summary refs log tree commit diff stats
path: root/block/file-posix.c
diff options
context:
space:
mode:
Diffstat (limited to 'block/file-posix.c')
-rw-r--r--block/file-posix.c2616
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);