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 "exec/cpu-common.h"
  27
  28
  29 /* This function writes a chunk of data to a file at the given position.
  30  * The pos argument can be ignored if the file is only being used for
  31  * streaming.  The handler must write all of the data or return a negative
  32  * errno value.
  33  */
  34 typedef ssize_t (QEMUFilePutBufferFunc)(void *opaque, const uint8_t *buf,
  35                                         int64_t pos, size_t size);
  36
  37 /* Read a chunk of data from a file at the given position.  The pos argument
  38  * can be ignored if the file is only be used for streaming.  The number of
  39  * bytes actually read should be returned.
  40  */
  41 typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
  42                                         int64_t pos, size_t size);
  43
  44 /* Close a file
  45  *
  46  * Return negative error number on error, 0 or positive value on success.
  47  *
  48  * The meaning of return value on success depends on the specific back-end being
  49  * used.
  50  */
  51 typedef int (QEMUFileCloseFunc)(void *opaque);
  52
  53 /* Called to return the OS file descriptor associated to the QEMUFile.
  54  */
  55 typedef int (QEMUFileGetFD)(void *opaque);
  56
  57 /* Called to change the blocking mode of the file
  58  */
  59 typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled);
  60
  61 /*
  62  * This function writes an iovec to file. The handler must write all
  63  * of the data or return a negative errno value.
  64  */
  65 typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
  66                                            int iovcnt, int64_t pos);
  67
  68 /*
  69  * This function provides hooks around different
  70  * stages of RAM migration.
  71  * 'opaque' is the backend specific data in QEMUFile
  72  * 'data' is call specific data associated with the 'flags' value
  73  */
  74 typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
  75                               void *data);
  76
  77 /*
  78  * Constants used by ram_control_* hooks
  79  */
  80 #define RAM_CONTROL_SETUP     0
  81 #define RAM_CONTROL_ROUND     1
  82 #define RAM_CONTROL_HOOK      2
  83 #define RAM_CONTROL_FINISH    3
  84 #define RAM_CONTROL_BLOCK_REG 4
  85
  86 /*
  87  * This function allows override of where the RAM page
  88  * is saved (such as RDMA, for example.)
  89  */
  90 typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
  91                                ram_addr_t block_offset,
  92                                ram_addr_t offset,
  93                                size_t size,
  94                                uint64_t *bytes_sent);
  95
  96 /*
  97  * Return a QEMUFile for comms in the opposite direction
  98  */
  99 typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
 100
 101 /*
 102  * Stop any read or write (depending on flags) on the underlying
 103  * transport on the QEMUFile.
 104  * Existing blocking reads/writes must be woken
 105  * Returns 0 on success, -err on error
 106  */
 107 typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr);
 108
 109 typedef struct QEMUFileOps {
 110     QEMUFilePutBufferFunc *put_buffer;
 111     QEMUFileGetBufferFunc *get_buffer;
 112     QEMUFileCloseFunc *close;
 113     QEMUFileGetFD *get_fd;
 114     QEMUFileSetBlocking *set_blocking;
 115     QEMUFileWritevBufferFunc *writev_buffer;
 116     QEMURetPathFunc *get_return_path;
 117     QEMUFileShutdownFunc *shut_down;
 118 } QEMUFileOps;
 119
 120 typedef struct QEMUFileHooks {
 121     QEMURamHookFunc *before_ram_iterate;
 122     QEMURamHookFunc *after_ram_iterate;
 123     QEMURamHookFunc *hook_ram_load;
 124     QEMURamSaveFunc *save_page;
 125 } QEMUFileHooks;
 126
 127 struct QEMUSizedBuffer {
 128     struct iovec *iov;
 129     size_t n_iov;
 130     size_t size; /* total allocated size in all iov's */
 131     size_t used; /* number of used bytes */
 132 };
 133
 134 QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 135 QEMUFile *qemu_fopen(const char *filename, const char *mode);
 136 QEMUFile *qemu_fdopen(int fd, const char *mode);
 137 QEMUFile *qemu_fopen_socket(int fd, const char *mode);
 138 QEMUFile *qemu_popen_cmd(const char *command, const char *mode);
 139 QEMUFile *qemu_bufopen(const char *mode, QEMUSizedBuffer *input);
 140 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 141 int qemu_get_fd(QEMUFile *f);
 142 int qemu_fclose(QEMUFile *f);
 143 int64_t qemu_ftell(QEMUFile *f);
 144 int64_t qemu_ftell_fast(QEMUFile *f);
 145 void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size);
 146 void qemu_put_byte(QEMUFile *f, int v);
 147 /*
 148  * put_buffer without copying the buffer.
 149  * The buffer should be available till it is sent asynchronously.
 150  */
 151 void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size);
 152 bool qemu_file_mode_is_not_valid(const char *mode);
 153 bool qemu_file_is_writable(QEMUFile *f);
 154
 155 QEMUSizedBuffer *qsb_create(const uint8_t *buffer, size_t len);
 156 void qsb_free(QEMUSizedBuffer *);
 157 size_t qsb_set_length(QEMUSizedBuffer *qsb, size_t length);
 158 size_t qsb_get_length(const QEMUSizedBuffer *qsb);
 159 ssize_t qsb_get_buffer(const QEMUSizedBuffer *, off_t start, size_t count,
 160                        uint8_t *buf);
 161 ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *buf,
 162                      off_t pos, size_t count);
 163
 164
 165 /*
 166  * For use on files opened with qemu_bufopen
 167  */
 168 const QEMUSizedBuffer *qemu_buf_get(QEMUFile *f);
 169
 170 static inline void qemu_put_ubyte(QEMUFile *f, unsigned int v)
 171 {
 172     qemu_put_byte(f, (int)v);
 173 }
 174
 175 #define qemu_put_sbyte qemu_put_byte
 176
 177 void qemu_put_be16(QEMUFile *f, unsigned int v);
 178 void qemu_put_be32(QEMUFile *f, unsigned int v);
 179 void qemu_put_be64(QEMUFile *f, uint64_t v);
 180 size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 181 size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size);
 182 size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 183 ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
 184                                   int level);
 185 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
 186
 187 /*
 188  * Note that you can only peek continuous bytes from where the current pointer
 189  * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 190  * previously peeked +n-1.
 191  */
 192 int qemu_peek_byte(QEMUFile *f, int offset);
 193 int qemu_get_byte(QEMUFile *f);
 194 void qemu_file_skip(QEMUFile *f, int size);
 195 void qemu_update_position(QEMUFile *f, size_t size);
 196
 197 static inline unsigned int qemu_get_ubyte(QEMUFile *f)
 198 {
 199     return (unsigned int)qemu_get_byte(f);
 200 }
 201
 202 #define qemu_get_sbyte qemu_get_byte
 203
 204 unsigned int qemu_get_be16(QEMUFile *f);
 205 unsigned int qemu_get_be32(QEMUFile *f);
 206 uint64_t qemu_get_be64(QEMUFile *f);
 207
 208 int qemu_file_rate_limit(QEMUFile *f);
 209 void qemu_file_reset_rate_limit(QEMUFile *f);
 210 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 211 int64_t qemu_file_get_rate_limit(QEMUFile *f);
 212 int qemu_file_get_error(QEMUFile *f);
 213 void qemu_file_set_error(QEMUFile *f, int ret);
 214 int qemu_file_shutdown(QEMUFile *f);
 215 QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 216 void qemu_fflush(QEMUFile *f);
 217 void qemu_file_set_blocking(QEMUFile *f, bool block);
 218
 219 static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
 220 {
 221     qemu_put_be64(f, *pv);
 222 }
 223
 224 static inline void qemu_put_be32s(QEMUFile *f, const uint32_t *pv)
 225 {
 226     qemu_put_be32(f, *pv);
 227 }
 228
 229 static inline void qemu_put_be16s(QEMUFile *f, const uint16_t *pv)
 230 {
 231     qemu_put_be16(f, *pv);
 232 }
 233
 234 static inline void qemu_put_8s(QEMUFile *f, const uint8_t *pv)
 235 {
 236     qemu_put_byte(f, *pv);
 237 }
 238
 239 static inline void qemu_get_be64s(QEMUFile *f, uint64_t *pv)
 240 {
 241     *pv = qemu_get_be64(f);
 242 }
 243
 244 static inline void qemu_get_be32s(QEMUFile *f, uint32_t *pv)
 245 {
 246     *pv = qemu_get_be32(f);
 247 }
 248
 249 static inline void qemu_get_be16s(QEMUFile *f, uint16_t *pv)
 250 {
 251     *pv = qemu_get_be16(f);
 252 }
 253
 254 static inline void qemu_get_8s(QEMUFile *f, uint8_t *pv)
 255 {
 256     *pv = qemu_get_byte(f);
 257 }
 258
 259 // Signed versions for type safety
 260 static inline void qemu_put_sbuffer(QEMUFile *f, const int8_t *buf, size_t size)
 261 {
 262     qemu_put_buffer(f, (const uint8_t *)buf, size);
 263 }
 264
 265 static inline void qemu_put_sbe16(QEMUFile *f, int v)
 266 {
 267     qemu_put_be16(f, (unsigned int)v);
 268 }
 269
 270 static inline void qemu_put_sbe32(QEMUFile *f, int v)
 271 {
 272     qemu_put_be32(f, (unsigned int)v);
 273 }
 274
 275 static inline void qemu_put_sbe64(QEMUFile *f, int64_t v)
 276 {
 277     qemu_put_be64(f, (uint64_t)v);
 278 }
 279
 280 static inline size_t qemu_get_sbuffer(QEMUFile *f, int8_t *buf, int size)
 281 {
 282     return qemu_get_buffer(f, (uint8_t *)buf, size);
 283 }
 284
 285 static inline int qemu_get_sbe16(QEMUFile *f)
 286 {
 287     return (int)qemu_get_be16(f);
 288 }
 289
 290 static inline int qemu_get_sbe32(QEMUFile *f)
 291 {
 292     return (int)qemu_get_be32(f);
 293 }
 294
 295 static inline int64_t qemu_get_sbe64(QEMUFile *f)
 296 {
 297     return (int64_t)qemu_get_be64(f);
 298 }
 299
 300 static inline void qemu_put_s8s(QEMUFile *f, const int8_t *pv)
 301 {
 302     qemu_put_8s(f, (const uint8_t *)pv);
 303 }
 304
 305 static inline void qemu_put_sbe16s(QEMUFile *f, const int16_t *pv)
 306 {
 307     qemu_put_be16s(f, (const uint16_t *)pv);
 308 }
 309
 310 static inline void qemu_put_sbe32s(QEMUFile *f, const int32_t *pv)
 311 {
 312     qemu_put_be32s(f, (const uint32_t *)pv);
 313 }
 314
 315 static inline void qemu_put_sbe64s(QEMUFile *f, const int64_t *pv)
 316 {
 317     qemu_put_be64s(f, (const uint64_t *)pv);
 318 }
 319
 320 static inline void qemu_get_s8s(QEMUFile *f, int8_t *pv)
 321 {
 322     qemu_get_8s(f, (uint8_t *)pv);
 323 }
 324
 325 static inline void qemu_get_sbe16s(QEMUFile *f, int16_t *pv)
 326 {
 327     qemu_get_be16s(f, (uint16_t *)pv);
 328 }
 329
 330 static inline void qemu_get_sbe32s(QEMUFile *f, int32_t *pv)
 331 {
 332     qemu_get_be32s(f, (uint32_t *)pv);
 333 }
 334
 335 static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
 336 {
 337     qemu_get_be64s(f, (uint64_t *)pv);
 338 }
 339
 340 size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
 341
 342 #endif