xref: /openbmc/qemu/block/file-win32.c (revision 40bd0502)
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     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                                         bool exact, PreallocMode prealloc,
472                                         Error **errp)
473 {
474     BDRVRawState *s = bs->opaque;
475     LONG low, high;
476     DWORD dwPtrLow;
477 
478     if (prealloc != PREALLOC_MODE_OFF) {
479         error_setg(errp, "Unsupported preallocation mode '%s'",
480                    PreallocMode_str(prealloc));
481         return -ENOTSUP;
482     }
483 
484     low = offset;
485     high = offset >> 32;
486 
487     /*
488      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
489      * and GetLastError doesn't return NO_ERROR.
490      */
491     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
492     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
493         error_setg_win32(errp, GetLastError(), "SetFilePointer error");
494         return -EIO;
495     }
496     if (SetEndOfFile(s->hfile) == 0) {
497         error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
498         return -EIO;
499     }
500     return 0;
501 }
502 
503 static int64_t raw_getlength(BlockDriverState *bs)
504 {
505     BDRVRawState *s = bs->opaque;
506     LARGE_INTEGER l;
507     ULARGE_INTEGER available, total, total_free;
508     DISK_GEOMETRY_EX dg;
509     DWORD count;
510     BOOL status;
511 
512     switch(s->type) {
513     case FTYPE_FILE:
514         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
515         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
516             return -EIO;
517         break;
518     case FTYPE_CD:
519         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
520             return -EIO;
521         l.QuadPart = total.QuadPart;
522         break;
523     case FTYPE_HARDDISK:
524         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
525                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
526         if (status != 0) {
527             l = dg.DiskSize;
528         }
529         break;
530     default:
531         return -EIO;
532     }
533     return l.QuadPart;
534 }
535 
536 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
537 {
538     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
539                                               DWORD * high);
540     get_compressed_t get_compressed;
541     struct _stati64 st;
542     const char *filename = bs->filename;
543     /* WinNT support GetCompressedFileSize to determine allocate size */
544     get_compressed =
545         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
546                                             "GetCompressedFileSizeA");
547     if (get_compressed) {
548         DWORD high, low;
549         low = get_compressed(filename, &high);
550         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
551             return (((int64_t) high) << 32) + low;
552         }
553     }
554 
555     if (_stati64(filename, &st) < 0) {
556         return -1;
557     }
558     return st.st_size;
559 }
560 
561 static int raw_co_create(BlockdevCreateOptions *options, Error **errp)
562 {
563     BlockdevCreateOptionsFile *file_opts;
564     int fd;
565 
566     assert(options->driver == BLOCKDEV_DRIVER_FILE);
567     file_opts = &options->u.file;
568 
569     if (file_opts->has_preallocation) {
570         error_setg(errp, "Preallocation is not supported on Windows");
571         return -EINVAL;
572     }
573     if (file_opts->has_nocow) {
574         error_setg(errp, "nocow is not supported on Windows");
575         return -EINVAL;
576     }
577 
578     fd = qemu_open(file_opts->filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
579                    0644);
580     if (fd < 0) {
581         error_setg_errno(errp, errno, "Could not create file");
582         return -EIO;
583     }
584     set_sparse(fd);
585     ftruncate(fd, file_opts->size);
586     qemu_close(fd);
587 
588     return 0;
589 }
590 
591 static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
592                                            const char *filename,
593                                            QemuOpts *opts,
594                                            Error **errp)
595 {
596     BlockdevCreateOptions options;
597     int64_t total_size = 0;
598 
599     strstart(filename, "file:", &filename);
600 
601     /* Read out options */
602     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
603                           BDRV_SECTOR_SIZE);
604 
605     options = (BlockdevCreateOptions) {
606         .driver     = BLOCKDEV_DRIVER_FILE,
607         .u.file     = {
608             .filename           = (char *) filename,
609             .size               = total_size,
610             .has_preallocation  = false,
611             .has_nocow          = false,
612         },
613     };
614     return raw_co_create(&options, errp);
615 }
616 
617 static QemuOptsList raw_create_opts = {
618     .name = "raw-create-opts",
619     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
620     .desc = {
621         {
622             .name = BLOCK_OPT_SIZE,
623             .type = QEMU_OPT_SIZE,
624             .help = "Virtual disk size"
625         },
626         { /* end of list */ }
627     }
628 };
629 
630 BlockDriver bdrv_file = {
631     .format_name	= "file",
632     .protocol_name	= "file",
633     .instance_size	= sizeof(BDRVRawState),
634     .bdrv_needs_filename = true,
635     .bdrv_parse_filename = raw_parse_filename,
636     .bdrv_file_open     = raw_open,
637     .bdrv_refresh_limits = raw_probe_alignment,
638     .bdrv_close         = raw_close,
639     .bdrv_co_create_opts = raw_co_create_opts,
640     .bdrv_has_zero_init = bdrv_has_zero_init_1,
641     .bdrv_has_zero_init_truncate = 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     qemu_opts_absorb_qdict(opts, options, &local_err);
741     if (local_err) {
742         error_propagate(errp, local_err);
743         ret = -EINVAL;
744         goto done;
745     }
746 
747     filename = qemu_opt_get(opts, "filename");
748 
749     use_aio = get_aio_option(opts, flags, &local_err);
750     if (!local_err && use_aio) {
751         error_setg(&local_err, "AIO is not supported on Windows host devices");
752     }
753     if (local_err) {
754         error_propagate(errp, local_err);
755         ret = -EINVAL;
756         goto done;
757     }
758 
759     if (strstart(filename, "/dev/cdrom", NULL)) {
760         if (find_cdrom(device_name, sizeof(device_name)) < 0) {
761             error_setg(errp, "Could not open CD-ROM drive");
762             ret = -ENOENT;
763             goto done;
764         }
765         filename = device_name;
766     } else {
767         /* transform drive letters into device name */
768         if (((filename[0] >= 'a' && filename[0] <= 'z') ||
769              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
770             filename[1] == ':' && filename[2] == '\0') {
771             snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
772             filename = device_name;
773         }
774     }
775     s->type = find_device_type(bs, filename);
776 
777     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
778 
779     create_flags = OPEN_EXISTING;
780 
781     s->hfile = CreateFile(filename, access_flags,
782                           FILE_SHARE_READ, NULL,
783                           create_flags, overlapped, NULL);
784     if (s->hfile == INVALID_HANDLE_VALUE) {
785         int err = GetLastError();
786 
787         if (err == ERROR_ACCESS_DENIED) {
788             ret = -EACCES;
789         } else {
790             ret = -EINVAL;
791         }
792         error_setg_errno(errp, -ret, "Could not open device");
793         goto done;
794     }
795 
796 done:
797     qemu_opts_del(opts);
798     return ret;
799 }
800 
801 static BlockDriver bdrv_host_device = {
802     .format_name	= "host_device",
803     .protocol_name	= "host_device",
804     .instance_size	= sizeof(BDRVRawState),
805     .bdrv_needs_filename = true,
806     .bdrv_parse_filename = hdev_parse_filename,
807     .bdrv_probe_device	= hdev_probe_device,
808     .bdrv_file_open	= hdev_open,
809     .bdrv_close		= raw_close,
810     .bdrv_refresh_limits = hdev_refresh_limits,
811 
812     .bdrv_aio_preadv    = raw_aio_preadv,
813     .bdrv_aio_pwritev   = raw_aio_pwritev,
814     .bdrv_aio_flush     = raw_aio_flush,
815 
816     .bdrv_detach_aio_context = raw_detach_aio_context,
817     .bdrv_attach_aio_context = raw_attach_aio_context,
818 
819     .bdrv_getlength      = raw_getlength,
820     .has_variable_length = true,
821 
822     .bdrv_get_allocated_file_size
823                         = raw_get_allocated_file_size,
824 };
825 
826 static void bdrv_file_init(void)
827 {
828     bdrv_register(&bdrv_file);
829     bdrv_register(&bdrv_host_device);
830 }
831 
832 block_init(bdrv_file_init);
833