hw/elf_ops: Fix a typo
[qemu/ar7.git] / block / qcow2-threads.c
blob1914baf456c71cb5caef3ca85c1ded57d837251b
1 /*
2 * Threaded data processing for Qcow2: compression, encryption
4 * Copyright (c) 2004-2006 Fabrice Bellard
5 * Copyright (c) 2018 Virtuozzo International GmbH. All rights reserved.
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:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
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.
26 #include "qemu/osdep.h"
28 #define ZLIB_CONST
29 #include <zlib.h>
31 #ifdef CONFIG_ZSTD
32 #include <zstd.h>
33 #include <zstd_errors.h>
34 #endif
36 #include "qcow2.h"
37 #include "block/thread-pool.h"
38 #include "crypto.h"
40 static int coroutine_fn
41 qcow2_co_process(BlockDriverState *bs, ThreadPoolFunc *func, void *arg)
43 int ret;
44 BDRVQcow2State *s = bs->opaque;
45 ThreadPool *pool = aio_get_thread_pool(bdrv_get_aio_context(bs));
47 qemu_co_mutex_lock(&s->lock);
48 while (s->nb_threads >= QCOW2_MAX_THREADS) {
49 qemu_co_queue_wait(&s->thread_task_queue, &s->lock);
51 s->nb_threads++;
52 qemu_co_mutex_unlock(&s->lock);
54 ret = thread_pool_submit_co(pool, func, arg);
56 qemu_co_mutex_lock(&s->lock);
57 s->nb_threads--;
58 qemu_co_queue_next(&s->thread_task_queue);
59 qemu_co_mutex_unlock(&s->lock);
61 return ret;
66 * Compression
69 typedef ssize_t (*Qcow2CompressFunc)(void *dest, size_t dest_size,
70 const void *src, size_t src_size);
71 typedef struct Qcow2CompressData {
72 void *dest;
73 size_t dest_size;
74 const void *src;
75 size_t src_size;
76 ssize_t ret;
78 Qcow2CompressFunc func;
79 } Qcow2CompressData;
82 * qcow2_zlib_compress()
84 * Compress @src_size bytes of data using zlib compression method
86 * @dest - destination buffer, @dest_size bytes
87 * @src - source buffer, @src_size bytes
89 * Returns: compressed size on success
90 * -ENOMEM destination buffer is not enough to store compressed data
91 * -EIO on any other error
93 static ssize_t qcow2_zlib_compress(void *dest, size_t dest_size,
94 const void *src, size_t src_size)
96 ssize_t ret;
97 z_stream strm;
99 /* best compression, small window, no zlib header */
100 memset(&strm, 0, sizeof(strm));
101 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
102 -12, 9, Z_DEFAULT_STRATEGY);
103 if (ret != Z_OK) {
104 return -EIO;
108 * strm.next_in is not const in old zlib versions, such as those used on
109 * OpenBSD/NetBSD, so cast the const away
111 strm.avail_in = src_size;
112 strm.next_in = (void *) src;
113 strm.avail_out = dest_size;
114 strm.next_out = dest;
116 ret = deflate(&strm, Z_FINISH);
117 if (ret == Z_STREAM_END) {
118 ret = dest_size - strm.avail_out;
119 } else {
120 ret = (ret == Z_OK ? -ENOMEM : -EIO);
123 deflateEnd(&strm);
125 return ret;
129 * qcow2_zlib_decompress()
131 * Decompress some data (not more than @src_size bytes) to produce exactly
132 * @dest_size bytes using zlib compression method
134 * @dest - destination buffer, @dest_size bytes
135 * @src - source buffer, @src_size bytes
137 * Returns: 0 on success
138 * -EIO on fail
140 static ssize_t qcow2_zlib_decompress(void *dest, size_t dest_size,
141 const void *src, size_t src_size)
143 int ret;
144 z_stream strm;
146 memset(&strm, 0, sizeof(strm));
147 strm.avail_in = src_size;
148 strm.next_in = (void *) src;
149 strm.avail_out = dest_size;
150 strm.next_out = dest;
152 ret = inflateInit2(&strm, -12);
153 if (ret != Z_OK) {
154 return -EIO;
157 ret = inflate(&strm, Z_FINISH);
158 if ((ret == Z_STREAM_END || ret == Z_BUF_ERROR) && strm.avail_out == 0) {
160 * We approve Z_BUF_ERROR because we need @dest buffer to be filled, but
161 * @src buffer may be processed partly (because in qcow2 we know size of
162 * compressed data with precision of one sector)
164 ret = 0;
165 } else {
166 ret = -EIO;
169 inflateEnd(&strm);
171 return ret;
174 #ifdef CONFIG_ZSTD
177 * qcow2_zstd_compress()
179 * Compress @src_size bytes of data using zstd compression method
181 * @dest - destination buffer, @dest_size bytes
182 * @src - source buffer, @src_size bytes
184 * Returns: compressed size on success
185 * -ENOMEM destination buffer is not enough to store compressed data
186 * -EIO on any other error
188 static ssize_t qcow2_zstd_compress(void *dest, size_t dest_size,
189 const void *src, size_t src_size)
191 ssize_t ret;
192 size_t zstd_ret;
193 ZSTD_outBuffer output = {
194 .dst = dest,
195 .size = dest_size,
196 .pos = 0
198 ZSTD_inBuffer input = {
199 .src = src,
200 .size = src_size,
201 .pos = 0
203 ZSTD_CCtx *cctx = ZSTD_createCCtx();
205 if (!cctx) {
206 return -EIO;
209 * Use the zstd streamed interface for symmetry with decompression,
210 * where streaming is essential since we don't record the exact
211 * compressed size.
213 * ZSTD_compressStream2() tries to compress everything it could
214 * with a single call. Although, ZSTD docs says that:
215 * "You must continue calling ZSTD_compressStream2() with ZSTD_e_end
216 * until it returns 0, at which point you are free to start a new frame",
217 * in out tests we saw the only case when it returned with >0 -
218 * when the output buffer was too small. In that case,
219 * ZSTD_compressStream2() expects a bigger buffer on the next call.
220 * We can't provide a bigger buffer because we are limited with dest_size
221 * which we pass to the ZSTD_compressStream2() at once.
222 * So, we don't need any loops and just abort the compression when we
223 * don't get 0 result on the first call.
225 zstd_ret = ZSTD_compressStream2(cctx, &output, &input, ZSTD_e_end);
227 if (zstd_ret) {
228 if (zstd_ret > output.size - output.pos) {
229 ret = -ENOMEM;
230 } else {
231 ret = -EIO;
233 goto out;
236 /* make sure that zstd didn't overflow the dest buffer */
237 assert(output.pos <= dest_size);
238 ret = output.pos;
239 out:
240 ZSTD_freeCCtx(cctx);
241 return ret;
245 * qcow2_zstd_decompress()
247 * Decompress some data (not more than @src_size bytes) to produce exactly
248 * @dest_size bytes using zstd compression method
250 * @dest - destination buffer, @dest_size bytes
251 * @src - source buffer, @src_size bytes
253 * Returns: 0 on success
254 * -EIO on any error
256 static ssize_t qcow2_zstd_decompress(void *dest, size_t dest_size,
257 const void *src, size_t src_size)
259 size_t zstd_ret = 0;
260 ssize_t ret = 0;
261 ZSTD_outBuffer output = {
262 .dst = dest,
263 .size = dest_size,
264 .pos = 0
266 ZSTD_inBuffer input = {
267 .src = src,
268 .size = src_size,
269 .pos = 0
271 ZSTD_DCtx *dctx = ZSTD_createDCtx();
273 if (!dctx) {
274 return -EIO;
278 * The compressed stream from the input buffer may consist of more
279 * than one zstd frame. So we iterate until we get a fully
280 * uncompressed cluster.
281 * From zstd docs related to ZSTD_decompressStream:
282 * "return : 0 when a frame is completely decoded and fully flushed"
283 * We suppose that this means: each time ZSTD_decompressStream reads
284 * only ONE full frame and returns 0 if and only if that frame
285 * is completely decoded and flushed. Only after returning 0,
286 * ZSTD_decompressStream reads another ONE full frame.
288 while (output.pos < output.size) {
289 size_t last_in_pos = input.pos;
290 size_t last_out_pos = output.pos;
291 zstd_ret = ZSTD_decompressStream(dctx, &output, &input);
293 if (ZSTD_isError(zstd_ret)) {
294 ret = -EIO;
295 break;
299 * The ZSTD manual is vague about what to do if it reads
300 * the buffer partially, and we don't want to get stuck
301 * in an infinite loop where ZSTD_decompressStream
302 * returns > 0 waiting for another input chunk. So, we add
303 * a check which ensures that the loop makes some progress
304 * on each step.
306 if (last_in_pos >= input.pos &&
307 last_out_pos >= output.pos) {
308 ret = -EIO;
309 break;
313 * Make sure that we have the frame fully flushed here
314 * if not, we somehow managed to get uncompressed cluster
315 * greater then the cluster size, possibly because of its
316 * damage.
318 if (zstd_ret > 0) {
319 ret = -EIO;
322 ZSTD_freeDCtx(dctx);
323 assert(ret == 0 || ret == -EIO);
324 return ret;
326 #endif
328 static int qcow2_compress_pool_func(void *opaque)
330 Qcow2CompressData *data = opaque;
332 data->ret = data->func(data->dest, data->dest_size,
333 data->src, data->src_size);
335 return 0;
338 static ssize_t coroutine_fn
339 qcow2_co_do_compress(BlockDriverState *bs, void *dest, size_t dest_size,
340 const void *src, size_t src_size, Qcow2CompressFunc func)
342 Qcow2CompressData arg = {
343 .dest = dest,
344 .dest_size = dest_size,
345 .src = src,
346 .src_size = src_size,
347 .func = func,
350 qcow2_co_process(bs, qcow2_compress_pool_func, &arg);
352 return arg.ret;
356 * qcow2_co_compress()
358 * Compress @src_size bytes of data using the compression
359 * method defined by the image compression type
361 * @dest - destination buffer, @dest_size bytes
362 * @src - source buffer, @src_size bytes
364 * Returns: compressed size on success
365 * a negative error code on failure
367 ssize_t coroutine_fn
368 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
369 const void *src, size_t src_size)
371 BDRVQcow2State *s = bs->opaque;
372 Qcow2CompressFunc fn;
374 switch (s->compression_type) {
375 case QCOW2_COMPRESSION_TYPE_ZLIB:
376 fn = qcow2_zlib_compress;
377 break;
379 #ifdef CONFIG_ZSTD
380 case QCOW2_COMPRESSION_TYPE_ZSTD:
381 fn = qcow2_zstd_compress;
382 break;
383 #endif
384 default:
385 abort();
388 return qcow2_co_do_compress(bs, dest, dest_size, src, src_size, fn);
392 * qcow2_co_decompress()
394 * Decompress some data (not more than @src_size bytes) to produce exactly
395 * @dest_size bytes using the compression method defined by the image
396 * compression type
398 * @dest - destination buffer, @dest_size bytes
399 * @src - source buffer, @src_size bytes
401 * Returns: 0 on success
402 * a negative error code on failure
404 ssize_t coroutine_fn
405 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
406 const void *src, size_t src_size)
408 BDRVQcow2State *s = bs->opaque;
409 Qcow2CompressFunc fn;
411 switch (s->compression_type) {
412 case QCOW2_COMPRESSION_TYPE_ZLIB:
413 fn = qcow2_zlib_decompress;
414 break;
416 #ifdef CONFIG_ZSTD
417 case QCOW2_COMPRESSION_TYPE_ZSTD:
418 fn = qcow2_zstd_decompress;
419 break;
420 #endif
421 default:
422 abort();
425 return qcow2_co_do_compress(bs, dest, dest_size, src, src_size, fn);
430 * Cryptography
434 * Qcow2EncDecFunc: common prototype of qcrypto_block_encrypt() and
435 * qcrypto_block_decrypt() functions.
437 typedef int (*Qcow2EncDecFunc)(QCryptoBlock *block, uint64_t offset,
438 uint8_t *buf, size_t len, Error **errp);
440 typedef struct Qcow2EncDecData {
441 QCryptoBlock *block;
442 uint64_t offset;
443 uint8_t *buf;
444 size_t len;
446 Qcow2EncDecFunc func;
447 } Qcow2EncDecData;
449 static int qcow2_encdec_pool_func(void *opaque)
451 Qcow2EncDecData *data = opaque;
453 return data->func(data->block, data->offset, data->buf, data->len, NULL);
456 static int coroutine_fn
457 qcow2_co_encdec(BlockDriverState *bs, uint64_t host_offset,
458 uint64_t guest_offset, void *buf, size_t len,
459 Qcow2EncDecFunc func)
461 BDRVQcow2State *s = bs->opaque;
462 Qcow2EncDecData arg = {
463 .block = s->crypto,
464 .offset = s->crypt_physical_offset ? host_offset : guest_offset,
465 .buf = buf,
466 .len = len,
467 .func = func,
469 uint64_t sector_size;
471 assert(s->crypto);
473 sector_size = qcrypto_block_get_sector_size(s->crypto);
474 assert(QEMU_IS_ALIGNED(guest_offset, sector_size));
475 assert(QEMU_IS_ALIGNED(host_offset, sector_size));
476 assert(QEMU_IS_ALIGNED(len, sector_size));
478 return len == 0 ? 0 : qcow2_co_process(bs, qcow2_encdec_pool_func, &arg);
482 * qcow2_co_encrypt()
484 * Encrypts one or more contiguous aligned sectors
486 * @host_offset - underlying storage offset of the first sector of the
487 * data to be encrypted
489 * @guest_offset - guest (virtual) offset of the first sector of the
490 * data to be encrypted
492 * @buf - buffer with the data to encrypt, that after encryption
493 * will be written to the underlying storage device at
494 * @host_offset
496 * @len - length of the buffer (must be a multiple of the encryption
497 * sector size)
499 * Depending on the encryption method, @host_offset and/or @guest_offset
500 * may be used for generating the initialization vector for
501 * encryption.
503 * Note that while the whole range must be aligned on sectors, it
504 * does not have to be aligned on clusters and can also cross cluster
505 * boundaries
507 int coroutine_fn
508 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
509 uint64_t guest_offset, void *buf, size_t len)
511 return qcow2_co_encdec(bs, host_offset, guest_offset, buf, len,
512 qcrypto_block_encrypt);
516 * qcow2_co_decrypt()
518 * Decrypts one or more contiguous aligned sectors
519 * Similar to qcow2_co_encrypt
521 int coroutine_fn
522 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
523 uint64_t guest_offset, void *buf, size_t len)
525 return qcow2_co_encdec(bs, host_offset, guest_offset, buf, len,
526 qcrypto_block_decrypt);