target/mips/rel6_translate: Change license to GNU LGPL v2.1 (or later)
[qemu/ar7.git] / migration / multifd-zstd.c
blob693bddf8c9e0ecb544bb53794c61000f48345d12
1 /*
2 * Multifd zlib compression implementation
4 * Copyright (c) 2020 Red Hat Inc
6 * Authors:
7 * Juan Quintela <quintela@redhat.com>
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.
13 #include "qemu/osdep.h"
14 #include <zstd.h>
15 #include "qemu/rcu.h"
16 #include "exec/target_page.h"
17 #include "qapi/error.h"
18 #include "migration.h"
19 #include "trace.h"
20 #include "multifd.h"
22 struct zstd_data {
23 /* stream for compression */
24 ZSTD_CStream *zcs;
25 /* stream for decompression */
26 ZSTD_DStream *zds;
27 /* buffers */
28 ZSTD_inBuffer in;
29 ZSTD_outBuffer out;
30 /* compressed buffer */
31 uint8_t *zbuff;
32 /* size of compressed buffer */
33 uint32_t zbuff_len;
36 /* Multifd zstd compression */
38 /**
39 * zstd_send_setup: setup send side
41 * Setup each channel with zstd compression.
43 * Returns 0 for success or -1 for error
45 * @p: Params for the channel that we are using
46 * @errp: pointer to an error
48 static int zstd_send_setup(MultiFDSendParams *p, Error **errp)
50 uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
51 struct zstd_data *z = g_new0(struct zstd_data, 1);
52 int res;
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;
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;
70 /* We will never have more than page_count pages */
71 z->zbuff_len = page_count * qemu_target_page_size();
72 z->zbuff_len *= 2;
73 z->zbuff = g_try_malloc(z->zbuff_len);
74 if (!z->zbuff) {
75 ZSTD_freeCStream(z->zcs);
76 g_free(z);
77 error_setg(errp, "multifd %d: out of memory for zbuff", p->id);
78 return -1;
80 return 0;
83 /**
84 * zstd_send_cleanup: cleanup send side
86 * Close the channel and return memory.
88 * @p: Params for the channel that we are using
90 static void zstd_send_cleanup(MultiFDSendParams *p, Error **errp)
92 struct zstd_data *z = p->data;
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;
103 * zstd_send_prepare: prepare date to be able to send
105 * Create a compressed buffer with all the pages that we are going to
106 * send.
108 * Returns 0 for success or -1 for error
110 * @p: Params for the channel that we are using
111 * @used: number of pages used
113 static int zstd_send_prepare(MultiFDSendParams *p, uint32_t used, Error **errp)
115 struct iovec *iov = p->pages->iov;
116 struct zstd_data *z = p->data;
117 int ret;
118 uint32_t i;
120 z->out.dst = z->zbuff;
121 z->out.size = z->zbuff_len;
122 z->out.pos = 0;
124 for (i = 0; i < used; i++) {
125 ZSTD_EndDirective flush = ZSTD_e_continue;
127 if (i == used - 1) {
128 flush = ZSTD_e_flush;
130 z->in.src = iov[i].iov_base;
131 z->in.size = iov[i].iov_len;
132 z->in.pos = 0;
135 * Welcome to compressStream2 semantics
137 * We need to loop while:
138 * - return is > 0
139 * - there is input available
140 * - there is output space free
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;
151 if (ZSTD_isError(ret)) {
152 error_setg(errp, "multifd %d: compressStream error %s",
153 p->id, ZSTD_getErrorName(ret));
154 return -1;
157 p->next_packet_size = z->out.pos;
158 p->flags |= MULTIFD_FLAG_ZSTD;
160 return 0;
164 * zstd_send_write: do the actual write of the data
166 * Do the actual write of the comprresed buffer.
168 * Returns 0 for success or -1 for error
170 * @p: Params for the channel that we are using
171 * @used: number of pages used
172 * @errp: pointer to an error
174 static int zstd_send_write(MultiFDSendParams *p, uint32_t used, Error **errp)
176 struct zstd_data *z = p->data;
178 return qio_channel_write_all(p->c, (void *)z->zbuff, p->next_packet_size,
179 errp);
183 * zstd_recv_setup: setup receive side
185 * Create the compressed channel and buffer.
187 * Returns 0 for success or -1 for error
189 * @p: Params for the channel that we are using
190 * @errp: pointer to an error
192 static int zstd_recv_setup(MultiFDRecvParams *p, Error **errp)
194 uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
195 struct zstd_data *z = g_new0(struct zstd_data, 1);
196 int ret;
198 p->data = z;
199 z->zds = ZSTD_createDStream();
200 if (!z->zds) {
201 g_free(z);
202 error_setg(errp, "multifd %d: zstd createDStream failed", p->id);
203 return -1;
206 ret = ZSTD_initDStream(z->zds);
207 if (ZSTD_isError(ret)) {
208 ZSTD_freeDStream(z->zds);
209 g_free(z);
210 error_setg(errp, "multifd %d: initDStream failed with error %s",
211 p->id, ZSTD_getErrorName(ret));
212 return -1;
215 /* We will never have more than page_count pages */
216 z->zbuff_len = page_count * qemu_target_page_size();
217 /* We know compression "could" use more space */
218 z->zbuff_len *= 2;
219 z->zbuff = g_try_malloc(z->zbuff_len);
220 if (!z->zbuff) {
221 ZSTD_freeDStream(z->zds);
222 g_free(z);
223 error_setg(errp, "multifd %d: out of memory for zbuff", p->id);
224 return -1;
226 return 0;
230 * zstd_recv_cleanup: setup receive side
232 * For no compression this function does nothing.
234 * @p: Params for the channel that we are using
236 static void zstd_recv_cleanup(MultiFDRecvParams *p)
238 struct zstd_data *z = p->data;
240 ZSTD_freeDStream(z->zds);
241 z->zds = NULL;
242 g_free(z->zbuff);
243 z->zbuff = NULL;
244 g_free(p->data);
245 p->data = NULL;
249 * zstd_recv_pages: read the data from the channel into actual pages
251 * Read the compressed buffer, and uncompress it into the actual
252 * pages.
254 * Returns 0 for success or -1 for error
256 * @p: Params for the channel that we are using
257 * @used: number of pages used
258 * @errp: pointer to an error
260 static int zstd_recv_pages(MultiFDRecvParams *p, uint32_t used, Error **errp)
262 uint32_t in_size = p->next_packet_size;
263 uint32_t out_size = 0;
264 uint32_t expected_size = used * qemu_target_page_size();
265 uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
266 struct zstd_data *z = p->data;
267 int ret;
268 int i;
270 if (flags != MULTIFD_FLAG_ZSTD) {
271 error_setg(errp, "multifd %d: flags received %x flags expected %x",
272 p->id, flags, MULTIFD_FLAG_ZSTD);
273 return -1;
275 ret = qio_channel_read_all(p->c, (void *)z->zbuff, in_size, errp);
277 if (ret != 0) {
278 return ret;
281 z->in.src = z->zbuff;
282 z->in.size = in_size;
283 z->in.pos = 0;
285 for (i = 0; i < used; i++) {
286 struct iovec *iov = &p->pages->iov[i];
288 z->out.dst = iov->iov_base;
289 z->out.size = iov->iov_len;
290 z->out.pos = 0;
293 * Welcome to decompressStream semantics
295 * We need to loop while:
296 * - return is > 0
297 * - there is input available
298 * - we haven't put out a full page
300 do {
301 ret = ZSTD_decompressStream(z->zds, &z->out, &z->in);
302 } while (ret > 0 && (z->in.size - z->in.pos > 0)
303 && (z->out.pos < iov->iov_len));
304 if (ret > 0 && (z->out.pos < iov->iov_len)) {
305 error_setg(errp, "multifd %d: decompressStream buffer too small",
306 p->id);
307 return -1;
309 if (ZSTD_isError(ret)) {
310 error_setg(errp, "multifd %d: decompressStream returned %s",
311 p->id, ZSTD_getErrorName(ret));
312 return ret;
314 out_size += z->out.pos;
316 if (out_size != expected_size) {
317 error_setg(errp, "multifd %d: packet size received %d size expected %d",
318 p->id, out_size, expected_size);
319 return -1;
321 return 0;
324 static MultiFDMethods multifd_zstd_ops = {
325 .send_setup = zstd_send_setup,
326 .send_cleanup = zstd_send_cleanup,
327 .send_prepare = zstd_send_prepare,
328 .send_write = zstd_send_write,
329 .recv_setup = zstd_recv_setup,
330 .recv_cleanup = zstd_recv_cleanup,
331 .recv_pages = zstd_recv_pages
334 static void multifd_zstd_register(void)
336 multifd_register_ops(MULTIFD_COMPRESSION_ZSTD, &multifd_zstd_ops);
339 migration_init(multifd_zstd_register);