Update version for v7.1.0-rc3 release
[qemu.git] / migration / multifd-zstd.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 <zstd.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 zstd_data {
24 /* stream for compression */
25 ZSTD_CStream *zcs;
26 /* stream for decompression */
27 ZSTD_DStream *zds;
28 /* buffers */
29 ZSTD_inBuffer in;
30 ZSTD_outBuffer out;
31 /* compressed buffer */
32 uint8_t *zbuff;
33 /* size of compressed buffer */
34 uint32_t zbuff_len;
35 };
36
37 /* Multifd zstd compression */
38
39 /**
40 * zstd_send_setup: setup send side
41 *
42 * Setup each channel with zstd compression.
43 *
44 * Returns 0 for success or -1 for error
45 *
46 * @p: Params for the channel that we are using
47 * @errp: pointer to an error
48 */
49 static int zstd_send_setup(MultiFDSendParams *p, Error **errp)
50 {
51 struct zstd_data *z = g_new0(struct zstd_data, 1);
52 int res;
53
54 p->data = z;
55 z->zcs = ZSTD_createCStream();
56 if (!z->zcs) {
57 g_free(z);
58 error_setg(errp, "multifd %d: zstd createCStream failed", p->id);
59 return -1;
60 }
61
62 res = ZSTD_initCStream(z->zcs, migrate_multifd_zstd_level());
63 if (ZSTD_isError(res)) {
64 ZSTD_freeCStream(z->zcs);
65 g_free(z);
66 error_setg(errp, "multifd %d: initCStream failed with error %s",
67 p->id, ZSTD_getErrorName(res));
68 return -1;
69 }
70 /* To be safe, we reserve twice the size of the packet */
71 z->zbuff_len = MULTIFD_PACKET_SIZE * 2;
72 z->zbuff = g_try_malloc(z->zbuff_len);
73 if (!z->zbuff) {
74 ZSTD_freeCStream(z->zcs);
75 g_free(z);
76 error_setg(errp, "multifd %d: out of memory for zbuff", p->id);
77 return -1;
78 }
79 return 0;
80 }
81
82 /**
83 * zstd_send_cleanup: cleanup send side
84 *
85 * Close the channel and return memory.
86 *
87 * @p: Params for the channel that we are using
88 * @errp: pointer to an error
89 */
90 static void zstd_send_cleanup(MultiFDSendParams *p, Error **errp)
91 {
92 struct zstd_data *z = p->data;
93
94 ZSTD_freeCStream(z->zcs);
95 z->zcs = NULL;
96 g_free(z->zbuff);
97 z->zbuff = NULL;
98 g_free(p->data);
99 p->data = NULL;
100 }
101
102 /**
103 * zstd_send_prepare: prepare date to be able to send
104 *
105 * Create a compressed buffer with all the pages that we are going to
106 * send.
107 *
108 * Returns 0 for success or -1 for error
109 *
110 * @p: Params for the channel that we are using
111 * @errp: pointer to an error
112 */
113 static int zstd_send_prepare(MultiFDSendParams *p, Error **errp)
114 {
115 struct zstd_data *z = p->data;
116 size_t page_size = qemu_target_page_size();
117 int ret;
118 uint32_t i;
119
120 z->out.dst = z->zbuff;
121 z->out.size = z->zbuff_len;
122 z->out.pos = 0;
123
124 for (i = 0; i < p->pages->num; i++) {
125 ZSTD_EndDirective flush = ZSTD_e_continue;
126
127 if (i == p->pages->num - 1) {
128 flush = ZSTD_e_flush;
129 }
130 z->in.src = p->pages->block->host + p->pages->offset[i];
131 z->in.size = page_size;
132 z->in.pos = 0;
133
134 /*
135 * Welcome to compressStream2 semantics
136 *
137 * We need to loop while:
138 * - return is > 0
139 * - there is input available
140 * - there is output space free
141 */
142 do {
143 ret = ZSTD_compressStream2(z->zcs, &z->out, &z->in, flush);
144 } while (ret > 0 && (z->in.size - z->in.pos > 0)
145 && (z->out.size - z->out.pos > 0));
146 if (ret > 0 && (z->in.size - z->in.pos > 0)) {
147 error_setg(errp, "multifd %d: compressStream buffer too small",
148 p->id);
149 return -1;
150 }
151 if (ZSTD_isError(ret)) {
152 error_setg(errp, "multifd %d: compressStream error %s",
153 p->id, ZSTD_getErrorName(ret));
154 return -1;
155 }
156 }
157 p->next_packet_size = z->out.pos;
158 p->flags |= MULTIFD_FLAG_ZSTD;
159
160 return 0;
161 }
162
163 /**
164 * zstd_send_write: do the actual write of the data
165 *
166 * Do the actual write of the comprresed buffer.
167 *
168 * Returns 0 for success or -1 for error
169 *
170 * @p: Params for the channel that we are using
171 * @used: number of pages used
172 * @errp: pointer to an error
173 */
174 static int zstd_send_write(MultiFDSendParams *p, uint32_t used, Error **errp)
175 {
176 struct zstd_data *z = p->data;
177
178 return qio_channel_write_all(p->c, (void *)z->zbuff, p->next_packet_size,
179 errp);
180 }
181
182 /**
183 * zstd_recv_setup: setup receive side
184 *
185 * Create the compressed channel and buffer.
186 *
187 * Returns 0 for success or -1 for error
188 *
189 * @p: Params for the channel that we are using
190 * @errp: pointer to an error
191 */
192 static int zstd_recv_setup(MultiFDRecvParams *p, Error **errp)
193 {
194 struct zstd_data *z = g_new0(struct zstd_data, 1);
195 int ret;
196
197 p->data = z;
198 z->zds = ZSTD_createDStream();
199 if (!z->zds) {
200 g_free(z);
201 error_setg(errp, "multifd %d: zstd createDStream failed", p->id);
202 return -1;
203 }
204
205 ret = ZSTD_initDStream(z->zds);
206 if (ZSTD_isError(ret)) {
207 ZSTD_freeDStream(z->zds);
208 g_free(z);
209 error_setg(errp, "multifd %d: initDStream failed with error %s",
210 p->id, ZSTD_getErrorName(ret));
211 return -1;
212 }
213
214 /* To be safe, we reserve twice the size of the packet */
215 z->zbuff_len = MULTIFD_PACKET_SIZE * 2;
216 z->zbuff = g_try_malloc(z->zbuff_len);
217 if (!z->zbuff) {
218 ZSTD_freeDStream(z->zds);
219 g_free(z);
220 error_setg(errp, "multifd %d: out of memory for zbuff", p->id);
221 return -1;
222 }
223 return 0;
224 }
225
226 /**
227 * zstd_recv_cleanup: setup receive side
228 *
229 * For no compression this function does nothing.
230 *
231 * @p: Params for the channel that we are using
232 */
233 static void zstd_recv_cleanup(MultiFDRecvParams *p)
234 {
235 struct zstd_data *z = p->data;
236
237 ZSTD_freeDStream(z->zds);
238 z->zds = NULL;
239 g_free(z->zbuff);
240 z->zbuff = NULL;
241 g_free(p->data);
242 p->data = NULL;
243 }
244
245 /**
246 * zstd_recv_pages: read the data from the channel into actual pages
247 *
248 * Read the compressed buffer, and uncompress it into the actual
249 * pages.
250 *
251 * Returns 0 for success or -1 for error
252 *
253 * @p: Params for the channel that we are using
254 * @errp: pointer to an error
255 */
256 static int zstd_recv_pages(MultiFDRecvParams *p, Error **errp)
257 {
258 uint32_t in_size = p->next_packet_size;
259 uint32_t out_size = 0;
260 size_t page_size = qemu_target_page_size();
261 uint32_t expected_size = p->pages->num * page_size;
262 uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
263 struct zstd_data *z = p->data;
264 int ret;
265 int i;
266
267 if (flags != MULTIFD_FLAG_ZSTD) {
268 error_setg(errp, "multifd %d: flags received %x flags expected %x",
269 p->id, flags, MULTIFD_FLAG_ZSTD);
270 return -1;
271 }
272 ret = qio_channel_read_all(p->c, (void *)z->zbuff, in_size, errp);
273
274 if (ret != 0) {
275 return ret;
276 }
277
278 z->in.src = z->zbuff;
279 z->in.size = in_size;
280 z->in.pos = 0;
281
282 for (i = 0; i < p->pages->num; i++) {
283 z->out.dst = p->pages->block->host + p->pages->offset[i];
284 z->out.size = page_size;
285 z->out.pos = 0;
286
287 /*
288 * Welcome to decompressStream semantics
289 *
290 * We need to loop while:
291 * - return is > 0
292 * - there is input available
293 * - we haven't put out a full page
294 */
295 do {
296 ret = ZSTD_decompressStream(z->zds, &z->out, &z->in);
297 } while (ret > 0 && (z->in.size - z->in.pos > 0)
298 && (z->out.pos < page_size));
299 if (ret > 0 && (z->out.pos < page_size)) {
300 error_setg(errp, "multifd %d: decompressStream buffer too small",
301 p->id);
302 return -1;
303 }
304 if (ZSTD_isError(ret)) {
305 error_setg(errp, "multifd %d: decompressStream returned %s",
306 p->id, ZSTD_getErrorName(ret));
307 return ret;
308 }
309 out_size += z->out.pos;
310 }
311 if (out_size != expected_size) {
312 error_setg(errp, "multifd %d: packet size received %d size expected %d",
313 p->id, out_size, expected_size);
314 return -1;
315 }
316 return 0;
317 }
318
319 static MultiFDMethods multifd_zstd_ops = {
320 .send_setup = zstd_send_setup,
321 .send_cleanup = zstd_send_cleanup,
322 .send_prepare = zstd_send_prepare,
323 .send_write = zstd_send_write,
324 .recv_setup = zstd_recv_setup,
325 .recv_cleanup = zstd_recv_cleanup,
326 .recv_pages = zstd_recv_pages
327 };
328
329 static void multifd_zstd_register(void)
330 {
331 multifd_register_ops(MULTIFD_COMPRESSION_ZSTD, &multifd_zstd_ops);
332 }
333
334 migration_init(multifd_zstd_register);