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