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
  25 #include "qemu/osdep.h"
  26 #include "qapi/error.h"
  27 #include "qemu/cutils.h"
  28 #include "block/block_int.h"
  29 #include "qemu/module.h"
  30 #include "qemu/option.h"
  31 #include "block/raw-aio.h"
  32 #include "trace.h"
  33 #include "block/thread-pool.h"
  34 #include "qemu/iov.h"
  35 #include "qapi/qmp/qdict.h"
  36 #include "qapi/qmp/qstring.h"
  37 #include <windows.h>
  38 #include <winioctl.h>
  39
  40 #define FTYPE_FILE 0
  41 #define FTYPE_CD     1
  42 #define FTYPE_HARDDISK 2
  43
  44 typedef struct RawWin32AIOData {
  45     BlockDriverState *bs;
  46     HANDLE hfile;
  47     struct iovec *aio_iov;
  48     int aio_niov;
  49     size_t aio_nbytes;
  50     off64_t aio_offset;
  51     int aio_type;
  52 } RawWin32AIOData;
  53
  54 typedef struct BDRVRawState {
  55     HANDLE hfile;
  56     int type;
  57     char drive_path[16]; /* format: "d:\" */
  58     QEMUWin32AIOState *aio;
  59 } BDRVRawState;
  60
  61 /*
  62  * Read/writes the data to/from a given linear buffer.
  63  *
  64  * Returns the number of bytes handles or -errno in case of an error. Short
  65  * reads are only returned if the end of the file is reached.
  66  */
  67 static size_t handle_aiocb_rw(RawWin32AIOData *aiocb)
  68 {
  69     size_t offset = 0;
  70     int i;
  71
  72     for (i = 0; i < aiocb->aio_niov; i++) {
  73         OVERLAPPED ov;
  74         DWORD ret, ret_count, len;
  75
  76         memset(&ov, 0, sizeof(ov));
  77         ov.Offset = (aiocb->aio_offset + offset);
  78         ov.OffsetHigh = (aiocb->aio_offset + offset) >> 32;
  79         len = aiocb->aio_iov[i].iov_len;
  80         if (aiocb->aio_type & QEMU_AIO_WRITE) {
  81             ret = WriteFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
  82                             len, &ret_count, &ov);
  83         } else {
  84             ret = ReadFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
  85                            len, &ret_count, &ov);
  86         }
  87         if (!ret) {
  88             ret_count = 0;
  89         }
  90         if (ret_count != len) {
  91             offset += ret_count;
  92             break;
  93         }
  94         offset += len;
  95     }
  96
  97     return offset;
  98 }
  99
 100 static int aio_worker(void *arg)
 101 {
 102     RawWin32AIOData *aiocb = arg;
 103     ssize_t ret = 0;
 104     size_t count;
 105
 106     switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
 107     case QEMU_AIO_READ:
 108         count = handle_aiocb_rw(aiocb);
 109         if (count < aiocb->aio_nbytes) {
 110             /* A short read means that we have reached EOF. Pad the buffer
 111              * with zeros for bytes after EOF. */
 112             iov_memset(aiocb->aio_iov, aiocb->aio_niov, count,
 113                       0, aiocb->aio_nbytes - count);
 114
 115             count = aiocb->aio_nbytes;
 116         }
 117         if (count == aiocb->aio_nbytes) {
 118             ret = 0;
 119         } else {
 120             ret = -EINVAL;
 121         }
 122         break;
 123     case QEMU_AIO_WRITE:
 124         count = handle_aiocb_rw(aiocb);
 125         if (count == aiocb->aio_nbytes) {
 126             ret = 0;
 127         } else {
 128             ret = -EINVAL;
 129         }
 130         break;
 131     case QEMU_AIO_FLUSH:
 132         if (!FlushFileBuffers(aiocb->hfile)) {
 133             return -EIO;
 134         }
 135         break;
 136     default:
 137         fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
 138         ret = -EINVAL;
 139         break;
 140     }
 141
 142     g_free(aiocb);
 143     return ret;
 144 }
 145
 146 static BlockAIOCB *paio_submit(BlockDriverState *bs, HANDLE hfile,
 147         int64_t offset, QEMUIOVector *qiov, int count,
 148         BlockCompletionFunc *cb, void *opaque, int type)
 149 {
 150     RawWin32AIOData *acb = g_new(RawWin32AIOData, 1);
 151     ThreadPool *pool;
 152
 153     acb->bs = bs;
 154     acb->hfile = hfile;
 155     acb->aio_type = type;
 156
 157     if (qiov) {
 158         acb->aio_iov = qiov->iov;
 159         acb->aio_niov = qiov->niov;
 160         assert(qiov->size == count);
 161     }
 162     acb->aio_nbytes = count;
 163     acb->aio_offset = offset;
 164
 165     trace_paio_submit(acb, opaque, offset, count, type);
 166     pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
 167     return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
 168 }
 169
 170 int qemu_ftruncate64(int fd, int64_t length)
 171 {
 172     LARGE_INTEGER li;
 173     DWORD dw;
 174     LONG high;
 175     HANDLE h;
 176     BOOL res;
 177
 178     if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
 179         return -1;
 180
 181     h = (HANDLE)_get_osfhandle(fd);
 182
 183     /* get current position, ftruncate do not change position */
 184     li.HighPart = 0;
 185     li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
 186     if (li.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 187         return -1;
 188     }
 189
 190     high = length >> 32;
 191     dw = SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN);
 192     if (dw == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 193         return -1;
 194     }
 195     res = SetEndOfFile(h);
 196
 197     /* back to old position */
 198     SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
 199     return res ? 0 : -1;
 200 }
 201
 202 static int set_sparse(int fd)
 203 {
 204     DWORD returned;
 205     return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
 206                                  NULL, 0, NULL, 0, &returned, NULL);
 207 }
 208
 209 static void raw_detach_aio_context(BlockDriverState *bs)
 210 {
 211     BDRVRawState *s = bs->opaque;
 212
 213     if (s->aio) {
 214         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 215     }
 216 }
 217
 218 static void raw_attach_aio_context(BlockDriverState *bs,
 219                                    AioContext *new_context)
 220 {
 221     BDRVRawState *s = bs->opaque;
 222
 223     if (s->aio) {
 224         win32_aio_attach_aio_context(s->aio, new_context);
 225     }
 226 }
 227
 228 static void raw_probe_alignment(BlockDriverState *bs, Error **errp)
 229 {
 230     BDRVRawState *s = bs->opaque;
 231     DWORD sectorsPerCluster, freeClusters, totalClusters, count;
 232     DISK_GEOMETRY_EX dg;
 233     BOOL status;
 234
 235     if (s->type == FTYPE_CD) {
 236         bs->bl.request_alignment = 2048;
 237         return;
 238     }
 239     if (s->type == FTYPE_HARDDISK) {
 240         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 241                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 242         if (status != 0) {
 243             bs->bl.request_alignment = dg.Geometry.BytesPerSector;
 244             return;
 245         }
 246         /* try GetDiskFreeSpace too */
 247     }
 248
 249     if (s->drive_path[0]) {
 250         GetDiskFreeSpace(s->drive_path, &sectorsPerCluster,
 251                          &dg.Geometry.BytesPerSector,
 252                          &freeClusters, &totalClusters);
 253         bs->bl.request_alignment = dg.Geometry.BytesPerSector;
 254         return;
 255     }
 256
 257     /* XXX Does Windows support AIO on less than 512-byte alignment? */
 258     bs->bl.request_alignment = 512;
 259 }
 260
 261 static void raw_parse_flags(int flags, bool use_aio, int *access_flags,
 262                             DWORD *overlapped)
 263 {
 264     assert(access_flags != NULL);
 265     assert(overlapped != NULL);
 266
 267     if (flags & BDRV_O_RDWR) {
 268         *access_flags = GENERIC_READ | GENERIC_WRITE;
 269     } else {
 270         *access_flags = GENERIC_READ;
 271     }
 272
 273     *overlapped = FILE_ATTRIBUTE_NORMAL;
 274     if (use_aio) {
 275         *overlapped |= FILE_FLAG_OVERLAPPED;
 276     }
 277     if (flags & BDRV_O_NOCACHE) {
 278         *overlapped |= FILE_FLAG_NO_BUFFERING;
 279     }
 280 }
 281
 282 static void raw_parse_filename(const char *filename, QDict *options,
 283                                Error **errp)
 284 {
 285     bdrv_parse_filename_strip_prefix(filename, "file:", options);
 286 }
 287
 288 static QemuOptsList raw_runtime_opts = {
 289     .name = "raw",
 290     .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
 291     .desc = {
 292         {
 293             .name = "filename",
 294             .type = QEMU_OPT_STRING,
 295             .help = "File name of the image",
 296         },
 297         {
 298             .name = "aio",
 299             .type = QEMU_OPT_STRING,
 300             .help = "host AIO implementation (threads, native)",
 301         },
 302         { /* end of list */ }
 303     },
 304 };
 305
 306 static bool get_aio_option(QemuOpts *opts, int flags, Error **errp)
 307 {
 308     BlockdevAioOptions aio, aio_default;
 309
 310     aio_default = (flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE
 311                                               : BLOCKDEV_AIO_OPTIONS_THREADS;
 312     aio = qapi_enum_parse(&BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
 313                           aio_default, errp);
 314
 315     switch (aio) {
 316     case BLOCKDEV_AIO_OPTIONS_NATIVE:
 317         return true;
 318     case BLOCKDEV_AIO_OPTIONS_THREADS:
 319         return false;
 320     default:
 321         error_setg(errp, "Invalid AIO option");
 322     }
 323     return false;
 324 }
 325
 326 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
 327                     Error **errp)
 328 {
 329     BDRVRawState *s = bs->opaque;
 330     int access_flags;
 331     DWORD overlapped;
 332     QemuOpts *opts;
 333     Error *local_err = NULL;
 334     const char *filename;
 335     bool use_aio;
 336     int ret;
 337
 338     s->type = FTYPE_FILE;
 339
 340     opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
 341     qemu_opts_absorb_qdict(opts, options, &local_err);
 342     if (local_err) {
 343         error_propagate(errp, local_err);
 344         ret = -EINVAL;
 345         goto fail;
 346     }
 347
 348     if (qdict_get_try_bool(options, "locking", false)) {
 349         error_setg(errp, "locking=on is not supported on Windows");
 350         ret = -EINVAL;
 351         goto fail;
 352     }
 353
 354     filename = qemu_opt_get(opts, "filename");
 355
 356     use_aio = get_aio_option(opts, flags, &local_err);
 357     if (local_err) {
 358         error_propagate(errp, local_err);
 359         ret = -EINVAL;
 360         goto fail;
 361     }
 362
 363     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
 364
 365     if (filename[0] && filename[1] == ':') {
 366         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
 367     } else if (filename[0] == '\\' && filename[1] == '\\') {
 368         s->drive_path[0] = 0;
 369     } else {
 370         /* Relative path.  */
 371         char buf[MAX_PATH];
 372         GetCurrentDirectory(MAX_PATH, buf);
 373         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
 374     }
 375
 376     s->hfile = CreateFile(filename, access_flags,
 377                           FILE_SHARE_READ, NULL,
 378                           OPEN_EXISTING, overlapped, NULL);
 379     if (s->hfile == INVALID_HANDLE_VALUE) {
 380         int err = GetLastError();
 381
 382         error_setg_win32(errp, err, "Could not open '%s'", filename);
 383         if (err == ERROR_ACCESS_DENIED) {
 384             ret = -EACCES;
 385         } else {
 386             ret = -EINVAL;
 387         }
 388         goto fail;
 389     }
 390
 391     if (use_aio) {
 392         s->aio = win32_aio_init();
 393         if (s->aio == NULL) {
 394             CloseHandle(s->hfile);
 395             error_setg(errp, "Could not initialize AIO");
 396             ret = -EINVAL;
 397             goto fail;
 398         }
 399
 400         ret = win32_aio_attach(s->aio, s->hfile);
 401         if (ret < 0) {
 402             win32_aio_cleanup(s->aio);
 403             CloseHandle(s->hfile);
 404             error_setg_errno(errp, -ret, "Could not enable AIO");
 405             goto fail;
 406         }
 407
 408         win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
 409     }
 410
 411     ret = 0;
 412 fail:
 413     qemu_opts_del(opts);
 414     return ret;
 415 }
 416
 417 static BlockAIOCB *raw_aio_preadv(BlockDriverState *bs,
 418                                   uint64_t offset, uint64_t bytes,
 419                                   QEMUIOVector *qiov, int flags,
 420                                   BlockCompletionFunc *cb, void *opaque)
 421 {
 422     BDRVRawState *s = bs->opaque;
 423     if (s->aio) {
 424         return win32_aio_submit(bs, s->aio, s->hfile, offset, bytes, qiov,
 425                                 cb, opaque, QEMU_AIO_READ);
 426     } else {
 427         return paio_submit(bs, s->hfile, offset, qiov, bytes,
 428                            cb, opaque, QEMU_AIO_READ);
 429     }
 430 }
 431
 432 static BlockAIOCB *raw_aio_pwritev(BlockDriverState *bs,
 433                                    uint64_t offset, uint64_t bytes,
 434                                    QEMUIOVector *qiov, int flags,
 435                                    BlockCompletionFunc *cb, void *opaque)
 436 {
 437     BDRVRawState *s = bs->opaque;
 438     if (s->aio) {
 439         return win32_aio_submit(bs, s->aio, s->hfile, offset, bytes, qiov,
 440                                 cb, opaque, QEMU_AIO_WRITE);
 441     } else {
 442         return paio_submit(bs, s->hfile, offset, qiov, bytes,
 443                            cb, opaque, QEMU_AIO_WRITE);
 444     }
 445 }
 446
 447 static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
 448                          BlockCompletionFunc *cb, void *opaque)
 449 {
 450     BDRVRawState *s = bs->opaque;
 451     return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
 452 }
 453
 454 static void raw_close(BlockDriverState *bs)
 455 {
 456     BDRVRawState *s = bs->opaque;
 457
 458     if (s->aio) {
 459         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 460         win32_aio_cleanup(s->aio);
 461         s->aio = NULL;
 462     }
 463
 464     CloseHandle(s->hfile);
 465     if (bs->open_flags & BDRV_O_TEMPORARY) {
 466         unlink(bs->filename);
 467     }
 468 }
 469
 470 static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset,
 471                                         PreallocMode prealloc, Error **errp)
 472 {
 473     BDRVRawState *s = bs->opaque;
 474     LONG low, high;
 475     DWORD dwPtrLow;
 476
 477     if (prealloc != PREALLOC_MODE_OFF) {
 478         error_setg(errp, "Unsupported preallocation mode '%s'",
 479                    PreallocMode_str(prealloc));
 480         return -ENOTSUP;
 481     }
 482
 483     low = offset;
 484     high = offset >> 32;
 485
 486     /*
 487      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
 488      * and GetLastError doesn't return NO_ERROR.
 489      */
 490     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
 491     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 492         error_setg_win32(errp, GetLastError(), "SetFilePointer error");
 493         return -EIO;
 494     }
 495     if (SetEndOfFile(s->hfile) == 0) {
 496         error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
 497         return -EIO;
 498     }
 499     return 0;
 500 }
 501
 502 static int64_t raw_getlength(BlockDriverState *bs)
 503 {
 504     BDRVRawState *s = bs->opaque;
 505     LARGE_INTEGER l;
 506     ULARGE_INTEGER available, total, total_free;
 507     DISK_GEOMETRY_EX dg;
 508     DWORD count;
 509     BOOL status;
 510
 511     switch(s->type) {
 512     case FTYPE_FILE:
 513         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
 514         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
 515             return -EIO;
 516         break;
 517     case FTYPE_CD:
 518         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
 519             return -EIO;
 520         l.QuadPart = total.QuadPart;
 521         break;
 522     case FTYPE_HARDDISK:
 523         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 524                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 525         if (status != 0) {
 526             l = dg.DiskSize;
 527         }
 528         break;
 529     default:
 530         return -EIO;
 531     }
 532     return l.QuadPart;
 533 }
 534
 535 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
 536 {
 537     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
 538                                               DWORD * high);
 539     get_compressed_t get_compressed;
 540     struct _stati64 st;
 541     const char *filename = bs->filename;
 542     /* WinNT support GetCompressedFileSize to determine allocate size */
 543     get_compressed =
 544         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
 545                                             "GetCompressedFileSizeA");
 546     if (get_compressed) {
 547         DWORD high, low;
 548         low = get_compressed(filename, &high);
 549         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
 550             return (((int64_t) high) << 32) + low;
 551         }
 552     }
 553
 554     if (_stati64(filename, &st) < 0) {
 555         return -1;
 556     }
 557     return st.st_size;
 558 }
 559
 560 static int raw_co_create(BlockdevCreateOptions *options, Error **errp)
 561 {
 562     BlockdevCreateOptionsFile *file_opts;
 563     int fd;
 564
 565     assert(options->driver == BLOCKDEV_DRIVER_FILE);
 566     file_opts = &options->u.file;
 567
 568     if (file_opts->has_preallocation) {
 569         error_setg(errp, "Preallocation is not supported on Windows");
 570         return -EINVAL;
 571     }
 572     if (file_opts->has_nocow) {
 573         error_setg(errp, "nocow is not supported on Windows");
 574         return -EINVAL;
 575     }
 576
 577     fd = qemu_open(file_opts->filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
 578                    0644);
 579     if (fd < 0) {
 580         error_setg_errno(errp, errno, "Could not create file");
 581         return -EIO;
 582     }
 583     set_sparse(fd);
 584     ftruncate(fd, file_opts->size);
 585     qemu_close(fd);
 586
 587     return 0;
 588 }
 589
 590 static int coroutine_fn raw_co_create_opts(const char *filename, QemuOpts *opts,
 591                                            Error **errp)
 592 {
 593     BlockdevCreateOptions options;
 594     int64_t total_size = 0;
 595
 596     strstart(filename, "file:", &filename);
 597
 598     /* Read out options */
 599     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 600                           BDRV_SECTOR_SIZE);
 601
 602     options = (BlockdevCreateOptions) {
 603         .driver     = BLOCKDEV_DRIVER_FILE,
 604         .u.file     = {
 605             .filename           = (char *) filename,
 606             .size               = total_size,
 607             .has_preallocation  = false,
 608             .has_nocow          = false,
 609         },
 610     };
 611     return raw_co_create(&options, errp);
 612 }
 613
 614 static QemuOptsList raw_create_opts = {
 615     .name = "raw-create-opts",
 616     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
 617     .desc = {
 618         {
 619             .name = BLOCK_OPT_SIZE,
 620             .type = QEMU_OPT_SIZE,
 621             .help = "Virtual disk size"
 622         },
 623         { /* end of list */ }
 624     }
 625 };
 626
 627 BlockDriver bdrv_file = {
 628     .format_name        = "file",
 629     .protocol_name      = "file",
 630     .instance_size      = sizeof(BDRVRawState),
 631     .bdrv_needs_filename = true,
 632     .bdrv_parse_filename = raw_parse_filename,
 633     .bdrv_file_open     = raw_open,
 634     .bdrv_refresh_limits = raw_probe_alignment,
 635     .bdrv_close         = raw_close,
 636     .bdrv_co_create_opts = raw_co_create_opts,
 637     .bdrv_has_zero_init = bdrv_has_zero_init_1,
 638
 639     .bdrv_aio_preadv    = raw_aio_preadv,
 640     .bdrv_aio_pwritev   = raw_aio_pwritev,
 641     .bdrv_aio_flush     = raw_aio_flush,
 642
 643     .bdrv_co_truncate   = raw_co_truncate,
 644     .bdrv_getlength     = raw_getlength,
 645     .bdrv_get_allocated_file_size
 646                         = raw_get_allocated_file_size,
 647
 648     .create_opts        = &raw_create_opts,
 649 };
 650
 651 /***********************************************/
 652 /* host device */
 653
 654 static int find_cdrom(char *cdrom_name, int cdrom_name_size)
 655 {
 656     char drives[256], *pdrv = drives;
 657     UINT type;
 658
 659     memset(drives, 0, sizeof(drives));
 660     GetLogicalDriveStrings(sizeof(drives), drives);
 661     while(pdrv[0] != '\0') {
 662         type = GetDriveType(pdrv);
 663         switch(type) {
 664         case DRIVE_CDROM:
 665             snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
 666             return 0;
 667             break;
 668         }
 669         pdrv += lstrlen(pdrv) + 1;
 670     }
 671     return -1;
 672 }
 673
 674 static int find_device_type(BlockDriverState *bs, const char *filename)
 675 {
 676     BDRVRawState *s = bs->opaque;
 677     UINT type;
 678     const char *p;
 679
 680     if (strstart(filename, "\\\\.\\", &p) ||
 681         strstart(filename, "//./", &p)) {
 682         if (stristart(p, "PhysicalDrive", NULL))
 683             return FTYPE_HARDDISK;
 684         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
 685         type = GetDriveType(s->drive_path);
 686         switch (type) {
 687         case DRIVE_REMOVABLE:
 688         case DRIVE_FIXED:
 689             return FTYPE_HARDDISK;
 690         case DRIVE_CDROM:
 691             return FTYPE_CD;
 692         default:
 693             return FTYPE_FILE;
 694         }
 695     } else {
 696         return FTYPE_FILE;
 697     }
 698 }
 699
 700 static int hdev_probe_device(const char *filename)
 701 {
 702     if (strstart(filename, "/dev/cdrom", NULL))
 703         return 100;
 704     if (is_windows_drive(filename))
 705         return 100;
 706     return 0;
 707 }
 708
 709 static void hdev_parse_filename(const char *filename, QDict *options,
 710                                 Error **errp)
 711 {
 712     bdrv_parse_filename_strip_prefix(filename, "host_device:", options);
 713 }
 714
 715 static void hdev_refresh_limits(BlockDriverState *bs, Error **errp)
 716 {
 717     /* XXX Does Windows support AIO on less than 512-byte alignment? */
 718     bs->bl.request_alignment = 512;
 719 }
 720
 721 static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
 722                      Error **errp)
 723 {
 724     BDRVRawState *s = bs->opaque;
 725     int access_flags, create_flags;
 726     int ret = 0;
 727     DWORD overlapped;
 728     char device_name[64];
 729
 730     Error *local_err = NULL;
 731     const char *filename;
 732     bool use_aio;
 733
 734     QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
 735                                       &error_abort);
 736     qemu_opts_absorb_qdict(opts, options, &local_err);
 737     if (local_err) {
 738         error_propagate(errp, local_err);
 739         ret = -EINVAL;
 740         goto done;
 741     }
 742
 743     filename = qemu_opt_get(opts, "filename");
 744
 745     use_aio = get_aio_option(opts, flags, &local_err);
 746     if (!local_err && use_aio) {
 747         error_setg(&local_err, "AIO is not supported on Windows host devices");
 748     }
 749     if (local_err) {
 750         error_propagate(errp, local_err);
 751         ret = -EINVAL;
 752         goto done;
 753     }
 754
 755     if (strstart(filename, "/dev/cdrom", NULL)) {
 756         if (find_cdrom(device_name, sizeof(device_name)) < 0) {
 757             error_setg(errp, "Could not open CD-ROM drive");
 758             ret = -ENOENT;
 759             goto done;
 760         }
 761         filename = device_name;
 762     } else {
 763         /* transform drive letters into device name */
 764         if (((filename[0] >= 'a' && filename[0] <= 'z') ||
 765              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 766             filename[1] == ':' && filename[2] == '\0') {
 767             snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
 768             filename = device_name;
 769         }
 770     }
 771     s->type = find_device_type(bs, filename);
 772
 773     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
 774
 775     create_flags = OPEN_EXISTING;
 776
 777     s->hfile = CreateFile(filename, access_flags,
 778                           FILE_SHARE_READ, NULL,
 779                           create_flags, overlapped, NULL);
 780     if (s->hfile == INVALID_HANDLE_VALUE) {
 781         int err = GetLastError();
 782
 783         if (err == ERROR_ACCESS_DENIED) {
 784             ret = -EACCES;
 785         } else {
 786             ret = -EINVAL;
 787         }
 788         error_setg_errno(errp, -ret, "Could not open device");
 789         goto done;
 790     }
 791
 792 done:
 793     qemu_opts_del(opts);
 794     return ret;
 795 }
 796
 797 static BlockDriver bdrv_host_device = {
 798     .format_name        = "host_device",
 799     .protocol_name      = "host_device",
 800     .instance_size      = sizeof(BDRVRawState),
 801     .bdrv_needs_filename = true,
 802     .bdrv_parse_filename = hdev_parse_filename,
 803     .bdrv_probe_device  = hdev_probe_device,
 804     .bdrv_file_open     = hdev_open,
 805     .bdrv_close         = raw_close,
 806     .bdrv_refresh_limits = hdev_refresh_limits,
 807
 808     .bdrv_aio_preadv    = raw_aio_preadv,
 809     .bdrv_aio_pwritev   = raw_aio_pwritev,
 810     .bdrv_aio_flush     = raw_aio_flush,
 811
 812     .bdrv_detach_aio_context = raw_detach_aio_context,
 813     .bdrv_attach_aio_context = raw_attach_aio_context,
 814
 815     .bdrv_getlength      = raw_getlength,
 816     .has_variable_length = true,
 817
 818     .bdrv_get_allocated_file_size
 819                         = raw_get_allocated_file_size,
 820 };
 821
 822 static void bdrv_file_init(void)
 823 {
 824     bdrv_register(&bdrv_file);
 825     bdrv_register(&bdrv_host_device);
 826 }
 827
 828 block_init(bdrv_file_init);