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