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