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_file_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     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 342         ret = -EINVAL;
 343         goto fail;
 344     }
 345
 346     if (qdict_get_try_bool(options, "locking", false)) {
 347         error_setg(errp, "locking=on is not supported on Windows");
 348         ret = -EINVAL;
 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     /* When extending regular files, we get zeros from the OS */
 410     bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
 411
 412     ret = 0;
 413 fail:
 414     qemu_opts_del(opts);
 415     return ret;
 416 }
 417
 418 static BlockAIOCB *raw_aio_preadv(BlockDriverState *bs,
 419                                   uint64_t offset, uint64_t bytes,
 420                                   QEMUIOVector *qiov, int flags,
 421                                   BlockCompletionFunc *cb, void *opaque)
 422 {
 423     BDRVRawState *s = bs->opaque;
 424     if (s->aio) {
 425         return win32_aio_submit(bs, s->aio, s->hfile, offset, bytes, qiov,
 426                                 cb, opaque, QEMU_AIO_READ);
 427     } else {
 428         return paio_submit(bs, s->hfile, offset, qiov, bytes,
 429                            cb, opaque, QEMU_AIO_READ);
 430     }
 431 }
 432
 433 static BlockAIOCB *raw_aio_pwritev(BlockDriverState *bs,
 434                                    uint64_t offset, uint64_t bytes,
 435                                    QEMUIOVector *qiov, int flags,
 436                                    BlockCompletionFunc *cb, void *opaque)
 437 {
 438     BDRVRawState *s = bs->opaque;
 439     if (s->aio) {
 440         return win32_aio_submit(bs, s->aio, s->hfile, offset, bytes, qiov,
 441                                 cb, opaque, QEMU_AIO_WRITE);
 442     } else {
 443         return paio_submit(bs, s->hfile, offset, qiov, bytes,
 444                            cb, opaque, QEMU_AIO_WRITE);
 445     }
 446 }
 447
 448 static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
 449                          BlockCompletionFunc *cb, void *opaque)
 450 {
 451     BDRVRawState *s = bs->opaque;
 452     return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
 453 }
 454
 455 static void raw_close(BlockDriverState *bs)
 456 {
 457     BDRVRawState *s = bs->opaque;
 458
 459     if (s->aio) {
 460         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
 461         win32_aio_cleanup(s->aio);
 462         s->aio = NULL;
 463     }
 464
 465     CloseHandle(s->hfile);
 466     if (bs->open_flags & BDRV_O_TEMPORARY) {
 467         unlink(bs->filename);
 468     }
 469 }
 470
 471 static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset,
 472                                         bool exact, PreallocMode prealloc,
 473                                         BdrvRequestFlags flags, Error **errp)
 474 {
 475     BDRVRawState *s = bs->opaque;
 476     LONG low, high;
 477     DWORD dwPtrLow;
 478
 479     if (prealloc != PREALLOC_MODE_OFF) {
 480         error_setg(errp, "Unsupported preallocation mode '%s'",
 481                    PreallocMode_str(prealloc));
 482         return -ENOTSUP;
 483     }
 484
 485     low = offset;
 486     high = offset >> 32;
 487
 488     /*
 489      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
 490      * and GetLastError doesn't return NO_ERROR.
 491      */
 492     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
 493     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 494         error_setg_win32(errp, GetLastError(), "SetFilePointer error");
 495         return -EIO;
 496     }
 497     if (SetEndOfFile(s->hfile) == 0) {
 498         error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
 499         return -EIO;
 500     }
 501     return 0;
 502 }
 503
 504 static int64_t raw_getlength(BlockDriverState *bs)
 505 {
 506     BDRVRawState *s = bs->opaque;
 507     LARGE_INTEGER l;
 508     ULARGE_INTEGER available, total, total_free;
 509     DISK_GEOMETRY_EX dg;
 510     DWORD count;
 511     BOOL status;
 512
 513     switch(s->type) {
 514     case FTYPE_FILE:
 515         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
 516         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
 517             return -EIO;
 518         break;
 519     case FTYPE_CD:
 520         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
 521             return -EIO;
 522         l.QuadPart = total.QuadPart;
 523         break;
 524     case FTYPE_HARDDISK:
 525         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
 526                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
 527         if (status != 0) {
 528             l = dg.DiskSize;
 529         }
 530         break;
 531     default:
 532         return -EIO;
 533     }
 534     return l.QuadPart;
 535 }
 536
 537 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
 538 {
 539     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
 540                                               DWORD * high);
 541     get_compressed_t get_compressed;
 542     struct _stati64 st;
 543     const char *filename = bs->filename;
 544     /* WinNT support GetCompressedFileSize to determine allocate size */
 545     get_compressed =
 546         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
 547                                             "GetCompressedFileSizeA");
 548     if (get_compressed) {
 549         DWORD high, low;
 550         low = get_compressed(filename, &high);
 551         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
 552             return (((int64_t) high) << 32) + low;
 553         }
 554     }
 555
 556     if (_stati64(filename, &st) < 0) {
 557         return -1;
 558     }
 559     return st.st_size;
 560 }
 561
 562 static int raw_co_create(BlockdevCreateOptions *options, Error **errp)
 563 {
 564     BlockdevCreateOptionsFile *file_opts;
 565     int fd;
 566
 567     assert(options->driver == BLOCKDEV_DRIVER_FILE);
 568     file_opts = &options->u.file;
 569
 570     if (file_opts->has_preallocation) {
 571         error_setg(errp, "Preallocation is not supported on Windows");
 572         return -EINVAL;
 573     }
 574     if (file_opts->has_nocow) {
 575         error_setg(errp, "nocow is not supported on Windows");
 576         return -EINVAL;
 577     }
 578
 579     fd = qemu_open(file_opts->filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
 580                    0644);
 581     if (fd < 0) {
 582         error_setg_errno(errp, errno, "Could not create file");
 583         return -EIO;
 584     }
 585     set_sparse(fd);
 586     ftruncate(fd, file_opts->size);
 587     qemu_close(fd);
 588
 589     return 0;
 590 }
 591
 592 static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
 593                                            const char *filename,
 594                                            QemuOpts *opts,
 595                                            Error **errp)
 596 {
 597     BlockdevCreateOptions options;
 598     int64_t total_size = 0;
 599
 600     strstart(filename, "file:", &filename);
 601
 602     /* Read out options */
 603     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 604                           BDRV_SECTOR_SIZE);
 605
 606     options = (BlockdevCreateOptions) {
 607         .driver     = BLOCKDEV_DRIVER_FILE,
 608         .u.file     = {
 609             .filename           = (char *) filename,
 610             .size               = total_size,
 611             .has_preallocation  = false,
 612             .has_nocow          = false,
 613         },
 614     };
 615     return raw_co_create(&options, errp);
 616 }
 617
 618 static QemuOptsList raw_create_opts = {
 619     .name = "raw-create-opts",
 620     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
 621     .desc = {
 622         {
 623             .name = BLOCK_OPT_SIZE,
 624             .type = QEMU_OPT_SIZE,
 625             .help = "Virtual disk size"
 626         },
 627         { /* end of list */ }
 628     }
 629 };
 630
 631 BlockDriver bdrv_file = {
 632     .format_name        = "file",
 633     .protocol_name      = "file",
 634     .instance_size      = sizeof(BDRVRawState),
 635     .bdrv_needs_filename = true,
 636     .bdrv_parse_filename = raw_parse_filename,
 637     .bdrv_file_open     = raw_open,
 638     .bdrv_refresh_limits = raw_probe_alignment,
 639     .bdrv_close         = raw_close,
 640     .bdrv_co_create_opts = raw_co_create_opts,
 641     .bdrv_has_zero_init = bdrv_has_zero_init_1,
 642
 643     .bdrv_aio_preadv    = raw_aio_preadv,
 644     .bdrv_aio_pwritev   = raw_aio_pwritev,
 645     .bdrv_aio_flush     = raw_aio_flush,
 646
 647     .bdrv_co_truncate   = raw_co_truncate,
 648     .bdrv_getlength     = raw_getlength,
 649     .bdrv_get_allocated_file_size
 650                         = raw_get_allocated_file_size,
 651
 652     .create_opts        = &raw_create_opts,
 653 };
 654
 655 /***********************************************/
 656 /* host device */
 657
 658 static int find_cdrom(char *cdrom_name, int cdrom_name_size)
 659 {
 660     char drives[256], *pdrv = drives;
 661     UINT type;
 662
 663     memset(drives, 0, sizeof(drives));
 664     GetLogicalDriveStrings(sizeof(drives), drives);
 665     while(pdrv[0] != '\0') {
 666         type = GetDriveType(pdrv);
 667         switch(type) {
 668         case DRIVE_CDROM:
 669             snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
 670             return 0;
 671             break;
 672         }
 673         pdrv += lstrlen(pdrv) + 1;
 674     }
 675     return -1;
 676 }
 677
 678 static int find_device_type(BlockDriverState *bs, const char *filename)
 679 {
 680     BDRVRawState *s = bs->opaque;
 681     UINT type;
 682     const char *p;
 683
 684     if (strstart(filename, "\\\\.\\", &p) ||
 685         strstart(filename, "//./", &p)) {
 686         if (stristart(p, "PhysicalDrive", NULL))
 687             return FTYPE_HARDDISK;
 688         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
 689         type = GetDriveType(s->drive_path);
 690         switch (type) {
 691         case DRIVE_REMOVABLE:
 692         case DRIVE_FIXED:
 693             return FTYPE_HARDDISK;
 694         case DRIVE_CDROM:
 695             return FTYPE_CD;
 696         default:
 697             return FTYPE_FILE;
 698         }
 699     } else {
 700         return FTYPE_FILE;
 701     }
 702 }
 703
 704 static int hdev_probe_device(const char *filename)
 705 {
 706     if (strstart(filename, "/dev/cdrom", NULL))
 707         return 100;
 708     if (is_windows_drive(filename))
 709         return 100;
 710     return 0;
 711 }
 712
 713 static void hdev_parse_filename(const char *filename, QDict *options,
 714                                 Error **errp)
 715 {
 716     bdrv_parse_filename_strip_prefix(filename, "host_device:", options);
 717 }
 718
 719 static void hdev_refresh_limits(BlockDriverState *bs, Error **errp)
 720 {
 721     /* XXX Does Windows support AIO on less than 512-byte alignment? */
 722     bs->bl.request_alignment = 512;
 723 }
 724
 725 static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
 726                      Error **errp)
 727 {
 728     BDRVRawState *s = bs->opaque;
 729     int access_flags, create_flags;
 730     int ret = 0;
 731     DWORD overlapped;
 732     char device_name[64];
 733
 734     Error *local_err = NULL;
 735     const char *filename;
 736     bool use_aio;
 737
 738     QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
 739                                       &error_abort);
 740     if (!qemu_opts_absorb_qdict(opts, options, errp)) {
 741         ret = -EINVAL;
 742         goto done;
 743     }
 744
 745     filename = qemu_opt_get(opts, "filename");
 746
 747     use_aio = get_aio_option(opts, flags, &local_err);
 748     if (!local_err && use_aio) {
 749         error_setg(&local_err, "AIO is not supported on Windows host devices");
 750     }
 751     if (local_err) {
 752         error_propagate(errp, local_err);
 753         ret = -EINVAL;
 754         goto done;
 755     }
 756
 757     if (strstart(filename, "/dev/cdrom", NULL)) {
 758         if (find_cdrom(device_name, sizeof(device_name)) < 0) {
 759             error_setg(errp, "Could not open CD-ROM drive");
 760             ret = -ENOENT;
 761             goto done;
 762         }
 763         filename = device_name;
 764     } else {
 765         /* transform drive letters into device name */
 766         if (((filename[0] >= 'a' && filename[0] <= 'z') ||
 767              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
 768             filename[1] == ':' && filename[2] == '\0') {
 769             snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
 770             filename = device_name;
 771         }
 772     }
 773     s->type = find_device_type(bs, filename);
 774
 775     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
 776
 777     create_flags = OPEN_EXISTING;
 778
 779     s->hfile = CreateFile(filename, access_flags,
 780                           FILE_SHARE_READ, NULL,
 781                           create_flags, overlapped, NULL);
 782     if (s->hfile == INVALID_HANDLE_VALUE) {
 783         int err = GetLastError();
 784
 785         if (err == ERROR_ACCESS_DENIED) {
 786             ret = -EACCES;
 787         } else {
 788             ret = -EINVAL;
 789         }
 790         error_setg_errno(errp, -ret, "Could not open device");
 791         goto done;
 792     }
 793
 794 done:
 795     qemu_opts_del(opts);
 796     return ret;
 797 }
 798
 799 static BlockDriver bdrv_host_device = {
 800     .format_name        = "host_device",
 801     .protocol_name      = "host_device",
 802     .instance_size      = sizeof(BDRVRawState),
 803     .bdrv_needs_filename = true,
 804     .bdrv_parse_filename = hdev_parse_filename,
 805     .bdrv_probe_device  = hdev_probe_device,
 806     .bdrv_file_open     = hdev_open,
 807     .bdrv_close         = raw_close,
 808     .bdrv_refresh_limits = hdev_refresh_limits,
 809
 810     .bdrv_aio_preadv    = raw_aio_preadv,
 811     .bdrv_aio_pwritev   = raw_aio_pwritev,
 812     .bdrv_aio_flush     = raw_aio_flush,
 813
 814     .bdrv_detach_aio_context = raw_detach_aio_context,
 815     .bdrv_attach_aio_context = raw_attach_aio_context,
 816
 817     .bdrv_getlength      = raw_getlength,
 818     .has_variable_length = true,
 819
 820     .bdrv_get_allocated_file_size
 821                         = raw_get_allocated_file_size,
 822 };
 823
 824 static void bdrv_file_init(void)
 825 {
 826     bdrv_register(&bdrv_file);
 827     bdrv_register(&bdrv_host_device);
 828 }
 829
 830 block_init(bdrv_file_init);