target-mips: optimize gen_mul_vr54xx()
[qemu] / block.c
diff --git a/block.c b/block.c
index 5ed7a02..823841d 100644 (file)
--- a/block.c
+++ b/block.c
@@ -1,8 +1,8 @@
 /*
  * 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
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-#include "vl.h"
+#include "config-host.h"
+#ifdef HOST_BSD
+/* include native header before sys-queue.h */
+#include <sys/queue.h>
+#endif
 
-#ifndef _WIN32
-#include <sys/mman.h>
+#include "qemu-common.h"
+#include "monitor.h"
+#include "block_int.h"
+
+#ifdef HOST_BSD
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#ifndef __DragonFly__
+#include <sys/disk.h>
+#endif
+#endif
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+#define SECTOR_BITS 9
+#define SECTOR_SIZE (1 << SECTOR_BITS)
+
+static AIOPool vectored_aio_pool;
+
+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);
+
+BlockDriverState *bdrv_first;
+
+static BlockDriver *first_drv;
+
+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);
+    }
+}
 
-#include "cow.h"
-
-struct BlockDriverState {
-    int fd; /* if -1, only COW mappings */
-    int64_t total_sectors;
-    int read_only; /* if true, the media is read only */
-    int inserted; /* if true, the media is present */
-    int removable; /* if true, the media can be removed */
-    int locked;    /* if true, the media cannot temporarily be ejected */
-    /* event callback when inserting/removing */
-    void (*change_cb)(void *opaque);
-    void *change_opaque;
-
-    uint8_t *cow_bitmap; /* if non NULL, COW mappings are used first */
-    uint8_t *cow_bitmap_addr; /* mmap address of cow_bitmap */
-    int cow_bitmap_size;
-    int cow_fd;
-    int64_t cow_sectors_offset;
-    int boot_sector_enabled;
-    uint8_t boot_sector_data[512];
-
-    char filename[1024];
-    
-    /* NOTE: the following infos are only hints for real hardware
-       drivers. They are not used by the block driver */
-    int cyls, heads, secs;
-    int type;
-    char device_name[32];
-    BlockDriverState *next;
-};
-
-static BlockDriverState *bdrv_first;
+
+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) {
+        /* add synchronous IO emulation layer */
+        bdrv->bdrv_read = bdrv_read_em;
+        bdrv->bdrv_write = bdrv_write_em;
+    }
+    aio_pool_init(&bdrv->aio_pool, bdrv->aiocb_size, bdrv->bdrv_aio_cancel);
+    bdrv->next = first_drv;
+    first_drv = bdrv;
+}
 
 /* create a new block device (by default it is empty) */
 BlockDriverState *bdrv_new(const char *device_name)
@@ -66,156 +160,331 @@ 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);
-    /* insert at the end */
-    pbs = &bdrv_first;
-    while (*pbs != NULL)
-        pbs = &(*pbs)->next;
-    *pbs = bs;
+    if (device_name[0] != '\0') {
+        /* insert at the end */
+        pbs = &bdrv_first;
+        while (*pbs != NULL)
+            pbs = &(*pbs)->next;
+        *pbs = bs;
+    }
     return bs;
 }
 
-int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)
+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_create2(BlockDriver *drv,
+                const char *filename, int64_t size_in_sectors,
+                const char *backing_file, const char *backing_format,
+                int flags)
+{
+    if (drv->bdrv_create2)
+        return drv->bdrv_create2(filename, size_in_sectors, backing_file,
+                                 backing_format, flags);
+    if (drv->bdrv_create)
+        return drv->bdrv_create(filename, size_in_sectors, backing_file,
+                                flags);
+    return -ENOTSUP;
+}
+
+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;
-    int64_t size;
-    struct cow_header_v2 cow_header;
-#ifndef _WIN32
-    char template[] = "/tmp/vl.XXXXXX";
-    int cow_fd;
-    struct stat st;
+    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
 
-    bs->read_only = 0;
-    bs->fd = -1;
-    bs->cow_fd = -1;
-    bs->cow_bitmap = NULL;
-    strcpy(bs->filename, filename);
+#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;
 
-    /* open standard HD image */
 #ifdef _WIN32
-    fd = open(filename, O_RDWR | O_BINARY);
-#else
-    fd = open(filename, O_RDWR | O_LARGEFILE);
+    if (is_windows_drive(filename) ||
+        is_windows_drive_prefix(filename))
+        return &bdrv_raw;
 #endif
-    if (fd < 0) {
-        /* read only image on disk */
+    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
-        fd = open(filename, O_RDONLY | O_BINARY);
+    if (is_windows_drive(filename))
+        return &bdrv_host_device;
 #else
-        fd = open(filename, O_RDONLY | O_LARGEFILE);
-#endif
-        if (fd < 0) {
-            perror(filename);
-            goto fail;
+    {
+        struct stat st;
+        if (stat(filename, &st) >= 0 &&
+            (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {
+            return &bdrv_host_device;
         }
-        if (!snapshot)
-            bs->read_only = 1;
     }
-    bs->fd = fd;
+#endif
 
-    /* see if it is a cow image */
-    if (read(fd, &cow_header, sizeof(cow_header)) != sizeof(cow_header)) {
-        fprintf(stderr, "%s: could not read header\n", filename);
-        goto fail;
+    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;
     }
-#ifndef _WIN32
-    if (be32_to_cpu(cow_header.magic) == COW_MAGIC &&
-        be32_to_cpu(cow_header.version) == COW_VERSION) {
-        /* cow image found */
-        size = cow_header.size;
-#ifndef WORDS_BIGENDIAN
-        size = bswap64(size);
-#endif    
-        bs->total_sectors = size / 512;
-
-        bs->cow_fd = fd;
-        bs->fd = -1;
-        if (cow_header.backing_file[0] != '\0') {
-            if (stat(cow_header.backing_file, &st) != 0) {
-                fprintf(stderr, "%s: could not find original disk image '%s'\n", filename, cow_header.backing_file);
-                goto fail;
-            }
-            if (st.st_mtime != be32_to_cpu(cow_header.mtime)) {
-                fprintf(stderr, "%s: original raw disk image '%s' does not match saved timestamp\n", filename, cow_header.backing_file);
-                goto fail;
+
+    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;
             }
-            fd = open(cow_header.backing_file, O_RDONLY | O_LARGEFILE);
-            if (fd < 0)
-                goto fail;
-            bs->fd = fd;
         }
-        /* mmap the bitmap */
-        bs->cow_bitmap_size = ((bs->total_sectors + 7) >> 3) + sizeof(cow_header);
-        bs->cow_bitmap_addr = mmap(get_mmap_addr(bs->cow_bitmap_size), 
-                                   bs->cow_bitmap_size, 
-                                   PROT_READ | PROT_WRITE,
-                                   MAP_SHARED, bs->cow_fd, 0);
-        if (bs->cow_bitmap_addr == MAP_FAILED)
-            goto fail;
-        bs->cow_bitmap = bs->cow_bitmap_addr + sizeof(cow_header);
-        bs->cow_sectors_offset = (bs->cow_bitmap_size + 511) & ~511;
-        snapshot = 0;
-    } else 
-#endif
-    {
-        /* standard raw image */
-        size = lseek64(fd, 0, SEEK_END);
-        bs->total_sectors = size / 512;
-        bs->fd = fd;
     }
+    return drv;
+}
+
+int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
+{
+    BlockDriverState *bs;
+    int ret;
+
+    bs = bdrv_new("");
+    ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
+    if (ret < 0) {
+        bdrv_delete(bs);
+        return ret;
+    }
+    bs->growable = 1;
+    *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;
+    bs->valid_key = 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("");
+        ret = bdrv_open2(bs1, filename, 0, drv);
+        if (ret < 0) {
+            bdrv_delete(bs1);
+            return ret;
+        }
+        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);
+
+        ret = bdrv_create2(&bdrv_qcow2, tmp_filename,
+                           total_size, backing_filename, 
+                           (drv ? drv->format_name : NULL), 0);
+        if (ret < 0) {
+            return ret;
+        }
+        filename = tmp_filename;
+        drv = &bdrv_qcow2;
+        bs->is_temporary = 1;
+    }
+
+    pstrcpy(bs->filename, sizeof(bs->filename), filename);
+    if (flags & BDRV_O_FILE) {
+        drv = find_protocol(filename);
+    } else if (!drv) {
+        drv = find_image_format(filename);
+    }
+    if (!drv) {
+        ret = -ENOENT;
+        goto unlink_and_fail;
+    }
+    bs->drv = drv;
+    bs->opaque = qemu_mallocz(drv->instance_size);
+    /* 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_CACHE_MASK);
+    else
+        open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
+    ret = drv->bdrv_open(bs, filename, open_flags);
+    if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) {
+        ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR);
+        bs->read_only = 1;
+    }
+    if (ret < 0) {
+        qemu_free(bs->opaque);
+        bs->opaque = NULL;
+        bs->drv = NULL;
+    unlink_and_fail:
+        if (bs->is_temporary)
+            unlink(filename);
+        return ret;
+    }
+    if (drv->bdrv_getlength) {
+        bs->total_sectors = bdrv_getlength(bs) >> SECTOR_BITS;
+    }
 #ifndef _WIN32
-    if (snapshot) {
-        /* create a temporary COW file */
-        cow_fd = mkstemp(template);
-        if (cow_fd < 0)
-            goto fail;
-        bs->cow_fd = cow_fd;
-       unlink(template);
-        
-        /* just need to allocate bitmap */
-        bs->cow_bitmap_size = (bs->total_sectors + 7) >> 3;
-        bs->cow_bitmap_addr = mmap(get_mmap_addr(bs->cow_bitmap_size), 
-                                   bs->cow_bitmap_size, 
-                                   PROT_READ | PROT_WRITE,
-                                   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-        if (bs->cow_bitmap_addr == MAP_FAILED)
-            goto fail;
-        bs->cow_bitmap = bs->cow_bitmap_addr;
-        bs->cow_sectors_offset = 0;
+    if (bs->is_temporary) {
+        unlink(filename);
     }
 #endif
-    
-    bs->inserted = 1;
-
-    /* call the change callback */
-    if (bs->change_cb)
-        bs->change_cb(bs->change_opaque);
+    if (bs->backing_file[0] != '\0') {
+        /* if there is a backing file, use it */
+        BlockDriver *back_drv = NULL;
+        bs->backing_hd = bdrv_new("");
+        path_combine(backing_filename, sizeof(backing_filename),
+                     filename, bs->backing_file);
+        if (bs->backing_format[0] != '\0')
+            back_drv = bdrv_find_format(bs->backing_format);
+        ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
+                         back_drv);
+        if (ret < 0) {
+            bdrv_close(bs);
+            return ret;
+        }
+    }
 
+    if (!bdrv_key_required(bs)) {
+        /* call the change callback */
+        bs->media_changed = 1;
+        if (bs->change_cb)
+            bs->change_cb(bs->change_opaque);
+    }
     return 0;
- fail:
-    bdrv_close(bs);
-    return -1;
 }
 
 void bdrv_close(BlockDriverState *bs)
 {
-    if (bs->inserted) {
-#ifndef _WIN32
-        /* we unmap the mapping so that it is written to the COW file */
-        if (bs->cow_bitmap_addr)
-            munmap(bs->cow_bitmap_addr, bs->cow_bitmap_size);
+    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
-        if (bs->cow_fd >= 0)
-            close(bs->cow_fd);
-        if (bs->fd >= 0)
-            close(bs->fd);
-        bs->inserted = 0;
+        bs->opaque = NULL;
+        bs->drv = NULL;
 
         /* call the change callback */
+        bs->media_changed = 1;
         if (bs->change_cb)
             bs->change_cb(bs->change_opaque);
     }
@@ -223,183 +492,377 @@ void bdrv_close(BlockDriverState *bs)
 
 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);
 }
 
-static inline void set_bit(uint8_t *bitmap, int64_t bitnum)
-{
-    bitmap[bitnum / 8] |= (1 << (bitnum%8));
-}
-
-static inline int is_bit_set(const uint8_t *bitmap, int64_t bitnum)
+/* commit COW file into the raw image */
+int bdrv_commit(BlockDriverState *bs)
 {
-    return !!(bitmap[bitnum / 8] & (1 << (bitnum%8)));
-}
+    BlockDriver *drv = bs->drv;
+    int64_t i, total_sectors;
+    int n, j;
+    unsigned char sector[512];
 
+    if (!drv)
+        return -ENOMEDIUM;
 
-/* Return true if first block has been changed (ie. current version is
- * in COW file).  Set the number of continuous blocks for which that
- * is true. */
-static int is_changed(uint8_t *bitmap,
-                      int64_t sector_num, int nb_sectors,
-                      int *num_same)
-{
-    int changed;
+    if (bs->read_only) {
+       return -EACCES;
+    }
 
-    if (!bitmap || nb_sectors == 0) {
-       *num_same = nb_sectors;
-       return 0;
+    if (!bs->backing_hd) {
+       return -ENOTSUP;
     }
 
-    changed = is_bit_set(bitmap, sector_num);
-    for (*num_same = 1; *num_same < nb_sectors; (*num_same)++) {
-       if (is_bit_set(bitmap, sector_num + *num_same) != changed)
-           break;
+    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;
+        }
     }
 
-    return changed;
+    if (drv->bdrv_make_empty)
+       return drv->bdrv_make_empty(bs);
+
+    return 0;
 }
 
-/* commit COW file into the raw image */
-int bdrv_commit(BlockDriverState *bs)
+static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
+                                   size_t size)
 {
-    int64_t i;
-    uint8_t *cow_bitmap;
+    int64_t len;
 
-    if (!bs->inserted)
-        return -1;
+    if (!bdrv_is_inserted(bs))
+        return -ENOMEDIUM;
 
-    if (!bs->cow_bitmap) {
-       fprintf(stderr, "Already committed to %s\n", bs->filename);
-       return 0;
-    }
+    if (bs->growable)
+        return 0;
 
-    if (bs->read_only) {
-       fprintf(stderr, "Can't commit to %s: read-only\n", bs->filename);
-       return -1;
-    }
-
-    cow_bitmap = bs->cow_bitmap;
-    for (i = 0; i < bs->total_sectors; i++) {
-       if (is_bit_set(cow_bitmap, i)) {
-           unsigned char sector[512];
-           if (bdrv_read(bs, i, sector, 1) != 0) {
-               fprintf(stderr, "Error reading sector %lli: aborting commit\n",
-                       (long long)i);
-               return -1;
-           }
+    len = bdrv_getlength(bs);
+
+    if ((offset + size) > len)
+        return -EIO;
 
-           /* Make bdrv_write write to real file for a moment. */
-           bs->cow_bitmap = NULL;
-           if (bdrv_write(bs, i, sector, 1) != 0) {
-               fprintf(stderr, "Error writing sector %lli: aborting commit\n",
-                       (long long)i);
-               bs->cow_bitmap = cow_bitmap;
-               return -1;
-           }
-           bs->cow_bitmap = cow_bitmap;
-       }
-    }
-    fprintf(stderr, "Committed snapshot to %s\n", bs->filename);
     return 0;
 }
 
-/* return -1 if error */
-int bdrv_read(BlockDriverState *bs, int64_t sector_num, 
-              uint8_t *buf, int nb_sectors)
+static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
+                              int nb_sectors)
 {
-    int ret, n, fd;
     int64_t offset;
-    
-    if (!bs->inserted)
-        return -1;
 
-    while (nb_sectors > 0) {
-        if (is_changed(bs->cow_bitmap, sector_num, nb_sectors, &n)) {
-            fd = bs->cow_fd;
-            offset = bs->cow_sectors_offset;
-        } else if (sector_num == 0 && bs->boot_sector_enabled) {
-            memcpy(buf, bs->boot_sector_data, 512);
-            n = 1;
-            goto next;
-        } else {
-            fd = bs->fd;
-            offset = 0;
-        }
+    /* Deal with byte accesses */
+    if (sector_num < 0)
+        offset = -sector_num;
+    else
+        offset = sector_num * 512;
 
-        if (fd < 0) {
-            /* no file, just return empty sectors */
-            memset(buf, 0, n * 512);
-        } else {
-            offset += sector_num * 512;
-            lseek64(fd, offset, SEEK_SET);
-            ret = read(fd, buf, n * 512);
-            if (ret != n * 512) {
-                return -1;
-            }
-        }
-    next:
-        nb_sectors -= n;
-        sector_num += n;
-        buf += n * 512;
-    }
-    return 0;
+    return bdrv_check_byte_request(bs, offset, nb_sectors * 512);
 }
 
-/* return -1 if error */
-int bdrv_write(BlockDriverState *bs, int64_t sector_num, 
+/* 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 (bdrv_check_request(bs, sector_num, nb_sectors))
+        return -EIO;
+
+    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)
 {
-    int ret, fd, i;
-    int64_t offset, retl;
-    
-    if (!bs->inserted)
-        return -1;
+    BlockDriver *drv = bs->drv;
+    if (!bs->drv)
+        return -ENOMEDIUM;
     if (bs->read_only)
-        return -1;
+        return -EACCES;
+    if (bdrv_check_request(bs, sector_num, nb_sectors))
+        return -EIO;
 
-    if (bs->cow_bitmap) {
-        fd = bs->cow_fd;
-        offset = bs->cow_sectors_offset;
-    } else {
-        fd = bs->fd;
-        offset = 0;
+    return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
+}
+
+int bdrv_pread(BlockDriverState *bs, int64_t offset,
+               void *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;
     }
-    
-    offset += sector_num * 512;
-    retl = lseek64(fd, offset, SEEK_SET);
-    if (retl == -1) {
-        return -1;
+
+    /* 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;
     }
-    ret = write(fd, buf, nb_sectors * 512);
-    if (ret != nb_sectors * 512) {
-        return -1;
+
+    /* 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;
+}
+
+int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
+                const void *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;
     }
 
-    if (bs->cow_bitmap) {
-       for (i = 0; i < nb_sectors; i++)
-           set_bit(bs->cow_bitmap, sector_num + i);
+    /* 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;
     }
-    return 0;
+
+    /* 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;
+}
+
+/**
+ * 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);
 }
 
-void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
+/**
+ * Length of a file in bytes. Return < 0 if error or unknown.
+ */
+int64_t bdrv_getlength(BlockDriverState *bs)
 {
-    *nb_sectors_ptr = bs->total_sectors;
+    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);
 }
 
-/* force a given boot sector. */
-void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
+/* return 0 as number of sectors if no device present or error */
+void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
 {
-    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);
+    int64_t length;
+    length = bdrv_getlength(bs);
+    if (length < 0)
+        length = 0;
+    else
+        length = length >> SECTOR_BITS;
+    *nb_sectors_ptr = length;
+}
+
+struct partition {
+        uint8_t boot_ind;           /* 0x80 - active */
+        uint8_t head;               /* starting head */
+        uint8_t sector;             /* starting sector */
+        uint8_t cyl;                /* starting cylinder */
+        uint8_t sys_ind;            /* What partition type */
+        uint8_t end_head;           /* end head */
+        uint8_t end_sector;         /* end sector */
+        uint8_t end_cyl;            /* end cylinder */
+        uint32_t start_sect;        /* starting sector counting from 0 */
+        uint32_t nr_sects;          /* nr of sectors in partition */
+} __attribute__((packed));
+
+/* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
+static int guess_disk_lchs(BlockDriverState *bs,
+                           int *pcylinders, int *pheads, int *psectors)
+{
+    uint8_t buf[512];
+    int ret, i, heads, sectors, cylinders;
+    struct partition *p;
+    uint32_t nr_sects;
+    uint64_t nb_sectors;
+
+    bdrv_get_geometry(bs, &nb_sectors);
+
+    ret = bdrv_read(bs, 0, buf, 1);
+    if (ret < 0)
+        return -1;
+    /* test msdos magic */
+    if (buf[510] != 0x55 || buf[511] != 0xaa)
+        return -1;
+    for(i = 0; i < 4; i++) {
+        p = ((struct partition *)(buf + 0x1be)) + i;
+        nr_sects = le32_to_cpu(p->nr_sects);
+        if (nr_sects && p->end_head) {
+            /* We make the assumption that the partition terminates on
+               a cylinder boundary */
+            heads = p->end_head + 1;
+            sectors = p->end_sector & 63;
+            if (sectors == 0)
+                continue;
+            cylinders = nb_sectors / (heads * sectors);
+            if (cylinders < 1 || cylinders > 16383)
+                continue;
+            *pheads = heads;
+            *psectors = sectors;
+            *pcylinders = cylinders;
+#if 0
+            printf("guessed geometry: LCHS=%d %d %d\n",
+                   cylinders, heads, sectors);
+#endif
+            return 0;
+        }
+    }
+    return -1;
+}
+
+void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
+{
+    int translation, lba_detected = 0;
+    int cylinders, heads, secs;
+    uint64_t nb_sectors;
+
+    /* if a geometry hint is available, use it */
+    bdrv_get_geometry(bs, &nb_sectors);
+    bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
+    translation = bdrv_get_translation_hint(bs);
+    if (cylinders != 0) {
+        *pcyls = cylinders;
+        *pheads = heads;
+        *psecs = secs;
+    } else {
+        if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
+            if (heads > 16) {
+                /* if heads > 16, it means that a BIOS LBA
+                   translation was active, so the default
+                   hardware geometry is OK */
+                lba_detected = 1;
+                goto default_geometry;
+            } else {
+                *pcyls = cylinders;
+                *pheads = heads;
+                *psecs = secs;
+                /* disable any translation to be in sync with
+                   the logical geometry */
+                if (translation == BIOS_ATA_TRANSLATION_AUTO) {
+                    bdrv_set_translation_hint(bs,
+                                              BIOS_ATA_TRANSLATION_NONE);
+                }
+            }
+        } else {
+        default_geometry:
+            /* if no geometry, use a standard physical disk geometry */
+            cylinders = nb_sectors / (16 * 63);
+
+            if (cylinders > 16383)
+                cylinders = 16383;
+            else if (cylinders < 2)
+                cylinders = 2;
+            *pcyls = cylinders;
+            *pheads = 16;
+            *psecs = 63;
+            if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
+                if ((*pcyls * *pheads) <= 131072) {
+                    bdrv_set_translation_hint(bs,
+                                              BIOS_ATA_TRANSLATION_LARGE);
+                } else {
+                    bdrv_set_translation_hint(bs,
+                                              BIOS_ATA_TRANSLATION_LBA);
+                }
+            }
+        }
+        bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
+    }
 }
 
-void bdrv_set_geometry_hint(BlockDriverState *bs, 
+void bdrv_set_geometry_hint(BlockDriverState *bs,
                             int cyls, int heads, int secs)
 {
     bs->cyls = cyls;
@@ -414,7 +877,12 @@ void bdrv_set_type_hint(BlockDriverState *bs, int type)
                       type == BDRV_TYPE_FLOPPY));
 }
 
-void bdrv_get_geometry_hint(BlockDriverState *bs, 
+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;
@@ -427,6 +895,11 @@ 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;
@@ -437,26 +910,77 @@ int bdrv_is_read_only(BlockDriverState *bs)
     return bs->read_only;
 }
 
-int bdrv_is_inserted(BlockDriverState *bs)
+int bdrv_is_sg(BlockDriverState *bs)
 {
-    return bs->inserted;
+    return bs->sg;
 }
 
-int bdrv_is_locked(BlockDriverState *bs)
+/* XXX: no longer used */
+void bdrv_set_change_cb(BlockDriverState *bs,
+                        void (*change_cb)(void *opaque), void *opaque)
 {
-    return bs->locked;
+    bs->change_cb = change_cb;
+    bs->change_opaque = opaque;
 }
 
-void bdrv_set_locked(BlockDriverState *bs, int locked)
+int bdrv_is_encrypted(BlockDriverState *bs)
 {
-    bs->locked = locked;
+    if (bs->backing_hd && bs->backing_hd->encrypted)
+        return 1;
+    return bs->encrypted;
 }
 
-void bdrv_set_change_cb(BlockDriverState *bs, 
-                        void (*change_cb)(void *opaque), void *opaque)
+int bdrv_key_required(BlockDriverState *bs)
 {
-    bs->change_cb = change_cb;
-    bs->change_opaque = opaque;
+    BlockDriverState *backing_hd = bs->backing_hd;
+
+    if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
+        return 1;
+    return (bs->encrypted && !bs->valid_key);
+}
+
+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;
+    ret = bs->drv->bdrv_set_key(bs, key);
+    if (ret < 0) {
+        bs->valid_key = 0;
+    } else if (!bs->valid_key) {
+        bs->valid_key = 1;
+        /* call the change callback now, we skipped it on open */
+        bs->media_changed = 1;
+        if (bs->change_cb)
+            bs->change_cb(bs->change_opaque);
+    }
+    return ret;
+}
+
+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)
@@ -470,34 +994,672 @@ BlockDriverState *bdrv_find(const char *name)
     return NULL;
 }
 
-void bdrv_info(void)
+void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
+{
+    BlockDriverState *bs;
+
+    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
+        it(opaque, bs);
+    }
+}
+
+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);
+}
+
+void bdrv_flush_all(void)
+{
+    BlockDriverState *bs;
+
+    for (bs = bdrv_first; bs != NULL; bs = bs->next)
+        if (bs->drv && !bdrv_is_read_only(bs) && 
+            (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
+            bdrv_flush(bs);
+}
+
+/*
+ * 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(Monitor *mon)
 {
     BlockDriverState *bs;
 
     for (bs = bdrv_first; bs != NULL; bs = bs->next) {
-        term_printf("%s:", bs->device_name);
-        term_printf(" type=");
+        monitor_printf(mon, "%s:", bs->device_name);
+        monitor_printf(mon, " type=");
         switch(bs->type) {
         case BDRV_TYPE_HD:
-            term_printf("hd");
+            monitor_printf(mon, "hd");
             break;
         case BDRV_TYPE_CDROM:
-            term_printf("cdrom");
+            monitor_printf(mon, "cdrom");
             break;
         case BDRV_TYPE_FLOPPY:
-            term_printf("floppy");
+            monitor_printf(mon, "floppy");
             break;
         }
-        term_printf(" removable=%d", bs->removable);
+        monitor_printf(mon, " removable=%d", bs->removable);
         if (bs->removable) {
-            term_printf(" locked=%d", bs->locked);
+            monitor_printf(mon, " locked=%d", bs->locked);
         }
-        if (bs->inserted) {
-            term_printf(" file=%s", bs->filename);
-            term_printf(" ro=%d", bs->read_only);
+        if (bs->drv) {
+            monitor_printf(mon, " file=");
+            monitor_print_filename(mon, bs->filename);
+            if (bs->backing_file[0] != '\0') {
+                monitor_printf(mon, " backing_file=");
+                monitor_print_filename(mon, bs->backing_file);
+            }
+            monitor_printf(mon, " ro=%d", bs->read_only);
+            monitor_printf(mon, " drv=%s", bs->drv->format_name);
+            monitor_printf(mon, " encrypted=%d", bdrv_is_encrypted(bs));
         } else {
-            term_printf(" [not inserted]");
+            monitor_printf(mon, " [not inserted]");
+        }
+        monitor_printf(mon, "\n");
+    }
+}
+
+/* The "info blockstats" command. */
+void bdrv_info_stats(Monitor *mon)
+{
+    BlockDriverState *bs;
+
+    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
+        monitor_printf(mon, "%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);
+    }
+}
+
+const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
+{
+    if (bs->backing_hd && bs->backing_hd->encrypted)
+        return bs->backing_file;
+    else if (bs->encrypted)
+        return bs->filename;
+    else
+        return NULL;
+}
+
+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;
         }
-        term_printf("\n");
     }
+    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 */
+
+typedef struct VectorTranslationAIOCB {
+    BlockDriverAIOCB common;
+    QEMUIOVector *iov;
+    uint8_t *bounce;
+    int is_write;
+    BlockDriverAIOCB *aiocb;
+} VectorTranslationAIOCB;
+
+static void bdrv_aio_cancel_vector(BlockDriverAIOCB *_acb)
+{
+    VectorTranslationAIOCB *acb
+        = container_of(_acb, VectorTranslationAIOCB, common);
+
+    bdrv_aio_cancel(acb->aiocb);
+}
+
+static void bdrv_aio_rw_vector_cb(void *opaque, int ret)
+{
+    VectorTranslationAIOCB *s = (VectorTranslationAIOCB *)opaque;
+
+    if (!s->is_write) {
+        qemu_iovec_from_buffer(s->iov, s->bounce, s->iov->size);
+    }
+    qemu_vfree(s->bounce);
+    s->common.cb(s->common.opaque, ret);
+    qemu_aio_release(s);
+}
+
+static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
+                                            int64_t sector_num,
+                                            QEMUIOVector *iov,
+                                            int nb_sectors,
+                                            BlockDriverCompletionFunc *cb,
+                                            void *opaque,
+                                            int is_write)
+
+{
+    VectorTranslationAIOCB *s = qemu_aio_get_pool(&vectored_aio_pool, bs,
+                                                  cb, opaque);
+
+    s->iov = iov;
+    s->bounce = qemu_memalign(512, nb_sectors * 512);
+    s->is_write = is_write;
+    if (is_write) {
+        qemu_iovec_to_buffer(s->iov, s->bounce);
+        s->aiocb = bdrv_aio_write(bs, sector_num, s->bounce, nb_sectors,
+                                  bdrv_aio_rw_vector_cb, s);
+    } else {
+        s->aiocb = bdrv_aio_read(bs, sector_num, s->bounce, nb_sectors,
+                                 bdrv_aio_rw_vector_cb, s);
+    }
+    if (!s->aiocb) {
+        qemu_vfree(s->bounce);
+        qemu_aio_release(s);
+        return NULL;
+    }
+    return &s->common;
+}
+
+BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
+                                 QEMUIOVector *iov, int nb_sectors,
+                                 BlockDriverCompletionFunc *cb, void *opaque)
+{
+    if (bdrv_check_request(bs, sector_num, nb_sectors))
+        return NULL;
+
+    return bdrv_aio_rw_vector(bs, sector_num, iov, nb_sectors,
+                              cb, opaque, 0);
+}
+
+BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
+                                  QEMUIOVector *iov, int nb_sectors,
+                                  BlockDriverCompletionFunc *cb, void *opaque)
+{
+    if (bdrv_check_request(bs, sector_num, nb_sectors))
+        return NULL;
+
+    return bdrv_aio_rw_vector(bs, sector_num, iov, nb_sectors,
+                              cb, opaque, 1);
+}
+
+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;
+    if (bdrv_check_request(bs, sector_num, nb_sectors))
+        return NULL;
+
+    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 (bdrv_check_request(bs, sector_num, nb_sectors))
+        return NULL;
+
+    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)
+{
+    acb->pool->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)
+{
+    aio_pool_init(&vectored_aio_pool, sizeof(VectorTranslationAIOCB),
+                  bdrv_aio_cancel_vector);
+
+    bdrv_register(&bdrv_raw);
+    bdrv_register(&bdrv_host_device);
+#ifndef _WIN32
+    bdrv_register(&bdrv_cow);
+#endif
+    bdrv_register(&bdrv_qcow);
+    bdrv_register(&bdrv_vmdk);
+    bdrv_register(&bdrv_cloop);
+    bdrv_register(&bdrv_dmg);
+    bdrv_register(&bdrv_bochs);
+    bdrv_register(&bdrv_vpc);
+    bdrv_register(&bdrv_vvfat);
+    bdrv_register(&bdrv_qcow2);
+    bdrv_register(&bdrv_parallels);
+    bdrv_register(&bdrv_nbd);
+}
+
+void aio_pool_init(AIOPool *pool, int aiocb_size,
+                   void (*cancel)(BlockDriverAIOCB *acb))
+{
+    pool->aiocb_size = aiocb_size;
+    pool->cancel = cancel;
+    pool->free_aiocb = NULL;
+}
+
+void *qemu_aio_get_pool(AIOPool *pool, BlockDriverState *bs,
+                        BlockDriverCompletionFunc *cb, void *opaque)
+{
+    BlockDriverAIOCB *acb;
+
+    if (pool->free_aiocb) {
+        acb = pool->free_aiocb;
+        pool->free_aiocb = acb->next;
+    } else {
+        acb = qemu_mallocz(pool->aiocb_size);
+        acb->pool = pool;
+    }
+    acb->bs = bs;
+    acb->cb = cb;
+    acb->opaque = opaque;
+    return acb;
+}
+
+void *qemu_aio_get(BlockDriverState *bs, BlockDriverCompletionFunc *cb,
+                   void *opaque)
+{
+    return qemu_aio_get_pool(&bs->drv->aio_pool, bs, cb, opaque);
+}
+
+void qemu_aio_release(void *p)
+{
+    BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
+    AIOPool *pool = acb->pool;
+    acb->next = pool->free_aiocb;
+    pool->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;
+}
+
+BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
+        unsigned long int req, void *buf,
+        BlockDriverCompletionFunc *cb, void *opaque)
+{
+    BlockDriver *drv = bs->drv;
+
+    if (drv && drv->bdrv_aio_ioctl)
+        return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
+    return NULL;
 }