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