xref: /openbmc/qemu/block/file-win32.c (revision a9ded601)
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     bdrv_parse_filename_strip_prefix(filename, "file:", options);
280 }
281 
282 static QemuOptsList raw_runtime_opts = {
283     .name = "raw",
284     .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
285     .desc = {
286         {
287             .name = "filename",
288             .type = QEMU_OPT_STRING,
289             .help = "File name of the image",
290         },
291         {
292             .name = "aio",
293             .type = QEMU_OPT_STRING,
294             .help = "host AIO implementation (threads, native)",
295         },
296         { /* end of list */ }
297     },
298 };
299 
300 static bool get_aio_option(QemuOpts *opts, int flags, Error **errp)
301 {
302     BlockdevAioOptions aio, aio_default;
303 
304     aio_default = (flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE
305                                               : BLOCKDEV_AIO_OPTIONS_THREADS;
306     aio = qapi_enum_parse(BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
307                           BLOCKDEV_AIO_OPTIONS__MAX, aio_default, errp);
308 
309     switch (aio) {
310     case BLOCKDEV_AIO_OPTIONS_NATIVE:
311         return true;
312     case BLOCKDEV_AIO_OPTIONS_THREADS:
313         return false;
314     default:
315         error_setg(errp, "Invalid AIO option");
316     }
317     return false;
318 }
319 
320 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
321                     Error **errp)
322 {
323     BDRVRawState *s = bs->opaque;
324     int access_flags;
325     DWORD overlapped;
326     QemuOpts *opts;
327     Error *local_err = NULL;
328     const char *filename;
329     bool use_aio;
330     int ret;
331 
332     s->type = FTYPE_FILE;
333 
334     opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
335     qemu_opts_absorb_qdict(opts, options, &local_err);
336     if (local_err) {
337         error_propagate(errp, local_err);
338         ret = -EINVAL;
339         goto fail;
340     }
341 
342     if (qdict_get_try_bool(options, "locking", false)) {
343         error_setg(errp, "locking=on is not supported on Windows");
344         ret = -EINVAL;
345         goto fail;
346     }
347 
348     filename = qemu_opt_get(opts, "filename");
349 
350     use_aio = get_aio_option(opts, flags, &local_err);
351     if (local_err) {
352         error_propagate(errp, local_err);
353         ret = -EINVAL;
354         goto fail;
355     }
356 
357     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
358 
359     if (filename[0] && filename[1] == ':') {
360         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
361     } else if (filename[0] == '\\' && filename[1] == '\\') {
362         s->drive_path[0] = 0;
363     } else {
364         /* Relative path.  */
365         char buf[MAX_PATH];
366         GetCurrentDirectory(MAX_PATH, buf);
367         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
368     }
369 
370     s->hfile = CreateFile(filename, access_flags,
371                           FILE_SHARE_READ, NULL,
372                           OPEN_EXISTING, overlapped, NULL);
373     if (s->hfile == INVALID_HANDLE_VALUE) {
374         int err = GetLastError();
375 
376         error_setg_win32(errp, err, "Could not open '%s'", filename);
377         if (err == ERROR_ACCESS_DENIED) {
378             ret = -EACCES;
379         } else {
380             ret = -EINVAL;
381         }
382         goto fail;
383     }
384 
385     if (use_aio) {
386         s->aio = win32_aio_init();
387         if (s->aio == NULL) {
388             CloseHandle(s->hfile);
389             error_setg(errp, "Could not initialize AIO");
390             ret = -EINVAL;
391             goto fail;
392         }
393 
394         ret = win32_aio_attach(s->aio, s->hfile);
395         if (ret < 0) {
396             win32_aio_cleanup(s->aio);
397             CloseHandle(s->hfile);
398             error_setg_errno(errp, -ret, "Could not enable AIO");
399             goto fail;
400         }
401 
402         win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
403     }
404 
405     ret = 0;
406 fail:
407     qemu_opts_del(opts);
408     return ret;
409 }
410 
411 static BlockAIOCB *raw_aio_readv(BlockDriverState *bs,
412                          int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
413                          BlockCompletionFunc *cb, void *opaque)
414 {
415     BDRVRawState *s = bs->opaque;
416     if (s->aio) {
417         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
418                                 nb_sectors, cb, opaque, QEMU_AIO_READ);
419     } else {
420         return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
421                            nb_sectors << BDRV_SECTOR_BITS,
422                            cb, opaque, QEMU_AIO_READ);
423     }
424 }
425 
426 static BlockAIOCB *raw_aio_writev(BlockDriverState *bs,
427                           int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
428                           BlockCompletionFunc *cb, void *opaque)
429 {
430     BDRVRawState *s = bs->opaque;
431     if (s->aio) {
432         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
433                                 nb_sectors, cb, opaque, QEMU_AIO_WRITE);
434     } else {
435         return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
436                            nb_sectors << BDRV_SECTOR_BITS,
437                            cb, opaque, QEMU_AIO_WRITE);
438     }
439 }
440 
441 static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
442                          BlockCompletionFunc *cb, void *opaque)
443 {
444     BDRVRawState *s = bs->opaque;
445     return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
446 }
447 
448 static void raw_close(BlockDriverState *bs)
449 {
450     BDRVRawState *s = bs->opaque;
451 
452     if (s->aio) {
453         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
454         win32_aio_cleanup(s->aio);
455         s->aio = NULL;
456     }
457 
458     CloseHandle(s->hfile);
459     if (bs->open_flags & BDRV_O_TEMPORARY) {
460         unlink(bs->filename);
461     }
462 }
463 
464 static int raw_truncate(BlockDriverState *bs, int64_t offset, Error **errp)
465 {
466     BDRVRawState *s = bs->opaque;
467     LONG low, high;
468     DWORD dwPtrLow;
469 
470     low = offset;
471     high = offset >> 32;
472 
473     /*
474      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
475      * and GetLastError doesn't return NO_ERROR.
476      */
477     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
478     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
479         error_setg_win32(errp, GetLastError(), "SetFilePointer error");
480         return -EIO;
481     }
482     if (SetEndOfFile(s->hfile) == 0) {
483         error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
484         return -EIO;
485     }
486     return 0;
487 }
488 
489 static int64_t raw_getlength(BlockDriverState *bs)
490 {
491     BDRVRawState *s = bs->opaque;
492     LARGE_INTEGER l;
493     ULARGE_INTEGER available, total, total_free;
494     DISK_GEOMETRY_EX dg;
495     DWORD count;
496     BOOL status;
497 
498     switch(s->type) {
499     case FTYPE_FILE:
500         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
501         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
502             return -EIO;
503         break;
504     case FTYPE_CD:
505         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
506             return -EIO;
507         l.QuadPart = total.QuadPart;
508         break;
509     case FTYPE_HARDDISK:
510         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
511                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
512         if (status != 0) {
513             l = dg.DiskSize;
514         }
515         break;
516     default:
517         return -EIO;
518     }
519     return l.QuadPart;
520 }
521 
522 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
523 {
524     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
525                                               DWORD * high);
526     get_compressed_t get_compressed;
527     struct _stati64 st;
528     const char *filename = bs->filename;
529     /* WinNT support GetCompressedFileSize to determine allocate size */
530     get_compressed =
531         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
532                                             "GetCompressedFileSizeA");
533     if (get_compressed) {
534         DWORD high, low;
535         low = get_compressed(filename, &high);
536         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
537             return (((int64_t) high) << 32) + low;
538         }
539     }
540 
541     if (_stati64(filename, &st) < 0) {
542         return -1;
543     }
544     return st.st_size;
545 }
546 
547 static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
548 {
549     int fd;
550     int64_t total_size = 0;
551 
552     strstart(filename, "file:", &filename);
553 
554     /* Read out options */
555     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
556                           BDRV_SECTOR_SIZE);
557 
558     fd = qemu_open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
559                    0644);
560     if (fd < 0) {
561         error_setg_errno(errp, errno, "Could not create file");
562         return -EIO;
563     }
564     set_sparse(fd);
565     ftruncate(fd, total_size);
566     qemu_close(fd);
567     return 0;
568 }
569 
570 
571 static QemuOptsList raw_create_opts = {
572     .name = "raw-create-opts",
573     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
574     .desc = {
575         {
576             .name = BLOCK_OPT_SIZE,
577             .type = QEMU_OPT_SIZE,
578             .help = "Virtual disk size"
579         },
580         { /* end of list */ }
581     }
582 };
583 
584 BlockDriver bdrv_file = {
585     .format_name	= "file",
586     .protocol_name	= "file",
587     .instance_size	= sizeof(BDRVRawState),
588     .bdrv_needs_filename = true,
589     .bdrv_parse_filename = raw_parse_filename,
590     .bdrv_file_open     = raw_open,
591     .bdrv_refresh_limits = raw_probe_alignment,
592     .bdrv_close         = raw_close,
593     .bdrv_create        = raw_create,
594     .bdrv_has_zero_init = bdrv_has_zero_init_1,
595 
596     .bdrv_aio_readv     = raw_aio_readv,
597     .bdrv_aio_writev    = raw_aio_writev,
598     .bdrv_aio_flush     = raw_aio_flush,
599 
600     .bdrv_truncate	= raw_truncate,
601     .bdrv_getlength	= raw_getlength,
602     .bdrv_get_allocated_file_size
603                         = raw_get_allocated_file_size,
604 
605     .create_opts        = &raw_create_opts,
606 };
607 
608 /***********************************************/
609 /* host device */
610 
611 static int find_cdrom(char *cdrom_name, int cdrom_name_size)
612 {
613     char drives[256], *pdrv = drives;
614     UINT type;
615 
616     memset(drives, 0, sizeof(drives));
617     GetLogicalDriveStrings(sizeof(drives), drives);
618     while(pdrv[0] != '\0') {
619         type = GetDriveType(pdrv);
620         switch(type) {
621         case DRIVE_CDROM:
622             snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
623             return 0;
624             break;
625         }
626         pdrv += lstrlen(pdrv) + 1;
627     }
628     return -1;
629 }
630 
631 static int find_device_type(BlockDriverState *bs, const char *filename)
632 {
633     BDRVRawState *s = bs->opaque;
634     UINT type;
635     const char *p;
636 
637     if (strstart(filename, "\\\\.\\", &p) ||
638         strstart(filename, "//./", &p)) {
639         if (stristart(p, "PhysicalDrive", NULL))
640             return FTYPE_HARDDISK;
641         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
642         type = GetDriveType(s->drive_path);
643         switch (type) {
644         case DRIVE_REMOVABLE:
645         case DRIVE_FIXED:
646             return FTYPE_HARDDISK;
647         case DRIVE_CDROM:
648             return FTYPE_CD;
649         default:
650             return FTYPE_FILE;
651         }
652     } else {
653         return FTYPE_FILE;
654     }
655 }
656 
657 static int hdev_probe_device(const char *filename)
658 {
659     if (strstart(filename, "/dev/cdrom", NULL))
660         return 100;
661     if (is_windows_drive(filename))
662         return 100;
663     return 0;
664 }
665 
666 static void hdev_parse_filename(const char *filename, QDict *options,
667                                 Error **errp)
668 {
669     bdrv_parse_filename_strip_prefix(filename, "host_device:", options);
670 }
671 
672 static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
673                      Error **errp)
674 {
675     BDRVRawState *s = bs->opaque;
676     int access_flags, create_flags;
677     int ret = 0;
678     DWORD overlapped;
679     char device_name[64];
680 
681     Error *local_err = NULL;
682     const char *filename;
683     bool use_aio;
684 
685     QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
686                                       &error_abort);
687     qemu_opts_absorb_qdict(opts, options, &local_err);
688     if (local_err) {
689         error_propagate(errp, local_err);
690         ret = -EINVAL;
691         goto done;
692     }
693 
694     filename = qemu_opt_get(opts, "filename");
695 
696     use_aio = get_aio_option(opts, flags, &local_err);
697     if (!local_err && use_aio) {
698         error_setg(&local_err, "AIO is not supported on Windows host devices");
699     }
700     if (local_err) {
701         error_propagate(errp, local_err);
702         ret = -EINVAL;
703         goto done;
704     }
705 
706     if (strstart(filename, "/dev/cdrom", NULL)) {
707         if (find_cdrom(device_name, sizeof(device_name)) < 0) {
708             error_setg(errp, "Could not open CD-ROM drive");
709             ret = -ENOENT;
710             goto done;
711         }
712         filename = device_name;
713     } else {
714         /* transform drive letters into device name */
715         if (((filename[0] >= 'a' && filename[0] <= 'z') ||
716              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
717             filename[1] == ':' && filename[2] == '\0') {
718             snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
719             filename = device_name;
720         }
721     }
722     s->type = find_device_type(bs, filename);
723 
724     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
725 
726     create_flags = OPEN_EXISTING;
727 
728     s->hfile = CreateFile(filename, access_flags,
729                           FILE_SHARE_READ, NULL,
730                           create_flags, overlapped, NULL);
731     if (s->hfile == INVALID_HANDLE_VALUE) {
732         int err = GetLastError();
733 
734         if (err == ERROR_ACCESS_DENIED) {
735             ret = -EACCES;
736         } else {
737             ret = -EINVAL;
738         }
739         error_setg_errno(errp, -ret, "Could not open device");
740         goto done;
741     }
742 
743 done:
744     qemu_opts_del(opts);
745     return ret;
746 }
747 
748 static BlockDriver bdrv_host_device = {
749     .format_name	= "host_device",
750     .protocol_name	= "host_device",
751     .instance_size	= sizeof(BDRVRawState),
752     .bdrv_needs_filename = true,
753     .bdrv_parse_filename = hdev_parse_filename,
754     .bdrv_probe_device	= hdev_probe_device,
755     .bdrv_file_open	= hdev_open,
756     .bdrv_close		= raw_close,
757 
758     .bdrv_aio_readv     = raw_aio_readv,
759     .bdrv_aio_writev    = raw_aio_writev,
760     .bdrv_aio_flush     = raw_aio_flush,
761 
762     .bdrv_detach_aio_context = raw_detach_aio_context,
763     .bdrv_attach_aio_context = raw_attach_aio_context,
764 
765     .bdrv_getlength      = raw_getlength,
766     .has_variable_length = true,
767 
768     .bdrv_get_allocated_file_size
769                         = raw_get_allocated_file_size,
770 };
771 
772 static void bdrv_file_init(void)
773 {
774     bdrv_register(&bdrv_file);
775     bdrv_register(&bdrv_host_device);
776 }
777 
778 block_init(bdrv_file_init);
779