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     /* The filename does not have to be prefixed by the protocol name, since
 280      * "file" is the default protocol; therefore, the return value of this
 281      * function call can be ignored. */
 282     strstart(filename, "file:", &filename);
 283
 284     qdict_put_str(options, "filename", filename);
 285 }
 286
 287 static QemuOptsList raw_runtime_opts = {
 288     .name = "raw",
 289     .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
 290     .desc = {
 291         {
 292             .name = "filename",
 293             .type = QEMU_OPT_STRING,
 294             .help = "File name of the image",
 295         },
 296         {
 297             .name = "aio",
 298             .type = QEMU_OPT_STRING,
 299             .help = "host AIO implementation (threads, native)",
 300         },
 301         { /* end of list */ }
 302     },
 303 };
 304
 305 static bool get_aio_option(QemuOpts *opts, int flags, Error **errp)
 306 {
 307     BlockdevAioOptions aio, aio_default;
 308
 309     aio_default = (flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE
 310                                               : BLOCKDEV_AIO_OPTIONS_THREADS;
 311     aio = qapi_enum_parse(BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
 312                           BLOCKDEV_AIO_OPTIONS__MAX, aio_default, errp);
 313
 314     switch (aio) {
 315     case BLOCKDEV_AIO_OPTIONS_NATIVE:
 316         return true;
 317     case BLOCKDEV_AIO_OPTIONS_THREADS:
 318         return false;
 319     default:
 320         error_setg(errp, "Invalid AIO option");
 321     }
 322     return false;
 323 }
 324
 325 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
 326                     Error **errp)
 327 {
 328     BDRVRawState *s = bs->opaque;
 329     int access_flags;
 330     DWORD overlapped;
 331     QemuOpts *opts;
 332     Error *local_err = NULL;
 333     const char *filename;
 334     bool use_aio;
 335     int ret;
 336
 337     s->type = FTYPE_FILE;
 338
 339     opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
 340     qemu_opts_absorb_qdict(opts, options, &local_err);
 341     if (local_err) {
 342         error_propagate(errp, local_err);
 343         ret = -EINVAL;
 344         goto fail;
 345     }
 346
 347     if (qdict_get_try_bool(options, "locking", false)) {
 348         error_setg(errp, "locking=on is not supported on Windows");
 349         goto fail;
 350     }
 351
 352     filename = qemu_opt_get(opts, "filename");
 353
 354     use_aio = get_aio_option(opts, flags, &local_err);
 355     if (local_err) {
 356         error_propagate(errp, local_err);
 357         ret = -EINVAL;
 358         goto fail;
 359     }
 360
 361     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
 362
 363     if (filename[0] && filename[1] == ':') {
 364         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
 365     } else if (filename[0] == '\\' && filename[1] == '\\') {
 366         s->drive_path[0] = 0;
 367     } else {
 368         /* Relative path.  */
 369         char buf[MAX_PATH];
 370         GetCurrentDirectory(MAX_PATH, buf);
 371         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
 372     }
 373
 374     s->hfile = CreateFile(filename, access_flags,
 375                           FILE_SHARE_READ, NULL,
 376                           OPEN_EXISTING, overlapped, NULL);
 377     if (s->hfile == INVALID_HANDLE_VALUE) {
 378         int err = GetLastError();
 379
 380         error_setg_win32(errp, err, "Could not open '%s'", filename);
 381         if (err == ERROR_ACCESS_DENIED) {
 382             ret = -EACCES;
 383         } else {
 384             ret = -EINVAL;
 385         }
 386         goto fail;
 387     }
 388
 389     if (use_aio) {
 390         s->aio = win32_aio_init();
 391         if (s->aio == NULL) {
 392             CloseHandle(s->hfile);
 393             error_setg(errp, "Could not initialize AIO");
 394             ret = -EINVAL;
 395             goto fail;
 396         }
 397
 398         ret = win32_aio_attach(s->aio, s->hfile);
 399         if (ret < 0) {
 400             win32_aio_cleanup(s->aio);
 401             CloseHandle(s->hfile);
 402             error_setg_errno(errp, -ret, "Could not enable AIO");
 403             goto fail;
 404         }
 405
 406         win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
 407     }
 408
 409     ret = 0;
 410 fail:
 411     qemu_opts_del(opts);
 412     return ret;
 413 }
 414
 415 static BlockAIOCB *raw_aio_readv(BlockDriverState *bs,
 416                          int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 417                          BlockCompletionFunc *cb, void *opaque)
 418 {
 419     BDRVRawState *s = bs->opaque;
 420     if (s->aio) {
 421         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
 422                                 nb_sectors, cb, opaque, QEMU_AIO_READ);
 423     } else {
 424         return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
 425                            nb_sectors << BDRV_SECTOR_BITS,
 426                            cb, opaque, QEMU_AIO_READ);
 427     }
 428 }
 429
 430 static BlockAIOCB *raw_aio_writev(BlockDriverState *bs,
 431                           int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 432                           BlockCompletionFunc *cb, void *opaque)
 433 {
 434     BDRVRawState *s = bs->opaque;
 435     if (s->aio) {
 436         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
 437                                 nb_sectors, cb, opaque, QEMU_AIO_WRITE);
 438     } else {
 439         return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
 440                            nb_sectors << BDRV_SECTOR_BITS,
 441                            cb, opaque, QEMU_AIO_WRITE);
 442     }
 443 }
 444
 445 static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
 446                          BlockCompletionFunc *cb, void *opaque)
 447 {
 448     BDRVRawState *s = bs->opaque;
 449     return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
 450 }
 451
 452 static void raw_close(BlockDriverState *bs)
 453 {
 454     BDRVRawState *s = bs->opaque;
 455
 456     if (s->aio) {
 457         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 458         win32_aio_cleanup(s->aio);
 459         s->aio = NULL;
 460     }
 461
 462     CloseHandle(s->hfile);
 463     if (bs->open_flags & BDRV_O_TEMPORARY) {
 464         unlink(bs->filename);
 465     }
 466 }
 467
 468 static int raw_truncate(BlockDriverState *bs, int64_t offset, Error **errp)
 469 {
 470     BDRVRawState *s = bs->opaque;
 471     LONG low, high;
 472     DWORD dwPtrLow;
 473
 474     low = offset;
 475     high = offset >> 32;
 476
 477     /*
 478      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
 479      * and GetLastError doesn't return NO_ERROR.
 480      */
 481     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
 482     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 483         error_setg_win32(errp, GetLastError(), "SetFilePointer error");
 484         return -EIO;
 485     }
 486     if (SetEndOfFile(s->hfile) == 0) {
 487         error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
 488         return -EIO;
 489     }
 490     return 0;
 491 }
 492
 493 static int64_t raw_getlength(BlockDriverState *bs)
 494 {
 495     BDRVRawState *s = bs->opaque;
 496     LARGE_INTEGER l;
 497     ULARGE_INTEGER available, total, total_free;
 498     DISK_GEOMETRY_EX dg;
 499     DWORD count;
 500     BOOL status;
 501
 502     switch(s->type) {
 503     case FTYPE_FILE:
 504         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
 505         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
 506             return -EIO;
 507         break;
 508     case FTYPE_CD:
 509         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
 510             return -EIO;
 511         l.QuadPart = total.QuadPart;
 512         break;
 513     case FTYPE_HARDDISK:
 514         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 515                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 516         if (status != 0) {
 517             l = dg.DiskSize;
 518         }
 519         break;
 520     default:
 521         return -EIO;
 522     }
 523     return l.QuadPart;
 524 }
 525
 526 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
 527 {
 528     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
 529                                               DWORD * high);
 530     get_compressed_t get_compressed;
 531     struct _stati64 st;
 532     const char *filename = bs->filename;
 533     /* WinNT support GetCompressedFileSize to determine allocate size */
 534     get_compressed =
 535         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
 536                                             "GetCompressedFileSizeA");
 537     if (get_compressed) {
 538         DWORD high, low;
 539         low = get_compressed(filename, &high);
 540         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
 541             return (((int64_t) high) << 32) + low;
 542         }
 543     }
 544
 545     if (_stati64(filename, &st) < 0) {
 546         return -1;
 547     }
 548     return st.st_size;
 549 }
 550
 551 static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
 552 {
 553     int fd;
 554     int64_t total_size = 0;
 555
 556     strstart(filename, "file:", &filename);
 557
 558     /* Read out options */
 559     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 560                           BDRV_SECTOR_SIZE);
 561
 562     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
 563                    0644);
 564     if (fd < 0) {
 565         error_setg_errno(errp, errno, "Could not create file");
 566         return -EIO;
 567     }
 568     set_sparse(fd);
 569     ftruncate(fd, total_size);
 570     qemu_close(fd);
 571     return 0;
 572 }
 573
 574
 575 static QemuOptsList raw_create_opts = {
 576     .name = "raw-create-opts",
 577     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
 578     .desc = {
 579         {
 580             .name = BLOCK_OPT_SIZE,
 581             .type = QEMU_OPT_SIZE,
 582             .help = "Virtual disk size"
 583         },
 584         { /* end of list */ }
 585     }
 586 };
 587
 588 BlockDriver bdrv_file = {
 589     .format_name        = "file",
 590     .protocol_name      = "file",
 591     .instance_size      = sizeof(BDRVRawState),
 592     .bdrv_needs_filename = true,
 593     .bdrv_parse_filename = raw_parse_filename,
 594     .bdrv_file_open     = raw_open,
 595     .bdrv_refresh_limits = raw_probe_alignment,
 596     .bdrv_close         = raw_close,
 597     .bdrv_create        = raw_create,
 598     .bdrv_has_zero_init = bdrv_has_zero_init_1,
 599
 600     .bdrv_aio_readv     = raw_aio_readv,
 601     .bdrv_aio_writev    = raw_aio_writev,
 602     .bdrv_aio_flush     = raw_aio_flush,
 603
 604     .bdrv_truncate      = raw_truncate,
 605     .bdrv_getlength     = raw_getlength,
 606     .bdrv_get_allocated_file_size
 607                         = raw_get_allocated_file_size,
 608
 609     .create_opts        = &raw_create_opts,
 610 };
 611
 612 /***********************************************/
 613 /* host device */
 614
 615 static int find_cdrom(char *cdrom_name, int cdrom_name_size)
 616 {
 617     char drives[256], *pdrv = drives;
 618     UINT type;
 619
 620     memset(drives, 0, sizeof(drives));
 621     GetLogicalDriveStrings(sizeof(drives), drives);
 622     while(pdrv[0] != '\0') {
 623         type = GetDriveType(pdrv);
 624         switch(type) {
 625         case DRIVE_CDROM:
 626             snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
 627             return 0;
 628             break;
 629         }
 630         pdrv += lstrlen(pdrv) + 1;
 631     }
 632     return -1;
 633 }
 634
 635 static int find_device_type(BlockDriverState *bs, const char *filename)
 636 {
 637     BDRVRawState *s = bs->opaque;
 638     UINT type;
 639     const char *p;
 640
 641     if (strstart(filename, "\\\\.\\", &p) ||
 642         strstart(filename, "//./", &p)) {
 643         if (stristart(p, "PhysicalDrive", NULL))
 644             return FTYPE_HARDDISK;
 645         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
 646         type = GetDriveType(s->drive_path);
 647         switch (type) {
 648         case DRIVE_REMOVABLE:
 649         case DRIVE_FIXED:
 650             return FTYPE_HARDDISK;
 651         case DRIVE_CDROM:
 652             return FTYPE_CD;
 653         default:
 654             return FTYPE_FILE;
 655         }
 656     } else {
 657         return FTYPE_FILE;
 658     }
 659 }
 660
 661 static int hdev_probe_device(const char *filename)
 662 {
 663     if (strstart(filename, "/dev/cdrom", NULL))
 664         return 100;
 665     if (is_windows_drive(filename))
 666         return 100;
 667     return 0;
 668 }
 669
 670 static void hdev_parse_filename(const char *filename, QDict *options,
 671                                 Error **errp)
 672 {
 673     /* The prefix is optional, just as for "file". */
 674     strstart(filename, "host_device:", &filename);
 675
 676     qdict_put_str(options, "filename", filename);
 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);