block/file-win32.c - qemu - Git at Google

 /*
  * Block driver for RAW files (win32)
  *
  * Copyright (c) 2006 Fabrice Bellard
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "qemu/cutils.h"
 #include "block/block_int.h"
 #include "qemu/module.h"
 #include "qemu/option.h"
 #include "block/raw-aio.h"
 #include "trace.h"
 #include "block/thread-pool.h"
 #include "qemu/iov.h"
 #include "qapi/qmp/qdict.h"
 #include "qapi/qmp/qstring.h"
 #include <windows.h>
 #include <winioctl.h>

 #define FTYPE_FILE 0
 #define FTYPE_CD     1
 #define FTYPE_HARDDISK 2

 typedef struct RawWin32AIOData {
     BlockDriverState *bs;
     HANDLE hfile;
     struct iovec *aio_iov;
     int aio_niov;
     size_t aio_nbytes;
     off64_t aio_offset;
     int aio_type;
 } RawWin32AIOData;

 typedef struct BDRVRawState {
     HANDLE hfile;
     int type;
     char drive_path[16]; /* format: "d:\" */
     QEMUWin32AIOState *aio;
 } BDRVRawState;

 /*
  * Read/writes the data to/from a given linear buffer.
  *
  * Returns the number of bytes handles or -errno in case of an error. Short
  * reads are only returned if the end of the file is reached.
  */
 static size_t handle_aiocb_rw(RawWin32AIOData *aiocb)
 {
     size_t offset = 0;
     int i;

     for (i = 0; i < aiocb->aio_niov; i++) {
         OVERLAPPED ov;
         DWORD ret, ret_count, len;

         memset(&ov, 0, sizeof(ov));
         ov.Offset = (aiocb->aio_offset + offset);
         ov.OffsetHigh = (aiocb->aio_offset + offset) >> 32;
         len = aiocb->aio_iov[i].iov_len;
         if (aiocb->aio_type & QEMU_AIO_WRITE) {
             ret = WriteFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
                             len, &ret_count, &ov);
         } else {
             ret = ReadFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
                            len, &ret_count, &ov);
         }
         if (!ret) {
             ret_count = 0;
         }
         if (ret_count != len) {
             offset += ret_count;
             break;
         }
         offset += len;
     }

     return offset;
 }

 static int aio_worker(void *arg)
 {
     RawWin32AIOData *aiocb = arg;
     ssize_t ret = 0;
     size_t count;

     switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
     case QEMU_AIO_READ:
         count = handle_aiocb_rw(aiocb);
         if (count < aiocb->aio_nbytes) {
             /* A short read means that we have reached EOF. Pad the buffer
              * with zeros for bytes after EOF. */
             iov_memset(aiocb->aio_iov, aiocb->aio_niov, count,
                       0, aiocb->aio_nbytes - count);

             count = aiocb->aio_nbytes;
         }
         if (count == aiocb->aio_nbytes) {
             ret = 0;
         } else {
             ret = -EINVAL;
         }
         break;
     case QEMU_AIO_WRITE:
         count = handle_aiocb_rw(aiocb);
         if (count == aiocb->aio_nbytes) {
             ret = 0;
         } else {
             ret = -EINVAL;
         }
         break;
     case QEMU_AIO_FLUSH:
         if (!FlushFileBuffers(aiocb->hfile)) {
             return -EIO;
         }
         break;
     default:
         fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
         ret = -EINVAL;
         break;
     }

     g_free(aiocb);
     return ret;
 }

 static BlockAIOCB *paio_submit(BlockDriverState *bs, HANDLE hfile,
         int64_t offset, QEMUIOVector *qiov, int count,
         BlockCompletionFunc *cb, void *opaque, int type)
 {
     RawWin32AIOData *acb = g_new(RawWin32AIOData, 1);
     ThreadPool *pool;

     acb->bs = bs;
     acb->hfile = hfile;
     acb->aio_type = type;

     if (qiov) {
         acb->aio_iov = qiov->iov;
         acb->aio_niov = qiov->niov;
         assert(qiov->size == count);
     }
     acb->aio_nbytes = count;
     acb->aio_offset = offset;

     trace_paio_submit(acb, opaque, offset, count, type);
     pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
     return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
 }

 int qemu_ftruncate64(int fd, int64_t length)
 {
     LARGE_INTEGER li;
     DWORD dw;
     LONG high;
     HANDLE h;
     BOOL res;

     if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
 	return -1;

     h = (HANDLE)_get_osfhandle(fd);

     /* get current position, ftruncate do not change position */
     li.HighPart = 0;
     li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
     if (li.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 	return -1;
     }

     high = length >> 32;
     dw = SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN);
     if (dw == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
 	return -1;
     }
     res = SetEndOfFile(h);

     /* back to old position */
     SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
     return res ? 0 : -1;
 }

 static int set_sparse(int fd)
 {
     DWORD returned;
     return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
 				 NULL, 0, NULL, 0, &returned, NULL);
 }

 static void raw_detach_aio_context(BlockDriverState *bs)
 {
     BDRVRawState *s = bs->opaque;

     if (s->aio) {
         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
     }
 }

 static void raw_attach_aio_context(BlockDriverState *bs,
                                    AioContext *new_context)
 {
     BDRVRawState *s = bs->opaque;

     if (s->aio) {
         win32_aio_attach_aio_context(s->aio, new_context);
     }
 }

 static void raw_probe_alignment(BlockDriverState *bs, Error **errp)
 {
     BDRVRawState *s = bs->opaque;
     DWORD sectorsPerCluster, freeClusters, totalClusters, count;
     DISK_GEOMETRY_EX dg;
     BOOL status;

     if (s->type == FTYPE_CD) {
         bs->bl.request_alignment = 2048;
         return;
     }
     if (s->type == FTYPE_HARDDISK) {
         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
         if (status != 0) {
             bs->bl.request_alignment = dg.Geometry.BytesPerSector;
             return;
         }
         /* try GetDiskFreeSpace too */
     }

     if (s->drive_path[0]) {
         GetDiskFreeSpace(s->drive_path, &sectorsPerCluster,
                          &dg.Geometry.BytesPerSector,
                          &freeClusters, &totalClusters);
         bs->bl.request_alignment = dg.Geometry.BytesPerSector;
     }
 }

 static void raw_parse_flags(int flags, bool use_aio, int *access_flags,
                             DWORD *overlapped)
 {
     assert(access_flags != NULL);
     assert(overlapped != NULL);

     if (flags & BDRV_O_RDWR) {
         *access_flags = GENERIC_READ | GENERIC_WRITE;
     } else {
         *access_flags = GENERIC_READ;
     }

     *overlapped = FILE_ATTRIBUTE_NORMAL;
     if (use_aio) {
         *overlapped |= FILE_FLAG_OVERLAPPED;
     }
     if (flags & BDRV_O_NOCACHE) {
         *overlapped |= FILE_FLAG_NO_BUFFERING;
     }
 }

 static void raw_parse_filename(const char *filename, QDict *options,
                                Error **errp)
 {
     bdrv_parse_filename_strip_prefix(filename, "file:", options);
 }

 static QemuOptsList raw_runtime_opts = {
     .name = "raw",
     .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
     .desc = {
         {
             .name = "filename",
             .type = QEMU_OPT_STRING,
             .help = "File name of the image",
         },
         {
             .name = "aio",
             .type = QEMU_OPT_STRING,
             .help = "host AIO implementation (threads, native)",
         },
         { /* end of list */ }
     },
 };

 static bool get_aio_option(QemuOpts *opts, int flags, Error **errp)
 {
     BlockdevAioOptions aio, aio_default;

     aio_default = (flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE
                                               : BLOCKDEV_AIO_OPTIONS_THREADS;
     aio = qapi_enum_parse(&BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
                           aio_default, errp);

     switch (aio) {
     case BLOCKDEV_AIO_OPTIONS_NATIVE:
         return true;
     case BLOCKDEV_AIO_OPTIONS_THREADS:
         return false;
     default:
         error_setg(errp, "Invalid AIO option");
     }
     return false;
 }

 static int raw_open(BlockDriverState *bs, QDict *options, int flags,
                     Error **errp)
 {
     BDRVRawState *s = bs->opaque;
     int access_flags;
     DWORD overlapped;
     QemuOpts *opts;
     Error *local_err = NULL;
     const char *filename;
     bool use_aio;
     int ret;

     s->type = FTYPE_FILE;

     opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
     qemu_opts_absorb_qdict(opts, options, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         ret = -EINVAL;
         goto fail;
     }

     if (qdict_get_try_bool(options, "locking", false)) {
         error_setg(errp, "locking=on is not supported on Windows");
         ret = -EINVAL;
         goto fail;
     }

     filename = qemu_opt_get(opts, "filename");

     use_aio = get_aio_option(opts, flags, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         ret = -EINVAL;
         goto fail;
     }

     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);

     if (filename[0] && filename[1] == ':') {
         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
     } else if (filename[0] == '\\' && filename[1] == '\\') {
         s->drive_path[0] = 0;
     } else {
         /* Relative path.  */
         char buf[MAX_PATH];
         GetCurrentDirectory(MAX_PATH, buf);
         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
     }

     s->hfile = CreateFile(filename, access_flags,
                           FILE_SHARE_READ, NULL,
                           OPEN_EXISTING, overlapped, NULL);
     if (s->hfile == INVALID_HANDLE_VALUE) {
         int err = GetLastError();

         error_setg_win32(errp, err, "Could not open '%s'", filename);
         if (err == ERROR_ACCESS_DENIED) {
             ret = -EACCES;
         } else {
             ret = -EINVAL;
         }
         goto fail;
     }

     if (use_aio) {
         s->aio = win32_aio_init();
         if (s->aio == NULL) {
             CloseHandle(s->hfile);
             error_setg(errp, "Could not initialize AIO");
             ret = -EINVAL;
             goto fail;
         }

         ret = win32_aio_attach(s->aio, s->hfile);
         if (ret < 0) {
             win32_aio_cleanup(s->aio);
             CloseHandle(s->hfile);
             error_setg_errno(errp, -ret, "Could not enable AIO");
             goto fail;
         }

         win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
     }

     ret = 0;
 fail:
     qemu_opts_del(opts);
     return ret;
 }

 static BlockAIOCB *raw_aio_readv(BlockDriverState *bs,
                          int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
                          BlockCompletionFunc *cb, void *opaque)
 {
     BDRVRawState *s = bs->opaque;
     if (s->aio) {
         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
                                 nb_sectors, cb, opaque, QEMU_AIO_READ);
     } else {
         return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
                            nb_sectors << BDRV_SECTOR_BITS,
                            cb, opaque, QEMU_AIO_READ);
     }
 }

 static BlockAIOCB *raw_aio_writev(BlockDriverState *bs,
                           int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
                           BlockCompletionFunc *cb, void *opaque)
 {
     BDRVRawState *s = bs->opaque;
     if (s->aio) {
         return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
                                 nb_sectors, cb, opaque, QEMU_AIO_WRITE);
     } else {
         return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
                            nb_sectors << BDRV_SECTOR_BITS,
                            cb, opaque, QEMU_AIO_WRITE);
     }
 }

 static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
                          BlockCompletionFunc *cb, void *opaque)
 {
     BDRVRawState *s = bs->opaque;
     return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
 }

 static void raw_close(BlockDriverState *bs)
 {
     BDRVRawState *s = bs->opaque;

     if (s->aio) {
         win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
         win32_aio_cleanup(s->aio);
         s->aio = NULL;
     }

     CloseHandle(s->hfile);
     if (bs->open_flags & BDRV_O_TEMPORARY) {
         unlink(bs->filename);
     }
 }

 static int raw_truncate(BlockDriverState *bs, int64_t offset,
                         PreallocMode prealloc, Error **errp)
 {
     BDRVRawState *s = bs->opaque;
     LONG low, high;
     DWORD dwPtrLow;

     if (prealloc != PREALLOC_MODE_OFF) {
         error_setg(errp, "Unsupported preallocation mode '%s'",
                    PreallocMode_str(prealloc));
         return -ENOTSUP;
     }

     low = offset;
     high = offset >> 32;

     /*
      * An error has occurred if the return value is INVALID_SET_FILE_POINTER
      * and GetLastError doesn't return NO_ERROR.
      */
     dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
     if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
         error_setg_win32(errp, GetLastError(), "SetFilePointer error");
         return -EIO;
     }
     if (SetEndOfFile(s->hfile) == 0) {
         error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
         return -EIO;
     }
     return 0;
 }

 static int64_t raw_getlength(BlockDriverState *bs)
 {
     BDRVRawState *s = bs->opaque;
     LARGE_INTEGER l;
     ULARGE_INTEGER available, total, total_free;
     DISK_GEOMETRY_EX dg;
     DWORD count;
     BOOL status;

     switch(s->type) {
     case FTYPE_FILE:
         l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
         if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
             return -EIO;
         break;
     case FTYPE_CD:
         if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
             return -EIO;
         l.QuadPart = total.QuadPart;
         break;
     case FTYPE_HARDDISK:
         status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
                                  NULL, 0, &dg, sizeof(dg), &count, NULL);
         if (status != 0) {
             l = dg.DiskSize;
         }
         break;
     default:
         return -EIO;
     }
     return l.QuadPart;
 }

 static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
 {
     typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
                                               DWORD * high);
     get_compressed_t get_compressed;
     struct _stati64 st;
     const char *filename = bs->filename;
     /* WinNT support GetCompressedFileSize to determine allocate size */
     get_compressed =
         (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
                                             "GetCompressedFileSizeA");
     if (get_compressed) {
         DWORD high, low;
         low = get_compressed(filename, &high);
         if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
             return (((int64_t) high) << 32) + low;
         }
     }

     if (_stati64(filename, &st) < 0) {
         return -1;
     }
     return st.st_size;
 }

 static int raw_co_create(BlockdevCreateOptions *options, Error **errp)
 {
     BlockdevCreateOptionsFile *file_opts;
     int fd;

     assert(options->driver == BLOCKDEV_DRIVER_FILE);
     file_opts = &options->u.file;

     if (file_opts->has_preallocation) {
         error_setg(errp, "Preallocation is not supported on Windows");
         return -EINVAL;
     }
     if (file_opts->has_nocow) {
         error_setg(errp, "nocow is not supported on Windows");
         return -EINVAL;
     }

     fd = qemu_open(file_opts->filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
                    0644);
     if (fd < 0) {
         error_setg_errno(errp, errno, "Could not create file");
         return -EIO;
     }
     set_sparse(fd);
     ftruncate(fd, file_opts->size);
     qemu_close(fd);

     return 0;
 }

 static int coroutine_fn raw_co_create_opts(const char *filename, QemuOpts *opts,
                                            Error **errp)
 {
     BlockdevCreateOptions options;
     int64_t total_size = 0;

     strstart(filename, "file:", &filename);

     /* Read out options */
     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
                           BDRV_SECTOR_SIZE);

     options = (BlockdevCreateOptions) {
         .driver     = BLOCKDEV_DRIVER_FILE,
         .u.file     = {
             .filename           = (char *) filename,
             .size               = total_size,
             .has_preallocation  = false,
             .has_nocow          = false,
         },
     };
     return raw_co_create(&options, errp);
 }

 static QemuOptsList raw_create_opts = {
     .name = "raw-create-opts",
     .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
     .desc = {
         {
             .name = BLOCK_OPT_SIZE,
             .type = QEMU_OPT_SIZE,
             .help = "Virtual disk size"
         },
         { /* end of list */ }
     }
 };

 BlockDriver bdrv_file = {
     .format_name	= "file",
     .protocol_name	= "file",
     .instance_size	= sizeof(BDRVRawState),
     .bdrv_needs_filename = true,
     .bdrv_parse_filename = raw_parse_filename,
     .bdrv_file_open     = raw_open,
     .bdrv_refresh_limits = raw_probe_alignment,
     .bdrv_close         = raw_close,
     .bdrv_co_create_opts = raw_co_create_opts,
     .bdrv_has_zero_init = bdrv_has_zero_init_1,

     .bdrv_aio_readv     = raw_aio_readv,
     .bdrv_aio_writev    = raw_aio_writev,
     .bdrv_aio_flush     = raw_aio_flush,

     .bdrv_truncate	= raw_truncate,
     .bdrv_getlength	= raw_getlength,
     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,

     .create_opts        = &raw_create_opts,
 };

 /***********************************************/
 /* host device */

 static int find_cdrom(char *cdrom_name, int cdrom_name_size)
 {
     char drives[256], *pdrv = drives;
     UINT type;

     memset(drives, 0, sizeof(drives));
     GetLogicalDriveStrings(sizeof(drives), drives);
     while(pdrv[0] != '\0') {
         type = GetDriveType(pdrv);
         switch(type) {
         case DRIVE_CDROM:
             snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
             return 0;
             break;
         }
         pdrv += lstrlen(pdrv) + 1;
     }
     return -1;
 }

 static int find_device_type(BlockDriverState *bs, const char *filename)
 {
     BDRVRawState *s = bs->opaque;
     UINT type;
     const char *p;

     if (strstart(filename, "\\\\.\\", &p) ||
         strstart(filename, "//./", &p)) {
         if (stristart(p, "PhysicalDrive", NULL))
             return FTYPE_HARDDISK;
         snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
         type = GetDriveType(s->drive_path);
         switch (type) {
         case DRIVE_REMOVABLE:
         case DRIVE_FIXED:
             return FTYPE_HARDDISK;
         case DRIVE_CDROM:
             return FTYPE_CD;
         default:
             return FTYPE_FILE;
         }
     } else {
         return FTYPE_FILE;
     }
 }

 static int hdev_probe_device(const char *filename)
 {
     if (strstart(filename, "/dev/cdrom", NULL))
         return 100;
     if (is_windows_drive(filename))
         return 100;
     return 0;
 }

 static void hdev_parse_filename(const char *filename, QDict *options,
                                 Error **errp)
 {
     bdrv_parse_filename_strip_prefix(filename, "host_device:", options);
 }

 static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
                      Error **errp)
 {
     BDRVRawState *s = bs->opaque;
     int access_flags, create_flags;
     int ret = 0;
     DWORD overlapped;
     char device_name[64];

     Error *local_err = NULL;
     const char *filename;
     bool use_aio;

     QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
                                       &error_abort);
     qemu_opts_absorb_qdict(opts, options, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         ret = -EINVAL;
         goto done;
     }

     filename = qemu_opt_get(opts, "filename");

     use_aio = get_aio_option(opts, flags, &local_err);
     if (!local_err && use_aio) {
         error_setg(&local_err, "AIO is not supported on Windows host devices");
     }
     if (local_err) {
         error_propagate(errp, local_err);
         ret = -EINVAL;
         goto done;
     }

     if (strstart(filename, "/dev/cdrom", NULL)) {
         if (find_cdrom(device_name, sizeof(device_name)) < 0) {
             error_setg(errp, "Could not open CD-ROM drive");
             ret = -ENOENT;
             goto done;
         }
         filename = device_name;
     } else {
         /* transform drive letters into device name */
         if (((filename[0] >= 'a' && filename[0] <= 'z') ||
              (filename[0] >= 'A' && filename[0] <= 'Z')) &&
             filename[1] == ':' && filename[2] == '\0') {
             snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
             filename = device_name;
         }
     }
     s->type = find_device_type(bs, filename);

     raw_parse_flags(flags, use_aio, &access_flags, &overlapped);

     create_flags = OPEN_EXISTING;

     s->hfile = CreateFile(filename, access_flags,
                           FILE_SHARE_READ, NULL,
                           create_flags, overlapped, NULL);
     if (s->hfile == INVALID_HANDLE_VALUE) {
         int err = GetLastError();

         if (err == ERROR_ACCESS_DENIED) {
             ret = -EACCES;
         } else {
             ret = -EINVAL;
         }
         error_setg_errno(errp, -ret, "Could not open device");
         goto done;
     }

 done:
     qemu_opts_del(opts);
     return ret;
 }

 static BlockDriver bdrv_host_device = {
     .format_name	= "host_device",
     .protocol_name	= "host_device",
     .instance_size	= sizeof(BDRVRawState),
     .bdrv_needs_filename = true,
     .bdrv_parse_filename = hdev_parse_filename,
     .bdrv_probe_device	= hdev_probe_device,
     .bdrv_file_open	= hdev_open,
     .bdrv_close		= raw_close,

     .bdrv_aio_readv     = raw_aio_readv,
     .bdrv_aio_writev    = raw_aio_writev,
     .bdrv_aio_flush     = raw_aio_flush,

     .bdrv_detach_aio_context = raw_detach_aio_context,
     .bdrv_attach_aio_context = raw_attach_aio_context,

     .bdrv_getlength      = raw_getlength,
     .has_variable_length = true,

     .bdrv_get_allocated_file_size
                         = raw_get_allocated_file_size,
 };

 static void bdrv_file_init(void)
 {
     bdrv_register(&bdrv_file);
     bdrv_register(&bdrv_host_device);
 }

 block_init(bdrv_file_init);
	/*
	* Block driver for RAW files (win32)
	*
	* Copyright (c) 2006 Fabrice Bellard
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include "qemu/osdep.h"
	#include "qapi/error.h"
	#include "qemu/cutils.h"
	#include "block/block_int.h"
	#include "qemu/module.h"
	#include "qemu/option.h"
	#include "block/raw-aio.h"
	#include "trace.h"
	#include "block/thread-pool.h"
	#include "qemu/iov.h"
	#include "qapi/qmp/qdict.h"
	#include "qapi/qmp/qstring.h"
	#include <windows.h>
	#include <winioctl.h>

	#define FTYPE_FILE 0
	#define FTYPE_CD 1
	#define FTYPE_HARDDISK 2

	typedef struct RawWin32AIOData {
	BlockDriverState *bs;
	HANDLE hfile;
	struct iovec *aio_iov;
	int aio_niov;
	size_t aio_nbytes;
	off64_t aio_offset;
	int aio_type;
	} RawWin32AIOData;

	typedef struct BDRVRawState {
	HANDLE hfile;
	int type;
	char drive_path[16]; /* format: "d:\" */
	QEMUWin32AIOState *aio;
	} BDRVRawState;

	/*
	* Read/writes the data to/from a given linear buffer.
	*
	* Returns the number of bytes handles or -errno in case of an error. Short
	* reads are only returned if the end of the file is reached.
	*/
	static size_t handle_aiocb_rw(RawWin32AIOData *aiocb)
	{
	size_t offset = 0;
	int i;

	for (i = 0; i < aiocb->aio_niov; i++) {
	OVERLAPPED ov;
	DWORD ret, ret_count, len;

	memset(&ov, 0, sizeof(ov));
	ov.Offset = (aiocb->aio_offset + offset);
	ov.OffsetHigh = (aiocb->aio_offset + offset) >> 32;
	len = aiocb->aio_iov[i].iov_len;
	if (aiocb->aio_type & QEMU_AIO_WRITE) {
	ret = WriteFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
	len, &ret_count, &ov);
	} else {
	ret = ReadFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
	len, &ret_count, &ov);
	}
	if (!ret) {
	ret_count = 0;
	}
	if (ret_count != len) {
	offset += ret_count;
	break;
	}
	offset += len;
	}

	return offset;
	}

	static int aio_worker(void *arg)
	{
	RawWin32AIOData *aiocb = arg;
	ssize_t ret = 0;
	size_t count;

	switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
	case QEMU_AIO_READ:
	count = handle_aiocb_rw(aiocb);
	if (count < aiocb->aio_nbytes) {
	/* A short read means that we have reached EOF. Pad the buffer
	* with zeros for bytes after EOF. */
	iov_memset(aiocb->aio_iov, aiocb->aio_niov, count,
	0, aiocb->aio_nbytes - count);

	count = aiocb->aio_nbytes;
	}
	if (count == aiocb->aio_nbytes) {
	ret = 0;
	} else {
	ret = -EINVAL;
	}
	break;
	case QEMU_AIO_WRITE:
	count = handle_aiocb_rw(aiocb);
	if (count == aiocb->aio_nbytes) {
	ret = 0;
	} else {
	ret = -EINVAL;
	}
	break;
	case QEMU_AIO_FLUSH:
	if (!FlushFileBuffers(aiocb->hfile)) {
	return -EIO;
	}
	break;
	default:
	fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
	ret = -EINVAL;
	break;
	}

	g_free(aiocb);
	return ret;
	}

	static BlockAIOCB paio_submit(BlockDriverState bs, HANDLE hfile,
	int64_t offset, QEMUIOVector *qiov, int count,
	BlockCompletionFunc cb, void opaque, int type)
	{
	RawWin32AIOData *acb = g_new(RawWin32AIOData, 1);
	ThreadPool *pool;

	acb->bs = bs;
	acb->hfile = hfile;
	acb->aio_type = type;

	if (qiov) {
	acb->aio_iov = qiov->iov;
	acb->aio_niov = qiov->niov;
	assert(qiov->size == count);
	}
	acb->aio_nbytes = count;
	acb->aio_offset = offset;

	trace_paio_submit(acb, opaque, offset, count, type);
	pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
	return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
	}

	int qemu_ftruncate64(int fd, int64_t length)
	{
	LARGE_INTEGER li;
	DWORD dw;
	LONG high;
	HANDLE h;
	BOOL res;

	if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
	return -1;

	h = (HANDLE)_get_osfhandle(fd);

	/* get current position, ftruncate do not change position */
	li.HighPart = 0;
	li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
	if (li.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
	return -1;
	}

	high = length >> 32;
	dw = SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN);
	if (dw == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
	return -1;
	}
	res = SetEndOfFile(h);

	/* back to old position */
	SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
	return res ? 0 : -1;
	}

	static int set_sparse(int fd)
	{
	DWORD returned;
	return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
	NULL, 0, NULL, 0, &returned, NULL);
	}

	static void raw_detach_aio_context(BlockDriverState *bs)
	{
	BDRVRawState *s = bs->opaque;

	if (s->aio) {
	win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
	}
	}

	static void raw_attach_aio_context(BlockDriverState *bs,
	AioContext *new_context)
	{
	BDRVRawState *s = bs->opaque;

	if (s->aio) {
	win32_aio_attach_aio_context(s->aio, new_context);
	}
	}

	static void raw_probe_alignment(BlockDriverState bs, Error *errp)
	{
	BDRVRawState *s = bs->opaque;
	DWORD sectorsPerCluster, freeClusters, totalClusters, count;
	DISK_GEOMETRY_EX dg;
	BOOL status;

	if (s->type == FTYPE_CD) {
	bs->bl.request_alignment = 2048;
	return;
	}
	if (s->type == FTYPE_HARDDISK) {
	status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
	NULL, 0, &dg, sizeof(dg), &count, NULL);
	if (status != 0) {
	bs->bl.request_alignment = dg.Geometry.BytesPerSector;
	return;
	}
	/* try GetDiskFreeSpace too */
	}

	if (s->drive_path[0]) {
	GetDiskFreeSpace(s->drive_path, &sectorsPerCluster,
	&dg.Geometry.BytesPerSector,
	&freeClusters, &totalClusters);
	bs->bl.request_alignment = dg.Geometry.BytesPerSector;
	}
	}

	static void raw_parse_flags(int flags, bool use_aio, int *access_flags,
	DWORD *overlapped)
	{
	assert(access_flags != NULL);
	assert(overlapped != NULL);

	if (flags & BDRV_O_RDWR) {
	*access_flags = GENERIC_READ \| GENERIC_WRITE;
	} else {
	*access_flags = GENERIC_READ;
	}

	*overlapped = FILE_ATTRIBUTE_NORMAL;
	if (use_aio) {
	*overlapped \|= FILE_FLAG_OVERLAPPED;
	}
	if (flags & BDRV_O_NOCACHE) {
	*overlapped \|= FILE_FLAG_NO_BUFFERING;
	}
	}

	static void raw_parse_filename(const char filename, QDict options,
	Error **errp)
	{
	bdrv_parse_filename_strip_prefix(filename, "file:", options);
	}

	static QemuOptsList raw_runtime_opts = {
	.name = "raw",
	.head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
	.desc = {
	{
	.name = "filename",
	.type = QEMU_OPT_STRING,
	.help = "File name of the image",
	},
	{
	.name = "aio",
	.type = QEMU_OPT_STRING,
	.help = "host AIO implementation (threads, native)",
	},
	{ /* end of list */ }
	},
	};

	static bool get_aio_option(QemuOpts opts, int flags, Error *errp)
	{
	BlockdevAioOptions aio, aio_default;

	aio_default = (flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE
	: BLOCKDEV_AIO_OPTIONS_THREADS;
	aio = qapi_enum_parse(&BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
	aio_default, errp);

	switch (aio) {
	case BLOCKDEV_AIO_OPTIONS_NATIVE:
	return true;
	case BLOCKDEV_AIO_OPTIONS_THREADS:
	return false;
	default:
	error_setg(errp, "Invalid AIO option");
	}
	return false;
	}

	static int raw_open(BlockDriverState bs, QDict options, int flags,
	Error **errp)
	{
	BDRVRawState *s = bs->opaque;
	int access_flags;
	DWORD overlapped;
	QemuOpts *opts;
	Error *local_err = NULL;
	const char *filename;
	bool use_aio;
	int ret;

	s->type = FTYPE_FILE;

	opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
	qemu_opts_absorb_qdict(opts, options, &local_err);
	if (local_err) {
	error_propagate(errp, local_err);
	ret = -EINVAL;
	goto fail;
	}

	if (qdict_get_try_bool(options, "locking", false)) {
	error_setg(errp, "locking=on is not supported on Windows");
	ret = -EINVAL;
	goto fail;
	}

	filename = qemu_opt_get(opts, "filename");

	use_aio = get_aio_option(opts, flags, &local_err);
	if (local_err) {
	error_propagate(errp, local_err);
	ret = -EINVAL;
	goto fail;
	}

	raw_parse_flags(flags, use_aio, &access_flags, &overlapped);

	if (filename[0] && filename[1] == ':') {
	snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
	} else if (filename[0] == '\\' && filename[1] == '\\') {
	s->drive_path[0] = 0;
	} else {
	/* Relative path. */
	char buf[MAX_PATH];
	GetCurrentDirectory(MAX_PATH, buf);
	snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
	}

	s->hfile = CreateFile(filename, access_flags,
	FILE_SHARE_READ, NULL,
	OPEN_EXISTING, overlapped, NULL);
	if (s->hfile == INVALID_HANDLE_VALUE) {
	int err = GetLastError();

	error_setg_win32(errp, err, "Could not open '%s'", filename);
	if (err == ERROR_ACCESS_DENIED) {
	ret = -EACCES;
	} else {
	ret = -EINVAL;
	}
	goto fail;
	}

	if (use_aio) {
	s->aio = win32_aio_init();
	if (s->aio == NULL) {
	CloseHandle(s->hfile);
	error_setg(errp, "Could not initialize AIO");
	ret = -EINVAL;
	goto fail;
	}

	ret = win32_aio_attach(s->aio, s->hfile);
	if (ret < 0) {
	win32_aio_cleanup(s->aio);
	CloseHandle(s->hfile);
	error_setg_errno(errp, -ret, "Could not enable AIO");
	goto fail;
	}

	win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
	}

	ret = 0;
	fail:
	qemu_opts_del(opts);
	return ret;
	}

	static BlockAIOCB raw_aio_readv(BlockDriverState bs,
	int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
	BlockCompletionFunc cb, void opaque)
	{
	BDRVRawState *s = bs->opaque;
	if (s->aio) {
	return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
	nb_sectors, cb, opaque, QEMU_AIO_READ);
	} else {
	return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
	nb_sectors << BDRV_SECTOR_BITS,
	cb, opaque, QEMU_AIO_READ);
	}
	}

	static BlockAIOCB raw_aio_writev(BlockDriverState bs,
	int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
	BlockCompletionFunc cb, void opaque)
	{
	BDRVRawState *s = bs->opaque;
	if (s->aio) {
	return win32_aio_submit(bs, s->aio, s->hfile, sector_num, qiov,
	nb_sectors, cb, opaque, QEMU_AIO_WRITE);
	} else {
	return paio_submit(bs, s->hfile, sector_num << BDRV_SECTOR_BITS, qiov,
	nb_sectors << BDRV_SECTOR_BITS,
	cb, opaque, QEMU_AIO_WRITE);
	}
	}

	static BlockAIOCB raw_aio_flush(BlockDriverState bs,
	BlockCompletionFunc cb, void opaque)
	{
	BDRVRawState *s = bs->opaque;
	return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
	}

	static void raw_close(BlockDriverState *bs)
	{
	BDRVRawState *s = bs->opaque;

	if (s->aio) {
	win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
	win32_aio_cleanup(s->aio);
	s->aio = NULL;
	}

	CloseHandle(s->hfile);
	if (bs->open_flags & BDRV_O_TEMPORARY) {
	unlink(bs->filename);
	}
	}

	static int raw_truncate(BlockDriverState *bs, int64_t offset,
	PreallocMode prealloc, Error **errp)
	{
	BDRVRawState *s = bs->opaque;
	LONG low, high;
	DWORD dwPtrLow;

	if (prealloc != PREALLOC_MODE_OFF) {
	error_setg(errp, "Unsupported preallocation mode '%s'",
	PreallocMode_str(prealloc));
	return -ENOTSUP;
	}

	low = offset;
	high = offset >> 32;

	/*
	* An error has occurred if the return value is INVALID_SET_FILE_POINTER
	* and GetLastError doesn't return NO_ERROR.
	*/
	dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
	if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
	error_setg_win32(errp, GetLastError(), "SetFilePointer error");
	return -EIO;
	}
	if (SetEndOfFile(s->hfile) == 0) {
	error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
	return -EIO;
	}
	return 0;
	}

	static int64_t raw_getlength(BlockDriverState *bs)
	{
	BDRVRawState *s = bs->opaque;
	LARGE_INTEGER l;
	ULARGE_INTEGER available, total, total_free;
	DISK_GEOMETRY_EX dg;
	DWORD count;
	BOOL status;

	switch(s->type) {
	case FTYPE_FILE:
	l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
	if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
	return -EIO;
	break;
	case FTYPE_CD:
	if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
	return -EIO;
	l.QuadPart = total.QuadPart;
	break;
	case FTYPE_HARDDISK:
	status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
	NULL, 0, &dg, sizeof(dg), &count, NULL);
	if (status != 0) {
	l = dg.DiskSize;
	}
	break;
	default:
	return -EIO;
	}
	return l.QuadPart;
	}

	static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
	{
	typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
	DWORD * high);
	get_compressed_t get_compressed;
	struct _stati64 st;
	const char *filename = bs->filename;
	/* WinNT support GetCompressedFileSize to determine allocate size */
	get_compressed =
	(get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
	"GetCompressedFileSizeA");
	if (get_compressed) {
	DWORD high, low;
	low = get_compressed(filename, &high);
	if (low != 0xFFFFFFFFlu \|\| GetLastError() == NO_ERROR) {
	return (((int64_t) high) << 32) + low;
	}
	}

	if (_stati64(filename, &st) < 0) {
	return -1;
	}
	return st.st_size;
	}

	static int raw_co_create(BlockdevCreateOptions options, Error *errp)
	{
	BlockdevCreateOptionsFile *file_opts;
	int fd;

	assert(options->driver == BLOCKDEV_DRIVER_FILE);
	file_opts = &options->u.file;

	if (file_opts->has_preallocation) {
	error_setg(errp, "Preallocation is not supported on Windows");
	return -EINVAL;
	}
	if (file_opts->has_nocow) {
	error_setg(errp, "nocow is not supported on Windows");
	return -EINVAL;
	}

	fd = qemu_open(file_opts->filename, O_WRONLY \| O_CREAT \| O_TRUNC \| O_BINARY,
	0644);
	if (fd < 0) {
	error_setg_errno(errp, errno, "Could not create file");
	return -EIO;
	}
	set_sparse(fd);
	ftruncate(fd, file_opts->size);
	qemu_close(fd);

	return 0;
	}

	static int coroutine_fn raw_co_create_opts(const char filename, QemuOpts opts,
	Error **errp)
	{
	BlockdevCreateOptions options;
	int64_t total_size = 0;

	strstart(filename, "file:", &filename);

	/* Read out options */
	total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
	BDRV_SECTOR_SIZE);

	options = (BlockdevCreateOptions) {
	.driver = BLOCKDEV_DRIVER_FILE,
	.u.file = {
	.filename = (char *) filename,
	.size = total_size,
	.has_preallocation = false,
	.has_nocow = false,
	},
	};
	return raw_co_create(&options, errp);
	}

	static QemuOptsList raw_create_opts = {
	.name = "raw-create-opts",
	.head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
	.desc = {
	{
	.name = BLOCK_OPT_SIZE,
	.type = QEMU_OPT_SIZE,
	.help = "Virtual disk size"
	},
	{ /* end of list */ }
	}
	};

	BlockDriver bdrv_file = {
	.format_name = "file",
	.protocol_name = "file",
	.instance_size = sizeof(BDRVRawState),
	.bdrv_needs_filename = true,
	.bdrv_parse_filename = raw_parse_filename,
	.bdrv_file_open = raw_open,
	.bdrv_refresh_limits = raw_probe_alignment,
	.bdrv_close = raw_close,
	.bdrv_co_create_opts = raw_co_create_opts,
	.bdrv_has_zero_init = bdrv_has_zero_init_1,

	.bdrv_aio_readv = raw_aio_readv,
	.bdrv_aio_writev = raw_aio_writev,
	.bdrv_aio_flush = raw_aio_flush,

	.bdrv_truncate = raw_truncate,
	.bdrv_getlength = raw_getlength,
	.bdrv_get_allocated_file_size
	= raw_get_allocated_file_size,

	.create_opts = &raw_create_opts,
	};

	/***********************************************/
	/* host device */

	static int find_cdrom(char *cdrom_name, int cdrom_name_size)
	{
	char drives[256], *pdrv = drives;
	UINT type;

	memset(drives, 0, sizeof(drives));
	GetLogicalDriveStrings(sizeof(drives), drives);
	while(pdrv[0] != '\0') {
	type = GetDriveType(pdrv);
	switch(type) {
	case DRIVE_CDROM:
	snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
	return 0;
	break;
	}
	pdrv += lstrlen(pdrv) + 1;
	}
	return -1;
	}

	static int find_device_type(BlockDriverState bs, const char filename)
	{
	BDRVRawState *s = bs->opaque;
	UINT type;
	const char *p;

	if (strstart(filename, "\\\\.\\", &p) \|\|
	strstart(filename, "//./", &p)) {
	if (stristart(p, "PhysicalDrive", NULL))
	return FTYPE_HARDDISK;
	snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
	type = GetDriveType(s->drive_path);
	switch (type) {
	case DRIVE_REMOVABLE:
	case DRIVE_FIXED:
	return FTYPE_HARDDISK;
	case DRIVE_CDROM:
	return FTYPE_CD;
	default:
	return FTYPE_FILE;
	}
	} else {
	return FTYPE_FILE;
	}
	}

	static int hdev_probe_device(const char *filename)
	{
	if (strstart(filename, "/dev/cdrom", NULL))
	return 100;
	if (is_windows_drive(filename))
	return 100;
	return 0;
	}

	static void hdev_parse_filename(const char filename, QDict options,
	Error **errp)
	{
	bdrv_parse_filename_strip_prefix(filename, "host_device:", options);
	}

	static int hdev_open(BlockDriverState bs, QDict options, int flags,
	Error **errp)
	{
	BDRVRawState *s = bs->opaque;
	int access_flags, create_flags;
	int ret = 0;
	DWORD overlapped;
	char device_name[64];

	Error *local_err = NULL;
	const char *filename;
	bool use_aio;

	QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
	&error_abort);
	qemu_opts_absorb_qdict(opts, options, &local_err);
	if (local_err) {
	error_propagate(errp, local_err);
	ret = -EINVAL;
	goto done;
	}

	filename = qemu_opt_get(opts, "filename");

	use_aio = get_aio_option(opts, flags, &local_err);
	if (!local_err && use_aio) {
	error_setg(&local_err, "AIO is not supported on Windows host devices");
	}
	if (local_err) {
	error_propagate(errp, local_err);
	ret = -EINVAL;
	goto done;
	}

	if (strstart(filename, "/dev/cdrom", NULL)) {
	if (find_cdrom(device_name, sizeof(device_name)) < 0) {
	error_setg(errp, "Could not open CD-ROM drive");
	ret = -ENOENT;
	goto done;
	}
	filename = device_name;
	} else {
	/* transform drive letters into device name */
	if (((filename[0] >= 'a' && filename[0] <= 'z') \|\|
	(filename[0] >= 'A' && filename[0] <= 'Z')) &&
	filename[1] == ':' && filename[2] == '\0') {
	snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
	filename = device_name;
	}
	}
	s->type = find_device_type(bs, filename);

	raw_parse_flags(flags, use_aio, &access_flags, &overlapped);

	create_flags = OPEN_EXISTING;

	s->hfile = CreateFile(filename, access_flags,
	FILE_SHARE_READ, NULL,
	create_flags, overlapped, NULL);
	if (s->hfile == INVALID_HANDLE_VALUE) {
	int err = GetLastError();

	if (err == ERROR_ACCESS_DENIED) {
	ret = -EACCES;
	} else {
	ret = -EINVAL;
	}
	error_setg_errno(errp, -ret, "Could not open device");
	goto done;
	}

	done:
	qemu_opts_del(opts);
	return ret;
	}

	static BlockDriver bdrv_host_device = {
	.format_name = "host_device",
	.protocol_name = "host_device",
	.instance_size = sizeof(BDRVRawState),
	.bdrv_needs_filename = true,
	.bdrv_parse_filename = hdev_parse_filename,
	.bdrv_probe_device = hdev_probe_device,
	.bdrv_file_open = hdev_open,
	.bdrv_close = raw_close,

	.bdrv_aio_readv = raw_aio_readv,
	.bdrv_aio_writev = raw_aio_writev,
	.bdrv_aio_flush = raw_aio_flush,

	.bdrv_detach_aio_context = raw_detach_aio_context,
	.bdrv_attach_aio_context = raw_attach_aio_context,

	.bdrv_getlength = raw_getlength,
	.has_variable_length = true,

	.bdrv_get_allocated_file_size
	= raw_get_allocated_file_size,
	};

	static void bdrv_file_init(void)
	{
	bdrv_register(&bdrv_file);
	bdrv_register(&bdrv_host_device);
	}

	block_init(bdrv_file_init);