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