include/migration/qemu-file.h

   1 /*
   2  * QEMU System Emulator
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #ifndef QEMU_FILE_H
  25 #define QEMU_FILE_H 1
  26 #include "qemu-common.h"
  27 #include "exec/cpu-common.h"
  28 #include "io/channel.h"
  29
  30
  31 /* This function writes a chunk of data to a file at the given position.
  32  * The pos argument can be ignored if the file is only being used for
  33  * streaming.  The handler must write all of the data or return a negative
  34  * errno value.
  35  */
  36 typedef ssize_t (QEMUFilePutBufferFunc)(void *opaque, const uint8_t *buf,
  37                                         int64_t pos, size_t size);
  38
  39 /* Read a chunk of data from a file at the given position.  The pos argument
  40  * can be ignored if the file is only be used for streaming.  The number of
  41  * bytes actually read should be returned.
  42  */
  43 typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
  44                                         int64_t pos, size_t size);
  45
  46 /* Close a file
  47  *
  48  * Return negative error number on error, 0 or positive value on success.
  49  *
  50  * The meaning of return value on success depends on the specific back-end being
  51  * used.
  52  */
  53 typedef int (QEMUFileCloseFunc)(void *opaque);
  54
  55 /* Called to return the OS file descriptor associated to the QEMUFile.
  56  */
  57 typedef int (QEMUFileGetFD)(void *opaque);
  58
  59 /* Called to change the blocking mode of the file
  60  */
  61 typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled);
  62
  63 /*
  64  * This function writes an iovec to file. The handler must write all
  65  * of the data or return a negative errno value.
  66  */
  67 typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
  68                                            int iovcnt, int64_t pos);
  69
  70 /*
  71  * This function provides hooks around different
  72  * stages of RAM migration.
  73  * 'opaque' is the backend specific data in QEMUFile
  74  * 'data' is call specific data associated with the 'flags' value
  75  */
  76 typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
  77                               void *data);
  78
  79 /*
  80  * Constants used by ram_control_* hooks
  81  */
  82 #define RAM_CONTROL_SETUP     0
  83 #define RAM_CONTROL_ROUND     1
  84 #define RAM_CONTROL_HOOK      2
  85 #define RAM_CONTROL_FINISH    3
  86 #define RAM_CONTROL_BLOCK_REG 4
  87
  88 /*
  89  * This function allows override of where the RAM page
  90  * is saved (such as RDMA, for example.)
  91  */
  92 typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
  93                                ram_addr_t block_offset,
  94                                ram_addr_t offset,
  95                                size_t size,
  96                                uint64_t *bytes_sent);
  97
  98 /*
  99  * Return a QEMUFile for comms in the opposite direction
 100  */
 101 typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
 102
 103 /*
 104  * Stop any read or write (depending on flags) on the underlying
 105  * transport on the QEMUFile.
 106  * Existing blocking reads/writes must be woken
 107  * Returns 0 on success, -err on error
 108  */
 109 typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr);
 110
 111 typedef struct QEMUFileOps {
 112     QEMUFilePutBufferFunc *put_buffer;
 113     QEMUFileGetBufferFunc *get_buffer;
 114     QEMUFileCloseFunc *close;
 115     QEMUFileGetFD *get_fd;
 116     QEMUFileSetBlocking *set_blocking;
 117     QEMUFileWritevBufferFunc *writev_buffer;
 118     QEMURetPathFunc *get_return_path;
 119     QEMUFileShutdownFunc *shut_down;
 120 } QEMUFileOps;
 121
 122 typedef struct QEMUFileHooks {
 123     QEMURamHookFunc *before_ram_iterate;
 124     QEMURamHookFunc *after_ram_iterate;
 125     QEMURamHookFunc *hook_ram_load;
 126     QEMURamSaveFunc *save_page;
 127 } QEMUFileHooks;
 128
 129 struct QEMUSizedBuffer {
 130     struct iovec *iov;
 131     size_t n_iov;
 132     size_t size; /* total allocated size in all iov's */
 133     size_t used; /* number of used bytes */
 134 };
 135
 136 QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 137 QEMUFile *qemu_fopen(const char *filename, const char *mode);
 138 QEMUFile *qemu_fdopen(int fd, const char *mode);
 139 QEMUFile *qemu_fopen_socket(int fd, const char *mode);
 140 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc);
 141 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc);
 142 QEMUFile *qemu_popen_cmd(const char *command, const char *mode);
 143 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 144 int qemu_get_fd(QEMUFile *f);
 145 int qemu_fclose(QEMUFile *f);
 146 int64_t qemu_ftell(QEMUFile *f);
 147 int64_t qemu_ftell_fast(QEMUFile *f);
 148 void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size);
 149 void qemu_put_byte(QEMUFile *f, int v);
 150 /*
 151  * put_buffer without copying the buffer.
 152  * The buffer should be available till it is sent asynchronously.
 153  */
 154 void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size);
 155 bool qemu_file_mode_is_not_valid(const char *mode);
 156 bool qemu_file_is_writable(QEMUFile *f);
 157
 158 QEMUSizedBuffer *qsb_create(const uint8_t *buffer, size_t len);
 159 void qsb_free(QEMUSizedBuffer *);
 160 size_t qsb_set_length(QEMUSizedBuffer *qsb, size_t length);
 161 size_t qsb_get_length(const QEMUSizedBuffer *qsb);
 162 ssize_t qsb_get_buffer(const QEMUSizedBuffer *, off_t start, size_t count,
 163                        uint8_t *buf);
 164 ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *buf,
 165                      off_t pos, size_t count);
 166
 167
 168 static inline void qemu_put_ubyte(QEMUFile *f, unsigned int v)
 169 {
 170     qemu_put_byte(f, (int)v);
 171 }
 172
 173 #define qemu_put_sbyte qemu_put_byte
 174
 175 void qemu_put_be16(QEMUFile *f, unsigned int v);
 176 void qemu_put_be32(QEMUFile *f, unsigned int v);
 177 void qemu_put_be64(QEMUFile *f, uint64_t v);
 178 size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 179 size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size);
 180 size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 181 ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
 182                                   int level);
 183 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
 184
 185 /*
 186  * Note that you can only peek continuous bytes from where the current pointer
 187  * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 188  * previously peeked +n-1.
 189  */
 190 int qemu_peek_byte(QEMUFile *f, int offset);
 191 int qemu_get_byte(QEMUFile *f);
 192 void qemu_file_skip(QEMUFile *f, int size);
 193 void qemu_update_position(QEMUFile *f, size_t size);
 194
 195 static inline unsigned int qemu_get_ubyte(QEMUFile *f)
 196 {
 197     return (unsigned int)qemu_get_byte(f);
 198 }
 199
 200 #define qemu_get_sbyte qemu_get_byte
 201
 202 unsigned int qemu_get_be16(QEMUFile *f);
 203 unsigned int qemu_get_be32(QEMUFile *f);
 204 uint64_t qemu_get_be64(QEMUFile *f);
 205
 206 int qemu_file_rate_limit(QEMUFile *f);
 207 void qemu_file_reset_rate_limit(QEMUFile *f);
 208 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 209 int64_t qemu_file_get_rate_limit(QEMUFile *f);
 210 int qemu_file_get_error(QEMUFile *f);
 211 void qemu_file_set_error(QEMUFile *f, int ret);
 212 int qemu_file_shutdown(QEMUFile *f);
 213 QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 214 void qemu_fflush(QEMUFile *f);
 215 void qemu_file_set_blocking(QEMUFile *f, bool block);
 216
 217 static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
 218 {
 219     qemu_put_be64(f, *pv);
 220 }
 221
 222 static inline void qemu_put_be32s(QEMUFile *f, const uint32_t *pv)
 223 {
 224     qemu_put_be32(f, *pv);
 225 }
 226
 227 static inline void qemu_put_be16s(QEMUFile *f, const uint16_t *pv)
 228 {
 229     qemu_put_be16(f, *pv);
 230 }
 231
 232 static inline void qemu_put_8s(QEMUFile *f, const uint8_t *pv)
 233 {
 234     qemu_put_byte(f, *pv);
 235 }
 236
 237 static inline void qemu_get_be64s(QEMUFile *f, uint64_t *pv)
 238 {
 239     *pv = qemu_get_be64(f);
 240 }
 241
 242 static inline void qemu_get_be32s(QEMUFile *f, uint32_t *pv)
 243 {
 244     *pv = qemu_get_be32(f);
 245 }
 246
 247 static inline void qemu_get_be16s(QEMUFile *f, uint16_t *pv)
 248 {
 249     *pv = qemu_get_be16(f);
 250 }
 251
 252 static inline void qemu_get_8s(QEMUFile *f, uint8_t *pv)
 253 {
 254     *pv = qemu_get_byte(f);
 255 }
 256
 257 // Signed versions for type safety
 258 static inline void qemu_put_sbuffer(QEMUFile *f, const int8_t *buf, size_t size)
 259 {
 260     qemu_put_buffer(f, (const uint8_t *)buf, size);
 261 }
 262
 263 static inline void qemu_put_sbe16(QEMUFile *f, int v)
 264 {
 265     qemu_put_be16(f, (unsigned int)v);
 266 }
 267
 268 static inline void qemu_put_sbe32(QEMUFile *f, int v)
 269 {
 270     qemu_put_be32(f, (unsigned int)v);
 271 }
 272
 273 static inline void qemu_put_sbe64(QEMUFile *f, int64_t v)
 274 {
 275     qemu_put_be64(f, (uint64_t)v);
 276 }
 277
 278 static inline size_t qemu_get_sbuffer(QEMUFile *f, int8_t *buf, int size)
 279 {
 280     return qemu_get_buffer(f, (uint8_t *)buf, size);
 281 }
 282
 283 static inline int qemu_get_sbe16(QEMUFile *f)
 284 {
 285     return (int)qemu_get_be16(f);
 286 }
 287
 288 static inline int qemu_get_sbe32(QEMUFile *f)
 289 {
 290     return (int)qemu_get_be32(f);
 291 }
 292
 293 static inline int64_t qemu_get_sbe64(QEMUFile *f)
 294 {
 295     return (int64_t)qemu_get_be64(f);
 296 }
 297
 298 static inline void qemu_put_s8s(QEMUFile *f, const int8_t *pv)
 299 {
 300     qemu_put_8s(f, (const uint8_t *)pv);
 301 }
 302
 303 static inline void qemu_put_sbe16s(QEMUFile *f, const int16_t *pv)
 304 {
 305     qemu_put_be16s(f, (const uint16_t *)pv);
 306 }
 307
 308 static inline void qemu_put_sbe32s(QEMUFile *f, const int32_t *pv)
 309 {
 310     qemu_put_be32s(f, (const uint32_t *)pv);
 311 }
 312
 313 static inline void qemu_put_sbe64s(QEMUFile *f, const int64_t *pv)
 314 {
 315     qemu_put_be64s(f, (const uint64_t *)pv);
 316 }
 317
 318 static inline void qemu_get_s8s(QEMUFile *f, int8_t *pv)
 319 {
 320     qemu_get_8s(f, (uint8_t *)pv);
 321 }
 322
 323 static inline void qemu_get_sbe16s(QEMUFile *f, int16_t *pv)
 324 {
 325     qemu_get_be16s(f, (uint16_t *)pv);
 326 }
 327
 328 static inline void qemu_get_sbe32s(QEMUFile *f, int32_t *pv)
 329 {
 330     qemu_get_be32s(f, (uint32_t *)pv);
 331 }
 332
 333 static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
 334 {
 335     qemu_get_be64s(f, (uint64_t *)pv);
 336 }
 337
 338 size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
 339
 340 #endif