raw_create,
 555     .bdrv_has_zero_init = bdrv_has_zero_init_1,
 556
 557     .bdrv_aio_readv     = raw_aio_readv,
 558     .bdrv_aio_writev    = raw_aio_writev,
 559     .bdrv_aio_flush     = raw_aio_flush,
 560
 561     .bdrv_truncate      = raw_truncate,
 562     .bdrv_getlength     = raw_getlength,
 563     .bdrv_get_allocated_file_size
 564                         = raw_get_allocated_file_size,
 565
 566     .create_opts        = &raw_create_opts,
 567 };
 568
 569 /***********************************************/
 570 /* host device */
 571
 572 static int find_cdrom(char *cdrom_name, int cdrom_name_size)
 573 {
 574     char drives[256], *pdrv = drives;
 575     UINT type;
 576
 577     memset(drives, 0, sizeof(drives));
 578     GetLogicalDriveStrings(sizeof(drives), drives);
 579     while(pdrv[0] != '\0') {
 580         type = GetDriveType(pdrv);
 581         switch(type) {
 582         case DRIVE_CDROM:
 583             snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
 584             return 0;
 585             break;
 586         }
 587         pdrv += lstrlen(pdrv) + 1;
 588     }
 589     return -1;
 590 }
 591
 592 static int find_device_type(BlockDriverState *bs, const char *filename)
 593 {
 594     BDRVRawState *s = bs->opaque;
 595     UINT type;
 596     const char *p;
 597
 598     if (strstart(filename, "\\\\.\\", &p) ||
 599         strstart(filename, "//./", &p)) {
 600         if (stristart(p, "PhysicalDrive", NULL))
 601             return FTYPE_HARDDISK;
 602         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
 603         type = GetDriveType(s->drive_path);
 604         switch (type) {
 605         case DRIVE_REMOVABLE:
 606         case DRIVE_FIXED:
 607             return FTYPE_HARDDISK;
 608         case DRIVE_CDROM:
 609             return FTYPE_CD;
 610         default:
 611             return FTYPE_FILE;
 612         }
 613     } else {
 614         return FTYPE_FILE;
 615     }
 616 }
 617
 618 static int hdev_probe_device(const char *filename)
 619 {
 620     if (strstart(filename, "/dev/cdrom", NULL))
 621         return 100;
 622     if (is_windows_drive(filename))
 623         return 100;
 624     return 0;
 625 }
 626
 627 static void hdev_parse_filename(const char *filename, QDict *options,
 628                                 Error **errp)
 629 {
 630     /* The prefix is optional, just as for "file". */
 631     strstart(filename, "host_device:", &filename);
 632
 633     qdict_put_obj(options, "filename", QOBJECT(qstring_from_str(filename)));
 634 }
 635
 636 static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
 637                      Error **errp)
 638 {
 639     BDRVRawState *s = bs->opaque;
 640     int access_flags, create_flags;
 641     int ret = 0;
 642     DWORD overlapped;
 643     char device_name[64];
 644
 645     Error *local_err = NULL;
 646     const char *filename;
 647
 648     QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
 649                                       &error_abort);
 650     qemu_opts_absorb_qdict(opts, options, &local_err);
 651     if (local_err) {
 652         error_propagate(errp, local_err);
 653         ret = -EINVAL;
 654         goto done;
 655     }
 656
 657     filename = qemu_opt_get(opts, "filename");
 658
 659     if (strstart(filename, "/dev/cdrom", NULL)) {
 660         if (find_cdrom(device_name, sizeof(device_name)) < 0) {
 661             error_setg(errp, "Could not open CD-ROM drive");
 662             ret = -ENOENT;
 663             goto done;
 664         }
 665         filename = device_name;
 666     } else {
 667         /* transform drive letters into device name */
 668         if (((filename[0] >= 'a' && filename[0] <= 'z') ||
 669              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 670             filename[1] == ':' && filename[2] == '\0') {
 671             snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
 672             filename = device_name;
 673         }
 674     }
 675     s->type = find_device_type(bs, filename);
 676
 677     raw_parse_flags(flags, &access_flags, &overlapped);
 678
 679     create_flags = OPEN_EXISTING;
 680
 681     s->hfile = CreateFile(filename, access_flags,
 682                           FILE_SHARE_READ, NULL,
 683                           create_flags, overlapped, NULL);
 684     if (s->hfile == INVALID_HANDLE_VALUE) {
 685         int err = GetLastError();
 686
 687         if (err == ERROR_ACCESS_DENIED) {
 688             ret = -EACCES;
 689         } else {
 690             ret = -EINVAL;
 691         }
 692         error_setg_errno(errp, -ret, "Could not open device");
 693         goto done;
 694     }
 695
 696 done:
 697     qemu_opts_del(opts);
 698     return ret;
 699 }
 700
 701 static BlockDriver bdrv_host_device = {
 702     .format_name        = "host_device",
 703     .protocol_name      = "host_device",
 704     .instance_size      = sizeof(BDRVRawState),
 705     .bdrv_needs_filename = true,
 706     .bdrv_parse_filename = hdev_parse_filename,
 707     .bdrv_probe_device  = hdev_probe_device,
 708     .bdrv_file_open     = hdev_open,
 709     .bdrv_close         = raw_close,
 710
 711     .bdrv_aio_readv     = raw_aio_readv,
 712     .bdrv_aio_writev    = raw_aio_writev,
 713     .bdrv_aio_flush     = raw_aio_flush,
 714
 715     .bdrv_detach_aio_context = raw_detach_aio_context,
 716     .bdrv_attach_aio_context = raw_attach_aio_context,
 717
 718     .bdrv_getlength      = raw_getlength,
 719     .has_variable_length = true,
 720
 721     .bdrv_get_allocated_file_size
 722                         = raw_get_allocated_file_size,
 723 };
 724
 725 static void bdrv_file_init(void)
 726 {
 727     bdrv_register(&bdrv_file);
 728     bdrv_register(&bdrv_host_device);
 729 }
 730
 731 block_init(bdrv_file_init);