Update version for v7.1.0-rc3 release
[qemu.git] / migration / multifd-zlib.c
1 /*
2 * Multifd zlib compression implementation
3 *
4 * Copyright (c) 2020 Red Hat Inc
5 *
6 * Authors:
7 * Juan Quintela <quintela@redhat.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
10 * See the COPYING file in the top-level directory.
11 */
12
13 #include "qemu/osdep.h"
14 #include <zlib.h>
15 #include "qemu/rcu.h"
16 #include "exec/ramblock.h"
17 #include "exec/target_page.h"
18 #include "qapi/error.h"
19 #include "migration.h"
20 #include "trace.h"
21 #include "multifd.h"
22
23 struct zlib_data {
24 /* stream for compression */
25 z_stream zs;
26 /* compressed buffer */
27 uint8_t *zbuff;
28 /* size of compressed buffer */
29 uint32_t zbuff_len;
30 };
31
32 /* Multifd zlib compression */
33
34 /**
35 * zlib_send_setup: setup send side
36 *
37 * Setup each channel with zlib compression.
38 *
39 * Returns 0 for success or -1 for error
40 *
41 * @p: Params for the channel that we are using
42 * @errp: pointer to an error
43 */
44 static int zlib_send_setup(MultiFDSendParams *p, Error **errp)
45 {
46 struct zlib_data *z = g_malloc0(sizeof(struct zlib_data));
47 z_stream *zs = &z->zs;
48
49 zs->zalloc = Z_NULL;
50 zs->zfree = Z_NULL;
51 zs->opaque = Z_NULL;
52 if (deflateInit(zs, migrate_multifd_zlib_level()) != Z_OK) {
53 g_free(z);
54 error_setg(errp, "multifd %d: deflate init failed", p->id);
55 return -1;
56 }
57 /* To be safe, we reserve twice the size of the packet */
58 z->zbuff_len = MULTIFD_PACKET_SIZE * 2;
59 z->zbuff = g_try_malloc(z->zbuff_len);
60 if (!z->zbuff) {
61 deflateEnd(&z->zs);
62 g_free(z);
63 error_setg(errp, "multifd %d: out of memory for zbuff", p->id);
64 return -1;
65 }
66 p->data = z;
67 return 0;
68 }
69
70 /**
71 * zlib_send_cleanup: cleanup send side
72 *
73 * Close the channel and return memory.
74 *
75 * @p: Params for the channel that we are using
76 * @errp: pointer to an error
77 */
78 static void zlib_send_cleanup(MultiFDSendParams *p, Error **errp)
79 {
80 struct zlib_data *z = p->data;
81
82 deflateEnd(&z->zs);
83 g_free(z->zbuff);
84 z->zbuff = NULL;
85 g_free(p->data);
86 p->data = NULL;
87 }
88
89 /**
90 * zlib_send_prepare: prepare date to be able to send
91 *
92 * Create a compressed buffer with all the pages that we are going to
93 * send.
94 *
95 * Returns 0 for success or -1 for error
96 *
97 * @p: Params for the channel that we are using
98 * @errp: pointer to an error
99 */
100 static int zlib_send_prepare(MultiFDSendParams *p, Error **errp)
101 {
102 struct zlib_data *z = p->data;
103 size_t page_size = qemu_target_page_size();
104 z_stream *zs = &z->zs;
105 uint32_t out_size = 0;
106 int ret;
107 uint32_t i;
108
109 for (i = 0; i < p->pages->num; i++) {
110 uint32_t available = z->zbuff_len - out_size;
111 int flush = Z_NO_FLUSH;
112
113 if (i == p->pages->num - 1) {
114 flush = Z_SYNC_FLUSH;
115 }
116
117 zs->avail_in = page_size;
118 zs->next_in = p->pages->block->host + p->pages->offset[i];
119
120 zs->avail_out = available;
121 zs->next_out = z->zbuff + out_size;
122
123 /*
124 * Welcome to deflate semantics
125 *
126 * We need to loop while:
127 * - return is Z_OK
128 * - there are stuff to be compressed
129 * - there are output space free
130 */
131 do {
132 ret = deflate(zs, flush);
133 } while (ret == Z_OK && zs->avail_in && zs->avail_out);
134 if (ret == Z_OK && zs->avail_in) {
135 error_setg(errp, "multifd %d: deflate failed to compress all input",
136 p->id);
137 return -1;
138 }
139 if (ret != Z_OK) {
140 error_setg(errp, "multifd %d: deflate returned %d instead of Z_OK",
141 p->id, ret);
142 return -1;
143 }
144 out_size += available - zs->avail_out;
145 }
146 p->next_packet_size = out_size;
147 p->flags |= MULTIFD_FLAG_ZLIB;
148
149 return 0;
150 }
151
152 /**
153 * zlib_send_write: do the actual write of the data
154 *
155 * Do the actual write of the comprresed buffer.
156 *
157 * Returns 0 for success or -1 for error
158 *
159 * @p: Params for the channel that we are using
160 * @used: number of pages used
161 * @errp: pointer to an error
162 */
163 static int zlib_send_write(MultiFDSendParams *p, uint32_t used, Error **errp)
164 {
165 struct zlib_data *z = p->data;
166
167 return qio_channel_write_all(p->c, (void *)z->zbuff, p->next_packet_size,
168 errp);
169 }
170
171 /**
172 * zlib_recv_setup: setup receive side
173 *
174 * Create the compressed channel and buffer.
175 *
176 * Returns 0 for success or -1 for error
177 *
178 * @p: Params for the channel that we are using
179 * @errp: pointer to an error
180 */
181 static int zlib_recv_setup(MultiFDRecvParams *p, Error **errp)
182 {
183 struct zlib_data *z = g_malloc0(sizeof(struct zlib_data));
184 z_stream *zs = &z->zs;
185
186 p->data = z;
187 zs->zalloc = Z_NULL;
188 zs->zfree = Z_NULL;
189 zs->opaque = Z_NULL;
190 zs->avail_in = 0;
191 zs->next_in = Z_NULL;
192 if (inflateInit(zs) != Z_OK) {
193 error_setg(errp, "multifd %d: inflate init failed", p->id);
194 return -1;
195 }
196 /* To be safe, we reserve twice the size of the packet */
197 z->zbuff_len = MULTIFD_PACKET_SIZE * 2;
198 z->zbuff = g_try_malloc(z->zbuff_len);
199 if (!z->zbuff) {
200 inflateEnd(zs);
201 error_setg(errp, "multifd %d: out of memory for zbuff", p->id);
202 return -1;
203 }
204 return 0;
205 }
206
207 /**
208 * zlib_recv_cleanup: setup receive side
209 *
210 * For no compression this function does nothing.
211 *
212 * @p: Params for the channel that we are using
213 */
214 static void zlib_recv_cleanup(MultiFDRecvParams *p)
215 {
216 struct zlib_data *z = p->data;
217
218 inflateEnd(&z->zs);
219 g_free(z->zbuff);
220 z->zbuff = NULL;
221 g_free(p->data);
222 p->data = NULL;
223 }
224
225 /**
226 * zlib_recv_pages: read the data from the channel into actual pages
227 *
228 * Read the compressed buffer, and uncompress it into the actual
229 * pages.
230 *
231 * Returns 0 for success or -1 for error
232 *
233 * @p: Params for the channel that we are using
234 * @errp: pointer to an error
235 */
236 static int zlib_recv_pages(MultiFDRecvParams *p, Error **errp)
237 {
238 struct zlib_data *z = p->data;
239 size_t page_size = qemu_target_page_size();
240 z_stream *zs = &z->zs;
241 uint32_t in_size = p->next_packet_size;
242 /* we measure the change of total_out */
243 uint32_t out_size = zs->total_out;
244 uint32_t expected_size = p->pages->num * qemu_target_page_size();
245 uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
246 int ret;
247 int i;
248
249 if (flags != MULTIFD_FLAG_ZLIB) {
250 error_setg(errp, "multifd %d: flags received %x flags expected %x",
251 p->id, flags, MULTIFD_FLAG_ZLIB);
252 return -1;
253 }
254 ret = qio_channel_read_all(p->c, (void *)z->zbuff, in_size, errp);
255
256 if (ret != 0) {
257 return ret;
258 }
259
260 zs->avail_in = in_size;
261 zs->next_in = z->zbuff;
262
263 for (i = 0; i < p->pages->num; i++) {
264 int flush = Z_NO_FLUSH;
265 unsigned long start = zs->total_out;
266
267 if (i == p->pages->num - 1) {
268 flush = Z_SYNC_FLUSH;
269 }
270
271 zs->avail_out = page_size;
272 zs->next_out = p->pages->block->host + p->pages->offset[i];
273
274 /*
275 * Welcome to inflate semantics
276 *
277 * We need to loop while:
278 * - return is Z_OK
279 * - there are input available
280 * - we haven't completed a full page
281 */
282 do {
283 ret = inflate(zs, flush);
284 } while (ret == Z_OK && zs->avail_in
285 && (zs->total_out - start) < page_size);
286 if (ret == Z_OK && (zs->total_out - start) < page_size) {
287 error_setg(errp, "multifd %d: inflate generated too few output",
288 p->id);
289 return -1;
290 }
291 if (ret != Z_OK) {
292 error_setg(errp, "multifd %d: inflate returned %d instead of Z_OK",
293 p->id, ret);
294 return -1;
295 }
296 }
297 out_size = zs->total_out - out_size;
298 if (out_size != expected_size) {
299 error_setg(errp, "multifd %d: packet size received %d size expected %d",
300 p->id, out_size, expected_size);
301 return -1;
302 }
303 return 0;
304 }
305
306 static MultiFDMethods multifd_zlib_ops = {
307 .send_setup = zlib_send_setup,
308 .send_cleanup = zlib_send_cleanup,
309 .send_prepare = zlib_send_prepare,
310 .send_write = zlib_send_write,
311 .recv_setup = zlib_recv_setup,
312 .recv_cleanup = zlib_recv_cleanup,
313 .recv_pages = zlib_recv_pages
314 };
315
316 static void multifd_zlib_register(void)
317 {
318 multifd_register_ops(MULTIFD_COMPRESSION_ZLIB, &multifd_zlib_ops);
319 }
320
321 migration_init(multifd_zlib_register);