diff options
Diffstat (limited to 'block/parallels-ext.c')
| -rw-r--r-- | block/parallels-ext.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/block/parallels-ext.c b/block/parallels-ext.c new file mode 100644 index 0000000000..e0dd0975c6 --- /dev/null +++ b/block/parallels-ext.c @@ -0,0 +1,300 @@ +/* + * Support of Parallels Format Extension. It's a part of Parallels format + * driver. + * + * Copyright (c) 2021 Virtuozzo International GmbH + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "block/block_int.h" +#include "parallels.h" +#include "crypto/hash.h" +#include "qemu/uuid.h" + +#define PARALLELS_FORMAT_EXTENSION_MAGIC 0xAB234CEF23DCEA87ULL + +#define PARALLELS_END_OF_FEATURES_MAGIC 0x0ULL +#define PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC 0x20385FAE252CB34AULL + +typedef struct ParallelsFormatExtensionHeader { + uint64_t magic; /* PARALLELS_FORMAT_EXTENSION_MAGIC */ + uint8_t check_sum[16]; +} QEMU_PACKED ParallelsFormatExtensionHeader; + +typedef struct ParallelsFeatureHeader { + uint64_t magic; + uint64_t flags; + uint32_t data_size; + uint32_t _unused; +} QEMU_PACKED ParallelsFeatureHeader; + +typedef struct ParallelsDirtyBitmapFeature { + uint64_t size; + uint8_t id[16]; + uint32_t granularity; + uint32_t l1_size; + /* L1 table follows */ +} QEMU_PACKED ParallelsDirtyBitmapFeature; + +/* Given L1 table read bitmap data from the image and populate @bitmap */ +static int parallels_load_bitmap_data(BlockDriverState *bs, + const uint64_t *l1_table, + uint32_t l1_size, + BdrvDirtyBitmap *bitmap, + Error **errp) +{ + BDRVParallelsState *s = bs->opaque; + int ret = 0; + uint64_t offset, limit; + uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); + uint8_t *buf = NULL; + uint64_t i, tab_size = + DIV_ROUND_UP(bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size), + s->cluster_size); + + if (tab_size != l1_size) { + error_setg(errp, "Bitmap table size %" PRIu32 " does not correspond " + "to bitmap size and cluster size. Expected %" PRIu64, + l1_size, tab_size); + return -EINVAL; + } + + buf = qemu_blockalign(bs, s->cluster_size); + limit = bdrv_dirty_bitmap_serialization_coverage(s->cluster_size, bitmap); + for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) { + uint64_t count = MIN(bm_size - offset, limit); + uint64_t entry = l1_table[i]; + + if (entry == 0) { + /* No need to deserialize zeros because @bitmap is cleared. */ + continue; + } + + if (entry == 1) { + bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count, false); + } else { + ret = bdrv_pread(bs->file, entry << BDRV_SECTOR_BITS, buf, + s->cluster_size); + if (ret < 0) { + error_setg_errno(errp, -ret, + "Failed to read bitmap data cluster"); + goto finish; + } + bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count, + false); + } + } + ret = 0; + + bdrv_dirty_bitmap_deserialize_finish(bitmap); + +finish: + qemu_vfree(buf); + + return ret; +} + +/* + * @data buffer (of @data_size size) is the Dirty bitmaps feature which + * consists of ParallelsDirtyBitmapFeature followed by L1 table. + */ +static BdrvDirtyBitmap *parallels_load_bitmap(BlockDriverState *bs, + uint8_t *data, + size_t data_size, + Error **errp) +{ + int ret; + ParallelsDirtyBitmapFeature bf; + g_autofree uint64_t *l1_table = NULL; + BdrvDirtyBitmap *bitmap; + QemuUUID uuid; + char uuidstr[UUID_FMT_LEN + 1]; + int i; + + if (data_size < sizeof(bf)) { + error_setg(errp, "Too small Bitmap Feature area in Parallels Format " + "Extension: %zu bytes, expected at least %zu bytes", + data_size, sizeof(bf)); + return NULL; + } + memcpy(&bf, data, sizeof(bf)); + bf.size = le64_to_cpu(bf.size); + bf.granularity = le32_to_cpu(bf.granularity) << BDRV_SECTOR_BITS; + bf.l1_size = le32_to_cpu(bf.l1_size); + data += sizeof(bf); + data_size -= sizeof(bf); + + if (bf.size != bs->total_sectors) { + error_setg(errp, "Bitmap size (in sectors) %" PRId64 " differs from " + "disk size in sectors %" PRId64, bf.size, bs->total_sectors); + return NULL; + } + + if (bf.l1_size * sizeof(uint64_t) > data_size) { + error_setg(errp, "Bitmaps feature corrupted: l1 table exceeds " + "extension data_size"); + return NULL; + } + + memcpy(&uuid, bf.id, sizeof(uuid)); + qemu_uuid_unparse(&uuid, uuidstr); + bitmap = bdrv_create_dirty_bitmap(bs, bf.granularity, uuidstr, errp); + if (!bitmap) { + return NULL; + } + + l1_table = g_new(uint64_t, bf.l1_size); + for (i = 0; i < bf.l1_size; i++, data += sizeof(uint64_t)) { + l1_table[i] = ldq_le_p(data); + } + + ret = parallels_load_bitmap_data(bs, l1_table, bf.l1_size, bitmap, errp); + if (ret < 0) { + bdrv_release_dirty_bitmap(bitmap); + return NULL; + } + + /* We support format extension only for RO parallels images. */ + assert(!(bs->open_flags & BDRV_O_RDWR)); + bdrv_dirty_bitmap_set_readonly(bitmap, true); + + return bitmap; +} + +static int parallels_parse_format_extension(BlockDriverState *bs, + uint8_t *ext_cluster, Error **errp) +{ + BDRVParallelsState *s = bs->opaque; + int ret; + int remaining = s->cluster_size; + uint8_t *pos = ext_cluster; + ParallelsFormatExtensionHeader eh; + g_autofree uint8_t *hash = NULL; + size_t hash_len = 0; + GSList *bitmaps = NULL, *el; + + memcpy(&eh, pos, sizeof(eh)); + eh.magic = le64_to_cpu(eh.magic); + pos += sizeof(eh); + remaining -= sizeof(eh); + + if (eh.magic != PARALLELS_FORMAT_EXTENSION_MAGIC) { + error_setg(errp, "Wrong parallels Format Extension magic: 0x%" PRIx64 + ", expected: 0x%llx", eh.magic, + PARALLELS_FORMAT_EXTENSION_MAGIC); + goto fail; + } + + ret = qcrypto_hash_bytes(QCRYPTO_HASH_ALG_MD5, (char *)pos, remaining, + &hash, &hash_len, errp); + if (ret < 0) { + goto fail; + } + + if (hash_len != sizeof(eh.check_sum) || + memcmp(hash, eh.check_sum, sizeof(eh.check_sum)) != 0) { + error_setg(errp, "Wrong checksum in Format Extension header. Format " + "extension is corrupted."); + goto fail; + } + + while (true) { + ParallelsFeatureHeader fh; + BdrvDirtyBitmap *bitmap; + + if (remaining < sizeof(fh)) { + error_setg(errp, "Can not read feature header, as remaining bytes " + "(%d) in Format Extension is less than Feature header " + "size (%zu)", remaining, sizeof(fh)); + goto fail; + } + + memcpy(&fh, pos, sizeof(fh)); + pos += sizeof(fh); + remaining -= sizeof(fh); + + fh.magic = le64_to_cpu(fh.magic); + fh.flags = le64_to_cpu(fh.flags); + fh.data_size = le32_to_cpu(fh.data_size); + + if (fh.flags) { + error_setg(errp, "Flags for extension feature are unsupported"); + goto fail; + } + + if (fh.data_size > remaining) { + error_setg(errp, "Feature data_size exceedes Format Extension " + "cluster"); + goto fail; + } + + switch (fh.magic) { + case PARALLELS_END_OF_FEATURES_MAGIC: + return 0; + + case PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC: + bitmap = parallels_load_bitmap(bs, pos, fh.data_size, errp); + if (!bitmap) { + goto fail; + } + bitmaps = g_slist_append(bitmaps, bitmap); + break; + + default: + error_setg(errp, "Unknown feature: 0x%" PRIu64, fh.magic); + goto fail; + } + + pos = ext_cluster + QEMU_ALIGN_UP(pos + fh.data_size - ext_cluster, 8); + } + +fail: + for (el = bitmaps; el; el = el->next) { + bdrv_release_dirty_bitmap(el->data); + } + g_slist_free(bitmaps); + + return -EINVAL; +} + +int parallels_read_format_extension(BlockDriverState *bs, + int64_t ext_off, Error **errp) +{ + BDRVParallelsState *s = bs->opaque; + int ret; + uint8_t *ext_cluster = qemu_blockalign(bs, s->cluster_size); + + assert(ext_off > 0); + + ret = bdrv_pread(bs->file, ext_off, ext_cluster, s->cluster_size); + if (ret < 0) { + error_setg_errno(errp, -ret, "Failed to read Format Extension cluster"); + goto out; + } + + ret = parallels_parse_format_extension(bs, ext_cluster, errp); + +out: + qemu_vfree(ext_cluster); + + return ret; +} |