Juan Quintela | 7ec2c2b | 2019-01-04 15:30:06 +0100 | [diff] [blame] | 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/target_page.h" |
| 17 | #include "qapi/error.h" |
| 18 | #include "migration.h" |
| 19 | #include "trace.h" |
| 20 | #include "multifd.h" |
| 21 | |
| 22 | struct zlib_data { |
| 23 | /* stream for compression */ |
| 24 | z_stream zs; |
| 25 | /* compressed buffer */ |
| 26 | uint8_t *zbuff; |
| 27 | /* size of compressed buffer */ |
| 28 | uint32_t zbuff_len; |
| 29 | }; |
| 30 | |
| 31 | /* Multifd zlib compression */ |
| 32 | |
| 33 | /** |
| 34 | * zlib_send_setup: setup send side |
| 35 | * |
| 36 | * Setup each channel with zlib compression. |
| 37 | * |
| 38 | * Returns 0 for success or -1 for error |
| 39 | * |
| 40 | * @p: Params for the channel that we are using |
| 41 | * @errp: pointer to an error |
| 42 | */ |
| 43 | static int zlib_send_setup(MultiFDSendParams *p, Error **errp) |
| 44 | { |
| 45 | uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); |
| 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 | /* We will never have more than page_count pages */ |
| 58 | z->zbuff_len = page_count * qemu_target_page_size(); |
| 59 | z->zbuff_len *= 2; |
| 60 | z->zbuff = g_try_malloc(z->zbuff_len); |
| 61 | if (!z->zbuff) { |
| 62 | deflateEnd(&z->zs); |
| 63 | g_free(z); |
| 64 | error_setg(errp, "multifd %d: out of memory for zbuff", p->id); |
| 65 | return -1; |
| 66 | } |
| 67 | p->data = z; |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | /** |
| 72 | * zlib_send_cleanup: cleanup send side |
| 73 | * |
| 74 | * Close the channel and return memory. |
| 75 | * |
| 76 | * @p: Params for the channel that we are using |
| 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 | * @used: number of pages used |
| 99 | */ |
| 100 | static int zlib_send_prepare(MultiFDSendParams *p, uint32_t used, Error **errp) |
| 101 | { |
| 102 | struct iovec *iov = p->pages->iov; |
| 103 | struct zlib_data *z = p->data; |
| 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 < used; i++) { |
| 110 | uint32_t available = z->zbuff_len - out_size; |
| 111 | int flush = Z_NO_FLUSH; |
| 112 | |
| 113 | if (i == used - 1) { |
| 114 | flush = Z_SYNC_FLUSH; |
| 115 | } |
| 116 | |
| 117 | zs->avail_in = iov[i].iov_len; |
| 118 | zs->next_in = iov[i].iov_base; |
| 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 | uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); |
| 184 | struct zlib_data *z = g_malloc0(sizeof(struct zlib_data)); |
| 185 | z_stream *zs = &z->zs; |
| 186 | |
| 187 | p->data = z; |
| 188 | zs->zalloc = Z_NULL; |
| 189 | zs->zfree = Z_NULL; |
| 190 | zs->opaque = Z_NULL; |
| 191 | zs->avail_in = 0; |
| 192 | zs->next_in = Z_NULL; |
| 193 | if (inflateInit(zs) != Z_OK) { |
| 194 | error_setg(errp, "multifd %d: inflate init failed", p->id); |
| 195 | return -1; |
| 196 | } |
| 197 | /* We will never have more than page_count pages */ |
| 198 | z->zbuff_len = page_count * qemu_target_page_size(); |
| 199 | /* We know compression "could" use more space */ |
| 200 | z->zbuff_len *= 2; |
| 201 | z->zbuff = g_try_malloc(z->zbuff_len); |
| 202 | if (!z->zbuff) { |
| 203 | inflateEnd(zs); |
| 204 | error_setg(errp, "multifd %d: out of memory for zbuff", p->id); |
| 205 | return -1; |
| 206 | } |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | /** |
| 211 | * zlib_recv_cleanup: setup receive side |
| 212 | * |
| 213 | * For no compression this function does nothing. |
| 214 | * |
| 215 | * @p: Params for the channel that we are using |
| 216 | */ |
| 217 | static void zlib_recv_cleanup(MultiFDRecvParams *p) |
| 218 | { |
| 219 | struct zlib_data *z = p->data; |
| 220 | |
| 221 | inflateEnd(&z->zs); |
| 222 | g_free(z->zbuff); |
| 223 | z->zbuff = NULL; |
| 224 | g_free(p->data); |
| 225 | p->data = NULL; |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * zlib_recv_pages: read the data from the channel into actual pages |
| 230 | * |
| 231 | * Read the compressed buffer, and uncompress it into the actual |
| 232 | * pages. |
| 233 | * |
| 234 | * Returns 0 for success or -1 for error |
| 235 | * |
| 236 | * @p: Params for the channel that we are using |
| 237 | * @used: number of pages used |
| 238 | * @errp: pointer to an error |
| 239 | */ |
| 240 | static int zlib_recv_pages(MultiFDRecvParams *p, uint32_t used, Error **errp) |
| 241 | { |
| 242 | struct zlib_data *z = p->data; |
| 243 | z_stream *zs = &z->zs; |
| 244 | uint32_t in_size = p->next_packet_size; |
| 245 | /* we measure the change of total_out */ |
| 246 | uint32_t out_size = zs->total_out; |
| 247 | uint32_t expected_size = used * qemu_target_page_size(); |
| 248 | uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK; |
| 249 | int ret; |
| 250 | int i; |
| 251 | |
| 252 | if (flags != MULTIFD_FLAG_ZLIB) { |
| 253 | error_setg(errp, "multifd %d: flags received %x flags expected %x", |
| 254 | p->id, flags, MULTIFD_FLAG_ZLIB); |
| 255 | return -1; |
| 256 | } |
| 257 | ret = qio_channel_read_all(p->c, (void *)z->zbuff, in_size, errp); |
| 258 | |
| 259 | if (ret != 0) { |
| 260 | return ret; |
| 261 | } |
| 262 | |
| 263 | zs->avail_in = in_size; |
| 264 | zs->next_in = z->zbuff; |
| 265 | |
| 266 | for (i = 0; i < used; i++) { |
| 267 | struct iovec *iov = &p->pages->iov[i]; |
| 268 | int flush = Z_NO_FLUSH; |
| 269 | unsigned long start = zs->total_out; |
| 270 | |
| 271 | if (i == used - 1) { |
| 272 | flush = Z_SYNC_FLUSH; |
| 273 | } |
| 274 | |
| 275 | zs->avail_out = iov->iov_len; |
| 276 | zs->next_out = iov->iov_base; |
| 277 | |
| 278 | /* |
| 279 | * Welcome to inflate semantics |
| 280 | * |
| 281 | * We need to loop while: |
| 282 | * - return is Z_OK |
| 283 | * - there are input available |
| 284 | * - we haven't completed a full page |
| 285 | */ |
| 286 | do { |
| 287 | ret = inflate(zs, flush); |
| 288 | } while (ret == Z_OK && zs->avail_in |
| 289 | && (zs->total_out - start) < iov->iov_len); |
| 290 | if (ret == Z_OK && (zs->total_out - start) < iov->iov_len) { |
| 291 | error_setg(errp, "multifd %d: inflate generated too few output", |
| 292 | p->id); |
| 293 | return -1; |
| 294 | } |
| 295 | if (ret != Z_OK) { |
| 296 | error_setg(errp, "multifd %d: inflate returned %d instead of Z_OK", |
| 297 | p->id, ret); |
| 298 | return -1; |
| 299 | } |
| 300 | } |
| 301 | out_size = zs->total_out - out_size; |
| 302 | if (out_size != expected_size) { |
| 303 | error_setg(errp, "multifd %d: packet size received %d size expected %d", |
| 304 | p->id, out_size, expected_size); |
| 305 | return -1; |
| 306 | } |
| 307 | return 0; |
| 308 | } |
| 309 | |
| 310 | static MultiFDMethods multifd_zlib_ops = { |
| 311 | .send_setup = zlib_send_setup, |
| 312 | .send_cleanup = zlib_send_cleanup, |
| 313 | .send_prepare = zlib_send_prepare, |
| 314 | .send_write = zlib_send_write, |
| 315 | .recv_setup = zlib_recv_setup, |
| 316 | .recv_cleanup = zlib_recv_cleanup, |
| 317 | .recv_pages = zlib_recv_pages |
| 318 | }; |
| 319 | |
| 320 | static void multifd_zlib_register(void) |
| 321 | { |
| 322 | multifd_register_ops(MULTIFD_COMPRESSION_ZLIB, &multifd_zlib_ops); |
| 323 | } |
| 324 | |
| 325 | migration_init(multifd_zlib_register); |