| 1 | /* |
| 2 | * Support of Parallels Format Extension. It's a part of Parallels format |
| 3 | * driver. |
| 4 | * |
| 5 | * Copyright (c) 2021 Virtuozzo International GmbH |
| 6 | * |
| 7 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 8 | * of this software and associated documentation files (the "Software"), to deal |
| 9 | * in the Software without restriction, including without limitation the rights |
| 10 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 11 | * copies of the Software, and to permit persons to whom the Software is |
| 12 | * furnished to do so, subject to the following conditions: |
| 13 | * |
| 14 | * The above copyright notice and this permission notice shall be included in |
| 15 | * all copies or substantial portions of the Software. |
| 16 | * |
| 17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 18 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 19 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 20 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 21 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 22 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 23 | * THE SOFTWARE. |
| 24 | */ |
| 25 | |
| 26 | #include "qemu/osdep.h" |
| 27 | #include "qapi/error.h" |
| 28 | #include "block/block-io.h" |
| 29 | #include "block/block_int.h" |
| 30 | #include "block/dirty-bitmap.h" |
| 31 | #include "parallels.h" |
| 32 | #include "crypto/hash.h" |
| 33 | #include "qemu/bswap.h" |
| 34 | #include "qemu/uuid.h" |
| 35 | #include "qemu/memalign.h" |
| 36 | |
| 37 | #define PARALLELS_FORMAT_EXTENSION_MAGIC 0xAB234CEF23DCEA87ULL |
| 38 | |
| 39 | #define PARALLELS_END_OF_FEATURES_MAGIC 0x0ULL |
| 40 | #define PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC 0x20385FAE252CB34AULL |
| 41 | |
| 42 | typedef struct ParallelsFormatExtensionHeader { |
| 43 | uint64_t magic; /* PARALLELS_FORMAT_EXTENSION_MAGIC */ |
| 44 | uint8_t check_sum[16]; |
| 45 | } QEMU_PACKED ParallelsFormatExtensionHeader; |
| 46 | |
| 47 | typedef struct ParallelsFeatureHeader { |
| 48 | uint64_t magic; |
| 49 | uint64_t flags; |
| 50 | uint32_t data_size; |
| 51 | uint32_t _unused; |
| 52 | } QEMU_PACKED ParallelsFeatureHeader; |
| 53 | |
| 54 | typedef struct ParallelsDirtyBitmapFeature { |
| 55 | uint64_t size; |
| 56 | uint8_t id[16]; |
| 57 | uint32_t granularity; |
| 58 | uint32_t l1_size; |
| 59 | /* L1 table follows */ |
| 60 | } QEMU_PACKED ParallelsDirtyBitmapFeature; |
| 61 | |
| 62 | /* Given L1 table read bitmap data from the image and populate @bitmap */ |
| 63 | static int GRAPH_RDLOCK |
| 64 | parallels_load_bitmap_data(BlockDriverState *bs, const uint64_t *l1_table, |
| 65 | uint32_t l1_size, BdrvDirtyBitmap *bitmap, |
| 66 | Error **errp) |
| 67 | { |
| 68 | BDRVParallelsState *s = bs->opaque; |
| 69 | int ret = 0; |
| 70 | uint64_t offset, limit; |
| 71 | uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); |
| 72 | uint8_t *buf = NULL; |
| 73 | uint64_t i; |
| 74 | |
| 75 | buf = qemu_blockalign(bs, s->cluster_size); |
| 76 | limit = bdrv_dirty_bitmap_serialization_coverage(s->cluster_size, bitmap); |
| 77 | for (i = 0, offset = 0; i < l1_size; ++i, offset += limit) { |
| 78 | uint64_t count = MIN(bm_size - offset, limit); |
| 79 | uint64_t entry = l1_table[i]; |
| 80 | |
| 81 | if (entry == 0) { |
| 82 | /* No need to deserialize zeros because @bitmap is cleared. */ |
| 83 | continue; |
| 84 | } |
| 85 | |
| 86 | if (entry == 1) { |
| 87 | bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count, false); |
| 88 | } else { |
| 89 | ret = bdrv_pread(bs->file, entry << BDRV_SECTOR_BITS, |
| 90 | s->cluster_size, buf, 0); |
| 91 | if (ret < 0) { |
| 92 | error_setg_errno(errp, -ret, |
| 93 | "Failed to read bitmap data cluster"); |
| 94 | goto finish; |
| 95 | } |
| 96 | bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count, |
| 97 | false); |
| 98 | } |
| 99 | } |
| 100 | ret = 0; |
| 101 | |
| 102 | bdrv_dirty_bitmap_deserialize_finish(bitmap); |
| 103 | |
| 104 | finish: |
| 105 | qemu_vfree(buf); |
| 106 | |
| 107 | return ret; |
| 108 | } |
| 109 | |
| 110 | /* |
| 111 | * @data buffer (of @data_size size) is the Dirty bitmaps feature which |
| 112 | * consists of ParallelsDirtyBitmapFeature followed by L1 table. |
| 113 | */ |
| 114 | static BdrvDirtyBitmap * GRAPH_RDLOCK |
| 115 | parallels_load_bitmap(BlockDriverState *bs, uint8_t *data, size_t data_size, |
| 116 | Error **errp) |
| 117 | { |
| 118 | BDRVParallelsState *s = bs->opaque; |
| 119 | int ret; |
| 120 | ParallelsDirtyBitmapFeature bf; |
| 121 | g_autofree uint64_t *l1_table = NULL; |
| 122 | BdrvDirtyBitmap *bitmap; |
| 123 | QemuUUID uuid; |
| 124 | char uuidstr[UUID_STR_LEN]; |
| 125 | uint64_t bm_size, tab_size; |
| 126 | int i; |
| 127 | |
| 128 | if (data_size < sizeof(bf)) { |
| 129 | error_setg(errp, "Too small Bitmap Feature area in Parallels Format " |
| 130 | "Extension: %zu bytes, expected at least %zu bytes", |
| 131 | data_size, sizeof(bf)); |
| 132 | return NULL; |
| 133 | } |
| 134 | memcpy(&bf, data, sizeof(bf)); |
| 135 | bf.size = le64_to_cpu(bf.size); |
| 136 | bf.granularity = le32_to_cpu(bf.granularity) << BDRV_SECTOR_BITS; |
| 137 | bf.l1_size = le32_to_cpu(bf.l1_size); |
| 138 | data += sizeof(bf); |
| 139 | data_size -= sizeof(bf); |
| 140 | |
| 141 | if (bf.size != bs->total_sectors) { |
| 142 | error_setg(errp, "Bitmap size (in sectors) %" PRId64 " differs from " |
| 143 | "disk size in sectors %" PRId64, bf.size, bs->total_sectors); |
| 144 | return NULL; |
| 145 | } |
| 146 | |
| 147 | if (bf.l1_size * sizeof(uint64_t) > data_size) { |
| 148 | error_setg(errp, "Bitmaps feature corrupted: l1 table exceeds " |
| 149 | "extension data_size"); |
| 150 | return NULL; |
| 151 | } |
| 152 | |
| 153 | memcpy(&uuid, bf.id, sizeof(uuid)); |
| 154 | qemu_uuid_unparse(&uuid, uuidstr); |
| 155 | bitmap = bdrv_create_dirty_bitmap(bs, bf.granularity, uuidstr, errp); |
| 156 | if (!bitmap) { |
| 157 | return NULL; |
| 158 | } |
| 159 | |
| 160 | bm_size = bdrv_dirty_bitmap_size(bitmap); |
| 161 | tab_size = DIV_ROUND_UP( |
| 162 | bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size), |
| 163 | s->cluster_size); |
| 164 | if (tab_size != bf.l1_size) { |
| 165 | error_setg(errp, "Bitmap table size %" PRIu32 " does not correspond " |
| 166 | "to bitmap size and cluster size. Expected %" PRIu64, |
| 167 | bf.l1_size, tab_size); |
| 168 | goto fail; |
| 169 | } |
| 170 | |
| 171 | if (bf.l1_size != 0) { |
| 172 | l1_table = g_try_new(uint64_t, bf.l1_size); |
| 173 | if (!l1_table) { |
| 174 | error_setg(errp, "Failed to allocate the bitmap L1 table " |
| 175 | "(%" PRIu32 " entries)", bf.l1_size); |
| 176 | goto fail; |
| 177 | } |
| 178 | |
| 179 | for (i = 0; i < bf.l1_size; i++, data += sizeof(uint64_t)) { |
| 180 | l1_table[i] = ldq_le_p(data); |
| 181 | } |
| 182 | |
| 183 | ret = parallels_load_bitmap_data(bs, l1_table, bf.l1_size, bitmap, |
| 184 | errp); |
| 185 | if (ret < 0) { |
| 186 | goto fail; |
| 187 | } |
| 188 | } |
| 189 | |
| 190 | /* We support format extension only for RO parallels images. */ |
| 191 | assert(!(bs->open_flags & BDRV_O_RDWR)); |
| 192 | bdrv_dirty_bitmap_set_readonly(bitmap, true); |
| 193 | |
| 194 | return bitmap; |
| 195 | |
| 196 | fail: |
| 197 | bdrv_release_dirty_bitmap(bitmap); |
| 198 | return NULL; |
| 199 | } |
| 200 | |
| 201 | static int GRAPH_RDLOCK |
| 202 | parallels_parse_format_extension(BlockDriverState *bs, uint8_t *ext_cluster, |
| 203 | Error **errp) |
| 204 | { |
| 205 | BDRVParallelsState *s = bs->opaque; |
| 206 | int ret; |
| 207 | int remaining = s->cluster_size; |
| 208 | uint8_t *pos = ext_cluster; |
| 209 | ParallelsFormatExtensionHeader eh; |
| 210 | g_autofree uint8_t *hash = NULL; |
| 211 | size_t hash_len = 0; |
| 212 | GSList *bitmaps = NULL, *el; |
| 213 | |
| 214 | memcpy(&eh, pos, sizeof(eh)); |
| 215 | eh.magic = le64_to_cpu(eh.magic); |
| 216 | pos += sizeof(eh); |
| 217 | remaining -= sizeof(eh); |
| 218 | |
| 219 | if (eh.magic != PARALLELS_FORMAT_EXTENSION_MAGIC) { |
| 220 | error_setg(errp, "Wrong parallels Format Extension magic: 0x%" PRIx64 |
| 221 | ", expected: 0x%llx", eh.magic, |
| 222 | PARALLELS_FORMAT_EXTENSION_MAGIC); |
| 223 | goto fail; |
| 224 | } |
| 225 | |
| 226 | ret = qcrypto_hash_bytes(QCRYPTO_HASH_ALGO_MD5, (char *)pos, remaining, |
| 227 | &hash, &hash_len, errp); |
| 228 | if (ret < 0) { |
| 229 | goto fail; |
| 230 | } |
| 231 | |
| 232 | if (hash_len != sizeof(eh.check_sum) || |
| 233 | memcmp(hash, eh.check_sum, sizeof(eh.check_sum)) != 0) { |
| 234 | error_setg(errp, "Wrong checksum in Format Extension header. Format " |
| 235 | "extension is corrupted."); |
| 236 | goto fail; |
| 237 | } |
| 238 | |
| 239 | while (true) { |
| 240 | ParallelsFeatureHeader fh; |
| 241 | BdrvDirtyBitmap *bitmap; |
| 242 | |
| 243 | if (remaining < sizeof(fh)) { |
| 244 | error_setg(errp, "Can not read feature header, as remaining bytes " |
| 245 | "(%d) in Format Extension is less than Feature header " |
| 246 | "size (%zu)", remaining, sizeof(fh)); |
| 247 | goto fail; |
| 248 | } |
| 249 | |
| 250 | memcpy(&fh, pos, sizeof(fh)); |
| 251 | pos += sizeof(fh); |
| 252 | remaining -= sizeof(fh); |
| 253 | |
| 254 | fh.magic = le64_to_cpu(fh.magic); |
| 255 | fh.flags = le64_to_cpu(fh.flags); |
| 256 | fh.data_size = le32_to_cpu(fh.data_size); |
| 257 | |
| 258 | if (fh.flags) { |
| 259 | error_setg(errp, "Flags for extension feature are unsupported"); |
| 260 | goto fail; |
| 261 | } |
| 262 | |
| 263 | if (fh.data_size > remaining) { |
| 264 | error_setg(errp, "Feature data_size exceedes Format Extension " |
| 265 | "cluster"); |
| 266 | goto fail; |
| 267 | } |
| 268 | |
| 269 | switch (fh.magic) { |
| 270 | case PARALLELS_END_OF_FEATURES_MAGIC: |
| 271 | return 0; |
| 272 | |
| 273 | case PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC: |
| 274 | bitmap = parallels_load_bitmap(bs, pos, fh.data_size, errp); |
| 275 | if (!bitmap) { |
| 276 | goto fail; |
| 277 | } |
| 278 | bitmaps = g_slist_append(bitmaps, bitmap); |
| 279 | break; |
| 280 | |
| 281 | default: |
| 282 | error_setg(errp, "Unknown feature: 0x%" PRIx64, fh.magic); |
| 283 | goto fail; |
| 284 | } |
| 285 | |
| 286 | pos = ext_cluster + QEMU_ALIGN_UP(pos + fh.data_size - ext_cluster, 8); |
| 287 | } |
| 288 | |
| 289 | fail: |
| 290 | for (el = bitmaps; el; el = el->next) { |
| 291 | bdrv_release_dirty_bitmap(el->data); |
| 292 | } |
| 293 | g_slist_free(bitmaps); |
| 294 | |
| 295 | return -EINVAL; |
| 296 | } |
| 297 | |
| 298 | int parallels_read_format_extension(BlockDriverState *bs, |
| 299 | int64_t ext_off, Error **errp) |
| 300 | { |
| 301 | BDRVParallelsState *s = bs->opaque; |
| 302 | int ret; |
| 303 | uint8_t *ext_cluster = qemu_blockalign(bs, s->cluster_size); |
| 304 | |
| 305 | assert(ext_off > 0); |
| 306 | |
| 307 | ret = bdrv_pread(bs->file, ext_off, s->cluster_size, ext_cluster, 0); |
| 308 | if (ret < 0) { |
| 309 | error_setg_errno(errp, -ret, "Failed to read Format Extension cluster"); |
| 310 | goto out; |
| 311 | } |
| 312 | |
| 313 | ret = parallels_parse_format_extension(bs, ext_cluster, errp); |
| 314 | |
| 315 | out: |
| 316 | qemu_vfree(ext_cluster); |
| 317 | |
| 318 | return ret; |
| 319 | } |