auto import from //depot/cupcake/@135843

1 files changed, 1433 insertions, 0 deletions

diff --git a/block.c b/block.c
new file mode 100644
index 0000000..06bea78
--- /dev/null
+++ b/block.c
@@ -0,0 +1,1433 @@
+/*
+ * QEMU System Emulator block driver
+ *
+ * Copyright (c) 2003 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "qemu-common.h"
+#include "console.h"
+#include "block_int.h"
+
+#ifdef _BSD
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/queue.h>
+#include <sys/disk.h>
+#endif
+
+#define SECTOR_BITS 9
+#define SECTOR_SIZE (1 << SECTOR_BITS)
+
+typedef struct BlockDriverAIOCBSync {
+    BlockDriverAIOCB common;
+    QEMUBH *bh;
+    int ret;
+} BlockDriverAIOCBSync;
+
+static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
+        int64_t sector_num, uint8_t *buf, int nb_sectors,
+        BlockDriverCompletionFunc *cb, void *opaque);
+static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
+        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+        BlockDriverCompletionFunc *cb, void *opaque);
+static void bdrv_aio_cancel_em(BlockDriverAIOCB *acb);
+static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
+                        uint8_t *buf, int nb_sectors);
+static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
+                         const uint8_t *buf, int nb_sectors);
+
+static BlockDriver *first_drv;
+
+static int path_is_absolute(const char *path)
+{
+    const char *p;
+#ifdef _WIN32
+    /* specific case for names like: "\\.\d:" */
+    if (*path == '/' || *path == '\\')
+        return 1;
+#endif
+    p = strchr(path, ':');
+    if (p)
+        p++;
+    else
+        p = path;
+#ifdef _WIN32
+    return (*p == '/' || *p == '\\');
+#else
+    return (*p == '/');
+#endif
+}
+
+/* if filename is absolute, just copy it to dest. Otherwise, build a
+   path to it by considering it is relative to base_path. URL are
+   supported. */
+void path_combine(char *dest, int dest_size,
+                  const char *base_path,
+                  const char *filename)
+{
+    const char *p, *p1;
+    int len;
+
+    if (dest_size <= 0)
+        return;
+    if (path_is_absolute(filename)) {
+        pstrcpy(dest, dest_size, filename);
+    } else {
+        p = strchr(base_path, ':');
+        if (p)
+            p++;
+        else
+            p = base_path;
+        p1 = strrchr(base_path, '/');
+#ifdef _WIN32
+        {
+            const char *p2;
+            p2 = strrchr(base_path, '\\');
+            if (!p1 || p2 > p1)
+                p1 = p2;
+        }
+#endif
+        if (p1)
+            p1++;
+        else
+            p1 = base_path;
+        if (p1 > p)
+            p = p1;
+        len = p - base_path;
+        if (len > dest_size - 1)
+            len = dest_size - 1;
+        memcpy(dest, base_path, len);
+        dest[len] = '\0';
+        pstrcat(dest, dest_size, filename);
+    }
+}
+
+
+static void bdrv_register(BlockDriver *bdrv)
+{
+    if (!bdrv->bdrv_aio_read) {
+        /* add AIO emulation layer */
+        bdrv->bdrv_aio_read = bdrv_aio_read_em;
+        bdrv->bdrv_aio_write = bdrv_aio_write_em;
+        bdrv->bdrv_aio_cancel = bdrv_aio_cancel_em;
+        bdrv->aiocb_size = sizeof(BlockDriverAIOCBSync);
+    } else if (!bdrv->bdrv_read && !bdrv->bdrv_pread) {
+        /* add synchronous IO emulation layer */
+        bdrv->bdrv_read = bdrv_read_em;
+        bdrv->bdrv_write = bdrv_write_em;
+    }
+    bdrv->next = first_drv;
+    first_drv = bdrv;
+}
+
+/* create a new block device (by default it is empty) */
+BlockDriverState *bdrv_new(const char *device_name)
+{
+    BlockDriverState **pbs, *bs;
+
+    bs = qemu_mallocz(sizeof(BlockDriverState));
+    if(!bs)
+        return NULL;
+    pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
+    if (device_name[0] != '\0') {
+        /* insert at the end */
+        pbs = &bdrv_first;
+        while (*pbs != NULL)
+            pbs = &(*pbs)->next;
+        *pbs = bs;
+    }
+    return bs;
+}
+
+BlockDriver *bdrv_find_format(const char *format_name)
+{
+    BlockDriver *drv1;
+    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
+        if (!strcmp(drv1->format_name, format_name))
+            return drv1;
+    }
+    return NULL;
+}
+
+int bdrv_create(BlockDriver *drv,
+                const char *filename, int64_t size_in_sectors,
+                const char *backing_file, int flags)
+{
+    if (!drv->bdrv_create)
+        return -ENOTSUP;
+    return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
+}
+
+#ifdef _WIN32
+void get_tmp_filename(char *filename, int size)
+{
+    char temp_dir[MAX_PATH];
+
+    GetTempPath(MAX_PATH, temp_dir);
+    GetTempFileName(temp_dir, "qem", 0, filename);
+}
+#else
+void get_tmp_filename(char *filename, int size)
+{
+    int fd;
+    const char *tmpdir;
+    /* XXX: race condition possible */
+    tmpdir = getenv("TMPDIR");
+    if (!tmpdir)
+        tmpdir = "/tmp";
+    snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
+    fd = mkstemp(filename);
+    close(fd);
+}
+#endif
+
+#ifdef _WIN32
+static int is_windows_drive_prefix(const char *filename)
+{
+    return (((filename[0] >= 'a' && filename[0] <= 'z') ||
+             (filename[0] >= 'A' && filename[0] <= 'Z')) &&
+            filename[1] == ':');
+}
+
+static int is_windows_drive(const char *filename)
+{
+    if (is_windows_drive_prefix(filename) &&
+        filename[2] == '\0')
+        return 1;
+    if (strstart(filename, "\\\\.\\", NULL) ||
+        strstart(filename, "//./", NULL))
+        return 1;
+    return 0;
+}
+#endif
+
+static BlockDriver *find_protocol(const char *filename)
+{
+    BlockDriver *drv1;
+    char protocol[128];
+    int len;
+    const char *p;
+
+#ifdef _WIN32
+    if (is_windows_drive(filename) ||
+        is_windows_drive_prefix(filename))
+        return &bdrv_raw;
+#endif
+    p = strchr(filename, ':');
+    if (!p)
+        return &bdrv_raw;
+    len = p - filename;
+    if (len > sizeof(protocol) - 1)
+        len = sizeof(protocol) - 1;
+    memcpy(protocol, filename, len);
+    protocol[len] = '\0';
+    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
+        if (drv1->protocol_name &&
+            !strcmp(drv1->protocol_name, protocol))
+            return drv1;
+    }
+    return NULL;
+}
+
+/* XXX: force raw format if block or character device ? It would
+   simplify the BSD case */
+static BlockDriver *find_image_format(const char *filename)
+{
+    int ret, score, score_max;
+    BlockDriver *drv1, *drv;
+    uint8_t buf[2048];
+    BlockDriverState *bs;
+
+    /* detect host devices. By convention, /dev/cdrom[N] is always
+       recognized as a host CDROM */
+    if (strstart(filename, "/dev/cdrom", NULL))
+        return &bdrv_host_device;
+#ifdef _WIN32
+    if (is_windows_drive(filename))
+        return &bdrv_host_device;
+#else
+    {
+        struct stat st;
+        if (stat(filename, &st) >= 0 &&
+            (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
+            return &bdrv_host_device;
+        }
+    }
+#endif
+
+    drv = find_protocol(filename);
+    /* no need to test disk image formats for vvfat */
+    if (drv == &bdrv_vvfat)
+        return drv;
+
+    ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
+    if (ret < 0)
+        return NULL;
+    ret = bdrv_pread(bs, 0, buf, sizeof(buf));
+    bdrv_delete(bs);
+    if (ret < 0) {
+        return NULL;
+    }
+
+    score_max = 0;
+    for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
+        if (drv1->bdrv_probe) {
+            score = drv1->bdrv_probe(buf, ret, filename);
+            if (score > score_max) {
+                score_max = score;
+                drv = drv1;
+            }
+        }
+    }
+    return drv;
+}
+
+int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
+{
+    BlockDriverState *bs;
+    int ret;
+
+    bs = bdrv_new("");
+    if (!bs)
+        return -ENOMEM;
+    ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
+    if (ret < 0) {
+        bdrv_delete(bs);
+        return ret;
+    }
+    *pbs = bs;
+    return 0;
+}
+
+int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
+{
+    return bdrv_open2(bs, filename, flags, NULL);
+}
+
+int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
+               BlockDriver *drv)
+{
+    int ret, open_flags;
+    char tmp_filename[PATH_MAX];
+    char backing_filename[PATH_MAX];
+
+    bs->read_only = 0;
+    bs->is_temporary = 0;
+    bs->encrypted = 0;
+
+    if (flags & BDRV_O_SNAPSHOT) {
+        BlockDriverState *bs1;
+        int64_t total_size;
+        int is_protocol = 0;
+
+        /* if snapshot, we create a temporary backing file and open it
+           instead of opening 'filename' directly */
+
+        /* if there is a backing file, use it */
+        bs1 = bdrv_new("");
+        if (!bs1) {
+            return -ENOMEM;
+        }
+        if (bdrv_open(bs1, filename, 0) < 0) {
+            bdrv_delete(bs1);
+            return -1;
+        }
+        total_size = bdrv_getlength(bs1) >> SECTOR_BITS;
+
+        if (bs1->drv && bs1->drv->protocol_name)
+            is_protocol = 1;
+
+        bdrv_delete(bs1);
+
+        get_tmp_filename(tmp_filename, sizeof(tmp_filename));
+
+        /* Real path is meaningless for protocols */
+        if (is_protocol)
+            snprintf(backing_filename, sizeof(backing_filename),
+                     "%s", filename);
+        else
+            realpath(filename, backing_filename);
+
+        if (bdrv_create(&bdrv_qcow2, tmp_filename,
+                        total_size, backing_filename, 0) < 0) {
+            return -1;
+        }
+        filename = tmp_filename;
+        bs->is_temporary = 1;
+    }
+
+    pstrcpy(bs->filename, sizeof(bs->filename), filename);
+    if (flags & BDRV_O_FILE) {
+        drv = find_protocol(filename);
+        if (!drv)
+            return -ENOENT;
+    } else {
+        if (!drv) {
+            drv = find_image_format(filename);
+            if (!drv)
+                return -1;
+        }
+    }
+    bs->drv = drv;
+    bs->opaque = qemu_mallocz(drv->instance_size);
+    if (bs->opaque == NULL && drv->instance_size > 0)
+        return -1;
+    /* Note: for compatibility, we open disk image files as RDWR, and
+       RDONLY as fallback */
+    if (!(flags & BDRV_O_FILE))
+        open_flags = BDRV_O_RDWR | (flags & BDRV_O_DIRECT);
+    else
+        open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
+    ret = drv->bdrv_open(bs, filename, open_flags);
+    if (ret == -EACCES && !(flags & BDRV_O_FILE)) {
+        ret = drv->bdrv_open(bs, filename, BDRV_O_RDONLY);
+        bs->read_only = 1;
+    }
+    if (ret < 0) {
+        qemu_free(bs->opaque);
+        bs->opaque = NULL;
+        bs->drv = NULL;
+        return ret;
+    }
+    if (drv->bdrv_getlength) {
+        bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
+    }
+#ifndef _WIN32
+    if (bs->is_temporary) {
+        unlink(filename);
+    }
+#endif
+    if (bs->backing_file[0] != '\0') {
+        /* if there is a backing file, use it */
+        bs->backing_hd = bdrv_new("");
+        if (!bs->backing_hd) {
+        fail:
+            bdrv_close(bs);
+            return -ENOMEM;
+        }
+        path_combine(backing_filename, sizeof(backing_filename),
+                     filename, bs->backing_file);
+        if (bdrv_open(bs->backing_hd, backing_filename, 0) < 0)
+            goto fail;
+    }
+
+    /* call the change callback */
+    bs->media_changed = 1;
+    if (bs->change_cb)
+        bs->change_cb(bs->change_opaque);
+
+    return 0;
+}
+
+void bdrv_close(BlockDriverState *bs)
+{
+    if (bs->drv) {
+        if (bs->backing_hd)
+            bdrv_delete(bs->backing_hd);
+        bs->drv->bdrv_close(bs);
+        qemu_free(bs->opaque);
+#ifdef _WIN32
+        if (bs->is_temporary) {
+            unlink(bs->filename);
+        }
+#endif
+        bs->opaque = NULL;
+        bs->drv = NULL;
+
+        /* call the change callback */
+        bs->media_changed = 1;
+        if (bs->change_cb)
+            bs->change_cb(bs->change_opaque);
+    }
+}
+
+void bdrv_delete(BlockDriverState *bs)
+{
+    BlockDriverState **pbs;
+
+    pbs = &bdrv_first;
+    while (*pbs != bs && *pbs != NULL)
+        pbs = &(*pbs)->next;
+    if (*pbs == bs)
+        *pbs = bs->next;
+
+    bdrv_close(bs);
+    qemu_free(bs);
+}
+
+/* commit COW file into the raw image */
+int bdrv_commit(BlockDriverState *bs)
+{
+    BlockDriver *drv = bs->drv;
+    int64_t i, total_sectors;
+    int n, j;
+    unsigned char sector[512];
+
+    if (!drv)
+        return -ENOMEDIUM;
+
+    if (bs->read_only) {
+	return -EACCES;
+    }
+
+    if (!bs->backing_hd) {
+	return -ENOTSUP;
+    }
+
+    total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
+    for (i = 0; i < total_sectors;) {
+        if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
+            for(j = 0; j < n; j++) {
+                if (bdrv_read(bs, i, sector, 1) != 0) {
+                    return -EIO;
+                }
+
+                if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
+                    return -EIO;
+                }
+                i++;
+	    }
+	} else {
+            i += n;
+        }
+    }
+
+    if (drv->bdrv_make_empty)
+	return drv->bdrv_make_empty(bs);
+
+    return 0;
+}
+
+/* return < 0 if error. See bdrv_write() for the return codes */
+int bdrv_read(BlockDriverState *bs, int64_t sector_num,
+              uint8_t *buf, int nb_sectors)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (!drv)
+        return -ENOMEDIUM;
+
+    if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
+            memcpy(buf, bs->boot_sector_data, 512);
+        sector_num++;
+        nb_sectors--;
+        buf += 512;
+        if (nb_sectors == 0)
+            return 0;
+    }
+    if (drv->bdrv_pread) {
+        int ret, len;
+        len = nb_sectors * 512;
+        ret = drv->bdrv_pread(bs, sector_num * 512, buf, len);
+        if (ret < 0)
+            return ret;
+        else if (ret != len)
+            return -EINVAL;
+        else {
+	    bs->rd_bytes += (unsigned) len;
+	    bs->rd_ops ++;
+            return 0;
+	}
+    } else {
+        return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
+    }
+}
+
+/* Return < 0 if error. Important errors are:
+  -EIO         generic I/O error (may happen for all errors)
+  -ENOMEDIUM   No media inserted.
+  -EINVAL      Invalid sector number or nb_sectors
+  -EACCES      Trying to write a read-only device
+*/
+int bdrv_write(BlockDriverState *bs, int64_t sector_num,
+               const uint8_t *buf, int nb_sectors)
+{
+    BlockDriver *drv = bs->drv;
+    if (!bs->drv)
+        return -ENOMEDIUM;
+    if (bs->read_only)
+        return -EACCES;
+    if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
+        memcpy(bs->boot_sector_data, buf, 512);
+    }
+    if (drv->bdrv_pwrite) {
+        int ret, len;
+        len = nb_sectors * 512;
+        ret = drv->bdrv_pwrite(bs, sector_num * 512, buf, len);
+        if (ret < 0)
+            return ret;
+        else if (ret != len)
+            return -EIO;
+        else {
+	    bs->wr_bytes += (unsigned) len;
+	    bs->wr_ops ++;
+            return 0;
+	}
+    } else {
+        return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
+    }
+}
+
+static int bdrv_pread_em(BlockDriverState *bs, int64_t offset,
+                         uint8_t *buf, int count1)
+{
+    uint8_t tmp_buf[SECTOR_SIZE];
+    int len, nb_sectors, count;
+    int64_t sector_num;
+
+    count = count1;
+    /* first read to align to sector start */
+    len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
+    if (len > count)
+        len = count;
+    sector_num = offset >> SECTOR_BITS;
+    if (len > 0) {
+        if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
+            return -EIO;
+        memcpy(buf, tmp_buf + (offset & (SECTOR_SIZE - 1)), len);
+        count -= len;
+        if (count == 0)
+            return count1;
+        sector_num++;
+        buf += len;
+    }
+
+    /* read the sectors "in place" */
+    nb_sectors = count >> SECTOR_BITS;
+    if (nb_sectors > 0) {
+        if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
+            return -EIO;
+        sector_num += nb_sectors;
+        len = nb_sectors << SECTOR_BITS;
+        buf += len;
+        count -= len;
+    }
+
+    /* add data from the last sector */
+    if (count > 0) {
+        if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
+            return -EIO;
+        memcpy(buf, tmp_buf, count);
+    }
+    return count1;
+}
+
+static int bdrv_pwrite_em(BlockDriverState *bs, int64_t offset,
+                          const uint8_t *buf, int count1)
+{
+    uint8_t tmp_buf[SECTOR_SIZE];
+    int len, nb_sectors, count;
+    int64_t sector_num;
+
+    count = count1;
+    /* first write to align to sector start */
+    len = (SECTOR_SIZE - offset) & (SECTOR_SIZE - 1);
+    if (len > count)
+        len = count;
+    sector_num = offset >> SECTOR_BITS;
+    if (len > 0) {
+        if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
+            return -EIO;
+        memcpy(tmp_buf + (offset & (SECTOR_SIZE - 1)), buf, len);
+        if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
+            return -EIO;
+        count -= len;
+        if (count == 0)
+            return count1;
+        sector_num++;
+        buf += len;
+    }
+
+    /* write the sectors "in place" */
+    nb_sectors = count >> SECTOR_BITS;
+    if (nb_sectors > 0) {
+        if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
+            return -EIO;
+        sector_num += nb_sectors;
+        len = nb_sectors << SECTOR_BITS;
+        buf += len;
+        count -= len;
+    }
+
+    /* add data from the last sector */
+    if (count > 0) {
+        if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
+            return -EIO;
+        memcpy(tmp_buf, buf, count);
+        if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
+            return -EIO;
+    }
+    return count1;
+}
+
+/**
+ * Read with byte offsets (needed only for file protocols)
+ */
+int bdrv_pread(BlockDriverState *bs, int64_t offset,
+               void *buf1, int count1)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_pread)
+        return bdrv_pread_em(bs, offset, buf1, count1);
+    return drv->bdrv_pread(bs, offset, buf1, count1);
+}
+
+/**
+ * Write with byte offsets (needed only for file protocols)
+ */
+int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
+                const void *buf1, int count1)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_pwrite)
+        return bdrv_pwrite_em(bs, offset, buf1, count1);
+    return drv->bdrv_pwrite(bs, offset, buf1, count1);
+}
+
+/**
+ * Truncate file to 'offset' bytes (needed only for file protocols)
+ */
+int bdrv_truncate(BlockDriverState *bs, int64_t offset)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_truncate)
+        return -ENOTSUP;
+    return drv->bdrv_truncate(bs, offset);
+}
+
+/**
+ * Length of a file in bytes. Return < 0 if error or unknown.
+ */
+int64_t bdrv_getlength(BlockDriverState *bs)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_getlength) {
+        /* legacy mode */
+        return bs->total_sectors * SECTOR_SIZE;
+    }
+    return drv->bdrv_getlength(bs);
+}
+
+/* return 0 as number of sectors if no device present or error */
+void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
+{
+    int64_t length;
+    length = bdrv_getlength(bs);
+    if (length < 0)
+        length = 0;
+    else
+        length = length >> SECTOR_BITS;
+    *nb_sectors_ptr = length;
+}
+
+/* force a given boot sector. */
+void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
+{
+    bs->boot_sector_enabled = 1;
+    if (size > 512)
+        size = 512;
+    memcpy(bs->boot_sector_data, data, size);
+    memset(bs->boot_sector_data + size, 0, 512 - size);
+}
+
+void bdrv_set_geometry_hint(BlockDriverState *bs,
+                            int cyls, int heads, int secs)
+{
+    bs->cyls = cyls;
+    bs->heads = heads;
+    bs->secs = secs;
+}
+
+void bdrv_set_type_hint(BlockDriverState *bs, int type)
+{
+    bs->type = type;
+    bs->removable = ((type == BDRV_TYPE_CDROM ||
+                      type == BDRV_TYPE_FLOPPY));
+}
+
+void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
+{
+    bs->translation = translation;
+}
+
+void bdrv_get_geometry_hint(BlockDriverState *bs,
+                            int *pcyls, int *pheads, int *psecs)
+{
+    *pcyls = bs->cyls;
+    *pheads = bs->heads;
+    *psecs = bs->secs;
+}
+
+int bdrv_get_type_hint(BlockDriverState *bs)
+{
+    return bs->type;
+}
+
+int bdrv_get_translation_hint(BlockDriverState *bs)
+{
+    return bs->translation;
+}
+
+int bdrv_is_removable(BlockDriverState *bs)
+{
+    return bs->removable;
+}
+
+int bdrv_is_read_only(BlockDriverState *bs)
+{
+    return bs->read_only;
+}
+
+int bdrv_is_sg(BlockDriverState *bs)
+{
+    return bs->sg;
+}
+
+/* XXX: no longer used */
+void bdrv_set_change_cb(BlockDriverState *bs,
+                        void (*change_cb)(void *opaque), void *opaque)
+{
+    bs->change_cb = change_cb;
+    bs->change_opaque = opaque;
+}
+
+int bdrv_is_encrypted(BlockDriverState *bs)
+{
+    if (bs->backing_hd && bs->backing_hd->encrypted)
+        return 1;
+    return bs->encrypted;
+}
+
+int bdrv_set_key(BlockDriverState *bs, const char *key)
+{
+    int ret;
+    if (bs->backing_hd && bs->backing_hd->encrypted) {
+        ret = bdrv_set_key(bs->backing_hd, key);
+        if (ret < 0)
+            return ret;
+        if (!bs->encrypted)
+            return 0;
+    }
+    if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
+        return -1;
+    return bs->drv->bdrv_set_key(bs, key);
+}
+
+void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
+{
+    if (!bs->drv) {
+        buf[0] = '\0';
+    } else {
+        pstrcpy(buf, buf_size, bs->drv->format_name);
+    }
+}
+
+void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
+                         void *opaque)
+{
+    BlockDriver *drv;
+
+    for (drv = first_drv; drv != NULL; drv = drv->next) {
+        it(opaque, drv->format_name);
+    }
+}
+
+BlockDriverState *bdrv_find(const char *name)
+{
+    BlockDriverState *bs;
+
+    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
+        if (!strcmp(name, bs->device_name))
+            return bs;
+    }
+    return NULL;
+}
+
+void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
+{
+    BlockDriverState *bs;
+
+    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
+        it(opaque, bs->device_name);
+    }
+}
+
+const char *bdrv_get_device_name(BlockDriverState *bs)
+{
+    return bs->device_name;
+}
+
+void bdrv_flush(BlockDriverState *bs)
+{
+    if (bs->drv->bdrv_flush)
+        bs->drv->bdrv_flush(bs);
+    if (bs->backing_hd)
+        bdrv_flush(bs->backing_hd);
+}
+
+/*
+ * Returns true iff the specified sector is present in the disk image. Drivers
+ * not implementing the functionality are assumed to not support backing files,
+ * hence all their sectors are reported as allocated.
+ *
+ * '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.
+ */
+int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
+	int *pnum)
+{
+    int64_t n;
+    if (!bs->drv->bdrv_is_allocated) {
+        if (sector_num >= bs->total_sectors) {
+            *pnum = 0;
+            return 0;
+        }
+        n = bs->total_sectors - sector_num;
+        *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
+        return 1;
+    }
+    return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
+}
+
+void bdrv_info(void)
+{
+    BlockDriverState *bs;
+
+    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
+        term_printf("%s:", bs->device_name);
+        term_printf(" type=");
+        switch(bs->type) {
+        case BDRV_TYPE_HD:
+            term_printf("hd");
+            break;
+        case BDRV_TYPE_CDROM:
+            term_printf("cdrom");
+            break;
+        case BDRV_TYPE_FLOPPY:
+            term_printf("floppy");
+            break;
+        }
+        term_printf(" removable=%d", bs->removable);
+        if (bs->removable) {
+            term_printf(" locked=%d", bs->locked);
+        }
+        if (bs->drv) {
+            term_printf(" file=");
+	    term_print_filename(bs->filename);
+            if (bs->backing_file[0] != '\0') {
+                term_printf(" backing_file=");
+		term_print_filename(bs->backing_file);
+	    }
+            term_printf(" ro=%d", bs->read_only);
+            term_printf(" drv=%s", bs->drv->format_name);
+            if (bs->encrypted)
+                term_printf(" encrypted");
+        } else {
+            term_printf(" [not inserted]");
+        }
+        term_printf("\n");
+    }
+}
+
+/* The "info blockstats" command. */
+void bdrv_info_stats (void)
+{
+    BlockDriverState *bs;
+
+    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
+	term_printf ("%s:"
+		     " rd_bytes=%" PRIu64
+		     " wr_bytes=%" PRIu64
+		     " rd_operations=%" PRIu64
+		     " wr_operations=%" PRIu64
+		     "\n",
+		     bs->device_name,
+		     bs->rd_bytes, bs->wr_bytes,
+		     bs->rd_ops, bs->wr_ops);
+    }
+}
+
+void bdrv_get_backing_filename(BlockDriverState *bs,
+                               char *filename, int filename_size)
+{
+    if (!bs->backing_hd) {
+        pstrcpy(filename, filename_size, "");
+    } else {
+        pstrcpy(filename, filename_size, bs->backing_file);
+    }
+}
+
+int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
+                          const uint8_t *buf, int nb_sectors)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_write_compressed)
+        return -ENOTSUP;
+    return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
+}
+
+int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_get_info)
+        return -ENOTSUP;
+    memset(bdi, 0, sizeof(*bdi));
+    return drv->bdrv_get_info(bs, bdi);
+}
+
+/**************************************************************/
+/* handling of snapshots */
+
+int bdrv_snapshot_create(BlockDriverState *bs,
+                         QEMUSnapshotInfo *sn_info)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_snapshot_create)
+        return -ENOTSUP;
+    return drv->bdrv_snapshot_create(bs, sn_info);
+}
+
+int bdrv_snapshot_goto(BlockDriverState *bs,
+                       const char *snapshot_id)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_snapshot_goto)
+        return -ENOTSUP;
+    return drv->bdrv_snapshot_goto(bs, snapshot_id);
+}
+
+int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_snapshot_delete)
+        return -ENOTSUP;
+    return drv->bdrv_snapshot_delete(bs, snapshot_id);
+}
+
+int bdrv_snapshot_list(BlockDriverState *bs,
+                       QEMUSnapshotInfo **psn_info)
+{
+    BlockDriver *drv = bs->drv;
+    if (!drv)
+        return -ENOMEDIUM;
+    if (!drv->bdrv_snapshot_list)
+        return -ENOTSUP;
+    return drv->bdrv_snapshot_list(bs, psn_info);
+}
+
+#define NB_SUFFIXES 4
+
+char *get_human_readable_size(char *buf, int buf_size, int64_t size)
+{
+    static const char suffixes[NB_SUFFIXES] = "KMGT";
+    int64_t base;
+    int i;
+
+    if (size <= 999) {
+        snprintf(buf, buf_size, "%" PRId64, size);
+    } else {
+        base = 1024;
+        for(i = 0; i < NB_SUFFIXES; i++) {
+            if (size < (10 * base)) {
+                snprintf(buf, buf_size, "%0.1f%c",
+                         (double)size / base,
+                         suffixes[i]);
+                break;
+            } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
+                snprintf(buf, buf_size, "%" PRId64 "%c",
+                         ((size + (base >> 1)) / base),
+                         suffixes[i]);
+                break;
+            }
+            base = base * 1024;
+        }
+    }
+    return buf;
+}
+
+char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
+{
+    char buf1[128], date_buf[128], clock_buf[128];
+#ifdef _WIN32
+    struct tm *ptm;
+#else
+    struct tm tm;
+#endif
+    time_t ti;
+    int64_t secs;
+
+    if (!sn) {
+        snprintf(buf, buf_size,
+                 "%-10s%-20s%7s%20s%15s",
+                 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
+    } else {
+        ti = sn->date_sec;
+#ifdef _WIN32
+        ptm = localtime(&ti);
+        strftime(date_buf, sizeof(date_buf),
+                 "%Y-%m-%d %H:%M:%S", ptm);
+#else
+        localtime_r(&ti, &tm);
+        strftime(date_buf, sizeof(date_buf),
+                 "%Y-%m-%d %H:%M:%S", &tm);
+#endif
+        secs = sn->vm_clock_nsec / 1000000000;
+        snprintf(clock_buf, sizeof(clock_buf),
+                 "%02d:%02d:%02d.%03d",
+                 (int)(secs / 3600),
+                 (int)((secs / 60) % 60),
+                 (int)(secs % 60),
+                 (int)((sn->vm_clock_nsec / 1000000) % 1000));
+        snprintf(buf, buf_size,
+                 "%-10s%-20s%7s%20s%15s",
+                 sn->id_str, sn->name,
+                 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
+                 date_buf,
+                 clock_buf);
+    }
+    return buf;
+}
+
+
+/**************************************************************/
+/* async I/Os */
+
+BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num,
+                                uint8_t *buf, int nb_sectors,
+                                BlockDriverCompletionFunc *cb, void *opaque)
+{
+    BlockDriver *drv = bs->drv;
+    BlockDriverAIOCB *ret;
+
+    if (!drv)
+        return NULL;
+
+    /* XXX: we assume that nb_sectors == 0 is suppored by the async read */
+    if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
+        memcpy(buf, bs->boot_sector_data, 512);
+        sector_num++;
+        nb_sectors--;
+        buf += 512;
+    }
+
+    ret = drv->bdrv_aio_read(bs, sector_num, buf, nb_sectors, cb, opaque);
+
+    if (ret) {
+	/* Update stats even though technically transfer has not happened. */
+	bs->rd_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
+	bs->rd_ops ++;
+    }
+
+    return ret;
+}
+
+BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num,
+                                 const uint8_t *buf, int nb_sectors,
+                                 BlockDriverCompletionFunc *cb, void *opaque)
+{
+    BlockDriver *drv = bs->drv;
+    BlockDriverAIOCB *ret;
+
+    if (!drv)
+        return NULL;
+    if (bs->read_only)
+        return NULL;
+    if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) {
+        memcpy(bs->boot_sector_data, buf, 512);
+    }
+
+    ret = drv->bdrv_aio_write(bs, sector_num, buf, nb_sectors, cb, opaque);
+
+    if (ret) {
+	/* Update stats even though technically transfer has not happened. */
+	bs->wr_bytes += (unsigned) nb_sectors * SECTOR_SIZE;
+	bs->wr_ops ++;
+    }
+
+    return ret;
+}
+
+void bdrv_aio_cancel(BlockDriverAIOCB *acb)
+{
+    BlockDriver *drv = acb->bs->drv;
+
+    drv->bdrv_aio_cancel(acb);
+}
+
+
+/**************************************************************/
+/* async block device emulation */
+
+static void bdrv_aio_bh_cb(void *opaque)
+{
+    BlockDriverAIOCBSync *acb = opaque;
+    acb->common.cb(acb->common.opaque, acb->ret);
+    qemu_aio_release(acb);
+}
+
+static BlockDriverAIOCB *bdrv_aio_read_em(BlockDriverState *bs,
+        int64_t sector_num, uint8_t *buf, int nb_sectors,
+        BlockDriverCompletionFunc *cb, void *opaque)
+{
+    BlockDriverAIOCBSync *acb;
+    int ret;
+
+    acb = qemu_aio_get(bs, cb, opaque);
+    if (!acb->bh)
+        acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
+    ret = bdrv_read(bs, sector_num, buf, nb_sectors);
+    acb->ret = ret;
+    qemu_bh_schedule(acb->bh);
+    return &acb->common;
+}
+
+static BlockDriverAIOCB *bdrv_aio_write_em(BlockDriverState *bs,
+        int64_t sector_num, const uint8_t *buf, int nb_sectors,
+        BlockDriverCompletionFunc *cb, void *opaque)
+{
+    BlockDriverAIOCBSync *acb;
+    int ret;
+
+    acb = qemu_aio_get(bs, cb, opaque);
+    if (!acb->bh)
+        acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
+    ret = bdrv_write(bs, sector_num, buf, nb_sectors);
+    acb->ret = ret;
+    qemu_bh_schedule(acb->bh);
+    return &acb->common;
+}
+
+static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
+{
+    BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
+    qemu_bh_cancel(acb->bh);
+    qemu_aio_release(acb);
+}
+
+/**************************************************************/
+/* sync block device emulation */
+
+static void bdrv_rw_em_cb(void *opaque, int ret)
+{
+    *(int *)opaque = ret;
+}
+
+#define NOT_DONE 0x7fffffff
+
+static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
+                        uint8_t *buf, int nb_sectors)
+{
+    int async_ret;
+    BlockDriverAIOCB *acb;
+
+    async_ret = NOT_DONE;
+    acb = bdrv_aio_read(bs, sector_num, buf, nb_sectors,
+                        bdrv_rw_em_cb, &async_ret);
+    if (acb == NULL)
+        return -1;
+
+    while (async_ret == NOT_DONE) {
+        qemu_aio_wait();
+    }
+
+    return async_ret;
+}
+
+static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
+                         const uint8_t *buf, int nb_sectors)
+{
+    int async_ret;
+    BlockDriverAIOCB *acb;
+
+    async_ret = NOT_DONE;
+    acb = bdrv_aio_write(bs, sector_num, buf, nb_sectors,
+                         bdrv_rw_em_cb, &async_ret);
+    if (acb == NULL)
+        return -1;
+    while (async_ret == NOT_DONE) {
+        qemu_aio_wait();
+    }
+    return async_ret;
+}
+
+void bdrv_init(void)
+{
+    bdrv_register(&bdrv_raw);
+    bdrv_register(&bdrv_host_device);
+#ifndef _WIN32
+    bdrv_register(&bdrv_cow);
+#endif
+    bdrv_register(&bdrv_qcow);
+#if 0
+    bdrv_register(&bdrv_vmdk);
+#endif
+    bdrv_register(&bdrv_cloop);
+    bdrv_register(&bdrv_dmg);
+#if 0
+    bdrv_register(&bdrv_bochs);
+    bdrv_register(&bdrv_vpc);
+#endif
+    bdrv_register(&bdrv_vvfat);
+#if 0
+    bdrv_register(&bdrv_qcow2);
+    bdrv_register(&bdrv_parallels);
+    bdrv_register(&bdrv_nbd);
+#endif
+    qemu_aio_init();
+}
+
+void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
+                   void *opaque)
+{
+    BlockDriver *drv;
+    BlockDriverAIOCB *acb;
+
+    drv = bs->drv;
+    if (drv->free_aiocb) {
+        acb = drv->free_aiocb;
+        drv->free_aiocb = acb->next;
+    } else {
+        acb = qemu_mallocz(drv->aiocb_size);
+        if (!acb)
+            return NULL;
+    }
+    acb->bs = bs;
+    acb->cb = cb;
+    acb->opaque = opaque;
+    return acb;
+}
+
+void qemu_aio_release(void *p)
+{
+    BlockDriverAIOCB *acb = p;
+    BlockDriver *drv = acb->bs->drv;
+    acb->next = drv->free_aiocb;
+    drv->free_aiocb = acb;
+}
+
+/**************************************************************/
+/* removable device support */
+
+/**
+ * Return TRUE if the media is present
+ */
+int bdrv_is_inserted(BlockDriverState *bs)
+{
+    BlockDriver *drv = bs->drv;
+    int ret;
+    if (!drv)
+        return 0;
+    if (!drv->bdrv_is_inserted)
+        return 1;
+    ret = drv->bdrv_is_inserted(bs);
+    return ret;
+}
+
+/**
+ * Return TRUE if the media changed since the last call to this
+ * function. It is currently only used for floppy disks
+ */
+int bdrv_media_changed(BlockDriverState *bs)
+{
+    BlockDriver *drv = bs->drv;
+    int ret;
+
+    if (!drv || !drv->bdrv_media_changed)
+        ret = -ENOTSUP;
+    else
+        ret = drv->bdrv_media_changed(bs);
+    if (ret == -ENOTSUP)
+        ret = bs->media_changed;
+    bs->media_changed = 0;
+    return ret;
+}
+
+/**
+ * If eject_flag is TRUE, eject the media. Otherwise, close the tray
+ */
+void bdrv_eject(BlockDriverState *bs, int eject_flag)
+{
+    BlockDriver *drv = bs->drv;
+    int ret;
+
+    if (!drv || !drv->bdrv_eject) {
+        ret = -ENOTSUP;
+    } else {
+        ret = drv->bdrv_eject(bs, eject_flag);
+    }
+    if (ret == -ENOTSUP) {
+        if (eject_flag)
+            bdrv_close(bs);
+    }
+}
+
+int bdrv_is_locked(BlockDriverState *bs)
+{
+    return bs->locked;
+}
+
+/**
+ * Lock or unlock the media (if it is locked, the user won't be able
+ * to eject it manually).
+ */
+void bdrv_set_locked(BlockDriverState *bs, int locked)
+{
+    BlockDriver *drv = bs->drv;
+
+    bs->locked = locked;
+    if (drv && drv->bdrv_set_locked) {
+        drv->bdrv_set_locked(bs, locked);
+    }
+}
+
+/* needed for generic scsi interface */
+
+int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (drv && drv->bdrv_ioctl)
+        return drv->bdrv_ioctl(bs, req, buf);
+    return -ENOTSUP;
+}