block: Rename raw-{posix,win32} to file-*.c

These files deal with the file protocol, not the raw format (the
file protocol is often used with other formats, and the raw
format is not forced to use the file protocol).  Rename things
to make it a bit easier to follow.

Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 2616 insertions, 0 deletions

diff --git a/block/file-posix.c b/block/file-posix.c
new file mode 100644
index 0000000000..28b47d977b
--- /dev/null
+++ b/block/file-posix.c
@@ -0,0 +1,2616 @@
+/*
+ * Block driver for RAW files (posix)
+ *
+ * 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 "qemu/error-report.h"
+#include "qemu/timer.h"
+#include "qemu/log.h"
+#include "block/block_int.h"
+#include "qemu/module.h"
+#include "trace.h"
+#include "block/thread-pool.h"
+#include "qemu/iov.h"
+#include "block/raw-aio.h"
+#include "qapi/util.h"
+#include "qapi/qmp/qstring.h"
+
+#if defined(__APPLE__) && (__MACH__)
+#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 <IOKit/storage/IODVDMedia.h>
+#include <CoreFoundation/CoreFoundation.h>
+#endif
+
+#ifdef __sun__
+#define _POSIX_PTHREAD_SEMANTICS 1
+#include <sys/dkio.h>
+#endif
+#ifdef __linux__
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#include <linux/cdrom.h>
+#include <linux/fd.h>
+#include <linux/fs.h>
+#include <linux/hdreg.h>
+#include <scsi/sg.h>
+#ifdef __s390__
+#include <asm/dasd.h>
+#endif
+#ifndef FS_NOCOW_FL
+#define FS_NOCOW_FL                     0x00800000 /* Do not cow file */
+#endif
+#endif
+#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) || defined(CONFIG_FALLOCATE_ZERO_RANGE)
+#include <linux/falloc.h>
+#endif
+#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)
+#include <sys/disk.h>
+#include <sys/cdio.h>
+#endif
+
+#ifdef __OpenBSD__
+#include <sys/ioctl.h>
+#include <sys/disklabel.h>
+#include <sys/dkio.h>
+#endif
+
+#ifdef __NetBSD__
+#include <sys/ioctl.h>
+#include <sys/disklabel.h>
+#include <sys/dkio.h>
+#include <sys/disk.h>
+#endif
+
+#ifdef __DragonFly__
+#include <sys/ioctl.h>
+#include <sys/diskslice.h>
+#endif
+
+#ifdef CONFIG_XFS
+#include <xfs/xfs.h>
+#endif
+
+//#define DEBUG_BLOCK
+
+#ifdef DEBUG_BLOCK
+# define DEBUG_BLOCK_PRINT 1
+#else
+# define DEBUG_BLOCK_PRINT 0
+#endif
+#define DPRINTF(fmt, ...) \
+do { \
+    if (DEBUG_BLOCK_PRINT) { \
+        printf(fmt, ## __VA_ARGS__); \
+    } \
+} while (0)
+
+/* OS X does not have O_DSYNC */
+#ifndef O_DSYNC
+#ifdef O_SYNC
+#define O_DSYNC O_SYNC
+#elif defined(O_FSYNC)
+#define O_DSYNC O_FSYNC
+#endif
+#endif
+
+/* Approximate O_DIRECT with O_DSYNC if O_DIRECT isn't available */
+#ifndef O_DIRECT
+#define O_DIRECT O_DSYNC
+#endif
+
+#define FTYPE_FILE   0
+#define FTYPE_CD     1
+
+#define MAX_BLOCKSIZE	4096
+
+typedef struct BDRVRawState {
+    int fd;
+    int type;
+    int open_flags;
+    size_t buf_align;
+
+#ifdef CONFIG_XFS
+    bool is_xfs:1;
+#endif
+    bool has_discard:1;
+    bool has_write_zeroes:1;
+    bool discard_zeroes:1;
+    bool use_linux_aio:1;
+    bool has_fallocate;
+    bool needs_alignment;
+} BDRVRawState;
+
+typedef struct BDRVRawReopenState {
+    int fd;
+    int open_flags;
+} BDRVRawReopenState;
+
+static int fd_open(BlockDriverState *bs);
+static int64_t raw_getlength(BlockDriverState *bs);
+
+typedef struct RawPosixAIOData {
+    BlockDriverState *bs;
+    int aio_fildes;
+    union {
+        struct iovec *aio_iov;
+        void *aio_ioctl_buf;
+    };
+    int aio_niov;
+    uint64_t aio_nbytes;
+#define aio_ioctl_cmd   aio_nbytes /* for QEMU_AIO_IOCTL */
+    off_t aio_offset;
+    int aio_type;
+} RawPosixAIOData;
+
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+static int cdrom_reopen(BlockDriverState *bs);
+#endif
+
+#if defined(__NetBSD__)
+static int raw_normalize_devicepath(const char **filename)
+{
+    static char namebuf[PATH_MAX];
+    const char *dp, *fname;
+    struct stat sb;
+
+    fname = *filename;
+    dp = strrchr(fname, '/');
+    if (lstat(fname, &sb) < 0) {
+        fprintf(stderr, "%s: stat failed: %s\n",
+            fname, strerror(errno));
+        return -errno;
+    }
+
+    if (!S_ISBLK(sb.st_mode)) {
+        return 0;
+    }
+
+    if (dp == NULL) {
+        snprintf(namebuf, PATH_MAX, "r%s", fname);
+    } else {
+        snprintf(namebuf, PATH_MAX, "%.*s/r%s",
+            (int)(dp - fname), fname, dp + 1);
+    }
+    fprintf(stderr, "%s is a block device", fname);
+    *filename = namebuf;
+    fprintf(stderr, ", using %s\n", *filename);
+
+    return 0;
+}
+#else
+static int raw_normalize_devicepath(const char **filename)
+{
+    return 0;
+}
+#endif
+
+/*
+ * Get logical block size via ioctl. On success store it in @sector_size_p.
+ */
+static int probe_logical_blocksize(int fd, unsigned int *sector_size_p)
+{
+    unsigned int sector_size;
+    bool success = false;
+
+    errno = ENOTSUP;
+
+    /* Try a few ioctls to get the right size */
+#ifdef BLKSSZGET
+    if (ioctl(fd, BLKSSZGET, &sector_size) >= 0) {
+        *sector_size_p = sector_size;
+        success = true;
+    }
+#endif
+#ifdef DKIOCGETBLOCKSIZE
+    if (ioctl(fd, DKIOCGETBLOCKSIZE, &sector_size) >= 0) {
+        *sector_size_p = sector_size;
+        success = true;
+    }
+#endif
+#ifdef DIOCGSECTORSIZE
+    if (ioctl(fd, DIOCGSECTORSIZE, &sector_size) >= 0) {
+        *sector_size_p = sector_size;
+        success = true;
+    }
+#endif
+
+    return success ? 0 : -errno;
+}
+
+/**
+ * Get physical block size of @fd.
+ * On success, store it in @blk_size and return 0.
+ * On failure, return -errno.
+ */
+static int probe_physical_blocksize(int fd, unsigned int *blk_size)
+{
+#ifdef BLKPBSZGET
+    if (ioctl(fd, BLKPBSZGET, blk_size) < 0) {
+        return -errno;
+    }
+    return 0;
+#else
+    return -ENOTSUP;
+#endif
+}
+
+/* Check if read is allowed with given memory buffer and length.
+ *
+ * This function is used to check O_DIRECT memory buffer and request alignment.
+ */
+static bool raw_is_io_aligned(int fd, void *buf, size_t len)
+{
+    ssize_t ret = pread(fd, buf, len, 0);
+
+    if (ret >= 0) {
+        return true;
+    }
+
+#ifdef __linux__
+    /* The Linux kernel returns EINVAL for misaligned O_DIRECT reads.  Ignore
+     * other errors (e.g. real I/O error), which could happen on a failed
+     * drive, since we only care about probing alignment.
+     */
+    if (errno != EINVAL) {
+        return true;
+    }
+#endif
+
+    return false;
+}
+
+static void raw_probe_alignment(BlockDriverState *bs, int fd, Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    char *buf;
+    size_t max_align = MAX(MAX_BLOCKSIZE, getpagesize());
+
+    /* For SCSI generic devices the alignment is not really used.
+       With buffered I/O, we don't have any restrictions. */
+    if (bdrv_is_sg(bs) || !s->needs_alignment) {
+        bs->bl.request_alignment = 1;
+        s->buf_align = 1;
+        return;
+    }
+
+    bs->bl.request_alignment = 0;
+    s->buf_align = 0;
+    /* Let's try to use the logical blocksize for the alignment. */
+    if (probe_logical_blocksize(fd, &bs->bl.request_alignment) < 0) {
+        bs->bl.request_alignment = 0;
+    }
+#ifdef CONFIG_XFS
+    if (s->is_xfs) {
+        struct dioattr da;
+        if (xfsctl(NULL, fd, XFS_IOC_DIOINFO, &da) >= 0) {
+            bs->bl.request_alignment = da.d_miniosz;
+            /* The kernel returns wrong information for d_mem */
+            /* s->buf_align = da.d_mem; */
+        }
+    }
+#endif
+
+    /* If we could not get the sizes so far, we can only guess them */
+    if (!s->buf_align) {
+        size_t align;
+        buf = qemu_memalign(max_align, 2 * max_align);
+        for (align = 512; align <= max_align; align <<= 1) {
+            if (raw_is_io_aligned(fd, buf + align, max_align)) {
+                s->buf_align = align;
+                break;
+            }
+        }
+        qemu_vfree(buf);
+    }
+
+    if (!bs->bl.request_alignment) {
+        size_t align;
+        buf = qemu_memalign(s->buf_align, max_align);
+        for (align = 512; align <= max_align; align <<= 1) {
+            if (raw_is_io_aligned(fd, buf, align)) {
+                bs->bl.request_alignment = align;
+                break;
+            }
+        }
+        qemu_vfree(buf);
+    }
+
+    if (!s->buf_align || !bs->bl.request_alignment) {
+        error_setg(errp, "Could not find working O_DIRECT alignment");
+        error_append_hint(errp, "Try cache.direct=off\n");
+    }
+}
+
+static void raw_parse_flags(int bdrv_flags, int *open_flags)
+{
+    assert(open_flags != NULL);
+
+    *open_flags |= O_BINARY;
+    *open_flags &= ~O_ACCMODE;
+    if (bdrv_flags & BDRV_O_RDWR) {
+        *open_flags |= O_RDWR;
+    } else {
+        *open_flags |= O_RDONLY;
+    }
+
+    /* Use O_DSYNC for write-through caching, no flags for write-back caching,
+     * and O_DIRECT for no caching. */
+    if ((bdrv_flags & BDRV_O_NOCACHE)) {
+        *open_flags |= O_DIRECT;
+    }
+}
+
+static void raw_parse_filename(const char *filename, QDict *options,
+                               Error **errp)
+{
+    /* The filename does not have to be prefixed by the protocol name, since
+     * "file" is the default protocol; therefore, the return value of this
+     * function call can be ignored. */
+    strstart(filename, "file:", &filename);
+
+    qdict_put_obj(options, "filename", QOBJECT(qstring_from_str(filename)));
+}
+
+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 int raw_open_common(BlockDriverState *bs, QDict *options,
+                           int bdrv_flags, int open_flags, Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    QemuOpts *opts;
+    Error *local_err = NULL;
+    const char *filename = NULL;
+    BlockdevAioOptions aio, aio_default;
+    int fd, ret;
+    struct stat st;
+
+    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;
+    }
+
+    filename = qemu_opt_get(opts, "filename");
+
+    ret = raw_normalize_devicepath(&filename);
+    if (ret != 0) {
+        error_setg_errno(errp, -ret, "Could not normalize device path");
+        goto fail;
+    }
+
+    aio_default = (bdrv_flags & BDRV_O_NATIVE_AIO)
+                  ? BLOCKDEV_AIO_OPTIONS_NATIVE
+                  : BLOCKDEV_AIO_OPTIONS_THREADS;
+    aio = qapi_enum_parse(BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
+                          BLOCKDEV_AIO_OPTIONS__MAX, aio_default, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto fail;
+    }
+    s->use_linux_aio = (aio == BLOCKDEV_AIO_OPTIONS_NATIVE);
+
+    s->open_flags = open_flags;
+    raw_parse_flags(bdrv_flags, &s->open_flags);
+
+    s->fd = -1;
+    fd = qemu_open(filename, s->open_flags, 0644);
+    if (fd < 0) {
+        ret = -errno;
+        error_setg_errno(errp, errno, "Could not open '%s'", filename);
+        if (ret == -EROFS) {
+            ret = -EACCES;
+        }
+        goto fail;
+    }
+    s->fd = fd;
+
+#ifdef CONFIG_LINUX_AIO
+     /* Currently Linux does AIO only for files opened with O_DIRECT */
+    if (s->use_linux_aio && !(s->open_flags & O_DIRECT)) {
+        error_setg(errp, "aio=native was specified, but it requires "
+                         "cache.direct=on, which was not specified.");
+        ret = -EINVAL;
+        goto fail;
+    }
+#else
+    if (s->use_linux_aio) {
+        error_setg(errp, "aio=native was specified, but is not supported "
+                         "in this build.");
+        ret = -EINVAL;
+        goto fail;
+    }
+#endif /* !defined(CONFIG_LINUX_AIO) */
+
+    s->has_discard = true;
+    s->has_write_zeroes = true;
+    bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
+    if ((bs->open_flags & BDRV_O_NOCACHE) != 0) {
+        s->needs_alignment = true;
+    }
+
+    if (fstat(s->fd, &st) < 0) {
+        ret = -errno;
+        error_setg_errno(errp, errno, "Could not stat file");
+        goto fail;
+    }
+    if (S_ISREG(st.st_mode)) {
+        s->discard_zeroes = true;
+        s->has_fallocate = true;
+    }
+    if (S_ISBLK(st.st_mode)) {
+#ifdef BLKDISCARDZEROES
+        unsigned int arg;
+        if (ioctl(s->fd, BLKDISCARDZEROES, &arg) == 0 && arg) {
+            s->discard_zeroes = true;
+        }
+#endif
+#ifdef __linux__
+        /* On Linux 3.10, BLKDISCARD leaves stale data in the page cache.  Do
+         * not rely on the contents of discarded blocks unless using O_DIRECT.
+         * Same for BLKZEROOUT.
+         */
+        if (!(bs->open_flags & BDRV_O_NOCACHE)) {
+            s->discard_zeroes = false;
+            s->has_write_zeroes = false;
+        }
+#endif
+    }
+#ifdef __FreeBSD__
+    if (S_ISCHR(st.st_mode)) {
+        /*
+         * The file is a char device (disk), which on FreeBSD isn't behind
+         * a pager, so force all requests to be aligned. This is needed
+         * so QEMU makes sure all IO operations on the device are aligned
+         * to sector size, or else FreeBSD will reject them with EINVAL.
+         */
+        s->needs_alignment = true;
+    }
+#endif
+
+#ifdef CONFIG_XFS
+    if (platform_test_xfs_fd(s->fd)) {
+        s->is_xfs = true;
+    }
+#endif
+
+    ret = 0;
+fail:
+    if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {
+        unlink(filename);
+    }
+    qemu_opts_del(opts);
+    return ret;
+}
+
+static int raw_open(BlockDriverState *bs, QDict *options, int flags,
+                    Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+
+    s->type = FTYPE_FILE;
+    return raw_open_common(bs, options, flags, 0, errp);
+}
+
+static int raw_reopen_prepare(BDRVReopenState *state,
+                              BlockReopenQueue *queue, Error **errp)
+{
+    BDRVRawState *s;
+    BDRVRawReopenState *rs;
+    int ret = 0;
+    Error *local_err = NULL;
+
+    assert(state != NULL);
+    assert(state->bs != NULL);
+
+    s = state->bs->opaque;
+
+    state->opaque = g_new0(BDRVRawReopenState, 1);
+    rs = state->opaque;
+
+    if (s->type == FTYPE_CD) {
+        rs->open_flags |= O_NONBLOCK;
+    }
+
+    raw_parse_flags(state->flags, &rs->open_flags);
+
+    rs->fd = -1;
+
+    int fcntl_flags = O_APPEND | O_NONBLOCK;
+#ifdef O_NOATIME
+    fcntl_flags |= O_NOATIME;
+#endif
+
+#ifdef O_ASYNC
+    /* Not all operating systems have O_ASYNC, and those that don't
+     * will not let us track the state into rs->open_flags (typically
+     * you achieve the same effect with an ioctl, for example I_SETSIG
+     * on Solaris). But we do not use O_ASYNC, so that's fine.
+     */
+    assert((s->open_flags & O_ASYNC) == 0);
+#endif
+
+    if ((rs->open_flags & ~fcntl_flags) == (s->open_flags & ~fcntl_flags)) {
+        /* dup the original fd */
+        rs->fd = qemu_dup(s->fd);
+        if (rs->fd >= 0) {
+            ret = fcntl_setfl(rs->fd, rs->open_flags);
+            if (ret) {
+                qemu_close(rs->fd);
+                rs->fd = -1;
+            }
+        }
+    }
+
+    /* If we cannot use fcntl, or fcntl failed, fall back to qemu_open() */
+    if (rs->fd == -1) {
+        const char *normalized_filename = state->bs->filename;
+        ret = raw_normalize_devicepath(&normalized_filename);
+        if (ret < 0) {
+            error_setg_errno(errp, -ret, "Could not normalize device path");
+        } else {
+            assert(!(rs->open_flags & O_CREAT));
+            rs->fd = qemu_open(normalized_filename, rs->open_flags);
+            if (rs->fd == -1) {
+                error_setg_errno(errp, errno, "Could not reopen file");
+                ret = -1;
+            }
+        }
+    }
+
+    /* Fail already reopen_prepare() if we can't get a working O_DIRECT
+     * alignment with the new fd. */
+    if (rs->fd != -1) {
+        raw_probe_alignment(state->bs, rs->fd, &local_err);
+        if (local_err) {
+            qemu_close(rs->fd);
+            rs->fd = -1;
+            error_propagate(errp, local_err);
+            ret = -EINVAL;
+        }
+    }
+
+    return ret;
+}
+
+static void raw_reopen_commit(BDRVReopenState *state)
+{
+    BDRVRawReopenState *rs = state->opaque;
+    BDRVRawState *s = state->bs->opaque;
+
+    s->open_flags = rs->open_flags;
+
+    qemu_close(s->fd);
+    s->fd = rs->fd;
+
+    g_free(state->opaque);
+    state->opaque = NULL;
+}
+
+
+static void raw_reopen_abort(BDRVReopenState *state)
+{
+    BDRVRawReopenState *rs = state->opaque;
+
+     /* nothing to do if NULL, we didn't get far enough */
+    if (rs == NULL) {
+        return;
+    }
+
+    if (rs->fd >= 0) {
+        qemu_close(rs->fd);
+        rs->fd = -1;
+    }
+    g_free(state->opaque);
+    state->opaque = NULL;
+}
+
+static int hdev_get_max_transfer_length(int fd)
+{
+#ifdef BLKSECTGET
+    int max_sectors = 0;
+    if (ioctl(fd, BLKSECTGET, &max_sectors) == 0) {
+        return max_sectors;
+    } else {
+        return -errno;
+    }
+#else
+    return -ENOSYS;
+#endif
+}
+
+static void raw_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    struct stat st;
+
+    if (!fstat(s->fd, &st)) {
+        if (S_ISBLK(st.st_mode)) {
+            int ret = hdev_get_max_transfer_length(s->fd);
+            if (ret > 0 && ret <= BDRV_REQUEST_MAX_SECTORS) {
+                bs->bl.max_transfer = pow2floor(ret << BDRV_SECTOR_BITS);
+            }
+        }
+    }
+
+    raw_probe_alignment(bs, s->fd, errp);
+    bs->bl.min_mem_alignment = s->buf_align;
+    bs->bl.opt_mem_alignment = MAX(s->buf_align, getpagesize());
+}
+
+static int check_for_dasd(int fd)
+{
+#ifdef BIODASDINFO2
+    struct dasd_information2_t info = {0};
+
+    return ioctl(fd, BIODASDINFO2, &info);
+#else
+    return -1;
+#endif
+}
+
+/**
+ * Try to get @bs's logical and physical block size.
+ * On success, store them in @bsz and return zero.
+ * On failure, return negative errno.
+ */
+static int hdev_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
+{
+    BDRVRawState *s = bs->opaque;
+    int ret;
+
+    /* If DASD, get blocksizes */
+    if (check_for_dasd(s->fd) < 0) {
+        return -ENOTSUP;
+    }
+    ret = probe_logical_blocksize(s->fd, &bsz->log);
+    if (ret < 0) {
+        return ret;
+    }
+    return probe_physical_blocksize(s->fd, &bsz->phys);
+}
+
+/**
+ * Try to get @bs's geometry: cyls, heads, sectors.
+ * On success, store them in @geo and return 0.
+ * On failure return -errno.
+ * (Allows block driver to assign default geometry values that guest sees)
+ */
+#ifdef __linux__
+static int hdev_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
+{
+    BDRVRawState *s = bs->opaque;
+    struct hd_geometry ioctl_geo = {0};
+
+    /* If DASD, get its geometry */
+    if (check_for_dasd(s->fd) < 0) {
+        return -ENOTSUP;
+    }
+    if (ioctl(s->fd, HDIO_GETGEO, &ioctl_geo) < 0) {
+        return -errno;
+    }
+    /* HDIO_GETGEO may return success even though geo contains zeros
+       (e.g. certain multipath setups) */
+    if (!ioctl_geo.heads || !ioctl_geo.sectors || !ioctl_geo.cylinders) {
+        return -ENOTSUP;
+    }
+    /* Do not return a geometry for partition */
+    if (ioctl_geo.start != 0) {
+        return -ENOTSUP;
+    }
+    geo->heads = ioctl_geo.heads;
+    geo->sectors = ioctl_geo.sectors;
+    geo->cylinders = ioctl_geo.cylinders;
+
+    return 0;
+}
+#else /* __linux__ */
+static int hdev_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
+{
+    return -ENOTSUP;
+}
+#endif
+
+static ssize_t handle_aiocb_ioctl(RawPosixAIOData *aiocb)
+{
+    int ret;
+
+    ret = ioctl(aiocb->aio_fildes, aiocb->aio_ioctl_cmd, aiocb->aio_ioctl_buf);
+    if (ret == -1) {
+        return -errno;
+    }
+
+    return 0;
+}
+
+static ssize_t handle_aiocb_flush(RawPosixAIOData *aiocb)
+{
+    int ret;
+
+    ret = qemu_fdatasync(aiocb->aio_fildes);
+    if (ret == -1) {
+        return -errno;
+    }
+    return 0;
+}
+
+#ifdef CONFIG_PREADV
+
+static bool preadv_present = true;
+
+static ssize_t
+qemu_preadv(int fd, const struct iovec *iov, int nr_iov, off_t offset)
+{
+    return preadv(fd, iov, nr_iov, offset);
+}
+
+static ssize_t
+qemu_pwritev(int fd, const struct iovec *iov, int nr_iov, off_t offset)
+{
+    return pwritev(fd, iov, nr_iov, offset);
+}
+
+#else
+
+static bool preadv_present = false;
+
+static ssize_t
+qemu_preadv(int fd, const struct iovec *iov, int nr_iov, off_t offset)
+{
+    return -ENOSYS;
+}
+
+static ssize_t
+qemu_pwritev(int fd, const struct iovec *iov, int nr_iov, off_t offset)
+{
+    return -ENOSYS;
+}
+
+#endif
+
+static ssize_t handle_aiocb_rw_vector(RawPosixAIOData *aiocb)
+{
+    ssize_t len;
+
+    do {
+        if (aiocb->aio_type & QEMU_AIO_WRITE)
+            len = qemu_pwritev(aiocb->aio_fildes,
+                               aiocb->aio_iov,
+                               aiocb->aio_niov,
+                               aiocb->aio_offset);
+         else
+            len = qemu_preadv(aiocb->aio_fildes,
+                              aiocb->aio_iov,
+                              aiocb->aio_niov,
+                              aiocb->aio_offset);
+    } while (len == -1 && errno == EINTR);
+
+    if (len == -1) {
+        return -errno;
+    }
+    return len;
+}
+
+/*
+ * 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 ssize_t handle_aiocb_rw_linear(RawPosixAIOData *aiocb, char *buf)
+{
+    ssize_t offset = 0;
+    ssize_t len;
+
+    while (offset < aiocb->aio_nbytes) {
+        if (aiocb->aio_type & QEMU_AIO_WRITE) {
+            len = pwrite(aiocb->aio_fildes,
+                         (const char *)buf + offset,
+                         aiocb->aio_nbytes - offset,
+                         aiocb->aio_offset + offset);
+        } else {
+            len = pread(aiocb->aio_fildes,
+                        buf + offset,
+                        aiocb->aio_nbytes - offset,
+                        aiocb->aio_offset + offset);
+        }
+        if (len == -1 && errno == EINTR) {
+            continue;
+        } else if (len == -1 && errno == EINVAL &&
+                   (aiocb->bs->open_flags & BDRV_O_NOCACHE) &&
+                   !(aiocb->aio_type & QEMU_AIO_WRITE) &&
+                   offset > 0) {
+            /* O_DIRECT pread() may fail with EINVAL when offset is unaligned
+             * after a short read.  Assume that O_DIRECT short reads only occur
+             * at EOF.  Therefore this is a short read, not an I/O error.
+             */
+            break;
+        } else if (len == -1) {
+            offset = -errno;
+            break;
+        } else if (len == 0) {
+            break;
+        }
+        offset += len;
+    }
+
+    return offset;
+}
+
+static ssize_t handle_aiocb_rw(RawPosixAIOData *aiocb)
+{
+    ssize_t nbytes;
+    char *buf;
+
+    if (!(aiocb->aio_type & QEMU_AIO_MISALIGNED)) {
+        /*
+         * If there is just a single buffer, and it is properly aligned
+         * we can just use plain pread/pwrite without any problems.
+         */
+        if (aiocb->aio_niov == 1) {
+             return handle_aiocb_rw_linear(aiocb, aiocb->aio_iov->iov_base);
+        }
+        /*
+         * We have more than one iovec, and all are properly aligned.
+         *
+         * Try preadv/pwritev first and fall back to linearizing the
+         * buffer if it's not supported.
+         */
+        if (preadv_present) {
+            nbytes = handle_aiocb_rw_vector(aiocb);
+            if (nbytes == aiocb->aio_nbytes ||
+                (nbytes < 0 && nbytes != -ENOSYS)) {
+                return nbytes;
+            }
+            preadv_present = false;
+        }
+
+        /*
+         * XXX(hch): short read/write.  no easy way to handle the reminder
+         * using these interfaces.  For now retry using plain
+         * pread/pwrite?
+         */
+    }
+
+    /*
+     * Ok, we have to do it the hard way, copy all segments into
+     * a single aligned buffer.
+     */
+    buf = qemu_try_blockalign(aiocb->bs, aiocb->aio_nbytes);
+    if (buf == NULL) {
+        return -ENOMEM;
+    }
+
+    if (aiocb->aio_type & QEMU_AIO_WRITE) {
+        char *p = buf;
+        int i;
+
+        for (i = 0; i < aiocb->aio_niov; ++i) {
+            memcpy(p, aiocb->aio_iov[i].iov_base, aiocb->aio_iov[i].iov_len);
+            p += aiocb->aio_iov[i].iov_len;
+        }
+        assert(p - buf == aiocb->aio_nbytes);
+    }
+
+    nbytes = handle_aiocb_rw_linear(aiocb, buf);
+    if (!(aiocb->aio_type & QEMU_AIO_WRITE)) {
+        char *p = buf;
+        size_t count = aiocb->aio_nbytes, copy;
+        int i;
+
+        for (i = 0; i < aiocb->aio_niov && count; ++i) {
+            copy = count;
+            if (copy > aiocb->aio_iov[i].iov_len) {
+                copy = aiocb->aio_iov[i].iov_len;
+            }
+            memcpy(aiocb->aio_iov[i].iov_base, p, copy);
+            assert(count >= copy);
+            p     += copy;
+            count -= copy;
+        }
+        assert(count == 0);
+    }
+    qemu_vfree(buf);
+
+    return nbytes;
+}
+
+#ifdef CONFIG_XFS
+static int xfs_write_zeroes(BDRVRawState *s, int64_t offset, uint64_t bytes)
+{
+    struct xfs_flock64 fl;
+    int err;
+
+    memset(&fl, 0, sizeof(fl));
+    fl.l_whence = SEEK_SET;
+    fl.l_start = offset;
+    fl.l_len = bytes;
+
+    if (xfsctl(NULL, s->fd, XFS_IOC_ZERO_RANGE, &fl) < 0) {
+        err = errno;
+        DPRINTF("cannot write zero range (%s)\n", strerror(errno));
+        return -err;
+    }
+
+    return 0;
+}
+
+static int xfs_discard(BDRVRawState *s, int64_t offset, uint64_t bytes)
+{
+    struct xfs_flock64 fl;
+    int err;
+
+    memset(&fl, 0, sizeof(fl));
+    fl.l_whence = SEEK_SET;
+    fl.l_start = offset;
+    fl.l_len = bytes;
+
+    if (xfsctl(NULL, s->fd, XFS_IOC_UNRESVSP64, &fl) < 0) {
+        err = errno;
+        DPRINTF("cannot punch hole (%s)\n", strerror(errno));
+        return -err;
+    }
+
+    return 0;
+}
+#endif
+
+static int translate_err(int err)
+{
+    if (err == -ENODEV || err == -ENOSYS || err == -EOPNOTSUPP ||
+        err == -ENOTTY) {
+        err = -ENOTSUP;
+    }
+    return err;
+}
+
+#ifdef CONFIG_FALLOCATE
+static int do_fallocate(int fd, int mode, off_t offset, off_t len)
+{
+    do {
+        if (fallocate(fd, mode, offset, len) == 0) {
+            return 0;
+        }
+    } while (errno == EINTR);
+    return translate_err(-errno);
+}
+#endif
+
+static ssize_t handle_aiocb_write_zeroes_block(RawPosixAIOData *aiocb)
+{
+    int ret = -ENOTSUP;
+    BDRVRawState *s = aiocb->bs->opaque;
+
+    if (!s->has_write_zeroes) {
+        return -ENOTSUP;
+    }
+
+#ifdef BLKZEROOUT
+    do {
+        uint64_t range[2] = { aiocb->aio_offset, aiocb->aio_nbytes };
+        if (ioctl(aiocb->aio_fildes, BLKZEROOUT, range) == 0) {
+            return 0;
+        }
+    } while (errno == EINTR);
+
+    ret = translate_err(-errno);
+#endif
+
+    if (ret == -ENOTSUP) {
+        s->has_write_zeroes = false;
+    }
+    return ret;
+}
+
+static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb)
+{
+#if defined(CONFIG_FALLOCATE) || defined(CONFIG_XFS)
+    BDRVRawState *s = aiocb->bs->opaque;
+#endif
+
+    if (aiocb->aio_type & QEMU_AIO_BLKDEV) {
+        return handle_aiocb_write_zeroes_block(aiocb);
+    }
+
+#ifdef CONFIG_XFS
+    if (s->is_xfs) {
+        return xfs_write_zeroes(s, aiocb->aio_offset, aiocb->aio_nbytes);
+    }
+#endif
+
+#ifdef CONFIG_FALLOCATE_ZERO_RANGE
+    if (s->has_write_zeroes) {
+        int ret = do_fallocate(s->fd, FALLOC_FL_ZERO_RANGE,
+                               aiocb->aio_offset, aiocb->aio_nbytes);
+        if (ret == 0 || ret != -ENOTSUP) {
+            return ret;
+        }
+        s->has_write_zeroes = false;
+    }
+#endif
+
+#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
+    if (s->has_discard && s->has_fallocate) {
+        int ret = do_fallocate(s->fd,
+                               FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+                               aiocb->aio_offset, aiocb->aio_nbytes);
+        if (ret == 0) {
+            ret = do_fallocate(s->fd, 0, aiocb->aio_offset, aiocb->aio_nbytes);
+            if (ret == 0 || ret != -ENOTSUP) {
+                return ret;
+            }
+            s->has_fallocate = false;
+        } else if (ret != -ENOTSUP) {
+            return ret;
+        } else {
+            s->has_discard = false;
+        }
+    }
+#endif
+
+#ifdef CONFIG_FALLOCATE
+    if (s->has_fallocate && aiocb->aio_offset >= bdrv_getlength(aiocb->bs)) {
+        int ret = do_fallocate(s->fd, 0, aiocb->aio_offset, aiocb->aio_nbytes);
+        if (ret == 0 || ret != -ENOTSUP) {
+            return ret;
+        }
+        s->has_fallocate = false;
+    }
+#endif
+
+    return -ENOTSUP;
+}
+
+static ssize_t handle_aiocb_discard(RawPosixAIOData *aiocb)
+{
+    int ret = -EOPNOTSUPP;
+    BDRVRawState *s = aiocb->bs->opaque;
+
+    if (!s->has_discard) {
+        return -ENOTSUP;
+    }
+
+    if (aiocb->aio_type & QEMU_AIO_BLKDEV) {
+#ifdef BLKDISCARD
+        do {
+            uint64_t range[2] = { aiocb->aio_offset, aiocb->aio_nbytes };
+            if (ioctl(aiocb->aio_fildes, BLKDISCARD, range) == 0) {
+                return 0;
+            }
+        } while (errno == EINTR);
+
+        ret = -errno;
+#endif
+    } else {
+#ifdef CONFIG_XFS
+        if (s->is_xfs) {
+            return xfs_discard(s, aiocb->aio_offset, aiocb->aio_nbytes);
+        }
+#endif
+
+#ifdef CONFIG_FALLOCATE_PUNCH_HOLE
+        ret = do_fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+                           aiocb->aio_offset, aiocb->aio_nbytes);
+#endif
+    }
+
+    ret = translate_err(ret);
+    if (ret == -ENOTSUP) {
+        s->has_discard = false;
+    }
+    return ret;
+}
+
+static int aio_worker(void *arg)
+{
+    RawPosixAIOData *aiocb = arg;
+    ssize_t ret = 0;
+
+    switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
+    case QEMU_AIO_READ:
+        ret = handle_aiocb_rw(aiocb);
+        if (ret >= 0 && ret < aiocb->aio_nbytes) {
+            iov_memset(aiocb->aio_iov, aiocb->aio_niov, ret,
+                      0, aiocb->aio_nbytes - ret);
+
+            ret = aiocb->aio_nbytes;
+        }
+        if (ret == aiocb->aio_nbytes) {
+            ret = 0;
+        } else if (ret >= 0 && ret < aiocb->aio_nbytes) {
+            ret = -EINVAL;
+        }
+        break;
+    case QEMU_AIO_WRITE:
+        ret = handle_aiocb_rw(aiocb);
+        if (ret == aiocb->aio_nbytes) {
+            ret = 0;
+        } else if (ret >= 0 && ret < aiocb->aio_nbytes) {
+            ret = -EINVAL;
+        }
+        break;
+    case QEMU_AIO_FLUSH:
+        ret = handle_aiocb_flush(aiocb);
+        break;
+    case QEMU_AIO_IOCTL:
+        ret = handle_aiocb_ioctl(aiocb);
+        break;
+    case QEMU_AIO_DISCARD:
+        ret = handle_aiocb_discard(aiocb);
+        break;
+    case QEMU_AIO_WRITE_ZEROES:
+        ret = handle_aiocb_write_zeroes(aiocb);
+        break;
+    default:
+        fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
+        ret = -EINVAL;
+        break;
+    }
+
+    g_free(aiocb);
+    return ret;
+}
+
+static int paio_submit_co(BlockDriverState *bs, int fd,
+                          int64_t offset, QEMUIOVector *qiov,
+                          int count, int type)
+{
+    RawPosixAIOData *acb = g_new(RawPosixAIOData, 1);
+    ThreadPool *pool;
+
+    acb->bs = bs;
+    acb->aio_type = type;
+    acb->aio_fildes = fd;
+
+    acb->aio_nbytes = count;
+    acb->aio_offset = offset;
+
+    if (qiov) {
+        acb->aio_iov = qiov->iov;
+        acb->aio_niov = qiov->niov;
+        assert(qiov->size == count);
+    }
+
+    trace_paio_submit_co(offset, count, type);
+    pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
+    return thread_pool_submit_co(pool, aio_worker, acb);
+}
+
+static BlockAIOCB *paio_submit(BlockDriverState *bs, int fd,
+        int64_t offset, QEMUIOVector *qiov, int count,
+        BlockCompletionFunc *cb, void *opaque, int type)
+{
+    RawPosixAIOData *acb = g_new(RawPosixAIOData, 1);
+    ThreadPool *pool;
+
+    acb->bs = bs;
+    acb->aio_type = type;
+    acb->aio_fildes = fd;
+
+    acb->aio_nbytes = count;
+    acb->aio_offset = offset;
+
+    if (qiov) {
+        acb->aio_iov = qiov->iov;
+        acb->aio_niov = qiov->niov;
+        assert(qiov->size == acb->aio_nbytes);
+    }
+
+    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);
+}
+
+static int coroutine_fn raw_co_prw(BlockDriverState *bs, uint64_t offset,
+                                   uint64_t bytes, QEMUIOVector *qiov, int type)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (fd_open(bs) < 0)
+        return -EIO;
+
+    /*
+     * Check if the underlying device requires requests to be aligned,
+     * and if the request we are trying to submit is aligned or not.
+     * If this is the case tell the low-level driver that it needs
+     * to copy the buffer.
+     */
+    if (s->needs_alignment) {
+        if (!bdrv_qiov_is_aligned(bs, qiov)) {
+            type |= QEMU_AIO_MISALIGNED;
+#ifdef CONFIG_LINUX_AIO
+        } else if (s->use_linux_aio) {
+            LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
+            assert(qiov->size == bytes);
+            return laio_co_submit(bs, aio, s->fd, offset, qiov, type);
+#endif
+        }
+    }
+
+    return paio_submit_co(bs, s->fd, offset, qiov, bytes, type);
+}
+
+static int coroutine_fn raw_co_preadv(BlockDriverState *bs, uint64_t offset,
+                                      uint64_t bytes, QEMUIOVector *qiov,
+                                      int flags)
+{
+    return raw_co_prw(bs, offset, bytes, qiov, QEMU_AIO_READ);
+}
+
+static int coroutine_fn raw_co_pwritev(BlockDriverState *bs, uint64_t offset,
+                                       uint64_t bytes, QEMUIOVector *qiov,
+                                       int flags)
+{
+    assert(flags == 0);
+    return raw_co_prw(bs, offset, bytes, qiov, QEMU_AIO_WRITE);
+}
+
+static void raw_aio_plug(BlockDriverState *bs)
+{
+#ifdef CONFIG_LINUX_AIO
+    BDRVRawState *s = bs->opaque;
+    if (s->use_linux_aio) {
+        LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
+        laio_io_plug(bs, aio);
+    }
+#endif
+}
+
+static void raw_aio_unplug(BlockDriverState *bs)
+{
+#ifdef CONFIG_LINUX_AIO
+    BDRVRawState *s = bs->opaque;
+    if (s->use_linux_aio) {
+        LinuxAioState *aio = aio_get_linux_aio(bdrv_get_aio_context(bs));
+        laio_io_unplug(bs, aio);
+    }
+#endif
+}
+
+static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
+        BlockCompletionFunc *cb, void *opaque)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (fd_open(bs) < 0)
+        return NULL;
+
+    return paio_submit(bs, s->fd, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
+}
+
+static void raw_close(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (s->fd >= 0) {
+        qemu_close(s->fd);
+        s->fd = -1;
+    }
+}
+
+static int raw_truncate(BlockDriverState *bs, int64_t offset)
+{
+    BDRVRawState *s = bs->opaque;
+    struct stat st;
+
+    if (fstat(s->fd, &st)) {
+        return -errno;
+    }
+
+    if (S_ISREG(st.st_mode)) {
+        if (ftruncate(s->fd, offset) < 0) {
+            return -errno;
+        }
+    } else if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {
+       if (offset > raw_getlength(bs)) {
+           return -EINVAL;
+       }
+    } else {
+        return -ENOTSUP;
+    }
+
+    return 0;
+}
+
+#ifdef __OpenBSD__
+static int64_t raw_getlength(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    int fd = s->fd;
+    struct stat st;
+
+    if (fstat(fd, &st))
+        return -errno;
+    if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {
+        struct disklabel dl;
+
+        if (ioctl(fd, DIOCGDINFO, &dl))
+            return -errno;
+        return (uint64_t)dl.d_secsize *
+            dl.d_partitions[DISKPART(st.st_rdev)].p_size;
+    } else
+        return st.st_size;
+}
+#elif defined(__NetBSD__)
+static int64_t raw_getlength(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    int fd = s->fd;
+    struct stat st;
+
+    if (fstat(fd, &st))
+        return -errno;
+    if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {
+        struct dkwedge_info dkw;
+
+        if (ioctl(fd, DIOCGWEDGEINFO, &dkw) != -1) {
+            return dkw.dkw_size * 512;
+        } else {
+            struct disklabel dl;
+
+            if (ioctl(fd, DIOCGDINFO, &dl))
+                return -errno;
+            return (uint64_t)dl.d_secsize *
+                dl.d_partitions[DISKPART(st.st_rdev)].p_size;
+        }
+    } else
+        return st.st_size;
+}
+#elif defined(__sun__)
+static int64_t raw_getlength(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    struct dk_minfo minfo;
+    int ret;
+    int64_t size;
+
+    ret = fd_open(bs);
+    if (ret < 0) {
+        return ret;
+    }
+
+    /*
+     * Use the DKIOCGMEDIAINFO ioctl to read the size.
+     */
+    ret = ioctl(s->fd, DKIOCGMEDIAINFO, &minfo);
+    if (ret != -1) {
+        return minfo.dki_lbsize * minfo.dki_capacity;
+    }
+
+    /*
+     * There are reports that lseek on some devices fails, but
+     * irc discussion said that contingency on contingency was overkill.
+     */
+    size = lseek(s->fd, 0, SEEK_END);
+    if (size < 0) {
+        return -errno;
+    }
+    return size;
+}
+#elif defined(CONFIG_BSD)
+static int64_t raw_getlength(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    int fd = s->fd;
+    int64_t size;
+    struct stat sb;
+#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)
+    int reopened = 0;
+#endif
+    int ret;
+
+    ret = fd_open(bs);
+    if (ret < 0)
+        return ret;
+
+#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)
+again:
+#endif
+    if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {
+#ifdef DIOCGMEDIASIZE
+	if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))
+#elif defined(DIOCGPART)
+        {
+                struct partinfo pi;
+                if (ioctl(fd, DIOCGPART, &pi) == 0)
+                        size = pi.media_size;
+                else
+                        size = 0;
+        }
+        if (size == 0)
+#endif
+#if defined(__APPLE__) && defined(__MACH__)
+        {
+            uint64_t sectors = 0;
+            uint32_t sector_size = 0;
+
+            if (ioctl(fd, DKIOCGETBLOCKCOUNT, &sectors) == 0
+               && ioctl(fd, DKIOCGETBLOCKSIZE, &sector_size) == 0) {
+                size = sectors * sector_size;
+            } else {
+                size = lseek(fd, 0LL, SEEK_END);
+                if (size < 0) {
+                    return -errno;
+                }
+            }
+        }
+#else
+        size = lseek(fd, 0LL, SEEK_END);
+        if (size < 0) {
+            return -errno;
+        }
+#endif
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+        switch(s->type) {
+        case FTYPE_CD:
+            /* XXX FreeBSD acd returns UINT_MAX sectors for an empty drive */
+            if (size == 2048LL * (unsigned)-1)
+                size = 0;
+            /* XXX no disc?  maybe we need to reopen... */
+            if (size <= 0 && !reopened && cdrom_reopen(bs) >= 0) {
+                reopened = 1;
+                goto again;
+            }
+        }
+#endif
+    } else {
+        size = lseek(fd, 0, SEEK_END);
+        if (size < 0) {
+            return -errno;
+        }
+    }
+    return size;
+}
+#else
+static int64_t raw_getlength(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    int ret;
+    int64_t size;
+
+    ret = fd_open(bs);
+    if (ret < 0) {
+        return ret;
+    }
+
+    size = lseek(s->fd, 0, SEEK_END);
+    if (size < 0) {
+        return -errno;
+    }
+    return size;
+}
+#endif
+
+static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
+{
+    struct stat st;
+    BDRVRawState *s = bs->opaque;
+
+    if (fstat(s->fd, &st) < 0) {
+        return -errno;
+    }
+    return (int64_t)st.st_blocks * 512;
+}
+
+static int raw_create(const char *filename, QemuOpts *opts, Error **errp)
+{
+    int fd;
+    int result = 0;
+    int64_t total_size = 0;
+    bool nocow = false;
+    PreallocMode prealloc;
+    char *buf = NULL;
+    Error *local_err = NULL;
+
+    strstart(filename, "file:", &filename);
+
+    /* Read out options */
+    total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+                          BDRV_SECTOR_SIZE);
+    nocow = qemu_opt_get_bool(opts, BLOCK_OPT_NOCOW, false);
+    buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
+    prealloc = qapi_enum_parse(PreallocMode_lookup, buf,
+                               PREALLOC_MODE__MAX, PREALLOC_MODE_OFF,
+                               &local_err);
+    g_free(buf);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        result = -EINVAL;
+        goto out;
+    }
+
+    fd = qemu_open(filename, O_RDWR | O_CREAT | O_TRUNC | O_BINARY,
+                   0644);
+    if (fd < 0) {
+        result = -errno;
+        error_setg_errno(errp, -result, "Could not create file");
+        goto out;
+    }
+
+    if (nocow) {
+#ifdef __linux__
+        /* Set NOCOW flag to solve performance issue on fs like btrfs.
+         * This is an optimisation. The FS_IOC_SETFLAGS ioctl return value
+         * will be ignored since any failure of this operation should not
+         * block the left work.
+         */
+        int attr;
+        if (ioctl(fd, FS_IOC_GETFLAGS, &attr) == 0) {
+            attr |= FS_NOCOW_FL;
+            ioctl(fd, FS_IOC_SETFLAGS, &attr);
+        }
+#endif
+    }
+
+    if (ftruncate(fd, total_size) != 0) {
+        result = -errno;
+        error_setg_errno(errp, -result, "Could not resize file");
+        goto out_close;
+    }
+
+    switch (prealloc) {
+#ifdef CONFIG_POSIX_FALLOCATE
+    case PREALLOC_MODE_FALLOC:
+        /* posix_fallocate() doesn't set errno. */
+        result = -posix_fallocate(fd, 0, total_size);
+        if (result != 0) {
+            error_setg_errno(errp, -result,
+                             "Could not preallocate data for the new file");
+        }
+        break;
+#endif
+    case PREALLOC_MODE_FULL:
+    {
+        int64_t num = 0, left = total_size;
+        buf = g_malloc0(65536);
+
+        while (left > 0) {
+            num = MIN(left, 65536);
+            result = write(fd, buf, num);
+            if (result < 0) {
+                result = -errno;
+                error_setg_errno(errp, -result,
+                                 "Could not write to the new file");
+                break;
+            }
+            left -= result;
+        }
+        if (result >= 0) {
+            result = fsync(fd);
+            if (result < 0) {
+                result = -errno;
+                error_setg_errno(errp, -result,
+                                 "Could not flush new file to disk");
+            }
+        }
+        g_free(buf);
+        break;
+    }
+    case PREALLOC_MODE_OFF:
+        break;
+    default:
+        result = -EINVAL;
+        error_setg(errp, "Unsupported preallocation mode: %s",
+                   PreallocMode_lookup[prealloc]);
+        break;
+    }
+
+out_close:
+    if (qemu_close(fd) != 0 && result == 0) {
+        result = -errno;
+        error_setg_errno(errp, -result, "Could not close the new file");
+    }
+out:
+    return result;
+}
+
+/*
+ * Find allocation range in @bs around offset @start.
+ * May change underlying file descriptor's file offset.
+ * If @start is not in a hole, store @start in @data, and the
+ * beginning of the next hole in @hole, and return 0.
+ * If @start is in a non-trailing hole, store @start in @hole and the
+ * beginning of the next non-hole in @data, and return 0.
+ * If @start is in a trailing hole or beyond EOF, return -ENXIO.
+ * If we can't find out, return a negative errno other than -ENXIO.
+ */
+static int find_allocation(BlockDriverState *bs, off_t start,
+                           off_t *data, off_t *hole)
+{
+#if defined SEEK_HOLE && defined SEEK_DATA
+    BDRVRawState *s = bs->opaque;
+    off_t offs;
+
+    /*
+     * SEEK_DATA cases:
+     * D1. offs == start: start is in data
+     * D2. offs > start: start is in a hole, next data at offs
+     * D3. offs < 0, errno = ENXIO: either start is in a trailing hole
+     *                              or start is beyond EOF
+     *     If the latter happens, the file has been truncated behind
+     *     our back since we opened it.  All bets are off then.
+     *     Treating like a trailing hole is simplest.
+     * D4. offs < 0, errno != ENXIO: we learned nothing
+     */
+    offs = lseek(s->fd, start, SEEK_DATA);
+    if (offs < 0) {
+        return -errno;          /* D3 or D4 */
+    }
+    assert(offs >= start);
+
+    if (offs > start) {
+        /* D2: in hole, next data at offs */
+        *hole = start;
+        *data = offs;
+        return 0;
+    }
+
+    /* D1: in data, end not yet known */
+
+    /*
+     * SEEK_HOLE cases:
+     * H1. offs == start: start is in a hole
+     *     If this happens here, a hole has been dug behind our back
+     *     since the previous lseek().
+     * H2. offs > start: either start is in data, next hole at offs,
+     *                   or start is in trailing hole, EOF at offs
+     *     Linux treats trailing holes like any other hole: offs ==
+     *     start.  Solaris seeks to EOF instead: offs > start (blech).
+     *     If that happens here, a hole has been dug behind our back
+     *     since the previous lseek().
+     * H3. offs < 0, errno = ENXIO: start is beyond EOF
+     *     If this happens, the file has been truncated behind our
+     *     back since we opened it.  Treat it like a trailing hole.
+     * H4. offs < 0, errno != ENXIO: we learned nothing
+     *     Pretend we know nothing at all, i.e. "forget" about D1.
+     */
+    offs = lseek(s->fd, start, SEEK_HOLE);
+    if (offs < 0) {
+        return -errno;          /* D1 and (H3 or H4) */
+    }
+    assert(offs >= start);
+
+    if (offs > start) {
+        /*
+         * D1 and H2: either in data, next hole at offs, or it was in
+         * data but is now in a trailing hole.  In the latter case,
+         * all bets are off.  Treating it as if it there was data all
+         * the way to EOF is safe, so simply do that.
+         */
+        *data = start;
+        *hole = offs;
+        return 0;
+    }
+
+    /* D1 and H1 */
+    return -EBUSY;
+#else
+    return -ENOTSUP;
+#endif
+}
+
+/*
+ * Returns the allocation status of the specified sectors.
+ *
+ * If 'sector_num' is beyond the end of the disk image the return value is 0
+ * and 'pnum' is set to 0.
+ *
+ * 'pnum' is set to the number of sectors (including and immediately following
+ * the specified sector) that are known to be in the same
+ * allocated/unallocated state.
+ *
+ * 'nb_sectors' is the max value 'pnum' should be set to.  If nb_sectors goes
+ * beyond the end of the disk image it will be clamped.
+ */
+static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
+                                                    int64_t sector_num,
+                                                    int nb_sectors, int *pnum,
+                                                    BlockDriverState **file)
+{
+    off_t start, data = 0, hole = 0;
+    int64_t total_size;
+    int ret;
+
+    ret = fd_open(bs);
+    if (ret < 0) {
+        return ret;
+    }
+
+    start = sector_num * BDRV_SECTOR_SIZE;
+    total_size = bdrv_getlength(bs);
+    if (total_size < 0) {
+        return total_size;
+    } else if (start >= total_size) {
+        *pnum = 0;
+        return 0;
+    } else if (start + nb_sectors * BDRV_SECTOR_SIZE > total_size) {
+        nb_sectors = DIV_ROUND_UP(total_size - start, BDRV_SECTOR_SIZE);
+    }
+
+    ret = find_allocation(bs, start, &data, &hole);
+    if (ret == -ENXIO) {
+        /* Trailing hole */
+        *pnum = nb_sectors;
+        ret = BDRV_BLOCK_ZERO;
+    } else if (ret < 0) {
+        /* No info available, so pretend there are no holes */
+        *pnum = nb_sectors;
+        ret = BDRV_BLOCK_DATA;
+    } else if (data == start) {
+        /* On a data extent, compute sectors to the end of the extent,
+         * possibly including a partial sector at EOF. */
+        *pnum = MIN(nb_sectors, DIV_ROUND_UP(hole - start, BDRV_SECTOR_SIZE));
+        ret = BDRV_BLOCK_DATA;
+    } else {
+        /* On a hole, compute sectors to the beginning of the next extent.  */
+        assert(hole == start);
+        *pnum = MIN(nb_sectors, (data - start) / BDRV_SECTOR_SIZE);
+        ret = BDRV_BLOCK_ZERO;
+    }
+    *file = bs;
+    return ret | BDRV_BLOCK_OFFSET_VALID | start;
+}
+
+static coroutine_fn BlockAIOCB *raw_aio_pdiscard(BlockDriverState *bs,
+    int64_t offset, int count,
+    BlockCompletionFunc *cb, void *opaque)
+{
+    BDRVRawState *s = bs->opaque;
+
+    return paio_submit(bs, s->fd, offset, NULL, count,
+                       cb, opaque, QEMU_AIO_DISCARD);
+}
+
+static int coroutine_fn raw_co_pwrite_zeroes(
+    BlockDriverState *bs, int64_t offset,
+    int count, BdrvRequestFlags flags)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (!(flags & BDRV_REQ_MAY_UNMAP)) {
+        return paio_submit_co(bs, s->fd, offset, NULL, count,
+                              QEMU_AIO_WRITE_ZEROES);
+    } else if (s->discard_zeroes) {
+        return paio_submit_co(bs, s->fd, offset, NULL, count,
+                              QEMU_AIO_DISCARD);
+    }
+    return -ENOTSUP;
+}
+
+static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+    BDRVRawState *s = bs->opaque;
+
+    bdi->unallocated_blocks_are_zero = s->discard_zeroes;
+    bdi->can_write_zeroes_with_unmap = s->discard_zeroes;
+    return 0;
+}
+
+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"
+        },
+        {
+            .name = BLOCK_OPT_NOCOW,
+            .type = QEMU_OPT_BOOL,
+            .help = "Turn off copy-on-write (valid only on btrfs)"
+        },
+        {
+            .name = BLOCK_OPT_PREALLOC,
+            .type = QEMU_OPT_STRING,
+            .help = "Preallocation mode (allowed values: off, falloc, full)"
+        },
+        { /* end of list */ }
+    }
+};
+
+BlockDriver bdrv_file = {
+    .format_name = "file",
+    .protocol_name = "file",
+    .instance_size = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
+    .bdrv_probe = NULL, /* no probe for protocols */
+    .bdrv_parse_filename = raw_parse_filename,
+    .bdrv_file_open = raw_open,
+    .bdrv_reopen_prepare = raw_reopen_prepare,
+    .bdrv_reopen_commit = raw_reopen_commit,
+    .bdrv_reopen_abort = raw_reopen_abort,
+    .bdrv_close = raw_close,
+    .bdrv_create = raw_create,
+    .bdrv_has_zero_init = bdrv_has_zero_init_1,
+    .bdrv_co_get_block_status = raw_co_get_block_status,
+    .bdrv_co_pwrite_zeroes = raw_co_pwrite_zeroes,
+
+    .bdrv_co_preadv         = raw_co_preadv,
+    .bdrv_co_pwritev        = raw_co_pwritev,
+    .bdrv_aio_flush = raw_aio_flush,
+    .bdrv_aio_pdiscard = raw_aio_pdiscard,
+    .bdrv_refresh_limits = raw_refresh_limits,
+    .bdrv_io_plug = raw_aio_plug,
+    .bdrv_io_unplug = raw_aio_unplug,
+
+    .bdrv_truncate = raw_truncate,
+    .bdrv_getlength = raw_getlength,
+    .bdrv_get_info = raw_get_info,
+    .bdrv_get_allocated_file_size
+                        = raw_get_allocated_file_size,
+
+    .create_opts = &raw_create_opts,
+};
+
+/***********************************************/
+/* host device */
+
+#if defined(__APPLE__) && defined(__MACH__)
+static kern_return_t GetBSDPath(io_iterator_t mediaIterator, char *bsdPath,
+                                CFIndex maxPathSize, int flags);
+static char *FindEjectableOpticalMedia(io_iterator_t *mediaIterator)
+{
+    kern_return_t kernResult = KERN_FAILURE;
+    mach_port_t     masterPort;
+    CFMutableDictionaryRef  classesToMatch;
+    const char *matching_array[] = {kIODVDMediaClass, kIOCDMediaClass};
+    char *mediaType = NULL;
+
+    kernResult = IOMasterPort( MACH_PORT_NULL, &masterPort );
+    if ( KERN_SUCCESS != kernResult ) {
+        printf( "IOMasterPort returned %d\n", kernResult );
+    }
+
+    int index;
+    for (index = 0; index < ARRAY_SIZE(matching_array); index++) {
+        classesToMatch = IOServiceMatching(matching_array[index]);
+        if (classesToMatch == NULL) {
+            error_report("IOServiceMatching returned NULL for %s",
+                         matching_array[index]);
+            continue;
+        }
+        CFDictionarySetValue(classesToMatch, CFSTR(kIOMediaEjectableKey),
+                             kCFBooleanTrue);
+        kernResult = IOServiceGetMatchingServices(masterPort, classesToMatch,
+                                                  mediaIterator);
+        if (kernResult != KERN_SUCCESS) {
+            error_report("Note: IOServiceGetMatchingServices returned %d",
+                         kernResult);
+            continue;
+        }
+
+        /* If a match was found, leave the loop */
+        if (*mediaIterator != 0) {
+            DPRINTF("Matching using %s\n", matching_array[index]);
+            mediaType = g_strdup(matching_array[index]);
+            break;
+        }
+    }
+    return mediaType;
+}
+
+kern_return_t GetBSDPath(io_iterator_t mediaIterator, char *bsdPath,
+                         CFIndex maxPathSize, int flags)
+{
+    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 );
+            if (flags & BDRV_O_NOCACHE) {
+                strcat(bsdPath, "r");
+            }
+            devPathLength = strlen( bsdPath );
+            if ( CFStringGetCString( bsdPathAsCFString, bsdPath + devPathLength, maxPathSize - devPathLength, kCFStringEncodingASCII ) ) {
+                kernResult = KERN_SUCCESS;
+            }
+            CFRelease( bsdPathAsCFString );
+        }
+        IOObjectRelease( nextMedia );
+    }
+
+    return kernResult;
+}
+
+/* Sets up a real cdrom for use in QEMU */
+static bool setup_cdrom(char *bsd_path, Error **errp)
+{
+    int index, num_of_test_partitions = 2, fd;
+    char test_partition[MAXPATHLEN];
+    bool partition_found = false;
+
+    /* look for a working partition */
+    for (index = 0; index < num_of_test_partitions; index++) {
+        snprintf(test_partition, sizeof(test_partition), "%ss%d", bsd_path,
+                 index);
+        fd = qemu_open(test_partition, O_RDONLY | O_BINARY | O_LARGEFILE);
+        if (fd >= 0) {
+            partition_found = true;
+            qemu_close(fd);
+            break;
+        }
+    }
+
+    /* if a working partition on the device was not found */
+    if (partition_found == false) {
+        error_setg(errp, "Failed to find a working partition on disc");
+    } else {
+        DPRINTF("Using %s as optical disc\n", test_partition);
+        pstrcpy(bsd_path, MAXPATHLEN, test_partition);
+    }
+    return partition_found;
+}
+
+/* Prints directions on mounting and unmounting a device */
+static void print_unmounting_directions(const char *file_name)
+{
+    error_report("If device %s is mounted on the desktop, unmount"
+                 " it first before using it in QEMU", file_name);
+    error_report("Command to unmount device: diskutil unmountDisk %s",
+                 file_name);
+    error_report("Command to mount device: diskutil mountDisk %s", file_name);
+}
+
+#endif /* defined(__APPLE__) && defined(__MACH__) */
+
+static int hdev_probe_device(const char *filename)
+{
+    struct stat st;
+
+    /* allow a dedicated CD-ROM driver to match with a higher priority */
+    if (strstart(filename, "/dev/cdrom", NULL))
+        return 50;
+
+    if (stat(filename, &st) >= 0 &&
+            (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
+        return 100;
+    }
+
+    return 0;
+}
+
+static int check_hdev_writable(BDRVRawState *s)
+{
+#if defined(BLKROGET)
+    /* Linux block devices can be configured "read-only" using blockdev(8).
+     * This is independent of device node permissions and therefore open(2)
+     * with O_RDWR succeeds.  Actual writes fail with EPERM.
+     *
+     * bdrv_open() is supposed to fail if the disk is read-only.  Explicitly
+     * check for read-only block devices so that Linux block devices behave
+     * properly.
+     */
+    struct stat st;
+    int readonly = 0;
+
+    if (fstat(s->fd, &st)) {
+        return -errno;
+    }
+
+    if (!S_ISBLK(st.st_mode)) {
+        return 0;
+    }
+
+    if (ioctl(s->fd, BLKROGET, &readonly) < 0) {
+        return -errno;
+    }
+
+    if (readonly) {
+        return -EACCES;
+    }
+#endif /* defined(BLKROGET) */
+    return 0;
+}
+
+static void hdev_parse_filename(const char *filename, QDict *options,
+                                Error **errp)
+{
+    /* The prefix is optional, just as for "file". */
+    strstart(filename, "host_device:", &filename);
+
+    qdict_put_obj(options, "filename", QOBJECT(qstring_from_str(filename)));
+}
+
+static bool hdev_is_sg(BlockDriverState *bs)
+{
+
+#if defined(__linux__)
+
+    BDRVRawState *s = bs->opaque;
+    struct stat st;
+    struct sg_scsi_id scsiid;
+    int sg_version;
+    int ret;
+
+    if (stat(bs->filename, &st) < 0 || !S_ISCHR(st.st_mode)) {
+        return false;
+    }
+
+    ret = ioctl(s->fd, SG_GET_VERSION_NUM, &sg_version);
+    if (ret < 0) {
+        return false;
+    }
+
+    ret = ioctl(s->fd, SG_GET_SCSI_ID, &scsiid);
+    if (ret >= 0) {
+        DPRINTF("SG device found: type=%d, version=%d\n",
+            scsiid.scsi_type, sg_version);
+        return true;
+    }
+
+#endif
+
+    return false;
+}
+
+static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
+                     Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    Error *local_err = NULL;
+    int ret;
+
+#if defined(__APPLE__) && defined(__MACH__)
+    const char *filename = qdict_get_str(options, "filename");
+    char bsd_path[MAXPATHLEN] = "";
+    bool error_occurred = false;
+
+    /* If using a real cdrom */
+    if (strcmp(filename, "/dev/cdrom") == 0) {
+        char *mediaType = NULL;
+        kern_return_t ret_val;
+        io_iterator_t mediaIterator = 0;
+
+        mediaType = FindEjectableOpticalMedia(&mediaIterator);
+        if (mediaType == NULL) {
+            error_setg(errp, "Please make sure your CD/DVD is in the optical"
+                       " drive");
+            error_occurred = true;
+            goto hdev_open_Mac_error;
+        }
+
+        ret_val = GetBSDPath(mediaIterator, bsd_path, sizeof(bsd_path), flags);
+        if (ret_val != KERN_SUCCESS) {
+            error_setg(errp, "Could not get BSD path for optical drive");
+            error_occurred = true;
+            goto hdev_open_Mac_error;
+        }
+
+        /* If a real optical drive was not found */
+        if (bsd_path[0] == '\0') {
+            error_setg(errp, "Failed to obtain bsd path for optical drive");
+            error_occurred = true;
+            goto hdev_open_Mac_error;
+        }
+
+        /* If using a cdrom disc and finding a partition on the disc failed */
+        if (strncmp(mediaType, kIOCDMediaClass, 9) == 0 &&
+            setup_cdrom(bsd_path, errp) == false) {
+            print_unmounting_directions(bsd_path);
+            error_occurred = true;
+            goto hdev_open_Mac_error;
+        }
+
+        qdict_put(options, "filename", qstring_from_str(bsd_path));
+
+hdev_open_Mac_error:
+        g_free(mediaType);
+        if (mediaIterator) {
+            IOObjectRelease(mediaIterator);
+        }
+        if (error_occurred) {
+            return -ENOENT;
+        }
+    }
+#endif /* defined(__APPLE__) && defined(__MACH__) */
+
+    s->type = FTYPE_FILE;
+
+    ret = raw_open_common(bs, options, flags, 0, &local_err);
+    if (ret < 0) {
+        error_propagate(errp, local_err);
+#if defined(__APPLE__) && defined(__MACH__)
+        if (*bsd_path) {
+            filename = bsd_path;
+        }
+        /* if a physical device experienced an error while being opened */
+        if (strncmp(filename, "/dev/", 5) == 0) {
+            print_unmounting_directions(filename);
+        }
+#endif /* defined(__APPLE__) && defined(__MACH__) */
+        return ret;
+    }
+
+    /* Since this does ioctl the device must be already opened */
+    bs->sg = hdev_is_sg(bs);
+
+    if (flags & BDRV_O_RDWR) {
+        ret = check_hdev_writable(s);
+        if (ret < 0) {
+            raw_close(bs);
+            error_setg_errno(errp, -ret, "The device is not writable");
+            return ret;
+        }
+    }
+
+    return ret;
+}
+
+#if defined(__linux__)
+
+static BlockAIOCB *hdev_aio_ioctl(BlockDriverState *bs,
+        unsigned long int req, void *buf,
+        BlockCompletionFunc *cb, void *opaque)
+{
+    BDRVRawState *s = bs->opaque;
+    RawPosixAIOData *acb;
+    ThreadPool *pool;
+
+    if (fd_open(bs) < 0)
+        return NULL;
+
+    acb = g_new(RawPosixAIOData, 1);
+    acb->bs = bs;
+    acb->aio_type = QEMU_AIO_IOCTL;
+    acb->aio_fildes = s->fd;
+    acb->aio_offset = 0;
+    acb->aio_ioctl_buf = buf;
+    acb->aio_ioctl_cmd = req;
+    pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
+    return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
+}
+#endif /* linux */
+
+static int fd_open(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+
+    /* this is just to ensure s->fd is sane (its called by io ops) */
+    if (s->fd >= 0)
+        return 0;
+    return -EIO;
+}
+
+static coroutine_fn BlockAIOCB *hdev_aio_pdiscard(BlockDriverState *bs,
+    int64_t offset, int count,
+    BlockCompletionFunc *cb, void *opaque)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (fd_open(bs) < 0) {
+        return NULL;
+    }
+    return paio_submit(bs, s->fd, offset, NULL, count,
+                       cb, opaque, QEMU_AIO_DISCARD|QEMU_AIO_BLKDEV);
+}
+
+static coroutine_fn int hdev_co_pwrite_zeroes(BlockDriverState *bs,
+    int64_t offset, int count, BdrvRequestFlags flags)
+{
+    BDRVRawState *s = bs->opaque;
+    int rc;
+
+    rc = fd_open(bs);
+    if (rc < 0) {
+        return rc;
+    }
+    if (!(flags & BDRV_REQ_MAY_UNMAP)) {
+        return paio_submit_co(bs, s->fd, offset, NULL, count,
+                              QEMU_AIO_WRITE_ZEROES|QEMU_AIO_BLKDEV);
+    } else if (s->discard_zeroes) {
+        return paio_submit_co(bs, s->fd, offset, NULL, count,
+                              QEMU_AIO_DISCARD|QEMU_AIO_BLKDEV);
+    }
+    return -ENOTSUP;
+}
+
+static int hdev_create(const char *filename, QemuOpts *opts,
+                       Error **errp)
+{
+    int fd;
+    int ret = 0;
+    struct stat stat_buf;
+    int64_t total_size = 0;
+    bool has_prefix;
+
+    /* This function is used by both protocol block drivers and therefore either
+     * of these prefixes may be given.
+     * The return value has to be stored somewhere, otherwise this is an error
+     * due to -Werror=unused-value. */
+    has_prefix =
+        strstart(filename, "host_device:", &filename) ||
+        strstart(filename, "host_cdrom:" , &filename);
+
+    (void)has_prefix;
+
+    ret = raw_normalize_devicepath(&filename);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Could not normalize device path");
+        return ret;
+    }
+
+    /* Read out options */
+    total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+                          BDRV_SECTOR_SIZE);
+
+    fd = qemu_open(filename, O_WRONLY | O_BINARY);
+    if (fd < 0) {
+        ret = -errno;
+        error_setg_errno(errp, -ret, "Could not open device");
+        return ret;
+    }
+
+    if (fstat(fd, &stat_buf) < 0) {
+        ret = -errno;
+        error_setg_errno(errp, -ret, "Could not stat device");
+    } else if (!S_ISBLK(stat_buf.st_mode) && !S_ISCHR(stat_buf.st_mode)) {
+        error_setg(errp,
+                   "The given file is neither a block nor a character device");
+        ret = -ENODEV;
+    } else if (lseek(fd, 0, SEEK_END) < total_size) {
+        error_setg(errp, "Device is too small");
+        ret = -ENOSPC;
+    }
+
+    qemu_close(fd);
+    return ret;
+}
+
+static BlockDriver bdrv_host_device = {
+    .format_name        = "host_device",
+    .protocol_name        = "host_device",
+    .instance_size      = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
+    .bdrv_probe_device  = hdev_probe_device,
+    .bdrv_parse_filename = hdev_parse_filename,
+    .bdrv_file_open     = hdev_open,
+    .bdrv_close         = raw_close,
+    .bdrv_reopen_prepare = raw_reopen_prepare,
+    .bdrv_reopen_commit  = raw_reopen_commit,
+    .bdrv_reopen_abort   = raw_reopen_abort,
+    .bdrv_create         = hdev_create,
+    .create_opts         = &raw_create_opts,
+    .bdrv_co_pwrite_zeroes = hdev_co_pwrite_zeroes,
+
+    .bdrv_co_preadv         = raw_co_preadv,
+    .bdrv_co_pwritev        = raw_co_pwritev,
+    .bdrv_aio_flush	= raw_aio_flush,
+    .bdrv_aio_pdiscard   = hdev_aio_pdiscard,
+    .bdrv_refresh_limits = raw_refresh_limits,
+    .bdrv_io_plug = raw_aio_plug,
+    .bdrv_io_unplug = raw_aio_unplug,
+
+    .bdrv_truncate      = raw_truncate,
+    .bdrv_getlength	= raw_getlength,
+    .bdrv_get_info = raw_get_info,
+    .bdrv_get_allocated_file_size
+                        = raw_get_allocated_file_size,
+    .bdrv_probe_blocksizes = hdev_probe_blocksizes,
+    .bdrv_probe_geometry = hdev_probe_geometry,
+
+    /* generic scsi device */
+#ifdef __linux__
+    .bdrv_aio_ioctl     = hdev_aio_ioctl,
+#endif
+};
+
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+static void cdrom_parse_filename(const char *filename, QDict *options,
+                                 Error **errp)
+{
+    /* The prefix is optional, just as for "file". */
+    strstart(filename, "host_cdrom:", &filename);
+
+    qdict_put_obj(options, "filename", QOBJECT(qstring_from_str(filename)));
+}
+#endif
+
+#ifdef __linux__
+static int cdrom_open(BlockDriverState *bs, QDict *options, int flags,
+                      Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+
+    s->type = FTYPE_CD;
+
+    /* open will not fail even if no CD is inserted, so add O_NONBLOCK */
+    return raw_open_common(bs, options, flags, O_NONBLOCK, errp);
+}
+
+static int cdrom_probe_device(const char *filename)
+{
+    int fd, ret;
+    int prio = 0;
+    struct stat st;
+
+    fd = qemu_open(filename, O_RDONLY | O_NONBLOCK);
+    if (fd < 0) {
+        goto out;
+    }
+    ret = fstat(fd, &st);
+    if (ret == -1 || !S_ISBLK(st.st_mode)) {
+        goto outc;
+    }
+
+    /* Attempt to detect via a CDROM specific ioctl */
+    ret = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
+    if (ret >= 0)
+        prio = 100;
+
+outc:
+    qemu_close(fd);
+out:
+    return prio;
+}
+
+static bool cdrom_is_inserted(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    int ret;
+
+    ret = ioctl(s->fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
+    return ret == CDS_DISC_OK;
+}
+
+static void cdrom_eject(BlockDriverState *bs, bool eject_flag)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (eject_flag) {
+        if (ioctl(s->fd, CDROMEJECT, NULL) < 0)
+            perror("CDROMEJECT");
+    } else {
+        if (ioctl(s->fd, CDROMCLOSETRAY, NULL) < 0)
+            perror("CDROMEJECT");
+    }
+}
+
+static void cdrom_lock_medium(BlockDriverState *bs, bool locked)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (ioctl(s->fd, CDROM_LOCKDOOR, locked) < 0) {
+        /*
+         * Note: an error can happen if the distribution automatically
+         * mounts the CD-ROM
+         */
+        /* perror("CDROM_LOCKDOOR"); */
+    }
+}
+
+static BlockDriver bdrv_host_cdrom = {
+    .format_name        = "host_cdrom",
+    .protocol_name      = "host_cdrom",
+    .instance_size      = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
+    .bdrv_probe_device	= cdrom_probe_device,
+    .bdrv_parse_filename = cdrom_parse_filename,
+    .bdrv_file_open     = cdrom_open,
+    .bdrv_close         = raw_close,
+    .bdrv_reopen_prepare = raw_reopen_prepare,
+    .bdrv_reopen_commit  = raw_reopen_commit,
+    .bdrv_reopen_abort   = raw_reopen_abort,
+    .bdrv_create         = hdev_create,
+    .create_opts         = &raw_create_opts,
+
+
+    .bdrv_co_preadv         = raw_co_preadv,
+    .bdrv_co_pwritev        = raw_co_pwritev,
+    .bdrv_aio_flush	= raw_aio_flush,
+    .bdrv_refresh_limits = raw_refresh_limits,
+    .bdrv_io_plug = raw_aio_plug,
+    .bdrv_io_unplug = raw_aio_unplug,
+
+    .bdrv_truncate      = raw_truncate,
+    .bdrv_getlength      = raw_getlength,
+    .has_variable_length = true,
+    .bdrv_get_allocated_file_size
+                        = raw_get_allocated_file_size,
+
+    /* removable device support */
+    .bdrv_is_inserted   = cdrom_is_inserted,
+    .bdrv_eject         = cdrom_eject,
+    .bdrv_lock_medium   = cdrom_lock_medium,
+
+    /* generic scsi device */
+    .bdrv_aio_ioctl     = hdev_aio_ioctl,
+};
+#endif /* __linux__ */
+
+#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)
+static int cdrom_open(BlockDriverState *bs, QDict *options, int flags,
+                      Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    Error *local_err = NULL;
+    int ret;
+
+    s->type = FTYPE_CD;
+
+    ret = raw_open_common(bs, options, flags, 0, &local_err);
+    if (ret) {
+        error_propagate(errp, local_err);
+        return ret;
+    }
+
+    /* make sure the door isn't locked at this time */
+    ioctl(s->fd, CDIOCALLOW);
+    return 0;
+}
+
+static int cdrom_probe_device(const char *filename)
+{
+    if (strstart(filename, "/dev/cd", NULL) ||
+            strstart(filename, "/dev/acd", NULL))
+        return 100;
+    return 0;
+}
+
+static int cdrom_reopen(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    int fd;
+
+    /*
+     * Force reread of possibly changed/newly loaded disc,
+     * FreeBSD seems to not notice sometimes...
+     */
+    if (s->fd >= 0)
+        qemu_close(s->fd);
+    fd = qemu_open(bs->filename, s->open_flags, 0644);
+    if (fd < 0) {
+        s->fd = -1;
+        return -EIO;
+    }
+    s->fd = fd;
+
+    /* make sure the door isn't locked at this time */
+    ioctl(s->fd, CDIOCALLOW);
+    return 0;
+}
+
+static bool cdrom_is_inserted(BlockDriverState *bs)
+{
+    return raw_getlength(bs) > 0;
+}
+
+static void cdrom_eject(BlockDriverState *bs, bool eject_flag)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (s->fd < 0)
+        return;
+
+    (void) ioctl(s->fd, CDIOCALLOW);
+
+    if (eject_flag) {
+        if (ioctl(s->fd, CDIOCEJECT) < 0)
+            perror("CDIOCEJECT");
+    } else {
+        if (ioctl(s->fd, CDIOCCLOSE) < 0)
+            perror("CDIOCCLOSE");
+    }
+
+    cdrom_reopen(bs);
+}
+
+static void cdrom_lock_medium(BlockDriverState *bs, bool locked)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (s->fd < 0)
+        return;
+    if (ioctl(s->fd, (locked ? CDIOCPREVENT : CDIOCALLOW)) < 0) {
+        /*
+         * Note: an error can happen if the distribution automatically
+         * mounts the CD-ROM
+         */
+        /* perror("CDROM_LOCKDOOR"); */
+    }
+}
+
+static BlockDriver bdrv_host_cdrom = {
+    .format_name        = "host_cdrom",
+    .protocol_name      = "host_cdrom",
+    .instance_size      = sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
+    .bdrv_probe_device	= cdrom_probe_device,
+    .bdrv_parse_filename = cdrom_parse_filename,
+    .bdrv_file_open     = cdrom_open,
+    .bdrv_close         = raw_close,
+    .bdrv_reopen_prepare = raw_reopen_prepare,
+    .bdrv_reopen_commit  = raw_reopen_commit,
+    .bdrv_reopen_abort   = raw_reopen_abort,
+    .bdrv_create        = hdev_create,
+    .create_opts        = &raw_create_opts,
+
+    .bdrv_co_preadv         = raw_co_preadv,
+    .bdrv_co_pwritev        = raw_co_pwritev,
+    .bdrv_aio_flush	= raw_aio_flush,
+    .bdrv_refresh_limits = raw_refresh_limits,
+    .bdrv_io_plug = raw_aio_plug,
+    .bdrv_io_unplug = raw_aio_unplug,
+
+    .bdrv_truncate      = raw_truncate,
+    .bdrv_getlength      = raw_getlength,
+    .has_variable_length = true,
+    .bdrv_get_allocated_file_size
+                        = raw_get_allocated_file_size,
+
+    /* removable device support */
+    .bdrv_is_inserted   = cdrom_is_inserted,
+    .bdrv_eject         = cdrom_eject,
+    .bdrv_lock_medium   = cdrom_lock_medium,
+};
+#endif /* __FreeBSD__ */
+
+static void bdrv_file_init(void)
+{
+    /*
+     * Register all the drivers.  Note that order is important, the driver
+     * registered last will get probed first.
+     */
+    bdrv_register(&bdrv_file);
+    bdrv_register(&bdrv_host_device);
+#ifdef __linux__
+    bdrv_register(&bdrv_host_cdrom);
+#endif
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+    bdrv_register(&bdrv_host_cdrom);
+#endif
+}
+
+block_init(bdrv_file_init);