Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 948 insertions, 0 deletions

diff --git a/block/file-win32.c b/block/file-win32.c
new file mode 100644
index 000000000..ec9d64d0e
--- /dev/null
+++ b/block/file-win32.c
@@ -0,0 +1,948 @@
+/*
+ * Block driver for RAW files (win32)
+ *
+ * Copyright (c) 2006 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/cutils.h"
+#include "block/block_int.h"
+#include "qemu/module.h"
+#include "qemu/option.h"
+#include "block/raw-aio.h"
+#include "trace.h"
+#include "block/thread-pool.h"
+#include "qemu/iov.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qstring.h"
+#include <windows.h>
+#include <winioctl.h>
+
+#define FTYPE_FILE 0
+#define FTYPE_CD     1
+#define FTYPE_HARDDISK 2
+
+typedef struct RawWin32AIOData {
+    BlockDriverState *bs;
+    HANDLE hfile;
+    struct iovec *aio_iov;
+    int aio_niov;
+    size_t aio_nbytes;
+    off64_t aio_offset;
+    int aio_type;
+} RawWin32AIOData;
+
+typedef struct BDRVRawState {
+    HANDLE hfile;
+    int type;
+    char drive_path[16]; /* format: "d:\" */
+    QEMUWin32AIOState *aio;
+} BDRVRawState;
+
+typedef struct BDRVRawReopenState {
+    HANDLE hfile;
+} BDRVRawReopenState;
+
+/*
+ * Read/writes the data to/from a given linear buffer.
+ *
+ * Returns the number of bytes handles or -errno in case of an error. Short
+ * reads are only returned if the end of the file is reached.
+ */
+static size_t handle_aiocb_rw(RawWin32AIOData *aiocb)
+{
+    size_t offset = 0;
+    int i;
+
+    for (i = 0; i < aiocb->aio_niov; i++) {
+        OVERLAPPED ov;
+        DWORD ret, ret_count, len;
+
+        memset(&ov, 0, sizeof(ov));
+        ov.Offset = (aiocb->aio_offset + offset);
+        ov.OffsetHigh = (aiocb->aio_offset + offset) >> 32;
+        len = aiocb->aio_iov[i].iov_len;
+        if (aiocb->aio_type & QEMU_AIO_WRITE) {
+            ret = WriteFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
+                            len, &ret_count, &ov);
+        } else {
+            ret = ReadFile(aiocb->hfile, aiocb->aio_iov[i].iov_base,
+                           len, &ret_count, &ov);
+        }
+        if (!ret) {
+            ret_count = 0;
+        }
+        if (ret_count != len) {
+            offset += ret_count;
+            break;
+        }
+        offset += len;
+    }
+
+    return offset;
+}
+
+static int aio_worker(void *arg)
+{
+    RawWin32AIOData *aiocb = arg;
+    ssize_t ret = 0;
+    size_t count;
+
+    switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
+    case QEMU_AIO_READ:
+        count = handle_aiocb_rw(aiocb);
+        if (count < aiocb->aio_nbytes) {
+            /* A short read means that we have reached EOF. Pad the buffer
+             * with zeros for bytes after EOF. */
+            iov_memset(aiocb->aio_iov, aiocb->aio_niov, count,
+                      0, aiocb->aio_nbytes - count);
+
+            count = aiocb->aio_nbytes;
+        }
+        if (count == aiocb->aio_nbytes) {
+            ret = 0;
+        } else {
+            ret = -EINVAL;
+        }
+        break;
+    case QEMU_AIO_WRITE:
+        count = handle_aiocb_rw(aiocb);
+        if (count == aiocb->aio_nbytes) {
+            ret = 0;
+        } else {
+            ret = -EINVAL;
+        }
+        break;
+    case QEMU_AIO_FLUSH:
+        if (!FlushFileBuffers(aiocb->hfile)) {
+            return -EIO;
+        }
+        break;
+    default:
+        fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
+        ret = -EINVAL;
+        break;
+    }
+
+    g_free(aiocb);
+    return ret;
+}
+
+static BlockAIOCB *paio_submit(BlockDriverState *bs, HANDLE hfile,
+        int64_t offset, QEMUIOVector *qiov, int count,
+        BlockCompletionFunc *cb, void *opaque, int type)
+{
+    RawWin32AIOData *acb = g_new(RawWin32AIOData, 1);
+    ThreadPool *pool;
+
+    acb->bs = bs;
+    acb->hfile = hfile;
+    acb->aio_type = type;
+
+    if (qiov) {
+        acb->aio_iov = qiov->iov;
+        acb->aio_niov = qiov->niov;
+        assert(qiov->size == count);
+    }
+    acb->aio_nbytes = count;
+    acb->aio_offset = offset;
+
+    trace_file_paio_submit(acb, opaque, offset, count, type);
+    pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
+    return thread_pool_submit_aio(pool, aio_worker, acb, cb, opaque);
+}
+
+int qemu_ftruncate64(int fd, int64_t length)
+{
+    LARGE_INTEGER li;
+    DWORD dw;
+    LONG high;
+    HANDLE h;
+    BOOL res;
+
+    if ((GetVersion() & 0x80000000UL) && (length >> 32) != 0)
+        return -1;
+
+    h = (HANDLE)_get_osfhandle(fd);
+
+    /* get current position, ftruncate do not change position */
+    li.HighPart = 0;
+    li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_CURRENT);
+    if (li.LowPart == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
+        return -1;
+    }
+
+    high = length >> 32;
+    dw = SetFilePointer(h, (DWORD) length, &high, FILE_BEGIN);
+    if (dw == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
+        return -1;
+    }
+    res = SetEndOfFile(h);
+
+    /* back to old position */
+    SetFilePointer(h, li.LowPart, &li.HighPart, FILE_BEGIN);
+    return res ? 0 : -1;
+}
+
+static int set_sparse(int fd)
+{
+    DWORD returned;
+    return (int) DeviceIoControl((HANDLE)_get_osfhandle(fd), FSCTL_SET_SPARSE,
+                                 NULL, 0, NULL, 0, &returned, NULL);
+}
+
+static void raw_detach_aio_context(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (s->aio) {
+        win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
+    }
+}
+
+static void raw_attach_aio_context(BlockDriverState *bs,
+                                   AioContext *new_context)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (s->aio) {
+        win32_aio_attach_aio_context(s->aio, new_context);
+    }
+}
+
+static void raw_probe_alignment(BlockDriverState *bs, Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    DWORD sectorsPerCluster, freeClusters, totalClusters, count;
+    DISK_GEOMETRY_EX dg;
+    BOOL status;
+
+    if (s->type == FTYPE_CD) {
+        bs->bl.request_alignment = 2048;
+        return;
+    }
+    if (s->type == FTYPE_HARDDISK) {
+        status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
+                                 NULL, 0, &dg, sizeof(dg), &count, NULL);
+        if (status != 0) {
+            bs->bl.request_alignment = dg.Geometry.BytesPerSector;
+            return;
+        }
+        /* try GetDiskFreeSpace too */
+    }
+
+    if (s->drive_path[0]) {
+        GetDiskFreeSpace(s->drive_path, &sectorsPerCluster,
+                         &dg.Geometry.BytesPerSector,
+                         &freeClusters, &totalClusters);
+        bs->bl.request_alignment = dg.Geometry.BytesPerSector;
+        return;
+    }
+
+    /* XXX Does Windows support AIO on less than 512-byte alignment? */
+    bs->bl.request_alignment = 512;
+}
+
+static void raw_parse_flags(int flags, bool use_aio, int *access_flags,
+                            DWORD *overlapped)
+{
+    assert(access_flags != NULL);
+    assert(overlapped != NULL);
+
+    if (flags & BDRV_O_RDWR) {
+        *access_flags = GENERIC_READ | GENERIC_WRITE;
+    } else {
+        *access_flags = GENERIC_READ;
+    }
+
+    *overlapped = FILE_ATTRIBUTE_NORMAL;
+    if (use_aio) {
+        *overlapped |= FILE_FLAG_OVERLAPPED;
+    }
+    if (flags & BDRV_O_NOCACHE) {
+        *overlapped |= FILE_FLAG_NO_BUFFERING;
+    }
+}
+
+static void raw_parse_filename(const char *filename, QDict *options,
+                               Error **errp)
+{
+    bdrv_parse_filename_strip_prefix(filename, "file:", options);
+}
+
+static QemuOptsList raw_runtime_opts = {
+    .name = "raw",
+    .head = QTAILQ_HEAD_INITIALIZER(raw_runtime_opts.head),
+    .desc = {
+        {
+            .name = "filename",
+            .type = QEMU_OPT_STRING,
+            .help = "File name of the image",
+        },
+        {
+            .name = "aio",
+            .type = QEMU_OPT_STRING,
+            .help = "host AIO implementation (threads, native)",
+        },
+        {
+            .name = "locking",
+            .type = QEMU_OPT_STRING,
+            .help = "file locking mode (on/off/auto, default: auto)",
+        },
+        { /* end of list */ }
+    },
+};
+
+static bool get_aio_option(QemuOpts *opts, int flags, Error **errp)
+{
+    BlockdevAioOptions aio, aio_default;
+
+    aio_default = (flags & BDRV_O_NATIVE_AIO) ? BLOCKDEV_AIO_OPTIONS_NATIVE
+                                              : BLOCKDEV_AIO_OPTIONS_THREADS;
+    aio = qapi_enum_parse(&BlockdevAioOptions_lookup, qemu_opt_get(opts, "aio"),
+                          aio_default, errp);
+
+    switch (aio) {
+    case BLOCKDEV_AIO_OPTIONS_NATIVE:
+        return true;
+    case BLOCKDEV_AIO_OPTIONS_THREADS:
+        return false;
+    default:
+        error_setg(errp, "Invalid AIO option");
+    }
+    return false;
+}
+
+static int raw_open(BlockDriverState *bs, QDict *options, int flags,
+                    Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    int access_flags;
+    DWORD overlapped;
+    QemuOpts *opts;
+    Error *local_err = NULL;
+    const char *filename;
+    bool use_aio;
+    OnOffAuto locking;
+    int ret;
+
+    s->type = FTYPE_FILE;
+
+    opts = qemu_opts_create(&raw_runtime_opts, NULL, 0, &error_abort);
+    if (!qemu_opts_absorb_qdict(opts, options, errp)) {
+        ret = -EINVAL;
+        goto fail;
+    }
+
+    locking = qapi_enum_parse(&OnOffAuto_lookup,
+                              qemu_opt_get(opts, "locking"),
+                              ON_OFF_AUTO_AUTO, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto fail;
+    }
+    switch (locking) {
+    case ON_OFF_AUTO_ON:
+        error_setg(errp, "locking=on is not supported on Windows");
+        ret = -EINVAL;
+        goto fail;
+    case ON_OFF_AUTO_OFF:
+    case ON_OFF_AUTO_AUTO:
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    filename = qemu_opt_get(opts, "filename");
+
+    use_aio = get_aio_option(opts, flags, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto fail;
+    }
+
+    raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
+
+    if (filename[0] && filename[1] == ':') {
+        snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", filename[0]);
+    } else if (filename[0] == '\\' && filename[1] == '\\') {
+        s->drive_path[0] = 0;
+    } else {
+        /* Relative path.  */
+        char buf[MAX_PATH];
+        GetCurrentDirectory(MAX_PATH, buf);
+        snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", buf[0]);
+    }
+
+    s->hfile = CreateFile(filename, access_flags,
+                          FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
+                          OPEN_EXISTING, overlapped, NULL);
+    if (s->hfile == INVALID_HANDLE_VALUE) {
+        int err = GetLastError();
+
+        error_setg_win32(errp, err, "Could not open '%s'", filename);
+        if (err == ERROR_ACCESS_DENIED) {
+            ret = -EACCES;
+        } else {
+            ret = -EINVAL;
+        }
+        goto fail;
+    }
+
+    if (use_aio) {
+        s->aio = win32_aio_init();
+        if (s->aio == NULL) {
+            CloseHandle(s->hfile);
+            error_setg(errp, "Could not initialize AIO");
+            ret = -EINVAL;
+            goto fail;
+        }
+
+        ret = win32_aio_attach(s->aio, s->hfile);
+        if (ret < 0) {
+            win32_aio_cleanup(s->aio);
+            CloseHandle(s->hfile);
+            error_setg_errno(errp, -ret, "Could not enable AIO");
+            goto fail;
+        }
+
+        win32_aio_attach_aio_context(s->aio, bdrv_get_aio_context(bs));
+    }
+
+    /* When extending regular files, we get zeros from the OS */
+    bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
+
+    ret = 0;
+fail:
+    qemu_opts_del(opts);
+    return ret;
+}
+
+static BlockAIOCB *raw_aio_preadv(BlockDriverState *bs,
+                                  int64_t offset, int64_t bytes,
+                                  QEMUIOVector *qiov, BdrvRequestFlags flags,
+                                  BlockCompletionFunc *cb, void *opaque)
+{
+    BDRVRawState *s = bs->opaque;
+    if (s->aio) {
+        return win32_aio_submit(bs, s->aio, s->hfile, offset, bytes, qiov,
+                                cb, opaque, QEMU_AIO_READ);
+    } else {
+        return paio_submit(bs, s->hfile, offset, qiov, bytes,
+                           cb, opaque, QEMU_AIO_READ);
+    }
+}
+
+static BlockAIOCB *raw_aio_pwritev(BlockDriverState *bs,
+                                   int64_t offset, int64_t bytes,
+                                   QEMUIOVector *qiov, BdrvRequestFlags flags,
+                                   BlockCompletionFunc *cb, void *opaque)
+{
+    BDRVRawState *s = bs->opaque;
+    if (s->aio) {
+        return win32_aio_submit(bs, s->aio, s->hfile, offset, bytes, qiov,
+                                cb, opaque, QEMU_AIO_WRITE);
+    } else {
+        return paio_submit(bs, s->hfile, offset, qiov, bytes,
+                           cb, opaque, QEMU_AIO_WRITE);
+    }
+}
+
+static BlockAIOCB *raw_aio_flush(BlockDriverState *bs,
+                         BlockCompletionFunc *cb, void *opaque)
+{
+    BDRVRawState *s = bs->opaque;
+    return paio_submit(bs, s->hfile, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);
+}
+
+static void raw_close(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+
+    if (s->aio) {
+        win32_aio_detach_aio_context(s->aio, bdrv_get_aio_context(bs));
+        win32_aio_cleanup(s->aio);
+        s->aio = NULL;
+    }
+
+    CloseHandle(s->hfile);
+    if (bs->open_flags & BDRV_O_TEMPORARY) {
+        unlink(bs->filename);
+    }
+}
+
+static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset,
+                                        bool exact, PreallocMode prealloc,
+                                        BdrvRequestFlags flags, Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    LONG low, high;
+    DWORD dwPtrLow;
+
+    if (prealloc != PREALLOC_MODE_OFF) {
+        error_setg(errp, "Unsupported preallocation mode '%s'",
+                   PreallocMode_str(prealloc));
+        return -ENOTSUP;
+    }
+
+    low = offset;
+    high = offset >> 32;
+
+    /*
+     * An error has occurred if the return value is INVALID_SET_FILE_POINTER
+     * and GetLastError doesn't return NO_ERROR.
+     */
+    dwPtrLow = SetFilePointer(s->hfile, low, &high, FILE_BEGIN);
+    if (dwPtrLow == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR) {
+        error_setg_win32(errp, GetLastError(), "SetFilePointer error");
+        return -EIO;
+    }
+    if (SetEndOfFile(s->hfile) == 0) {
+        error_setg_win32(errp, GetLastError(), "SetEndOfFile error");
+        return -EIO;
+    }
+    return 0;
+}
+
+static int64_t raw_getlength(BlockDriverState *bs)
+{
+    BDRVRawState *s = bs->opaque;
+    LARGE_INTEGER l;
+    ULARGE_INTEGER available, total, total_free;
+    DISK_GEOMETRY_EX dg;
+    DWORD count;
+    BOOL status;
+
+    switch(s->type) {
+    case FTYPE_FILE:
+        l.LowPart = GetFileSize(s->hfile, (PDWORD)&l.HighPart);
+        if (l.LowPart == 0xffffffffUL && GetLastError() != NO_ERROR)
+            return -EIO;
+        break;
+    case FTYPE_CD:
+        if (!GetDiskFreeSpaceEx(s->drive_path, &available, &total, &total_free))
+            return -EIO;
+        l.QuadPart = total.QuadPart;
+        break;
+    case FTYPE_HARDDISK:
+        status = DeviceIoControl(s->hfile, IOCTL_DISK_GET_DRIVE_GEOMETRY_EX,
+                                 NULL, 0, &dg, sizeof(dg), &count, NULL);
+        if (status != 0) {
+            l = dg.DiskSize;
+        }
+        break;
+    default:
+        return -EIO;
+    }
+    return l.QuadPart;
+}
+
+static int64_t raw_get_allocated_file_size(BlockDriverState *bs)
+{
+    typedef DWORD (WINAPI * get_compressed_t)(const char *filename,
+                                              DWORD * high);
+    get_compressed_t get_compressed;
+    struct _stati64 st;
+    const char *filename = bs->filename;
+    /* WinNT support GetCompressedFileSize to determine allocate size */
+    get_compressed =
+        (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"),
+                                            "GetCompressedFileSizeA");
+    if (get_compressed) {
+        DWORD high, low;
+        low = get_compressed(filename, &high);
+        if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR) {
+            return (((int64_t) high) << 32) + low;
+        }
+    }
+
+    if (_stati64(filename, &st) < 0) {
+        return -1;
+    }
+    return st.st_size;
+}
+
+static int raw_co_create(BlockdevCreateOptions *options, Error **errp)
+{
+    BlockdevCreateOptionsFile *file_opts;
+    int fd;
+
+    assert(options->driver == BLOCKDEV_DRIVER_FILE);
+    file_opts = &options->u.file;
+
+    if (file_opts->has_preallocation) {
+        error_setg(errp, "Preallocation is not supported on Windows");
+        return -EINVAL;
+    }
+    if (file_opts->has_nocow) {
+        error_setg(errp, "nocow is not supported on Windows");
+        return -EINVAL;
+    }
+
+    fd = qemu_create(file_opts->filename, O_WRONLY | O_TRUNC | O_BINARY,
+                     0644, errp);
+    if (fd < 0) {
+        return -EIO;
+    }
+    set_sparse(fd);
+    ftruncate(fd, file_opts->size);
+    qemu_close(fd);
+
+    return 0;
+}
+
+static int coroutine_fn raw_co_create_opts(BlockDriver *drv,
+                                           const char *filename,
+                                           QemuOpts *opts,
+                                           Error **errp)
+{
+    BlockdevCreateOptions options;
+    int64_t total_size = 0;
+
+    strstart(filename, "file:", &filename);
+
+    /* Read out options */
+    total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+                          BDRV_SECTOR_SIZE);
+
+    options = (BlockdevCreateOptions) {
+        .driver     = BLOCKDEV_DRIVER_FILE,
+        .u.file     = {
+            .filename           = (char *) filename,
+            .size               = total_size,
+            .has_preallocation  = false,
+            .has_nocow          = false,
+        },
+    };
+    return raw_co_create(&options, errp);
+}
+
+static int raw_reopen_prepare(BDRVReopenState *state,
+                              BlockReopenQueue *queue, Error **errp)
+{
+    BDRVRawState *s = state->bs->opaque;
+    BDRVRawReopenState *rs;
+    int access_flags;
+    DWORD overlapped;
+    int ret = 0;
+
+    if (s->type != FTYPE_FILE) {
+        error_setg(errp, "Can only reopen files");
+        return -EINVAL;
+    }
+
+    rs = g_new0(BDRVRawReopenState, 1);
+
+    /*
+     * We do not support changing any options (only flags). By leaving
+     * all options in state->options, we tell the generic reopen code
+     * that we do not support changing any of them, so it will verify
+     * that their values did not change.
+     */
+
+    raw_parse_flags(state->flags, s->aio != NULL, &access_flags, &overlapped);
+    rs->hfile = CreateFile(state->bs->filename, access_flags,
+                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
+                           OPEN_EXISTING, overlapped, NULL);
+
+    if (rs->hfile == INVALID_HANDLE_VALUE) {
+        int err = GetLastError();
+
+        error_setg_win32(errp, err, "Could not reopen '%s'",
+                         state->bs->filename);
+        if (err == ERROR_ACCESS_DENIED) {
+            ret = -EACCES;
+        } else {
+            ret = -EINVAL;
+        }
+        goto fail;
+    }
+
+    if (s->aio) {
+        ret = win32_aio_attach(s->aio, rs->hfile);
+        if (ret < 0) {
+            error_setg_errno(errp, -ret, "Could not enable AIO");
+            CloseHandle(rs->hfile);
+            goto fail;
+        }
+    }
+
+    state->opaque = rs;
+
+    return 0;
+
+fail:
+    g_free(rs);
+    state->opaque = NULL;
+
+    return ret;
+}
+
+static void raw_reopen_commit(BDRVReopenState *state)
+{
+    BDRVRawState *s = state->bs->opaque;
+    BDRVRawReopenState *rs = state->opaque;
+
+    assert(rs != NULL);
+
+    CloseHandle(s->hfile);
+    s->hfile = rs->hfile;
+
+    g_free(rs);
+    state->opaque = NULL;
+}
+
+static void raw_reopen_abort(BDRVReopenState *state)
+{
+    BDRVRawReopenState *rs = state->opaque;
+
+    if (!rs) {
+        return;
+    }
+
+    if (rs->hfile != INVALID_HANDLE_VALUE) {
+        CloseHandle(rs->hfile);
+    }
+
+    g_free(rs);
+    state->opaque = NULL;
+}
+
+static QemuOptsList raw_create_opts = {
+    .name = "raw-create-opts",
+    .head = QTAILQ_HEAD_INITIALIZER(raw_create_opts.head),
+    .desc = {
+        {
+            .name = BLOCK_OPT_SIZE,
+            .type = QEMU_OPT_SIZE,
+            .help = "Virtual disk size"
+        },
+        { /* end of list */ }
+    }
+};
+
+BlockDriver bdrv_file = {
+    .format_name	= "file",
+    .protocol_name	= "file",
+    .instance_size	= sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
+    .bdrv_parse_filename = raw_parse_filename,
+    .bdrv_file_open     = raw_open,
+    .bdrv_refresh_limits = raw_probe_alignment,
+    .bdrv_close         = raw_close,
+    .bdrv_co_create_opts = raw_co_create_opts,
+    .bdrv_has_zero_init = bdrv_has_zero_init_1,
+
+    .bdrv_reopen_prepare = raw_reopen_prepare,
+    .bdrv_reopen_commit  = raw_reopen_commit,
+    .bdrv_reopen_abort   = raw_reopen_abort,
+
+    .bdrv_aio_preadv    = raw_aio_preadv,
+    .bdrv_aio_pwritev   = raw_aio_pwritev,
+    .bdrv_aio_flush     = raw_aio_flush,
+
+    .bdrv_co_truncate   = raw_co_truncate,
+    .bdrv_getlength	= raw_getlength,
+    .bdrv_get_allocated_file_size
+                        = raw_get_allocated_file_size,
+
+    .create_opts        = &raw_create_opts,
+};
+
+/***********************************************/
+/* host device */
+
+static int find_cdrom(char *cdrom_name, int cdrom_name_size)
+{
+    char drives[256], *pdrv = drives;
+    UINT type;
+
+    memset(drives, 0, sizeof(drives));
+    GetLogicalDriveStrings(sizeof(drives), drives);
+    while(pdrv[0] != '\0') {
+        type = GetDriveType(pdrv);
+        switch(type) {
+        case DRIVE_CDROM:
+            snprintf(cdrom_name, cdrom_name_size, "\\\\.\\%c:", pdrv[0]);
+            return 0;
+            break;
+        }
+        pdrv += lstrlen(pdrv) + 1;
+    }
+    return -1;
+}
+
+static int find_device_type(BlockDriverState *bs, const char *filename)
+{
+    BDRVRawState *s = bs->opaque;
+    UINT type;
+    const char *p;
+
+    if (strstart(filename, "\\\\.\\", &p) ||
+        strstart(filename, "//./", &p)) {
+        if (stristart(p, "PhysicalDrive", NULL))
+            return FTYPE_HARDDISK;
+        snprintf(s->drive_path, sizeof(s->drive_path), "%c:\\", p[0]);
+        type = GetDriveType(s->drive_path);
+        switch (type) {
+        case DRIVE_REMOVABLE:
+        case DRIVE_FIXED:
+            return FTYPE_HARDDISK;
+        case DRIVE_CDROM:
+            return FTYPE_CD;
+        default:
+            return FTYPE_FILE;
+        }
+    } else {
+        return FTYPE_FILE;
+    }
+}
+
+static int hdev_probe_device(const char *filename)
+{
+    if (strstart(filename, "/dev/cdrom", NULL))
+        return 100;
+    if (is_windows_drive(filename))
+        return 100;
+    return 0;
+}
+
+static void hdev_parse_filename(const char *filename, QDict *options,
+                                Error **errp)
+{
+    bdrv_parse_filename_strip_prefix(filename, "host_device:", options);
+}
+
+static void hdev_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+    /* XXX Does Windows support AIO on less than 512-byte alignment? */
+    bs->bl.request_alignment = 512;
+}
+
+static int hdev_open(BlockDriverState *bs, QDict *options, int flags,
+                     Error **errp)
+{
+    BDRVRawState *s = bs->opaque;
+    int access_flags, create_flags;
+    int ret = 0;
+    DWORD overlapped;
+    char device_name[64];
+
+    Error *local_err = NULL;
+    const char *filename;
+    bool use_aio;
+
+    QemuOpts *opts = qemu_opts_create(&raw_runtime_opts, NULL, 0,
+                                      &error_abort);
+    if (!qemu_opts_absorb_qdict(opts, options, errp)) {
+        ret = -EINVAL;
+        goto done;
+    }
+
+    filename = qemu_opt_get(opts, "filename");
+
+    use_aio = get_aio_option(opts, flags, &local_err);
+    if (!local_err && use_aio) {
+        error_setg(&local_err, "AIO is not supported on Windows host devices");
+    }
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto done;
+    }
+
+    if (strstart(filename, "/dev/cdrom", NULL)) {
+        if (find_cdrom(device_name, sizeof(device_name)) < 0) {
+            error_setg(errp, "Could not open CD-ROM drive");
+            ret = -ENOENT;
+            goto done;
+        }
+        filename = device_name;
+    } else {
+        /* transform drive letters into device name */
+        if (((filename[0] >= 'a' && filename[0] <= 'z') ||
+             (filename[0] >= 'A' && filename[0] <= 'Z')) &&
+            filename[1] == ':' && filename[2] == '\0') {
+            snprintf(device_name, sizeof(device_name), "\\\\.\\%c:", filename[0]);
+            filename = device_name;
+        }
+    }
+    s->type = find_device_type(bs, filename);
+
+    raw_parse_flags(flags, use_aio, &access_flags, &overlapped);
+
+    create_flags = OPEN_EXISTING;
+
+    s->hfile = CreateFile(filename, access_flags,
+                          FILE_SHARE_READ, NULL,
+                          create_flags, overlapped, NULL);
+    if (s->hfile == INVALID_HANDLE_VALUE) {
+        int err = GetLastError();
+
+        if (err == ERROR_ACCESS_DENIED) {
+            ret = -EACCES;
+        } else {
+            ret = -EINVAL;
+        }
+        error_setg_errno(errp, -ret, "Could not open device");
+        goto done;
+    }
+
+done:
+    qemu_opts_del(opts);
+    return ret;
+}
+
+static BlockDriver bdrv_host_device = {
+    .format_name	= "host_device",
+    .protocol_name	= "host_device",
+    .instance_size	= sizeof(BDRVRawState),
+    .bdrv_needs_filename = true,
+    .bdrv_parse_filename = hdev_parse_filename,
+    .bdrv_probe_device	= hdev_probe_device,
+    .bdrv_file_open	= hdev_open,
+    .bdrv_close		= raw_close,
+    .bdrv_refresh_limits = hdev_refresh_limits,
+
+    .bdrv_aio_preadv    = raw_aio_preadv,
+    .bdrv_aio_pwritev   = raw_aio_pwritev,
+    .bdrv_aio_flush     = raw_aio_flush,
+
+    .bdrv_detach_aio_context = raw_detach_aio_context,
+    .bdrv_attach_aio_context = raw_attach_aio_context,
+
+    .bdrv_getlength      = raw_getlength,
+    .has_variable_length = true,
+
+    .bdrv_get_allocated_file_size
+                        = raw_get_allocated_file_size,
+};
+
+static void bdrv_file_init(void)
+{
+    bdrv_register(&bdrv_file);
+    bdrv_register(&bdrv_host_device);
+}
+
+block_init(bdrv_file_init);