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e8d4e5ff JC |
1 | /* |
2 | * Block driver for Hyper-V VHDX Images | |
3 | * | |
4 | * Copyright (c) 2013 Red Hat, Inc., | |
5 | * | |
6 | * Authors: | |
7 | * Jeff Cody <jcody@redhat.com> | |
8 | * | |
9 | * This is based on the "VHDX Format Specification v0.95", published 4/12/2012 | |
10 | * by Microsoft: | |
11 | * https://www.microsoft.com/en-us/download/details.aspx?id=29681 | |
12 | * | |
13 | * This work is licensed under the terms of the GNU LGPL, version 2 or later. | |
14 | * See the COPYING.LIB file in the top-level directory. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include "qemu-common.h" | |
19 | #include "block/block_int.h" | |
20 | #include "qemu/module.h" | |
21 | #include "qemu/crc32c.h" | |
22 | #include "block/vhdx.h" | |
23 | ||
24 | ||
25 | /* Several metadata and region table data entries are identified by | |
26 | * guids in a MS-specific GUID format. */ | |
27 | ||
28 | ||
29 | /* ------- Known Region Table GUIDs ---------------------- */ | |
30 | static const MSGUID bat_guid = { .data1 = 0x2dc27766, | |
31 | .data2 = 0xf623, | |
32 | .data3 = 0x4200, | |
33 | .data4 = { 0x9d, 0x64, 0x11, 0x5e, | |
34 | 0x9b, 0xfd, 0x4a, 0x08} }; | |
35 | ||
36 | static const MSGUID metadata_guid = { .data1 = 0x8b7ca206, | |
37 | .data2 = 0x4790, | |
38 | .data3 = 0x4b9a, | |
39 | .data4 = { 0xb8, 0xfe, 0x57, 0x5f, | |
40 | 0x05, 0x0f, 0x88, 0x6e} }; | |
41 | ||
42 | ||
43 | ||
44 | /* ------- Known Metadata Entry GUIDs ---------------------- */ | |
45 | static const MSGUID file_param_guid = { .data1 = 0xcaa16737, | |
46 | .data2 = 0xfa36, | |
47 | .data3 = 0x4d43, | |
48 | .data4 = { 0xb3, 0xb6, 0x33, 0xf0, | |
49 | 0xaa, 0x44, 0xe7, 0x6b} }; | |
50 | ||
51 | static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224, | |
52 | .data2 = 0xcd1b, | |
53 | .data3 = 0x4876, | |
54 | .data4 = { 0xb2, 0x11, 0x5d, 0xbe, | |
55 | 0xd8, 0x3b, 0xf4, 0xb8} }; | |
56 | ||
57 | static const MSGUID page83_guid = { .data1 = 0xbeca12ab, | |
58 | .data2 = 0xb2e6, | |
59 | .data3 = 0x4523, | |
60 | .data4 = { 0x93, 0xef, 0xc3, 0x09, | |
61 | 0xe0, 0x00, 0xc7, 0x46} }; | |
62 | ||
63 | ||
64 | static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7, | |
65 | .data2 = 0x445d, | |
66 | .data3 = 0x4471, | |
67 | .data4 = { 0x9c, 0xc9, 0xe9, 0x88, | |
68 | 0x52, 0x51, 0xc5, 0x56} }; | |
69 | ||
70 | static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d, | |
71 | .data2 = 0xb30b, | |
72 | .data3 = 0x454d, | |
73 | .data4 = { 0xab, 0xf7, 0xd3, | |
74 | 0xd8, 0x48, 0x34, | |
75 | 0xab, 0x0c} }; | |
76 | ||
77 | static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d, | |
78 | .data2 = 0xa96f, | |
79 | .data3 = 0x4709, | |
80 | .data4 = { 0xba, 0x47, 0xf2, | |
81 | 0x33, 0xa8, 0xfa, | |
82 | 0xab, 0x5f} }; | |
83 | ||
84 | /* Each parent type must have a valid GUID; this is for parent images | |
85 | * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would | |
86 | * need to make up our own QCOW2 GUID type */ | |
87 | static const MSGUID parent_vhdx_guid = { .data1 = 0xb04aefb7, | |
88 | .data2 = 0xd19e, | |
89 | .data3 = 0x4a81, | |
90 | .data4 = { 0xb7, 0x89, 0x25, 0xb8, | |
91 | 0xe9, 0x44, 0x59, 0x13} }; | |
92 | ||
93 | ||
94 | #define META_FILE_PARAMETER_PRESENT 0x01 | |
95 | #define META_VIRTUAL_DISK_SIZE_PRESENT 0x02 | |
96 | #define META_PAGE_83_PRESENT 0x04 | |
97 | #define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08 | |
98 | #define META_PHYS_SECTOR_SIZE_PRESENT 0x10 | |
99 | #define META_PARENT_LOCATOR_PRESENT 0x20 | |
100 | ||
101 | #define META_ALL_PRESENT \ | |
102 | (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \ | |
103 | META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \ | |
104 | META_PHYS_SECTOR_SIZE_PRESENT) | |
105 | ||
106 | typedef struct VHDXMetadataEntries { | |
107 | VHDXMetadataTableEntry file_parameters_entry; | |
108 | VHDXMetadataTableEntry virtual_disk_size_entry; | |
109 | VHDXMetadataTableEntry page83_data_entry; | |
110 | VHDXMetadataTableEntry logical_sector_size_entry; | |
111 | VHDXMetadataTableEntry phys_sector_size_entry; | |
112 | VHDXMetadataTableEntry parent_locator_entry; | |
113 | uint16_t present; | |
114 | } VHDXMetadataEntries; | |
115 | ||
116 | ||
059e2fbb JC |
117 | typedef struct VHDXSectorInfo { |
118 | uint32_t bat_idx; /* BAT entry index */ | |
119 | uint32_t sectors_avail; /* sectors available in payload block */ | |
120 | uint32_t bytes_left; /* bytes left in the block after data to r/w */ | |
121 | uint32_t bytes_avail; /* bytes available in payload block */ | |
122 | uint64_t file_offset; /* absolute offset in bytes, in file */ | |
123 | uint64_t block_offset; /* block offset, in bytes */ | |
124 | } VHDXSectorInfo; | |
125 | ||
126 | ||
127 | ||
e8d4e5ff JC |
128 | typedef struct BDRVVHDXState { |
129 | CoMutex lock; | |
130 | ||
131 | int curr_header; | |
132 | VHDXHeader *headers[2]; | |
133 | ||
134 | VHDXRegionTableHeader rt; | |
135 | VHDXRegionTableEntry bat_rt; /* region table for the BAT */ | |
136 | VHDXRegionTableEntry metadata_rt; /* region table for the metadata */ | |
137 | ||
138 | VHDXMetadataTableHeader metadata_hdr; | |
139 | VHDXMetadataEntries metadata_entries; | |
140 | ||
141 | VHDXFileParameters params; | |
142 | uint32_t block_size; | |
143 | uint32_t block_size_bits; | |
144 | uint32_t sectors_per_block; | |
145 | uint32_t sectors_per_block_bits; | |
146 | ||
147 | uint64_t virtual_disk_size; | |
148 | uint32_t logical_sector_size; | |
149 | uint32_t physical_sector_size; | |
150 | ||
151 | uint64_t chunk_ratio; | |
152 | uint32_t chunk_ratio_bits; | |
153 | uint32_t logical_sector_size_bits; | |
154 | ||
155 | uint32_t bat_entries; | |
156 | VHDXBatEntry *bat; | |
157 | uint64_t bat_offset; | |
158 | ||
159 | VHDXParentLocatorHeader parent_header; | |
160 | VHDXParentLocatorEntry *parent_entries; | |
161 | ||
162 | } BDRVVHDXState; | |
163 | ||
164 | uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, | |
165 | int crc_offset) | |
166 | { | |
167 | uint32_t crc_new; | |
168 | uint32_t crc_orig; | |
169 | assert(buf != NULL); | |
170 | ||
171 | if (crc_offset > 0) { | |
172 | memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); | |
173 | memset(buf + crc_offset, 0, sizeof(crc_orig)); | |
174 | } | |
175 | ||
176 | crc_new = crc32c(crc, buf, size); | |
177 | if (crc_offset > 0) { | |
178 | memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig)); | |
179 | } | |
180 | ||
181 | return crc_new; | |
182 | } | |
183 | ||
184 | /* Validates the checksum of the buffer, with an in-place CRC. | |
185 | * | |
186 | * Zero is substituted during crc calculation for the original crc field, | |
187 | * and the crc field is restored afterwards. But the buffer will be modifed | |
188 | * during the calculation, so this may not be not suitable for multi-threaded | |
189 | * use. | |
190 | * | |
191 | * crc_offset: byte offset in buf of the buffer crc | |
192 | * buf: buffer pointer | |
193 | * size: size of buffer (must be > crc_offset+4) | |
194 | * | |
195 | * returns true if checksum is valid, false otherwise | |
196 | */ | |
197 | bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) | |
198 | { | |
199 | uint32_t crc_orig; | |
200 | uint32_t crc; | |
201 | ||
202 | assert(buf != NULL); | |
203 | assert(size > (crc_offset + 4)); | |
204 | ||
205 | memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); | |
206 | crc_orig = le32_to_cpu(crc_orig); | |
207 | ||
208 | crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset); | |
209 | ||
210 | return crc == crc_orig; | |
211 | } | |
212 | ||
213 | ||
214 | /* | |
215 | * Per the MS VHDX Specification, for every VHDX file: | |
216 | * - The header section is fixed size - 1 MB | |
217 | * - The header section is always the first "object" | |
218 | * - The first 64KB of the header is the File Identifier | |
219 | * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile") | |
220 | * - The following 512 bytes constitute a UTF-16 string identifiying the | |
221 | * software that created the file, and is optional and diagnostic only. | |
222 | * | |
223 | * Therefore, we probe by looking for the vhdxfile signature "vhdxfile" | |
224 | */ | |
225 | static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) | |
226 | { | |
227 | if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) { | |
228 | return 100; | |
229 | } | |
230 | return 0; | |
231 | } | |
232 | ||
233 | /* All VHDX structures on disk are little endian */ | |
234 | static void vhdx_header_le_import(VHDXHeader *h) | |
235 | { | |
236 | assert(h != NULL); | |
237 | ||
238 | le32_to_cpus(&h->signature); | |
239 | le32_to_cpus(&h->checksum); | |
240 | le64_to_cpus(&h->sequence_number); | |
241 | ||
242 | leguid_to_cpus(&h->file_write_guid); | |
243 | leguid_to_cpus(&h->data_write_guid); | |
244 | leguid_to_cpus(&h->log_guid); | |
245 | ||
246 | le16_to_cpus(&h->log_version); | |
247 | le16_to_cpus(&h->version); | |
248 | le32_to_cpus(&h->log_length); | |
249 | le64_to_cpus(&h->log_offset); | |
250 | } | |
251 | ||
252 | ||
253 | /* opens the specified header block from the VHDX file header section */ | |
254 | static int vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s) | |
255 | { | |
256 | int ret = 0; | |
257 | VHDXHeader *header1; | |
258 | VHDXHeader *header2; | |
259 | bool h1_valid = false; | |
260 | bool h2_valid = false; | |
261 | uint64_t h1_seq = 0; | |
262 | uint64_t h2_seq = 0; | |
263 | uint8_t *buffer; | |
264 | ||
265 | header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); | |
266 | header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); | |
267 | ||
268 | buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); | |
269 | ||
270 | s->headers[0] = header1; | |
271 | s->headers[1] = header2; | |
272 | ||
273 | /* We have to read the whole VHDX_HEADER_SIZE instead of | |
274 | * sizeof(VHDXHeader), because the checksum is over the whole | |
275 | * region */ | |
276 | ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, VHDX_HEADER_SIZE); | |
277 | if (ret < 0) { | |
278 | goto fail; | |
279 | } | |
280 | /* copy over just the relevant portion that we need */ | |
281 | memcpy(header1, buffer, sizeof(VHDXHeader)); | |
282 | vhdx_header_le_import(header1); | |
283 | ||
284 | if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) && | |
285 | !memcmp(&header1->signature, "head", 4) && | |
286 | header1->version == 1) { | |
287 | h1_seq = header1->sequence_number; | |
288 | h1_valid = true; | |
289 | } | |
290 | ||
291 | ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, VHDX_HEADER_SIZE); | |
292 | if (ret < 0) { | |
293 | goto fail; | |
294 | } | |
295 | /* copy over just the relevant portion that we need */ | |
296 | memcpy(header2, buffer, sizeof(VHDXHeader)); | |
297 | vhdx_header_le_import(header2); | |
298 | ||
299 | if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) && | |
300 | !memcmp(&header2->signature, "head", 4) && | |
301 | header2->version == 1) { | |
302 | h2_seq = header2->sequence_number; | |
303 | h2_valid = true; | |
304 | } | |
305 | ||
306 | /* If there is only 1 valid header (or no valid headers), we | |
307 | * don't care what the sequence numbers are */ | |
308 | if (h1_valid && !h2_valid) { | |
309 | s->curr_header = 0; | |
310 | } else if (!h1_valid && h2_valid) { | |
311 | s->curr_header = 1; | |
312 | } else if (!h1_valid && !h2_valid) { | |
313 | ret = -EINVAL; | |
314 | goto fail; | |
315 | } else { | |
316 | /* If both headers are valid, then we choose the active one by the | |
317 | * highest sequence number. If the sequence numbers are equal, that is | |
318 | * invalid */ | |
319 | if (h1_seq > h2_seq) { | |
320 | s->curr_header = 0; | |
321 | } else if (h2_seq > h1_seq) { | |
322 | s->curr_header = 1; | |
323 | } else { | |
324 | ret = -EINVAL; | |
325 | goto fail; | |
326 | } | |
327 | } | |
328 | ||
329 | ret = 0; | |
330 | ||
331 | goto exit; | |
332 | ||
333 | fail: | |
334 | qerror_report(ERROR_CLASS_GENERIC_ERROR, "No valid VHDX header found"); | |
335 | qemu_vfree(header1); | |
336 | qemu_vfree(header2); | |
337 | s->headers[0] = NULL; | |
338 | s->headers[1] = NULL; | |
339 | exit: | |
340 | qemu_vfree(buffer); | |
341 | return ret; | |
342 | } | |
343 | ||
344 | ||
345 | static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) | |
346 | { | |
347 | int ret = 0; | |
348 | uint8_t *buffer; | |
349 | int offset = 0; | |
350 | VHDXRegionTableEntry rt_entry; | |
351 | uint32_t i; | |
352 | bool bat_rt_found = false; | |
353 | bool metadata_rt_found = false; | |
354 | ||
355 | /* We have to read the whole 64KB block, because the crc32 is over the | |
356 | * whole block */ | |
357 | buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); | |
358 | ||
359 | ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, | |
360 | VHDX_HEADER_BLOCK_SIZE); | |
361 | if (ret < 0) { | |
362 | goto fail; | |
363 | } | |
364 | memcpy(&s->rt, buffer, sizeof(s->rt)); | |
365 | le32_to_cpus(&s->rt.signature); | |
366 | le32_to_cpus(&s->rt.checksum); | |
367 | le32_to_cpus(&s->rt.entry_count); | |
368 | le32_to_cpus(&s->rt.reserved); | |
369 | offset += sizeof(s->rt); | |
370 | ||
371 | if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4) || | |
372 | memcmp(&s->rt.signature, "regi", 4)) { | |
373 | ret = -EINVAL; | |
374 | goto fail; | |
375 | } | |
376 | ||
377 | /* Per spec, maximum region table entry count is 2047 */ | |
378 | if (s->rt.entry_count > 2047) { | |
379 | ret = -EINVAL; | |
380 | goto fail; | |
381 | } | |
382 | ||
383 | for (i = 0; i < s->rt.entry_count; i++) { | |
384 | memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); | |
385 | offset += sizeof(rt_entry); | |
386 | ||
387 | leguid_to_cpus(&rt_entry.guid); | |
388 | le64_to_cpus(&rt_entry.file_offset); | |
389 | le32_to_cpus(&rt_entry.length); | |
390 | le32_to_cpus(&rt_entry.data_bits); | |
391 | ||
392 | /* see if we recognize the entry */ | |
393 | if (guid_eq(rt_entry.guid, bat_guid)) { | |
394 | /* must be unique; if we have already found it this is invalid */ | |
395 | if (bat_rt_found) { | |
396 | ret = -EINVAL; | |
397 | goto fail; | |
398 | } | |
399 | bat_rt_found = true; | |
400 | s->bat_rt = rt_entry; | |
401 | continue; | |
402 | } | |
403 | ||
404 | if (guid_eq(rt_entry.guid, metadata_guid)) { | |
405 | /* must be unique; if we have already found it this is invalid */ | |
406 | if (metadata_rt_found) { | |
407 | ret = -EINVAL; | |
408 | goto fail; | |
409 | } | |
410 | metadata_rt_found = true; | |
411 | s->metadata_rt = rt_entry; | |
412 | continue; | |
413 | } | |
414 | ||
415 | if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { | |
416 | /* cannot read vhdx file - required region table entry that | |
417 | * we do not understand. per spec, we must fail to open */ | |
418 | ret = -ENOTSUP; | |
419 | goto fail; | |
420 | } | |
421 | } | |
422 | ret = 0; | |
423 | ||
424 | fail: | |
425 | qemu_vfree(buffer); | |
426 | return ret; | |
427 | } | |
428 | ||
429 | ||
430 | ||
431 | /* Metadata initial parser | |
432 | * | |
433 | * This loads all the metadata entry fields. This may cause additional | |
434 | * fields to be processed (e.g. parent locator, etc..). | |
435 | * | |
436 | * There are 5 Metadata items that are always required: | |
437 | * - File Parameters (block size, has a parent) | |
438 | * - Virtual Disk Size (size, in bytes, of the virtual drive) | |
439 | * - Page 83 Data (scsi page 83 guid) | |
440 | * - Logical Sector Size (logical sector size in bytes, either 512 or | |
441 | * 4096. We only support 512 currently) | |
442 | * - Physical Sector Size (512 or 4096) | |
443 | * | |
444 | * Also, if the File Parameters indicate this is a differencing file, | |
445 | * we must also look for the Parent Locator metadata item. | |
446 | */ | |
447 | static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) | |
448 | { | |
449 | int ret = 0; | |
450 | uint8_t *buffer; | |
451 | int offset = 0; | |
452 | uint32_t i = 0; | |
453 | VHDXMetadataTableEntry md_entry; | |
454 | ||
455 | buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); | |
456 | ||
457 | ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, | |
458 | VHDX_METADATA_TABLE_MAX_SIZE); | |
459 | if (ret < 0) { | |
460 | goto exit; | |
461 | } | |
462 | memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); | |
463 | offset += sizeof(s->metadata_hdr); | |
464 | ||
465 | le64_to_cpus(&s->metadata_hdr.signature); | |
466 | le16_to_cpus(&s->metadata_hdr.reserved); | |
467 | le16_to_cpus(&s->metadata_hdr.entry_count); | |
468 | ||
469 | if (memcmp(&s->metadata_hdr.signature, "metadata", 8)) { | |
470 | ret = -EINVAL; | |
471 | goto exit; | |
472 | } | |
473 | ||
474 | s->metadata_entries.present = 0; | |
475 | ||
476 | if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > | |
477 | (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { | |
478 | ret = -EINVAL; | |
479 | goto exit; | |
480 | } | |
481 | ||
482 | for (i = 0; i < s->metadata_hdr.entry_count; i++) { | |
483 | memcpy(&md_entry, buffer + offset, sizeof(md_entry)); | |
484 | offset += sizeof(md_entry); | |
485 | ||
486 | leguid_to_cpus(&md_entry.item_id); | |
487 | le32_to_cpus(&md_entry.offset); | |
488 | le32_to_cpus(&md_entry.length); | |
489 | le32_to_cpus(&md_entry.data_bits); | |
490 | le32_to_cpus(&md_entry.reserved2); | |
491 | ||
492 | if (guid_eq(md_entry.item_id, file_param_guid)) { | |
493 | if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { | |
494 | ret = -EINVAL; | |
495 | goto exit; | |
496 | } | |
497 | s->metadata_entries.file_parameters_entry = md_entry; | |
498 | s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; | |
499 | continue; | |
500 | } | |
501 | ||
502 | if (guid_eq(md_entry.item_id, virtual_size_guid)) { | |
503 | if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { | |
504 | ret = -EINVAL; | |
505 | goto exit; | |
506 | } | |
507 | s->metadata_entries.virtual_disk_size_entry = md_entry; | |
508 | s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; | |
509 | continue; | |
510 | } | |
511 | ||
512 | if (guid_eq(md_entry.item_id, page83_guid)) { | |
513 | if (s->metadata_entries.present & META_PAGE_83_PRESENT) { | |
514 | ret = -EINVAL; | |
515 | goto exit; | |
516 | } | |
517 | s->metadata_entries.page83_data_entry = md_entry; | |
518 | s->metadata_entries.present |= META_PAGE_83_PRESENT; | |
519 | continue; | |
520 | } | |
521 | ||
522 | if (guid_eq(md_entry.item_id, logical_sector_guid)) { | |
523 | if (s->metadata_entries.present & | |
524 | META_LOGICAL_SECTOR_SIZE_PRESENT) { | |
525 | ret = -EINVAL; | |
526 | goto exit; | |
527 | } | |
528 | s->metadata_entries.logical_sector_size_entry = md_entry; | |
529 | s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; | |
530 | continue; | |
531 | } | |
532 | ||
533 | if (guid_eq(md_entry.item_id, phys_sector_guid)) { | |
534 | if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { | |
535 | ret = -EINVAL; | |
536 | goto exit; | |
537 | } | |
538 | s->metadata_entries.phys_sector_size_entry = md_entry; | |
539 | s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; | |
540 | continue; | |
541 | } | |
542 | ||
543 | if (guid_eq(md_entry.item_id, parent_locator_guid)) { | |
544 | if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { | |
545 | ret = -EINVAL; | |
546 | goto exit; | |
547 | } | |
548 | s->metadata_entries.parent_locator_entry = md_entry; | |
549 | s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; | |
550 | continue; | |
551 | } | |
552 | ||
553 | if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { | |
554 | /* cannot read vhdx file - required region table entry that | |
555 | * we do not understand. per spec, we must fail to open */ | |
556 | ret = -ENOTSUP; | |
557 | goto exit; | |
558 | } | |
559 | } | |
560 | ||
561 | if (s->metadata_entries.present != META_ALL_PRESENT) { | |
562 | ret = -ENOTSUP; | |
563 | goto exit; | |
564 | } | |
565 | ||
566 | ret = bdrv_pread(bs->file, | |
567 | s->metadata_entries.file_parameters_entry.offset | |
568 | + s->metadata_rt.file_offset, | |
569 | &s->params, | |
570 | sizeof(s->params)); | |
571 | ||
572 | if (ret < 0) { | |
573 | goto exit; | |
574 | } | |
575 | ||
576 | le32_to_cpus(&s->params.block_size); | |
577 | le32_to_cpus(&s->params.data_bits); | |
578 | ||
579 | ||
580 | /* We now have the file parameters, so we can tell if this is a | |
581 | * differencing file (i.e.. has_parent), is dynamic or fixed | |
582 | * sized (leave_blocks_allocated), and the block size */ | |
583 | ||
584 | /* The parent locator required iff the file parameters has_parent set */ | |
585 | if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { | |
586 | if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { | |
587 | /* TODO: parse parent locator fields */ | |
588 | ret = -ENOTSUP; /* temp, until differencing files are supported */ | |
589 | goto exit; | |
590 | } else { | |
591 | /* if has_parent is set, but there is not parent locator present, | |
592 | * then that is an invalid combination */ | |
593 | ret = -EINVAL; | |
594 | goto exit; | |
595 | } | |
596 | } | |
597 | ||
598 | /* determine virtual disk size, logical sector size, | |
599 | * and phys sector size */ | |
600 | ||
601 | ret = bdrv_pread(bs->file, | |
602 | s->metadata_entries.virtual_disk_size_entry.offset | |
603 | + s->metadata_rt.file_offset, | |
604 | &s->virtual_disk_size, | |
605 | sizeof(uint64_t)); | |
606 | if (ret < 0) { | |
607 | goto exit; | |
608 | } | |
609 | ret = bdrv_pread(bs->file, | |
610 | s->metadata_entries.logical_sector_size_entry.offset | |
611 | + s->metadata_rt.file_offset, | |
612 | &s->logical_sector_size, | |
613 | sizeof(uint32_t)); | |
614 | if (ret < 0) { | |
615 | goto exit; | |
616 | } | |
617 | ret = bdrv_pread(bs->file, | |
618 | s->metadata_entries.phys_sector_size_entry.offset | |
619 | + s->metadata_rt.file_offset, | |
620 | &s->physical_sector_size, | |
621 | sizeof(uint32_t)); | |
622 | if (ret < 0) { | |
623 | goto exit; | |
624 | } | |
625 | ||
626 | le64_to_cpus(&s->virtual_disk_size); | |
627 | le32_to_cpus(&s->logical_sector_size); | |
628 | le32_to_cpus(&s->physical_sector_size); | |
629 | ||
630 | if (s->logical_sector_size == 0 || s->params.block_size == 0) { | |
631 | ret = -EINVAL; | |
632 | goto exit; | |
633 | } | |
634 | ||
635 | /* both block_size and sector_size are guaranteed powers of 2 */ | |
636 | s->sectors_per_block = s->params.block_size / s->logical_sector_size; | |
637 | s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * | |
638 | (uint64_t)s->logical_sector_size / | |
639 | (uint64_t)s->params.block_size; | |
640 | ||
641 | /* These values are ones we will want to use for division / multiplication | |
642 | * later on, and they are all guaranteed (per the spec) to be powers of 2, | |
643 | * so we can take advantage of that for shift operations during | |
644 | * reads/writes */ | |
645 | if (s->logical_sector_size & (s->logical_sector_size - 1)) { | |
646 | ret = -EINVAL; | |
647 | goto exit; | |
648 | } | |
649 | if (s->sectors_per_block & (s->sectors_per_block - 1)) { | |
650 | ret = -EINVAL; | |
651 | goto exit; | |
652 | } | |
653 | if (s->chunk_ratio & (s->chunk_ratio - 1)) { | |
654 | ret = -EINVAL; | |
655 | goto exit; | |
656 | } | |
657 | s->block_size = s->params.block_size; | |
658 | if (s->block_size & (s->block_size - 1)) { | |
659 | ret = -EINVAL; | |
660 | goto exit; | |
661 | } | |
662 | ||
663 | s->logical_sector_size_bits = 31 - clz32(s->logical_sector_size); | |
664 | s->sectors_per_block_bits = 31 - clz32(s->sectors_per_block); | |
665 | s->chunk_ratio_bits = 63 - clz64(s->chunk_ratio); | |
666 | s->block_size_bits = 31 - clz32(s->block_size); | |
667 | ||
668 | ret = 0; | |
669 | ||
670 | exit: | |
671 | qemu_vfree(buffer); | |
672 | return ret; | |
673 | } | |
674 | ||
675 | /* Parse the replay log. Per the VHDX spec, if the log is present | |
676 | * it must be replayed prior to opening the file, even read-only. | |
677 | * | |
678 | * If read-only, we must replay the log in RAM (or refuse to open | |
679 | * a dirty VHDX file read-only */ | |
680 | static int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s) | |
681 | { | |
682 | int ret = 0; | |
683 | int i; | |
684 | VHDXHeader *hdr; | |
685 | ||
686 | hdr = s->headers[s->curr_header]; | |
687 | ||
688 | /* either the log guid, or log length is zero, | |
689 | * then a replay log is present */ | |
690 | for (i = 0; i < sizeof(hdr->log_guid.data4); i++) { | |
691 | ret |= hdr->log_guid.data4[i]; | |
692 | } | |
693 | if (hdr->log_guid.data1 == 0 && | |
694 | hdr->log_guid.data2 == 0 && | |
695 | hdr->log_guid.data3 == 0 && | |
696 | ret == 0) { | |
697 | goto exit; | |
698 | } | |
699 | ||
700 | /* per spec, only log version of 0 is supported */ | |
701 | if (hdr->log_version != 0) { | |
702 | ret = -EINVAL; | |
703 | goto exit; | |
704 | } | |
705 | ||
706 | if (hdr->log_length == 0) { | |
707 | goto exit; | |
708 | } | |
709 | ||
710 | /* We currently do not support images with logs to replay */ | |
711 | ret = -ENOTSUP; | |
712 | ||
713 | exit: | |
714 | return ret; | |
715 | } | |
716 | ||
717 | ||
718 | static int vhdx_open(BlockDriverState *bs, QDict *options, int flags) | |
719 | { | |
720 | BDRVVHDXState *s = bs->opaque; | |
721 | int ret = 0; | |
722 | uint32_t i; | |
723 | uint64_t signature; | |
724 | uint32_t data_blocks_cnt, bitmap_blocks_cnt; | |
725 | ||
726 | ||
727 | s->bat = NULL; | |
728 | ||
729 | qemu_co_mutex_init(&s->lock); | |
730 | ||
731 | /* validate the file signature */ | |
732 | ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); | |
733 | if (ret < 0) { | |
734 | goto fail; | |
735 | } | |
736 | if (memcmp(&signature, "vhdxfile", 8)) { | |
737 | ret = -EINVAL; | |
738 | goto fail; | |
739 | } | |
740 | ||
741 | ret = vhdx_parse_header(bs, s); | |
742 | if (ret) { | |
743 | goto fail; | |
744 | } | |
745 | ||
746 | ret = vhdx_parse_log(bs, s); | |
747 | if (ret) { | |
748 | goto fail; | |
749 | } | |
750 | ||
751 | ret = vhdx_open_region_tables(bs, s); | |
752 | if (ret) { | |
753 | goto fail; | |
754 | } | |
755 | ||
756 | ret = vhdx_parse_metadata(bs, s); | |
757 | if (ret) { | |
758 | goto fail; | |
759 | } | |
760 | s->block_size = s->params.block_size; | |
761 | ||
762 | /* the VHDX spec dictates that virtual_disk_size is always a multiple of | |
763 | * logical_sector_size */ | |
764 | bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; | |
765 | ||
766 | data_blocks_cnt = s->virtual_disk_size >> s->block_size_bits; | |
767 | if (s->virtual_disk_size - (data_blocks_cnt << s->block_size_bits)) { | |
768 | data_blocks_cnt++; | |
769 | } | |
770 | bitmap_blocks_cnt = data_blocks_cnt >> s->chunk_ratio_bits; | |
771 | if (data_blocks_cnt - (bitmap_blocks_cnt << s->chunk_ratio_bits)) { | |
772 | bitmap_blocks_cnt++; | |
773 | } | |
774 | ||
775 | if (s->parent_entries) { | |
776 | s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); | |
777 | } else { | |
778 | s->bat_entries = data_blocks_cnt + | |
779 | ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); | |
780 | } | |
781 | ||
782 | s->bat_offset = s->bat_rt.file_offset; | |
783 | ||
784 | if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { | |
785 | /* BAT allocation is not large enough for all entries */ | |
786 | ret = -EINVAL; | |
787 | goto fail; | |
788 | } | |
789 | ||
790 | s->bat = qemu_blockalign(bs, s->bat_rt.length); | |
791 | ||
792 | ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); | |
793 | if (ret < 0) { | |
794 | goto fail; | |
795 | } | |
796 | ||
797 | for (i = 0; i < s->bat_entries; i++) { | |
798 | le64_to_cpus(&s->bat[i]); | |
799 | } | |
800 | ||
801 | if (flags & BDRV_O_RDWR) { | |
802 | ret = -ENOTSUP; | |
803 | goto fail; | |
804 | } | |
805 | ||
059e2fbb | 806 | /* TODO: differencing files, write */ |
e8d4e5ff JC |
807 | |
808 | return 0; | |
809 | fail: | |
810 | qemu_vfree(s->headers[0]); | |
811 | qemu_vfree(s->headers[1]); | |
812 | qemu_vfree(s->bat); | |
813 | qemu_vfree(s->parent_entries); | |
814 | return ret; | |
815 | } | |
816 | ||
817 | static int vhdx_reopen_prepare(BDRVReopenState *state, | |
818 | BlockReopenQueue *queue, Error **errp) | |
819 | { | |
820 | return 0; | |
821 | } | |
822 | ||
823 | ||
059e2fbb JC |
824 | /* |
825 | * Perform sector to block offset translations, to get various | |
826 | * sector and file offsets into the image. See VHDXSectorInfo | |
827 | */ | |
828 | static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, | |
829 | int nb_sectors, VHDXSectorInfo *sinfo) | |
830 | { | |
831 | uint32_t block_offset; | |
832 | ||
833 | sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; | |
834 | /* effectively a modulo - this gives us the offset into the block | |
835 | * (in sector sizes) for our sector number */ | |
836 | block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); | |
837 | /* the chunk ratio gives us the interleaving of the sector | |
838 | * bitmaps, so we need to advance our page block index by the | |
839 | * sector bitmaps entry number */ | |
840 | sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; | |
841 | ||
842 | /* the number of sectors we can read/write in this cycle */ | |
843 | sinfo->sectors_avail = s->sectors_per_block - block_offset; | |
844 | ||
845 | sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; | |
846 | ||
847 | if (sinfo->sectors_avail > nb_sectors) { | |
848 | sinfo->sectors_avail = nb_sectors; | |
849 | } | |
850 | ||
851 | sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; | |
852 | ||
853 | sinfo->file_offset = s->bat[sinfo->bat_idx] >> VHDX_BAT_FILE_OFF_BITS; | |
854 | ||
855 | sinfo->block_offset = block_offset << s->logical_sector_size_bits; | |
856 | ||
857 | /* The file offset must be past the header section, so must be > 0 */ | |
858 | if (sinfo->file_offset == 0) { | |
859 | return; | |
860 | } | |
861 | ||
862 | /* block offset is the offset in vhdx logical sectors, in | |
863 | * the payload data block. Convert that to a byte offset | |
864 | * in the block, and add in the payload data block offset | |
865 | * in the file, in bytes, to get the final read address */ | |
866 | ||
867 | sinfo->file_offset <<= 20; /* now in bytes, rather than 1MB units */ | |
868 | sinfo->file_offset += sinfo->block_offset; | |
869 | } | |
870 | ||
871 | ||
872 | ||
e8d4e5ff JC |
873 | static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, |
874 | int nb_sectors, QEMUIOVector *qiov) | |
875 | { | |
059e2fbb JC |
876 | BDRVVHDXState *s = bs->opaque; |
877 | int ret = 0; | |
878 | VHDXSectorInfo sinfo; | |
879 | uint64_t bytes_done = 0; | |
880 | QEMUIOVector hd_qiov; | |
881 | ||
882 | qemu_iovec_init(&hd_qiov, qiov->niov); | |
883 | ||
884 | qemu_co_mutex_lock(&s->lock); | |
885 | ||
886 | while (nb_sectors > 0) { | |
887 | /* We are a differencing file, so we need to inspect the sector bitmap | |
888 | * to see if we have the data or not */ | |
889 | if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { | |
890 | /* not supported yet */ | |
891 | ret = -ENOTSUP; | |
892 | goto exit; | |
893 | } else { | |
894 | vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); | |
895 | ||
896 | qemu_iovec_reset(&hd_qiov); | |
897 | qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); | |
898 | ||
899 | /* check the payload block state */ | |
900 | switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { | |
901 | case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ | |
902 | case PAYLOAD_BLOCK_UNDEFINED: /* fall through */ | |
903 | case PAYLOAD_BLOCK_UNMAPPED: /* fall through */ | |
904 | case PAYLOAD_BLOCK_ZERO: | |
905 | /* return zero */ | |
906 | qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); | |
907 | break; | |
908 | case PAYLOAD_BLOCK_FULL_PRESENT: | |
909 | qemu_co_mutex_unlock(&s->lock); | |
910 | ret = bdrv_co_readv(bs->file, | |
911 | sinfo.file_offset >> BDRV_SECTOR_BITS, | |
912 | sinfo.sectors_avail, &hd_qiov); | |
913 | qemu_co_mutex_lock(&s->lock); | |
914 | if (ret < 0) { | |
915 | goto exit; | |
916 | } | |
917 | break; | |
918 | case PAYLOAD_BLOCK_PARTIALLY_PRESENT: | |
919 | /* we don't yet support difference files, fall through | |
920 | * to error */ | |
921 | default: | |
922 | ret = -EIO; | |
923 | goto exit; | |
924 | break; | |
925 | } | |
926 | nb_sectors -= sinfo.sectors_avail; | |
927 | sector_num += sinfo.sectors_avail; | |
928 | bytes_done += sinfo.bytes_avail; | |
929 | } | |
930 | } | |
931 | ret = 0; | |
932 | exit: | |
933 | qemu_co_mutex_unlock(&s->lock); | |
934 | qemu_iovec_destroy(&hd_qiov); | |
935 | return ret; | |
e8d4e5ff JC |
936 | } |
937 | ||
938 | ||
939 | ||
940 | static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, | |
941 | int nb_sectors, QEMUIOVector *qiov) | |
942 | { | |
943 | return -ENOTSUP; | |
944 | } | |
945 | ||
946 | ||
947 | static void vhdx_close(BlockDriverState *bs) | |
948 | { | |
949 | BDRVVHDXState *s = bs->opaque; | |
950 | qemu_vfree(s->headers[0]); | |
951 | qemu_vfree(s->headers[1]); | |
952 | qemu_vfree(s->bat); | |
953 | qemu_vfree(s->parent_entries); | |
954 | } | |
955 | ||
956 | static BlockDriver bdrv_vhdx = { | |
957 | .format_name = "vhdx", | |
958 | .instance_size = sizeof(BDRVVHDXState), | |
959 | .bdrv_probe = vhdx_probe, | |
960 | .bdrv_open = vhdx_open, | |
961 | .bdrv_close = vhdx_close, | |
962 | .bdrv_reopen_prepare = vhdx_reopen_prepare, | |
963 | .bdrv_co_readv = vhdx_co_readv, | |
964 | .bdrv_co_writev = vhdx_co_writev, | |
965 | }; | |
966 | ||
967 | static void bdrv_vhdx_init(void) | |
968 | { | |
969 | bdrv_register(&bdrv_vhdx); | |
970 | } | |
971 | ||
972 | block_init(bdrv_vhdx_init); |