cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

parallels.c (29329B)


      1/*
      2 * Block driver for Parallels disk image format
      3 *
      4 * Copyright (c) 2007 Alex Beregszaszi
      5 * Copyright (c) 2015 Denis V. Lunev <den@openvz.org>
      6 *
      7 * This code was originally based on comparing different disk images created
      8 * by Parallels. Currently it is based on opened OpenVZ sources
      9 * available at
     10 *     http://git.openvz.org/?p=ploop;a=summary
     11 *
     12 * Permission is hereby granted, free of charge, to any person obtaining a copy
     13 * of this software and associated documentation files (the "Software"), to deal
     14 * in the Software without restriction, including without limitation the rights
     15 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     16 * copies of the Software, and to permit persons to whom the Software is
     17 * furnished to do so, subject to the following conditions:
     18 *
     19 * The above copyright notice and this permission notice shall be included in
     20 * all copies or substantial portions of the Software.
     21 *
     22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     23 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     24 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     25 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     26 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     27 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     28 * THE SOFTWARE.
     29 */
     30
     31#include "qemu/osdep.h"
     32#include "qemu/error-report.h"
     33#include "qapi/error.h"
     34#include "block/block_int.h"
     35#include "block/qdict.h"
     36#include "sysemu/block-backend.h"
     37#include "qemu/module.h"
     38#include "qemu/option.h"
     39#include "qapi/qmp/qdict.h"
     40#include "qapi/qobject-input-visitor.h"
     41#include "qapi/qapi-visit-block-core.h"
     42#include "qemu/bswap.h"
     43#include "qemu/bitmap.h"
     44#include "migration/blocker.h"
     45#include "parallels.h"
     46
     47/**************************************************************/
     48
     49#define HEADER_MAGIC "WithoutFreeSpace"
     50#define HEADER_MAGIC2 "WithouFreSpacExt"
     51#define HEADER_VERSION 2
     52#define HEADER_INUSE_MAGIC  (0x746F6E59)
     53#define MAX_PARALLELS_IMAGE_FACTOR (1ull << 32)
     54
     55static QEnumLookup prealloc_mode_lookup = {
     56    .array = (const char *const[]) {
     57        "falloc",
     58        "truncate",
     59    },
     60    .size = PRL_PREALLOC_MODE__MAX
     61};
     62
     63#define PARALLELS_OPT_PREALLOC_MODE     "prealloc-mode"
     64#define PARALLELS_OPT_PREALLOC_SIZE     "prealloc-size"
     65
     66static QemuOptsList parallels_runtime_opts = {
     67    .name = "parallels",
     68    .head = QTAILQ_HEAD_INITIALIZER(parallels_runtime_opts.head),
     69    .desc = {
     70        {
     71            .name = PARALLELS_OPT_PREALLOC_SIZE,
     72            .type = QEMU_OPT_SIZE,
     73            .help = "Preallocation size on image expansion",
     74            .def_value_str = "128M",
     75        },
     76        {
     77            .name = PARALLELS_OPT_PREALLOC_MODE,
     78            .type = QEMU_OPT_STRING,
     79            .help = "Preallocation mode on image expansion "
     80                    "(allowed values: falloc, truncate)",
     81            .def_value_str = "falloc",
     82        },
     83        { /* end of list */ },
     84    },
     85};
     86
     87static QemuOptsList parallels_create_opts = {
     88    .name = "parallels-create-opts",
     89    .head = QTAILQ_HEAD_INITIALIZER(parallels_create_opts.head),
     90    .desc = {
     91        {
     92            .name = BLOCK_OPT_SIZE,
     93            .type = QEMU_OPT_SIZE,
     94            .help = "Virtual disk size",
     95        },
     96        {
     97            .name = BLOCK_OPT_CLUSTER_SIZE,
     98            .type = QEMU_OPT_SIZE,
     99            .help = "Parallels image cluster size",
    100            .def_value_str = stringify(DEFAULT_CLUSTER_SIZE),
    101        },
    102        { /* end of list */ }
    103    }
    104};
    105
    106
    107static int64_t bat2sect(BDRVParallelsState *s, uint32_t idx)
    108{
    109    return (uint64_t)le32_to_cpu(s->bat_bitmap[idx]) * s->off_multiplier;
    110}
    111
    112static uint32_t bat_entry_off(uint32_t idx)
    113{
    114    return sizeof(ParallelsHeader) + sizeof(uint32_t) * idx;
    115}
    116
    117static int64_t seek_to_sector(BDRVParallelsState *s, int64_t sector_num)
    118{
    119    uint32_t index, offset;
    120
    121    index = sector_num / s->tracks;
    122    offset = sector_num % s->tracks;
    123
    124    /* not allocated */
    125    if ((index >= s->bat_size) || (s->bat_bitmap[index] == 0)) {
    126        return -1;
    127    }
    128    return bat2sect(s, index) + offset;
    129}
    130
    131static int cluster_remainder(BDRVParallelsState *s, int64_t sector_num,
    132        int nb_sectors)
    133{
    134    int ret = s->tracks - sector_num % s->tracks;
    135    return MIN(nb_sectors, ret);
    136}
    137
    138static int64_t block_status(BDRVParallelsState *s, int64_t sector_num,
    139                            int nb_sectors, int *pnum)
    140{
    141    int64_t start_off = -2, prev_end_off = -2;
    142
    143    *pnum = 0;
    144    while (nb_sectors > 0 || start_off == -2) {
    145        int64_t offset = seek_to_sector(s, sector_num);
    146        int to_end;
    147
    148        if (start_off == -2) {
    149            start_off = offset;
    150            prev_end_off = offset;
    151        } else if (offset != prev_end_off) {
    152            break;
    153        }
    154
    155        to_end = cluster_remainder(s, sector_num, nb_sectors);
    156        nb_sectors -= to_end;
    157        sector_num += to_end;
    158        *pnum += to_end;
    159
    160        if (offset > 0) {
    161            prev_end_off += to_end;
    162        }
    163    }
    164    return start_off;
    165}
    166
    167static int64_t allocate_clusters(BlockDriverState *bs, int64_t sector_num,
    168                                 int nb_sectors, int *pnum)
    169{
    170    int ret = 0;
    171    BDRVParallelsState *s = bs->opaque;
    172    int64_t pos, space, idx, to_allocate, i, len;
    173
    174    pos = block_status(s, sector_num, nb_sectors, pnum);
    175    if (pos > 0) {
    176        return pos;
    177    }
    178
    179    idx = sector_num / s->tracks;
    180    to_allocate = DIV_ROUND_UP(sector_num + *pnum, s->tracks) - idx;
    181
    182    /* This function is called only by parallels_co_writev(), which will never
    183     * pass a sector_num at or beyond the end of the image (because the block
    184     * layer never passes such a sector_num to that function). Therefore, idx
    185     * is always below s->bat_size.
    186     * block_status() will limit *pnum so that sector_num + *pnum will not
    187     * exceed the image end. Therefore, idx + to_allocate cannot exceed
    188     * s->bat_size.
    189     * Note that s->bat_size is an unsigned int, therefore idx + to_allocate
    190     * will always fit into a uint32_t. */
    191    assert(idx < s->bat_size && idx + to_allocate <= s->bat_size);
    192
    193    space = to_allocate * s->tracks;
    194    len = bdrv_getlength(bs->file->bs);
    195    if (len < 0) {
    196        return len;
    197    }
    198    if (s->data_end + space > (len >> BDRV_SECTOR_BITS)) {
    199        space += s->prealloc_size;
    200        /*
    201         * We require the expanded size to read back as zero. If the
    202         * user permitted truncation, we try that; but if it fails, we
    203         * force the safer-but-slower fallocate.
    204         */
    205        if (s->prealloc_mode == PRL_PREALLOC_MODE_TRUNCATE) {
    206            ret = bdrv_truncate(bs->file,
    207                                (s->data_end + space) << BDRV_SECTOR_BITS,
    208                                false, PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE,
    209                                NULL);
    210            if (ret == -ENOTSUP) {
    211                s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
    212            }
    213        }
    214        if (s->prealloc_mode == PRL_PREALLOC_MODE_FALLOCATE) {
    215            ret = bdrv_pwrite_zeroes(bs->file,
    216                                     s->data_end << BDRV_SECTOR_BITS,
    217                                     space << BDRV_SECTOR_BITS, 0);
    218        }
    219        if (ret < 0) {
    220            return ret;
    221        }
    222    }
    223
    224    /* Try to read from backing to fill empty clusters
    225     * FIXME: 1. previous write_zeroes may be redundant
    226     *        2. most of data we read from backing will be rewritten by
    227     *           parallels_co_writev. On aligned-to-cluster write we do not need
    228     *           this read at all.
    229     *        3. it would be good to combine write of data from backing and new
    230     *           data into one write call */
    231    if (bs->backing) {
    232        int64_t nb_cow_sectors = to_allocate * s->tracks;
    233        int64_t nb_cow_bytes = nb_cow_sectors << BDRV_SECTOR_BITS;
    234        void *buf = qemu_blockalign(bs, nb_cow_bytes);
    235
    236        ret = bdrv_co_pread(bs->backing, idx * s->tracks * BDRV_SECTOR_SIZE,
    237                            nb_cow_bytes, buf, 0);
    238        if (ret < 0) {
    239            qemu_vfree(buf);
    240            return ret;
    241        }
    242
    243        ret = bdrv_co_pwritev(bs->file, s->data_end * BDRV_SECTOR_SIZE,
    244                              nb_cow_bytes, buf, 0);
    245        qemu_vfree(buf);
    246        if (ret < 0) {
    247            return ret;
    248        }
    249    }
    250
    251    for (i = 0; i < to_allocate; i++) {
    252        s->bat_bitmap[idx + i] = cpu_to_le32(s->data_end / s->off_multiplier);
    253        s->data_end += s->tracks;
    254        bitmap_set(s->bat_dirty_bmap,
    255                   bat_entry_off(idx + i) / s->bat_dirty_block, 1);
    256    }
    257
    258    return bat2sect(s, idx) + sector_num % s->tracks;
    259}
    260
    261
    262static coroutine_fn int parallels_co_flush_to_os(BlockDriverState *bs)
    263{
    264    BDRVParallelsState *s = bs->opaque;
    265    unsigned long size = DIV_ROUND_UP(s->header_size, s->bat_dirty_block);
    266    unsigned long bit;
    267
    268    qemu_co_mutex_lock(&s->lock);
    269
    270    bit = find_first_bit(s->bat_dirty_bmap, size);
    271    while (bit < size) {
    272        uint32_t off = bit * s->bat_dirty_block;
    273        uint32_t to_write = s->bat_dirty_block;
    274        int ret;
    275
    276        if (off + to_write > s->header_size) {
    277            to_write = s->header_size - off;
    278        }
    279        ret = bdrv_pwrite(bs->file, off, (uint8_t *)s->header + off,
    280                          to_write);
    281        if (ret < 0) {
    282            qemu_co_mutex_unlock(&s->lock);
    283            return ret;
    284        }
    285        bit = find_next_bit(s->bat_dirty_bmap, size, bit + 1);
    286    }
    287    bitmap_zero(s->bat_dirty_bmap, size);
    288
    289    qemu_co_mutex_unlock(&s->lock);
    290    return 0;
    291}
    292
    293
    294static int coroutine_fn parallels_co_block_status(BlockDriverState *bs,
    295                                                  bool want_zero,
    296                                                  int64_t offset,
    297                                                  int64_t bytes,
    298                                                  int64_t *pnum,
    299                                                  int64_t *map,
    300                                                  BlockDriverState **file)
    301{
    302    BDRVParallelsState *s = bs->opaque;
    303    int count;
    304
    305    assert(QEMU_IS_ALIGNED(offset | bytes, BDRV_SECTOR_SIZE));
    306    qemu_co_mutex_lock(&s->lock);
    307    offset = block_status(s, offset >> BDRV_SECTOR_BITS,
    308                          bytes >> BDRV_SECTOR_BITS, &count);
    309    qemu_co_mutex_unlock(&s->lock);
    310
    311    *pnum = count * BDRV_SECTOR_SIZE;
    312    if (offset < 0) {
    313        return 0;
    314    }
    315
    316    *map = offset * BDRV_SECTOR_SIZE;
    317    *file = bs->file->bs;
    318    return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
    319}
    320
    321static coroutine_fn int parallels_co_writev(BlockDriverState *bs,
    322                                            int64_t sector_num, int nb_sectors,
    323                                            QEMUIOVector *qiov, int flags)
    324{
    325    BDRVParallelsState *s = bs->opaque;
    326    uint64_t bytes_done = 0;
    327    QEMUIOVector hd_qiov;
    328    int ret = 0;
    329
    330    assert(!flags);
    331    qemu_iovec_init(&hd_qiov, qiov->niov);
    332
    333    while (nb_sectors > 0) {
    334        int64_t position;
    335        int n, nbytes;
    336
    337        qemu_co_mutex_lock(&s->lock);
    338        position = allocate_clusters(bs, sector_num, nb_sectors, &n);
    339        qemu_co_mutex_unlock(&s->lock);
    340        if (position < 0) {
    341            ret = (int)position;
    342            break;
    343        }
    344
    345        nbytes = n << BDRV_SECTOR_BITS;
    346
    347        qemu_iovec_reset(&hd_qiov);
    348        qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
    349
    350        ret = bdrv_co_pwritev(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
    351                              &hd_qiov, 0);
    352        if (ret < 0) {
    353            break;
    354        }
    355
    356        nb_sectors -= n;
    357        sector_num += n;
    358        bytes_done += nbytes;
    359    }
    360
    361    qemu_iovec_destroy(&hd_qiov);
    362    return ret;
    363}
    364
    365static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
    366        int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
    367{
    368    BDRVParallelsState *s = bs->opaque;
    369    uint64_t bytes_done = 0;
    370    QEMUIOVector hd_qiov;
    371    int ret = 0;
    372
    373    qemu_iovec_init(&hd_qiov, qiov->niov);
    374
    375    while (nb_sectors > 0) {
    376        int64_t position;
    377        int n, nbytes;
    378
    379        qemu_co_mutex_lock(&s->lock);
    380        position = block_status(s, sector_num, nb_sectors, &n);
    381        qemu_co_mutex_unlock(&s->lock);
    382
    383        nbytes = n << BDRV_SECTOR_BITS;
    384
    385        qemu_iovec_reset(&hd_qiov);
    386        qemu_iovec_concat(&hd_qiov, qiov, bytes_done, nbytes);
    387
    388        if (position < 0) {
    389            if (bs->backing) {
    390                ret = bdrv_co_preadv(bs->backing, sector_num * BDRV_SECTOR_SIZE,
    391                                     nbytes, &hd_qiov, 0);
    392                if (ret < 0) {
    393                    break;
    394                }
    395            } else {
    396                qemu_iovec_memset(&hd_qiov, 0, 0, nbytes);
    397            }
    398        } else {
    399            ret = bdrv_co_preadv(bs->file, position * BDRV_SECTOR_SIZE, nbytes,
    400                                 &hd_qiov, 0);
    401            if (ret < 0) {
    402                break;
    403            }
    404        }
    405
    406        nb_sectors -= n;
    407        sector_num += n;
    408        bytes_done += nbytes;
    409    }
    410
    411    qemu_iovec_destroy(&hd_qiov);
    412    return ret;
    413}
    414
    415
    416static int coroutine_fn parallels_co_check(BlockDriverState *bs,
    417                                           BdrvCheckResult *res,
    418                                           BdrvCheckMode fix)
    419{
    420    BDRVParallelsState *s = bs->opaque;
    421    int64_t size, prev_off, high_off;
    422    int ret;
    423    uint32_t i;
    424    bool flush_bat = false;
    425
    426    size = bdrv_getlength(bs->file->bs);
    427    if (size < 0) {
    428        res->check_errors++;
    429        return size;
    430    }
    431
    432    qemu_co_mutex_lock(&s->lock);
    433    if (s->header_unclean) {
    434        fprintf(stderr, "%s image was not closed correctly\n",
    435                fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
    436        res->corruptions++;
    437        if (fix & BDRV_FIX_ERRORS) {
    438            /* parallels_close will do the job right */
    439            res->corruptions_fixed++;
    440            s->header_unclean = false;
    441        }
    442    }
    443
    444    res->bfi.total_clusters = s->bat_size;
    445    res->bfi.compressed_clusters = 0; /* compression is not supported */
    446
    447    high_off = 0;
    448    prev_off = 0;
    449    for (i = 0; i < s->bat_size; i++) {
    450        int64_t off = bat2sect(s, i) << BDRV_SECTOR_BITS;
    451        if (off == 0) {
    452            prev_off = 0;
    453            continue;
    454        }
    455
    456        /* cluster outside the image */
    457        if (off > size) {
    458            fprintf(stderr, "%s cluster %u is outside image\n",
    459                    fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
    460            res->corruptions++;
    461            if (fix & BDRV_FIX_ERRORS) {
    462                prev_off = 0;
    463                s->bat_bitmap[i] = 0;
    464                res->corruptions_fixed++;
    465                flush_bat = true;
    466                continue;
    467            }
    468        }
    469
    470        res->bfi.allocated_clusters++;
    471        if (off > high_off) {
    472            high_off = off;
    473        }
    474
    475        if (prev_off != 0 && (prev_off + s->cluster_size) != off) {
    476            res->bfi.fragmented_clusters++;
    477        }
    478        prev_off = off;
    479    }
    480
    481    ret = 0;
    482    if (flush_bat) {
    483        ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
    484        if (ret < 0) {
    485            res->check_errors++;
    486            goto out;
    487        }
    488    }
    489
    490    res->image_end_offset = high_off + s->cluster_size;
    491    if (size > res->image_end_offset) {
    492        int64_t count;
    493        count = DIV_ROUND_UP(size - res->image_end_offset, s->cluster_size);
    494        fprintf(stderr, "%s space leaked at the end of the image %" PRId64 "\n",
    495                fix & BDRV_FIX_LEAKS ? "Repairing" : "ERROR",
    496                size - res->image_end_offset);
    497        res->leaks += count;
    498        if (fix & BDRV_FIX_LEAKS) {
    499            Error *local_err = NULL;
    500
    501            /*
    502             * In order to really repair the image, we must shrink it.
    503             * That means we have to pass exact=true.
    504             */
    505            ret = bdrv_truncate(bs->file, res->image_end_offset, true,
    506                                PREALLOC_MODE_OFF, 0, &local_err);
    507            if (ret < 0) {
    508                error_report_err(local_err);
    509                res->check_errors++;
    510                goto out;
    511            }
    512            res->leaks_fixed += count;
    513        }
    514    }
    515
    516out:
    517    qemu_co_mutex_unlock(&s->lock);
    518    return ret;
    519}
    520
    521
    522static int coroutine_fn parallels_co_create(BlockdevCreateOptions* opts,
    523                                            Error **errp)
    524{
    525    BlockdevCreateOptionsParallels *parallels_opts;
    526    BlockDriverState *bs;
    527    BlockBackend *blk;
    528    int64_t total_size, cl_size;
    529    uint32_t bat_entries, bat_sectors;
    530    ParallelsHeader header;
    531    uint8_t tmp[BDRV_SECTOR_SIZE];
    532    int ret;
    533
    534    assert(opts->driver == BLOCKDEV_DRIVER_PARALLELS);
    535    parallels_opts = &opts->u.parallels;
    536
    537    /* Sanity checks */
    538    total_size = parallels_opts->size;
    539
    540    if (parallels_opts->has_cluster_size) {
    541        cl_size = parallels_opts->cluster_size;
    542    } else {
    543        cl_size = DEFAULT_CLUSTER_SIZE;
    544    }
    545
    546    /* XXX What is the real limit here? This is an insanely large maximum. */
    547    if (cl_size >= INT64_MAX / MAX_PARALLELS_IMAGE_FACTOR) {
    548        error_setg(errp, "Cluster size is too large");
    549        return -EINVAL;
    550    }
    551    if (total_size >= MAX_PARALLELS_IMAGE_FACTOR * cl_size) {
    552        error_setg(errp, "Image size is too large for this cluster size");
    553        return -E2BIG;
    554    }
    555
    556    if (!QEMU_IS_ALIGNED(total_size, BDRV_SECTOR_SIZE)) {
    557        error_setg(errp, "Image size must be a multiple of 512 bytes");
    558        return -EINVAL;
    559    }
    560
    561    if (!QEMU_IS_ALIGNED(cl_size, BDRV_SECTOR_SIZE)) {
    562        error_setg(errp, "Cluster size must be a multiple of 512 bytes");
    563        return -EINVAL;
    564    }
    565
    566    /* Create BlockBackend to write to the image */
    567    bs = bdrv_open_blockdev_ref(parallels_opts->file, errp);
    568    if (bs == NULL) {
    569        return -EIO;
    570    }
    571
    572    blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
    573                          errp);
    574    if (!blk) {
    575        ret = -EPERM;
    576        goto out;
    577    }
    578    blk_set_allow_write_beyond_eof(blk, true);
    579
    580    /* Create image format */
    581    bat_entries = DIV_ROUND_UP(total_size, cl_size);
    582    bat_sectors = DIV_ROUND_UP(bat_entry_off(bat_entries), cl_size);
    583    bat_sectors = (bat_sectors *  cl_size) >> BDRV_SECTOR_BITS;
    584
    585    memset(&header, 0, sizeof(header));
    586    memcpy(header.magic, HEADER_MAGIC2, sizeof(header.magic));
    587    header.version = cpu_to_le32(HEADER_VERSION);
    588    /* don't care much about geometry, it is not used on image level */
    589    header.heads = cpu_to_le32(HEADS_NUMBER);
    590    header.cylinders = cpu_to_le32(total_size / BDRV_SECTOR_SIZE
    591                                   / HEADS_NUMBER / SEC_IN_CYL);
    592    header.tracks = cpu_to_le32(cl_size >> BDRV_SECTOR_BITS);
    593    header.bat_entries = cpu_to_le32(bat_entries);
    594    header.nb_sectors = cpu_to_le64(DIV_ROUND_UP(total_size, BDRV_SECTOR_SIZE));
    595    header.data_off = cpu_to_le32(bat_sectors);
    596
    597    /* write all the data */
    598    memset(tmp, 0, sizeof(tmp));
    599    memcpy(tmp, &header, sizeof(header));
    600
    601    ret = blk_pwrite(blk, 0, tmp, BDRV_SECTOR_SIZE, 0);
    602    if (ret < 0) {
    603        goto exit;
    604    }
    605    ret = blk_pwrite_zeroes(blk, BDRV_SECTOR_SIZE,
    606                            (bat_sectors - 1) << BDRV_SECTOR_BITS, 0);
    607    if (ret < 0) {
    608        goto exit;
    609    }
    610
    611    ret = 0;
    612out:
    613    blk_unref(blk);
    614    bdrv_unref(bs);
    615    return ret;
    616
    617exit:
    618    error_setg_errno(errp, -ret, "Failed to create Parallels image");
    619    goto out;
    620}
    621
    622static int coroutine_fn parallels_co_create_opts(BlockDriver *drv,
    623                                                 const char *filename,
    624                                                 QemuOpts *opts,
    625                                                 Error **errp)
    626{
    627    BlockdevCreateOptions *create_options = NULL;
    628    BlockDriverState *bs = NULL;
    629    QDict *qdict;
    630    Visitor *v;
    631    int ret;
    632
    633    static const QDictRenames opt_renames[] = {
    634        { BLOCK_OPT_CLUSTER_SIZE,       "cluster-size" },
    635        { NULL, NULL },
    636    };
    637
    638    /* Parse options and convert legacy syntax */
    639    qdict = qemu_opts_to_qdict_filtered(opts, NULL, &parallels_create_opts,
    640                                        true);
    641
    642    if (!qdict_rename_keys(qdict, opt_renames, errp)) {
    643        ret = -EINVAL;
    644        goto done;
    645    }
    646
    647    /* Create and open the file (protocol layer) */
    648    ret = bdrv_create_file(filename, opts, errp);
    649    if (ret < 0) {
    650        goto done;
    651    }
    652
    653    bs = bdrv_open(filename, NULL, NULL,
    654                   BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
    655    if (bs == NULL) {
    656        ret = -EIO;
    657        goto done;
    658    }
    659
    660    /* Now get the QAPI type BlockdevCreateOptions */
    661    qdict_put_str(qdict, "driver", "parallels");
    662    qdict_put_str(qdict, "file", bs->node_name);
    663
    664    v = qobject_input_visitor_new_flat_confused(qdict, errp);
    665    if (!v) {
    666        ret = -EINVAL;
    667        goto done;
    668    }
    669
    670    visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
    671    visit_free(v);
    672    if (!create_options) {
    673        ret = -EINVAL;
    674        goto done;
    675    }
    676
    677    /* Silently round up sizes */
    678    create_options->u.parallels.size =
    679        ROUND_UP(create_options->u.parallels.size, BDRV_SECTOR_SIZE);
    680    create_options->u.parallels.cluster_size =
    681        ROUND_UP(create_options->u.parallels.cluster_size, BDRV_SECTOR_SIZE);
    682
    683    /* Create the Parallels image (format layer) */
    684    ret = parallels_co_create(create_options, errp);
    685    if (ret < 0) {
    686        goto done;
    687    }
    688    ret = 0;
    689
    690done:
    691    qobject_unref(qdict);
    692    bdrv_unref(bs);
    693    qapi_free_BlockdevCreateOptions(create_options);
    694    return ret;
    695}
    696
    697
    698static int parallels_probe(const uint8_t *buf, int buf_size,
    699                           const char *filename)
    700{
    701    const ParallelsHeader *ph = (const void *)buf;
    702
    703    if (buf_size < sizeof(ParallelsHeader)) {
    704        return 0;
    705    }
    706
    707    if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
    708           !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
    709           (le32_to_cpu(ph->version) == HEADER_VERSION)) {
    710        return 100;
    711    }
    712
    713    return 0;
    714}
    715
    716static int parallels_update_header(BlockDriverState *bs)
    717{
    718    BDRVParallelsState *s = bs->opaque;
    719    unsigned size = MAX(bdrv_opt_mem_align(bs->file->bs),
    720                        sizeof(ParallelsHeader));
    721
    722    if (size > s->header_size) {
    723        size = s->header_size;
    724    }
    725    return bdrv_pwrite_sync(bs->file, 0, s->header, size);
    726}
    727
    728static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
    729                          Error **errp)
    730{
    731    BDRVParallelsState *s = bs->opaque;
    732    ParallelsHeader ph;
    733    int ret, size, i;
    734    QemuOpts *opts = NULL;
    735    Error *local_err = NULL;
    736    char *buf;
    737
    738    bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
    739                               BDRV_CHILD_IMAGE, false, errp);
    740    if (!bs->file) {
    741        return -EINVAL;
    742    }
    743
    744    ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
    745    if (ret < 0) {
    746        goto fail;
    747    }
    748
    749    bs->total_sectors = le64_to_cpu(ph.nb_sectors);
    750
    751    if (le32_to_cpu(ph.version) != HEADER_VERSION) {
    752        goto fail_format;
    753    }
    754    if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
    755        s->off_multiplier = 1;
    756        bs->total_sectors = 0xffffffff & bs->total_sectors;
    757    } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
    758        s->off_multiplier = le32_to_cpu(ph.tracks);
    759    } else {
    760        goto fail_format;
    761    }
    762
    763    s->tracks = le32_to_cpu(ph.tracks);
    764    if (s->tracks == 0) {
    765        error_setg(errp, "Invalid image: Zero sectors per track");
    766        ret = -EINVAL;
    767        goto fail;
    768    }
    769    if (s->tracks > INT32_MAX/513) {
    770        error_setg(errp, "Invalid image: Too big cluster");
    771        ret = -EFBIG;
    772        goto fail;
    773    }
    774    s->cluster_size = s->tracks << BDRV_SECTOR_BITS;
    775
    776    s->bat_size = le32_to_cpu(ph.bat_entries);
    777    if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
    778        error_setg(errp, "Catalog too large");
    779        ret = -EFBIG;
    780        goto fail;
    781    }
    782
    783    size = bat_entry_off(s->bat_size);
    784    s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
    785    s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
    786    if (s->header == NULL) {
    787        ret = -ENOMEM;
    788        goto fail;
    789    }
    790    s->data_end = le32_to_cpu(ph.data_off);
    791    if (s->data_end == 0) {
    792        s->data_end = ROUND_UP(bat_entry_off(s->bat_size), BDRV_SECTOR_SIZE);
    793    }
    794    if (s->data_end < s->header_size) {
    795        /* there is not enough unused space to fit to block align between BAT
    796           and actual data. We can't avoid read-modify-write... */
    797        s->header_size = size;
    798    }
    799
    800    ret = bdrv_pread(bs->file, 0, s->header, s->header_size);
    801    if (ret < 0) {
    802        goto fail;
    803    }
    804    s->bat_bitmap = (uint32_t *)(s->header + 1);
    805
    806    for (i = 0; i < s->bat_size; i++) {
    807        int64_t off = bat2sect(s, i);
    808        if (off >= s->data_end) {
    809            s->data_end = off + s->tracks;
    810        }
    811    }
    812
    813    if (le32_to_cpu(ph.inuse) == HEADER_INUSE_MAGIC) {
    814        /* Image was not closed correctly. The check is mandatory */
    815        s->header_unclean = true;
    816        if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
    817            error_setg(errp, "parallels: Image was not closed correctly; "
    818                       "cannot be opened read/write");
    819            ret = -EACCES;
    820            goto fail;
    821        }
    822    }
    823
    824    opts = qemu_opts_create(&parallels_runtime_opts, NULL, 0, errp);
    825    if (!opts) {
    826        goto fail_options;
    827    }
    828
    829    if (!qemu_opts_absorb_qdict(opts, options, errp)) {
    830        goto fail_options;
    831    }
    832
    833    s->prealloc_size =
    834        qemu_opt_get_size_del(opts, PARALLELS_OPT_PREALLOC_SIZE, 0);
    835    s->prealloc_size = MAX(s->tracks, s->prealloc_size >> BDRV_SECTOR_BITS);
    836    buf = qemu_opt_get_del(opts, PARALLELS_OPT_PREALLOC_MODE);
    837    /* prealloc_mode can be downgraded later during allocate_clusters */
    838    s->prealloc_mode = qapi_enum_parse(&prealloc_mode_lookup, buf,
    839                                       PRL_PREALLOC_MODE_FALLOCATE,
    840                                       &local_err);
    841    g_free(buf);
    842    if (local_err != NULL) {
    843        error_propagate(errp, local_err);
    844        goto fail_options;
    845    }
    846
    847    if (ph.ext_off) {
    848        if (flags & BDRV_O_RDWR) {
    849            /*
    850             * It's unsafe to open image RW if there is an extension (as we
    851             * don't support it). But parallels driver in QEMU historically
    852             * ignores the extension, so print warning and don't care.
    853             */
    854            warn_report("Format Extension ignored in RW mode");
    855        } else {
    856            ret = parallels_read_format_extension(
    857                    bs, le64_to_cpu(ph.ext_off) << BDRV_SECTOR_BITS, errp);
    858            if (ret < 0) {
    859                goto fail;
    860            }
    861        }
    862    }
    863
    864    if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
    865        s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
    866        ret = parallels_update_header(bs);
    867        if (ret < 0) {
    868            goto fail;
    869        }
    870    }
    871
    872    s->bat_dirty_block = 4 * qemu_real_host_page_size;
    873    s->bat_dirty_bmap =
    874        bitmap_new(DIV_ROUND_UP(s->header_size, s->bat_dirty_block));
    875
    876    /* Disable migration until bdrv_invalidate_cache method is added */
    877    error_setg(&s->migration_blocker, "The Parallels format used by node '%s' "
    878               "does not support live migration",
    879               bdrv_get_device_or_node_name(bs));
    880    ret = migrate_add_blocker(s->migration_blocker, errp);
    881    if (ret < 0) {
    882        error_free(s->migration_blocker);
    883        goto fail;
    884    }
    885    qemu_co_mutex_init(&s->lock);
    886    return 0;
    887
    888fail_format:
    889    error_setg(errp, "Image not in Parallels format");
    890fail_options:
    891    ret = -EINVAL;
    892fail:
    893    qemu_vfree(s->header);
    894    return ret;
    895}
    896
    897
    898static void parallels_close(BlockDriverState *bs)
    899{
    900    BDRVParallelsState *s = bs->opaque;
    901
    902    if ((bs->open_flags & BDRV_O_RDWR) && !(bs->open_flags & BDRV_O_INACTIVE)) {
    903        s->header->inuse = 0;
    904        parallels_update_header(bs);
    905
    906        /* errors are ignored, so we might as well pass exact=true */
    907        bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS, true,
    908                      PREALLOC_MODE_OFF, 0, NULL);
    909    }
    910
    911    g_free(s->bat_dirty_bmap);
    912    qemu_vfree(s->header);
    913
    914    migrate_del_blocker(s->migration_blocker);
    915    error_free(s->migration_blocker);
    916}
    917
    918static BlockDriver bdrv_parallels = {
    919    .format_name	= "parallels",
    920    .instance_size	= sizeof(BDRVParallelsState),
    921    .bdrv_probe		= parallels_probe,
    922    .bdrv_open		= parallels_open,
    923    .bdrv_close		= parallels_close,
    924    .bdrv_child_perm          = bdrv_default_perms,
    925    .bdrv_co_block_status     = parallels_co_block_status,
    926    .bdrv_has_zero_init       = bdrv_has_zero_init_1,
    927    .bdrv_co_flush_to_os      = parallels_co_flush_to_os,
    928    .bdrv_co_readv  = parallels_co_readv,
    929    .bdrv_co_writev = parallels_co_writev,
    930    .is_format      = true,
    931    .supports_backing = true,
    932    .bdrv_co_create      = parallels_co_create,
    933    .bdrv_co_create_opts = parallels_co_create_opts,
    934    .bdrv_co_check  = parallels_co_check,
    935    .create_opts    = &parallels_create_opts,
    936};
    937
    938static void bdrv_parallels_init(void)
    939{
    940    bdrv_register(&bdrv_parallels);
    941}
    942
    943block_init(bdrv_parallels_init);