block-raw.c

/*
 * Block driver for RAW files
 * 
 * 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-common.h"
#include "block.h"
#include "block_int.h"
#include <assert.h>
#ifndef _WIN32

#ifdef X49GP
#define QEMU_TOOL
#endif

#ifdef CONFIG_COCOA
#include <paths.h>
#include <sys/param.h>
#include <IOKit/IOKitLib.h>
#include <IOKit/IOBSD.h>
#include <IOKit/storage/IOMediaBSDClient.h>
#include <IOKit/storage/IOMedia.h>
#include <IOKit/storage/IOCDMedia.h>
//#include <IOKit/storage/IOCDTypes.h>
#include <CoreFoundation/CoreFoundation.h>
#endif

#ifdef __sun__
#define _POSIX_PTHREAD_SEMANTICS 1
#include <signal.h>
#include <sys/dkio.h>
#endif
#ifdef __linux__
#include <sys/ioctl.h>
#include <linux/cdrom.h>
#include <linux/fd.h>
#endif
#ifdef __FreeBSD__
#include <sys/disk.h>
#endif

//#define DEBUG_FLOPPY

#define FTYPE_FILE   0
#define FTYPE_CD     1
#define FTYPE_FD     2

/* if the FD is not accessed during that time (in ms), we try to
   reopen it to see if the disk has been changed */
#define FD_OPEN_TIMEOUT 1000

typedef struct BDRVRawState {
    int fd;
    int type;
#if defined(__linux__)
    /* linux floppy specific */
    int fd_open_flags;
    int64_t fd_open_time;
    int64_t fd_error_time;
    int fd_got_error;
    int fd_media_changed;
#endif
} BDRVRawState;

static int fd_open(BlockDriverState *bs);

static int raw_open(BlockDriverState *bs, const char *filename, int flags)
{
    BDRVRawState *s = bs->opaque;
    int fd, open_flags, ret;

    open_flags = O_BINARY;
    if ((flags & BDRV_O_ACCESS) == O_RDWR) {
        open_flags |= O_RDWR;
    } else {
        open_flags |= O_RDONLY;
        bs->read_only = 1;
    }
    if (flags & BDRV_O_CREAT)
        open_flags |= O_CREAT | O_TRUNC;

    s->type = FTYPE_FILE;

    fd = open(filename, open_flags, 0644);
    if (fd < 0) {
        ret = -errno;
        if (ret == -EROFS)
            ret = -EACCES;
        return ret;
    }
    s->fd = fd;
    return 0;
}

/* XXX: use host sector size if necessary with:
#ifdef DIOCGSECTORSIZE
        {
            unsigned int sectorsize = 512;
            if (!ioctl(fd, DIOCGSECTORSIZE, &sectorsize) &&
                sectorsize > bufsize)
                bufsize = sectorsize;
        }
#endif
#ifdef CONFIG_COCOA
        u_int32_t   blockSize = 512;
        if ( !ioctl( fd, DKIOCGETBLOCKSIZE, &blockSize ) && blockSize > bufsize) {
            bufsize = blockSize;
        }
#endif
*/

static int raw_pread(BlockDriverState *bs, int64_t offset, 
                     uint8_t *buf, int count)
{
    BDRVRawState *s = bs->opaque;
    int ret;
    
    ret = fd_open(bs);
    if (ret < 0)
        return ret;

    lseek(s->fd, offset, SEEK_SET);
    ret = read(s->fd, buf, count);
    return ret;
}

static int raw_pwrite(BlockDriverState *bs, int64_t offset, 
                      const uint8_t *buf, int count)
{
    BDRVRawState *s = bs->opaque;
    int ret;
    
    ret = fd_open(bs);
    if (ret < 0)
        return ret;

    lseek(s->fd, offset, SEEK_SET);
    ret = write(s->fd, buf, count);
    return ret;
}

static void raw_close(BlockDriverState *bs)
{
    BDRVRawState *s = bs->opaque;
    if (s->fd >= 0) {
        close(s->fd);
        s->fd = -1;
    }
}

static int raw_truncate(BlockDriverState *bs, int64_t offset)
{
    BDRVRawState *s = bs->opaque;
    if (s->type != FTYPE_FILE)
        return -ENOTSUP;
    if (ftruncate(s->fd, offset) < 0)
        return -errno;
    return 0;
}

static int64_t  raw_getlength(BlockDriverState *bs)
{
    BDRVRawState *s = bs->opaque;
    int fd = s->fd;
    int64_t size;
#ifdef _BSD
    struct stat sb;
#endif
#ifdef __sun__
    struct dk_minfo minfo;
    int rv;
#endif
    int ret;

    ret = fd_open(bs);
    if (ret < 0)
        return ret;

#ifdef _BSD
    if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {
#ifdef DIOCGMEDIASIZE
	if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))
#endif
#ifdef CONFIG_COCOA
        size = LONG_LONG_MAX;
#else
        size = lseek(fd, 0LL, SEEK_END);
#endif
    } else
#endif
#ifdef __sun__
    /*
     * use the DKIOCGMEDIAINFO ioctl to read the size.
     */
    rv = ioctl ( fd, DKIOCGMEDIAINFO, &minfo );
    if ( rv != -1 ) {
        size = minfo.dki_lbsize * minfo.dki_capacity;
    } else /* there are reports that lseek on some devices
              fails, but irc discussion said that contingency
              on contingency was overkill */
#endif
    {
        size = lseek(fd, 0, SEEK_END);
    }
    return size;
}

static int raw_create(const char *filename, int64_t total_size,
                      const char *backing_file, int flags)
{
    int fd;
	int result = 0;

    if (flags || backing_file)
        return -ENOTSUP;

    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 
              0644);
    if (fd < 0) {
        result=-errno;
    } else {
        if (ftruncate(fd, total_size * 512)) {
            result=-errno;
        }
        if (close(fd) != 0) {
            result=-errno;
        }
	}
    return result;
}

static void raw_flush(BlockDriverState *bs)
{
    BDRVRawState *s = bs->opaque;
    fsync(s->fd);
}

BlockDriver bdrv_raw = {
    "raw",
    sizeof(BDRVRawState),
    NULL, /* no probe for protocols */
    raw_open,
    NULL,
    NULL,
    raw_close,
    raw_create,
    raw_flush,
    .protocol_name = "file",
    .bdrv_pread = raw_pread,
    .bdrv_pwrite = raw_pwrite,
    .bdrv_truncate = raw_truncate,
    .bdrv_getlength = raw_getlength,
};

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

#ifdef CONFIG_COCOA
static kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator );
static kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize );

kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator )
{
    kern_return_t       kernResult; 
    mach_port_t     masterPort;
    CFMutableDictionaryRef  classesToMatch;

    kernResult = IOMasterPort( MACH_PORT_NULL, &masterPort );
    if ( KERN_SUCCESS != kernResult ) {
        printf( "IOMasterPort returned %d\n", kernResult );
    }
    
    classesToMatch = IOServiceMatching( kIOCDMediaClass ); 
    if ( classesToMatch == NULL ) {
        printf( "IOServiceMatching returned a NULL dictionary.\n" );
    } else {
    CFDictionarySetValue( classesToMatch, CFSTR( kIOMediaEjectableKey ), kCFBooleanTrue );
    }
    kernResult = IOServiceGetMatchingServices( masterPort, classesToMatch, mediaIterator );
    if ( KERN_SUCCESS != kernResult )
    {
        printf( "IOServiceGetMatchingServices returned %d\n", kernResult );
    }
    
    return kernResult;
}

kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize )
{
    io_object_t     nextMedia;
    kern_return_t   kernResult = KERN_FAILURE;
    *bsdPath = '\0';
    nextMedia = IOIteratorNext( mediaIterator );
    if ( nextMedia )
    {
        CFTypeRef   bsdPathAsCFString;
    bsdPathAsCFString = IORegistryEntryCreateCFProperty( nextMedia, CFSTR( kIOBSDNameKey ), kCFAllocatorDefault, 0 );
        if ( bsdPathAsCFString ) {
            size_t devPathLength;
            strcpy( bsdPath, _PATH_DEV );
            strcat( bsdPath, "r" );
            devPathLength = strlen( bsdPath );
            if ( CFStringGetCString( bsdPathAsCFString, bsdPath + devPathLength, maxPathSize - devPathLength, kCFStringEncodingASCII ) ) {
                kernResult = KERN_SUCCESS;
            }
            CFRelease( bsdPathAsCFString );
        }
        IOObjectRelease( nextMedia );
    }
    
    return kernResult;
}

#endif

static int hdev_open(BlockDriverState *bs, const char *filename, int flags)
{
    BDRVRawState *s = bs->opaque;
    int fd, open_flags, ret;

#ifdef CONFIG_COCOA
    if (strstart(filename, "/dev/cdrom", NULL)) {
        kern_return_t kernResult;
        io_iterator_t mediaIterator;
        char bsdPath[ MAXPATHLEN ];
        int fd;
 
        kernResult = FindEjectableCDMedia( &mediaIterator );
        kernResult = GetBSDPath( mediaIterator, bsdPath, sizeof( bsdPath ) );
    
        if ( bsdPath[ 0 ] != '\0' ) {
            strcat(bsdPath,"s0");
            /* some CDs don't have a partition 0 */
            fd = open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);
            if (fd < 0) {
                bsdPath[strlen(bsdPath)-1] = '1';
            } else {
                close(fd);
            }
            filename = bsdPath;
        }
        
        if ( mediaIterator )
            IOObjectRelease( mediaIterator );
    }
#endif
    open_flags = O_BINARY;
    if ((flags & BDRV_O_ACCESS) == O_RDWR) {
        open_flags |= O_RDWR;
    } else {
        open_flags |= O_RDONLY;
        bs->read_only = 1;
    }

    s->type = FTYPE_FILE;
#if defined(__linux__)
    if (strstart(filename, "/dev/cd", NULL)) {
        /* open will not fail even if no CD is inserted */
        open_flags |= O_NONBLOCK;
        s->type = FTYPE_CD;
    } else if (strstart(filename, "/dev/fd", NULL)) {
        s->type = FTYPE_FD;
        s->fd_open_flags = open_flags;
        /* open will not fail even if no floppy is inserted */
        open_flags |= O_NONBLOCK;
    }
#endif
    fd = open(filename, open_flags, 0644);
    if (fd < 0) {
        ret = -errno;
        if (ret == -EROFS)
            ret = -EACCES;
        return ret;
    }
    s->fd = fd;
#if defined(__linux__)
    /* close fd so that we can reopen it as needed */
    if (s->type == FTYPE_FD) {
        close(s->fd);
        s->fd = -1;
        s->fd_media_changed = 1;
    }
#endif
    return 0;
}

static int fd_open(BlockDriverState *bs)
{
    return 0;
}

#if defined(__linux__)

static int raw_is_inserted(BlockDriverState *bs)
{
    BDRVRawState *s = bs->opaque;
    int ret;

    switch(s->type) {
    case FTYPE_CD:
        ret = ioctl(s->fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
        if (ret == CDS_DISC_OK)
            return 1;
        else
            return 0;
        break;
    case FTYPE_FD:
        ret = fd_open(bs);
        return (ret >= 0);
    default:
        return 1;
    }
}

/* currently only used by fdc.c, but a CD version would be good too */
static int raw_media_changed(BlockDriverState *bs)
{
    BDRVRawState *s = bs->opaque;

    switch(s->type) {
    case FTYPE_FD:
        {
            int ret;
            /* XXX: we do not have a true media changed indication. It
               does not work if the floppy is changed without trying
               to read it */
            fd_open(bs);
            ret = s->fd_media_changed;
            s->fd_media_changed = 0;
#ifdef DEBUG_FLOPPY
            printf("Floppy changed=%d\n", ret);
#endif
            return ret;
        }
    default:
        return -ENOTSUP;
    }
}

static int raw_eject(BlockDriverState *bs, int eject_flag)
{
    BDRVRawState *s = bs->opaque;

    switch(s->type) {
    case FTYPE_CD:
        if (eject_flag) {
            if (ioctl (s->fd, CDROMEJECT, NULL) < 0)
                perror("CDROMEJECT");
        } else {
            if (ioctl (s->fd, CDROMCLOSETRAY, NULL) < 0)
                perror("CDROMEJECT");
        }
        break;
    case FTYPE_FD:
        {
            int fd;
            if (s->fd >= 0) {
                close(s->fd);
                s->fd = -1;
            }
            fd = open(bs->filename, s->fd_open_flags | O_NONBLOCK);
            if (fd >= 0) {
                if (ioctl(fd, FDEJECT, 0) < 0)
                    perror("FDEJECT");
                close(fd);
            }
        }
        break;
    default:
        return -ENOTSUP;
    }
    return 0;
}

static int raw_set_locked(BlockDriverState *bs, int locked)
{
    BDRVRawState *s = bs->opaque;

    switch(s->type) {
    case FTYPE_CD:
        if (ioctl (s->fd, CDROM_LOCKDOOR, locked) < 0) {
            /* Note: an error can happen if the distribution automatically
               mounts the CD-ROM */
            //        perror("CDROM_LOCKDOOR");
        }
        break;
    default:
        return -ENOTSUP;
    }
    return 0;
}

#else

static int raw_is_inserted(BlockDriverState *bs)
{
    return 1;
}

static int raw_media_changed(BlockDriverState *bs)
{
    return -ENOTSUP;
}

static int raw_eject(BlockDriverState *bs, int eject_flag)
{
    return -ENOTSUP;
}

static int raw_set_locked(BlockDriverState *bs, int locked)
{
    return -ENOTSUP;
}

#endif /* !linux */

BlockDriver bdrv_host_device = {
    "host_device",
    sizeof(BDRVRawState),
    NULL, /* no probe for protocols */
    hdev_open,
    NULL,
    NULL,
    raw_close,
    NULL,
    raw_flush,
    .bdrv_pread = raw_pread,
    .bdrv_pwrite = raw_pwrite,
    .bdrv_getlength = raw_getlength,

    /* removable device support */
    .bdrv_is_inserted = raw_is_inserted,
    .bdrv_media_changed = raw_media_changed,
    .bdrv_eject = raw_eject,
    .bdrv_set_locked = raw_set_locked,
};

#else /* _WIN32 */

/* XXX: use another file ? */
#include <winioctl.h>

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

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

int qemu_ftruncate64(int fd, int64_t length)
{
    LARGE_INTEGER li;
    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 == 0xffffffffUL && GetLastError() != NO_ERROR)
	return -1;

    high = length >> 32;
    if (!SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN))
	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 int raw_open(BlockDriverState *bs, const char *filename, int flags)
{
    BDRVRawState *s = bs->opaque;
    int access_flags, create_flags;
    DWORD overlapped;

    s->type = FTYPE_FILE;

    if ((flags & BDRV_O_ACCESS) == O_RDWR) {
        access_flags = GENERIC_READ | GENERIC_WRITE;
    } else {
        access_flags = GENERIC_READ;
    }
    if (flags & BDRV_O_CREAT) {
        create_flags = CREATE_ALWAYS;
    } else {
        create_flags = OPEN_EXISTING;
    }
#ifdef QEMU_TOOL
    overlapped = FILE_ATTRIBUTE_NORMAL;
#else
    overlapped = FILE_FLAG_OVERLAPPED;
#endif
    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)
            return -EACCES;
        return -1;
    }
    return 0;
}

static int raw_pread(BlockDriverState *bs, int64_t offset, 
                     uint8_t *buf, int count)
{
    BDRVRawState *s = bs->opaque;
    OVERLAPPED ov;
    DWORD ret_count;
    int ret;
    
    memset(&ov, 0, sizeof(ov));
    ov.Offset = offset;
    ov.OffsetHigh = offset >> 32;
    ret = ReadFile(s->hfile, buf, count, &ret_count, &ov);
    if (!ret) {
        ret = GetOverlappedResult(s->hfile, &ov, &ret_count, TRUE);
        if (!ret)
            return -EIO;
        else
            return ret_count;
    }
    return ret_count;
}

static int raw_pwrite(BlockDriverState *bs, int64_t offset, 
                      const uint8_t *buf, int count)
{
    BDRVRawState *s = bs->opaque;
    OVERLAPPED ov;
    DWORD ret_count;
    int ret;
    
    memset(&ov, 0, sizeof(ov));
    ov.Offset = offset;
    ov.OffsetHigh = offset >> 32;
    ret = WriteFile(s->hfile, buf, count, &ret_count, &ov);
    if (!ret) {
        ret = GetOverlappedResult(s->hfile, &ov, &ret_count, TRUE);
        if (!ret)
            return -EIO;
        else
            return ret_count;
    }
    return ret_count;
}

static void raw_flush(BlockDriverState *bs)
{
    BDRVRawState *s = bs->opaque;
    FlushFileBuffers(s->hfile);
}

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

static int raw_truncate(BlockDriverState *bs, int64_t offset)
{
    BDRVRawState *s = bs->opaque;
    DWORD low, high;

    low = offset;
    high = offset >> 32;
    if (!SetFilePointer(s->hfile, low, &high, FILE_BEGIN))
	return -EIO;
    if (!SetEndOfFile(s->hfile))
        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 dg;
    DWORD count;
    BOOL status;

    switch(s->type) {
    case FTYPE_FILE:
        l.LowPart = GetFileSize(s->hfile, &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,
                                 NULL, 0, &dg, sizeof(dg), &count, NULL);
        if (status != FALSE) {
            l.QuadPart = dg.Cylinders.QuadPart * dg.TracksPerCylinder
                * dg.SectorsPerTrack * dg.BytesPerSector;
        }
        break;
    default:
        return -EIO;
    }
    return l.QuadPart;
}

static int raw_create(const char *filename, int64_t total_size,
                      const char *backing_file, int flags)
{
    int fd;

    if (flags || backing_file)
        return -ENOTSUP;

    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 
              0644);
    if (fd < 0)
        return -EIO;
    set_sparse(fd);
    ftruncate(fd, total_size * 512);
    close(fd);
    return 0;
}

BlockDriver bdrv_raw = {
    "raw",
    sizeof(BDRVRawState),
    NULL, /* no probe for protocols */
    raw_open,
    NULL,
    NULL,
    raw_close,
    raw_create,
    raw_flush,

    .protocol_name = "file",
    .bdrv_pread = raw_pread,
    .bdrv_pwrite = raw_pwrite,
    .bdrv_truncate = raw_truncate,
    .bdrv_getlength = raw_getlength,
};

/***********************************************/
/* 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);
        if (type == DRIVE_CDROM)
            return FTYPE_CD;
        else
            return FTYPE_FILE;
    } else {
        return FTYPE_FILE;
    }
}

static int hdev_open(BlockDriverState *bs, const char *filename, int flags)
{
    BDRVRawState *s = bs->opaque;
    int access_flags, create_flags;
    DWORD overlapped;
    char device_name[64];

    if (strstart(filename, "/dev/cdrom", NULL)) {
        if (find_cdrom(device_name, sizeof(device_name)) < 0)
            return -ENOENT;
        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);
    
    if ((flags & BDRV_O_ACCESS) == O_RDWR) {
        access_flags = GENERIC_READ | GENERIC_WRITE;
    } else {
        access_flags = GENERIC_READ;
    }
    create_flags = OPEN_EXISTING;

#ifdef QEMU_TOOL
    overlapped = FILE_ATTRIBUTE_NORMAL;
#else
    overlapped = FILE_FLAG_OVERLAPPED;
#endif
    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)
            return -EACCES;
        return -1;
    }
    return 0;
}

BlockDriver bdrv_host_device = {
    "host_device",
    sizeof(BDRVRawState),
    NULL, /* no probe for protocols */
    hdev_open,
    NULL,
    NULL,
    raw_close,
    NULL,
    raw_flush,

    .bdrv_pread = raw_pread,
    .bdrv_pwrite = raw_pwrite,
    .bdrv_getlength = raw_getlength,
};
#endif /* _WIN32 */