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baefd977 VSO |
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" | |
e2c1c34f | 28 | #include "block/block-io.h" |
baefd977 | 29 | #include "block/block_int.h" |
e2c1c34f | 30 | #include "block/dirty-bitmap.h" |
baefd977 VSO |
31 | #include "parallels.h" |
32 | #include "crypto/hash.h" | |
33 | #include "qemu/uuid.h" | |
5df022cf | 34 | #include "qemu/memalign.h" |
baefd977 VSO |
35 | |
36 | #define PARALLELS_FORMAT_EXTENSION_MAGIC 0xAB234CEF23DCEA87ULL | |
37 | ||
38 | #define PARALLELS_END_OF_FEATURES_MAGIC 0x0ULL | |
39 | #define PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC 0x20385FAE252CB34AULL | |
40 | ||
41 | typedef struct ParallelsFormatExtensionHeader { | |
42 | uint64_t magic; /* PARALLELS_FORMAT_EXTENSION_MAGIC */ | |
43 | uint8_t check_sum[16]; | |
44 | } QEMU_PACKED ParallelsFormatExtensionHeader; | |
45 | ||
46 | typedef struct ParallelsFeatureHeader { | |
47 | uint64_t magic; | |
48 | uint64_t flags; | |
49 | uint32_t data_size; | |
50 | uint32_t _unused; | |
51 | } QEMU_PACKED ParallelsFeatureHeader; | |
52 | ||
53 | typedef struct ParallelsDirtyBitmapFeature { | |
54 | uint64_t size; | |
55 | uint8_t id[16]; | |
56 | uint32_t granularity; | |
57 | uint32_t l1_size; | |
58 | /* L1 table follows */ | |
59 | } QEMU_PACKED ParallelsDirtyBitmapFeature; | |
60 | ||
61 | /* Given L1 table read bitmap data from the image and populate @bitmap */ | |
62 | static int parallels_load_bitmap_data(BlockDriverState *bs, | |
63 | const uint64_t *l1_table, | |
64 | uint32_t l1_size, | |
65 | 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, tab_size = | |
74 | DIV_ROUND_UP(bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size), | |
75 | s->cluster_size); | |
76 | ||
77 | if (tab_size != l1_size) { | |
78 | error_setg(errp, "Bitmap table size %" PRIu32 " does not correspond " | |
79 | "to bitmap size and cluster size. Expected %" PRIu64, | |
80 | l1_size, tab_size); | |
81 | return -EINVAL; | |
82 | } | |
83 | ||
84 | buf = qemu_blockalign(bs, s->cluster_size); | |
85 | limit = bdrv_dirty_bitmap_serialization_coverage(s->cluster_size, bitmap); | |
86 | for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) { | |
87 | uint64_t count = MIN(bm_size - offset, limit); | |
88 | uint64_t entry = l1_table[i]; | |
89 | ||
90 | if (entry == 0) { | |
91 | /* No need to deserialize zeros because @bitmap is cleared. */ | |
92 | continue; | |
93 | } | |
94 | ||
95 | if (entry == 1) { | |
96 | bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count, false); | |
97 | } else { | |
32cc71de AF |
98 | ret = bdrv_pread(bs->file, entry << BDRV_SECTOR_BITS, |
99 | s->cluster_size, buf, 0); | |
baefd977 VSO |
100 | if (ret < 0) { |
101 | error_setg_errno(errp, -ret, | |
102 | "Failed to read bitmap data cluster"); | |
103 | goto finish; | |
104 | } | |
105 | bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count, | |
106 | false); | |
107 | } | |
108 | } | |
109 | ret = 0; | |
110 | ||
111 | bdrv_dirty_bitmap_deserialize_finish(bitmap); | |
112 | ||
113 | finish: | |
114 | qemu_vfree(buf); | |
115 | ||
116 | return ret; | |
117 | } | |
118 | ||
119 | /* | |
120 | * @data buffer (of @data_size size) is the Dirty bitmaps feature which | |
121 | * consists of ParallelsDirtyBitmapFeature followed by L1 table. | |
122 | */ | |
123 | static BdrvDirtyBitmap *parallels_load_bitmap(BlockDriverState *bs, | |
124 | uint8_t *data, | |
125 | size_t data_size, | |
126 | Error **errp) | |
127 | { | |
128 | int ret; | |
129 | ParallelsDirtyBitmapFeature bf; | |
130 | g_autofree uint64_t *l1_table = NULL; | |
131 | BdrvDirtyBitmap *bitmap; | |
132 | QemuUUID uuid; | |
133 | char uuidstr[UUID_FMT_LEN + 1]; | |
134 | int i; | |
135 | ||
136 | if (data_size < sizeof(bf)) { | |
137 | error_setg(errp, "Too small Bitmap Feature area in Parallels Format " | |
138 | "Extension: %zu bytes, expected at least %zu bytes", | |
139 | data_size, sizeof(bf)); | |
140 | return NULL; | |
141 | } | |
142 | memcpy(&bf, data, sizeof(bf)); | |
143 | bf.size = le64_to_cpu(bf.size); | |
144 | bf.granularity = le32_to_cpu(bf.granularity) << BDRV_SECTOR_BITS; | |
145 | bf.l1_size = le32_to_cpu(bf.l1_size); | |
146 | data += sizeof(bf); | |
147 | data_size -= sizeof(bf); | |
148 | ||
149 | if (bf.size != bs->total_sectors) { | |
150 | error_setg(errp, "Bitmap size (in sectors) %" PRId64 " differs from " | |
151 | "disk size in sectors %" PRId64, bf.size, bs->total_sectors); | |
152 | return NULL; | |
153 | } | |
154 | ||
155 | if (bf.l1_size * sizeof(uint64_t) > data_size) { | |
156 | error_setg(errp, "Bitmaps feature corrupted: l1 table exceeds " | |
157 | "extension data_size"); | |
158 | return NULL; | |
159 | } | |
160 | ||
161 | memcpy(&uuid, bf.id, sizeof(uuid)); | |
162 | qemu_uuid_unparse(&uuid, uuidstr); | |
163 | bitmap = bdrv_create_dirty_bitmap(bs, bf.granularity, uuidstr, errp); | |
164 | if (!bitmap) { | |
165 | return NULL; | |
166 | } | |
167 | ||
168 | l1_table = g_new(uint64_t, bf.l1_size); | |
169 | for (i = 0; i < bf.l1_size; i++, data += sizeof(uint64_t)) { | |
170 | l1_table[i] = ldq_le_p(data); | |
171 | } | |
172 | ||
173 | ret = parallels_load_bitmap_data(bs, l1_table, bf.l1_size, bitmap, errp); | |
174 | if (ret < 0) { | |
175 | bdrv_release_dirty_bitmap(bitmap); | |
176 | return NULL; | |
177 | } | |
178 | ||
179 | /* We support format extension only for RO parallels images. */ | |
180 | assert(!(bs->open_flags & BDRV_O_RDWR)); | |
181 | bdrv_dirty_bitmap_set_readonly(bitmap, true); | |
182 | ||
183 | return bitmap; | |
184 | } | |
185 | ||
186 | static int parallels_parse_format_extension(BlockDriverState *bs, | |
187 | uint8_t *ext_cluster, Error **errp) | |
188 | { | |
189 | BDRVParallelsState *s = bs->opaque; | |
190 | int ret; | |
191 | int remaining = s->cluster_size; | |
192 | uint8_t *pos = ext_cluster; | |
193 | ParallelsFormatExtensionHeader eh; | |
194 | g_autofree uint8_t *hash = NULL; | |
195 | size_t hash_len = 0; | |
196 | GSList *bitmaps = NULL, *el; | |
197 | ||
198 | memcpy(&eh, pos, sizeof(eh)); | |
199 | eh.magic = le64_to_cpu(eh.magic); | |
200 | pos += sizeof(eh); | |
201 | remaining -= sizeof(eh); | |
202 | ||
203 | if (eh.magic != PARALLELS_FORMAT_EXTENSION_MAGIC) { | |
204 | error_setg(errp, "Wrong parallels Format Extension magic: 0x%" PRIx64 | |
205 | ", expected: 0x%llx", eh.magic, | |
206 | PARALLELS_FORMAT_EXTENSION_MAGIC); | |
207 | goto fail; | |
208 | } | |
209 | ||
210 | ret = qcrypto_hash_bytes(QCRYPTO_HASH_ALG_MD5, (char *)pos, remaining, | |
211 | &hash, &hash_len, errp); | |
212 | if (ret < 0) { | |
213 | goto fail; | |
214 | } | |
215 | ||
216 | if (hash_len != sizeof(eh.check_sum) || | |
217 | memcmp(hash, eh.check_sum, sizeof(eh.check_sum)) != 0) { | |
218 | error_setg(errp, "Wrong checksum in Format Extension header. Format " | |
219 | "extension is corrupted."); | |
220 | goto fail; | |
221 | } | |
222 | ||
223 | while (true) { | |
224 | ParallelsFeatureHeader fh; | |
225 | BdrvDirtyBitmap *bitmap; | |
226 | ||
227 | if (remaining < sizeof(fh)) { | |
228 | error_setg(errp, "Can not read feature header, as remaining bytes " | |
229 | "(%d) in Format Extension is less than Feature header " | |
230 | "size (%zu)", remaining, sizeof(fh)); | |
231 | goto fail; | |
232 | } | |
233 | ||
234 | memcpy(&fh, pos, sizeof(fh)); | |
235 | pos += sizeof(fh); | |
236 | remaining -= sizeof(fh); | |
237 | ||
238 | fh.magic = le64_to_cpu(fh.magic); | |
239 | fh.flags = le64_to_cpu(fh.flags); | |
240 | fh.data_size = le32_to_cpu(fh.data_size); | |
241 | ||
242 | if (fh.flags) { | |
243 | error_setg(errp, "Flags for extension feature are unsupported"); | |
244 | goto fail; | |
245 | } | |
246 | ||
247 | if (fh.data_size > remaining) { | |
248 | error_setg(errp, "Feature data_size exceedes Format Extension " | |
249 | "cluster"); | |
250 | goto fail; | |
251 | } | |
252 | ||
253 | switch (fh.magic) { | |
254 | case PARALLELS_END_OF_FEATURES_MAGIC: | |
255 | return 0; | |
256 | ||
257 | case PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC: | |
258 | bitmap = parallels_load_bitmap(bs, pos, fh.data_size, errp); | |
259 | if (!bitmap) { | |
260 | goto fail; | |
261 | } | |
262 | bitmaps = g_slist_append(bitmaps, bitmap); | |
263 | break; | |
264 | ||
265 | default: | |
3f1db959 | 266 | error_setg(errp, "Unknown feature: 0x%" PRIx64, fh.magic); |
baefd977 VSO |
267 | goto fail; |
268 | } | |
269 | ||
270 | pos = ext_cluster + QEMU_ALIGN_UP(pos + fh.data_size - ext_cluster, 8); | |
271 | } | |
272 | ||
273 | fail: | |
274 | for (el = bitmaps; el; el = el->next) { | |
275 | bdrv_release_dirty_bitmap(el->data); | |
276 | } | |
277 | g_slist_free(bitmaps); | |
278 | ||
279 | return -EINVAL; | |
280 | } | |
281 | ||
282 | int parallels_read_format_extension(BlockDriverState *bs, | |
283 | int64_t ext_off, Error **errp) | |
284 | { | |
285 | BDRVParallelsState *s = bs->opaque; | |
286 | int ret; | |
287 | uint8_t *ext_cluster = qemu_blockalign(bs, s->cluster_size); | |
288 | ||
289 | assert(ext_off > 0); | |
290 | ||
32cc71de | 291 | ret = bdrv_pread(bs->file, ext_off, s->cluster_size, ext_cluster, 0); |
baefd977 VSO |
292 | if (ret < 0) { |
293 | error_setg_errno(errp, -ret, "Failed to read Format Extension cluster"); | |
294 | goto out; | |
295 | } | |
296 | ||
297 | ret = parallels_parse_format_extension(bs, ext_cluster, errp); | |
298 | ||
299 | out: | |
300 | qemu_vfree(ext_cluster); | |
301 | ||
302 | return ret; | |
303 | } |