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
  25 #ifndef QEMU_FILE_H
  26 #define QEMU_FILE_H
  27
  28 #include "qemu-common.h"
  29 #include "exec/cpu-common.h"
  30 #include "io/channel.h"
  31
  32
  33 /* Read a chunk of data from a file at the given position.  The pos argument
  34  * can be ignored if the file is only be used for streaming.  The number of
  35  * bytes actually read should be returned.
  36  */
  37 typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
  38                                         int64_t pos, size_t size);
  39
  40 /* Close a file
  41  *
  42  * Return negative error number on error, 0 or positive value on success.
  43  *
  44  * The meaning of return value on success depends on the specific back-end being
  45  * used.
  46  */
  47 typedef int (QEMUFileCloseFunc)(void *opaque);
  48
  49 /* Called to return the OS file descriptor associated to the QEMUFile.
  50  */
  51 typedef int (QEMUFileGetFD)(void *opaque);
  52
  53 /* Called to change the blocking mode of the file
  54  */
  55 typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled);
  56
  57 /*
  58  * This function writes an iovec to file. The handler must write all
  59  * of the data or return a negative errno value.
  60  */
  61 typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
  62                                            int iovcnt, int64_t pos);
  63
  64 /*
  65  * This function provides hooks around different
  66  * stages of RAM migration.
  67  * 'opaque' is the backend specific data in QEMUFile
  68  * 'data' is call specific data associated with the 'flags' value
  69  */
  70 typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
  71                               void *data);
  72
  73 /*
  74  * Constants used by ram_control_* hooks
  75  */
  76 #define RAM_CONTROL_SETUP     0
  77 #define RAM_CONTROL_ROUND     1
  78 #define RAM_CONTROL_HOOK      2
  79 #define RAM_CONTROL_FINISH    3
  80 #define RAM_CONTROL_BLOCK_REG 4
  81
  82 /*
  83  * This function allows override of where the RAM page
  84  * is saved (such as RDMA, for example.)
  85  */
  86 typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
  87                                ram_addr_t block_offset,
  88                                ram_addr_t offset,
  89                                size_t size,
  90                                uint64_t *bytes_sent);
  91
  92 /*
  93  * Return a QEMUFile for comms in the opposite direction
  94  */
  95 typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
  96
  97 /*
  98  * Stop any read or write (depending on flags) on the underlying
  99  * transport on the QEMUFile.
 100  * Existing blocking reads/writes must be woken
 101  * Returns 0 on success, -err on error
 102  */
 103 typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr);
 104
 105 typedef struct QEMUFileOps {
 106     QEMUFileGetBufferFunc *get_buffer;
 107     QEMUFileCloseFunc *close;
 108     QEMUFileSetBlocking *set_blocking;
 109     QEMUFileWritevBufferFunc *writev_buffer;
 110     QEMURetPathFunc *get_return_path;
 111     QEMUFileShutdownFunc *shut_down;
 112 } QEMUFileOps;
 113
 114 typedef struct QEMUFileHooks {
 115     QEMURamHookFunc *before_ram_iterate;
 116     QEMURamHookFunc *after_ram_iterate;
 117     QEMURamHookFunc *hook_ram_load;
 118     QEMURamSaveFunc *save_page;
 119 } QEMUFileHooks;
 120
 121 QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 122 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc);
 123 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc);
 124 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 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
 140 static inline void qemu_put_ubyte(QEMUFile *f, unsigned int v)
 141 {
 142     qemu_put_byte(f, (int)v);
 143 }
 144
 145 #define qemu_put_sbyte qemu_put_byte
 146
 147 void qemu_put_be16(QEMUFile *f, unsigned int v);
 148 void qemu_put_be32(QEMUFile *f, unsigned int v);
 149 void qemu_put_be64(QEMUFile *f, uint64_t v);
 150 size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 151 size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size);
 152 size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 153 ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
 154                                   int level);
 155 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
 156
 157 /*
 158  * Note that you can only peek continuous bytes from where the current pointer
 159  * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 160  * previously peeked +n-1.
 161  */
 162 int qemu_peek_byte(QEMUFile *f, int offset);
 163 int qemu_get_byte(QEMUFile *f);
 164 void qemu_file_skip(QEMUFile *f, int size);
 165 void qemu_update_position(QEMUFile *f, size_t size);
 166
 167 static inline unsigned int qemu_get_ubyte(QEMUFile *f)
 168 {
 169     return (unsigned int)qemu_get_byte(f);
 170 }
 171
 172 #define qemu_get_sbyte qemu_get_byte
 173
 174 unsigned int qemu_get_be16(QEMUFile *f);
 175 unsigned int qemu_get_be32(QEMUFile *f);
 176 uint64_t qemu_get_be64(QEMUFile *f);
 177
 178 int qemu_file_rate_limit(QEMUFile *f);
 179 void qemu_file_reset_rate_limit(QEMUFile *f);
 180 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 181 int64_t qemu_file_get_rate_limit(QEMUFile *f);
 182 int qemu_file_get_error(QEMUFile *f);
 183 void qemu_file_set_error(QEMUFile *f, int ret);
 184 int qemu_file_shutdown(QEMUFile *f);
 185 QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 186 void qemu_fflush(QEMUFile *f);
 187 void qemu_file_set_blocking(QEMUFile *f, bool block);
 188
 189 static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
 190 {
 191     qemu_put_be64(f, *pv);
 192 }
 193
 194 static inline void qemu_put_be32s(QEMUFile *f, const uint32_t *pv)
 195 {
 196     qemu_put_be32(f, *pv);
 197 }
 198
 199 static inline void qemu_put_be16s(QEMUFile *f, const uint16_t *pv)
 200 {
 201     qemu_put_be16(f, *pv);
 202 }
 203
 204 static inline void qemu_put_8s(QEMUFile *f, const uint8_t *pv)
 205 {
 206     qemu_put_byte(f, *pv);
 207 }
 208
 209 static inline void qemu_get_be64s(QEMUFile *f, uint64_t *pv)
 210 {
 211     *pv = qemu_get_be64(f);
 212 }
 213
 214 static inline void qemu_get_be32s(QEMUFile *f, uint32_t *pv)
 215 {
 216     *pv = qemu_get_be32(f);
 217 }
 218
 219 static inline void qemu_get_be16s(QEMUFile *f, uint16_t *pv)
 220 {
 221     *pv = qemu_get_be16(f);
 222 }
 223
 224 static inline void qemu_get_8s(QEMUFile *f, uint8_t *pv)
 225 {
 226     *pv = qemu_get_byte(f);
 227 }
 228
 229 // Signed versions for type safety
 230 static inline void qemu_put_sbuffer(QEMUFile *f, const int8_t *buf, size_t size)
 231 {
 232     qemu_put_buffer(f, (const uint8_t *)buf, size);
 233 }
 234
 235 static inline void qemu_put_sbe16(QEMUFile *f, int v)
 236 {
 237     qemu_put_be16(f, (unsigned int)v);
 238 }
 239
 240 static inline void qemu_put_sbe32(QEMUFile *f, int v)
 241 {
 242     qemu_put_be32(f, (unsigned int)v);
 243 }
 244
 245 static inline void qemu_put_sbe64(QEMUFile *f, int64_t v)
 246 {
 247     qemu_put_be64(f, (uint64_t)v);
 248 }
 249
 250 static inline size_t qemu_get_sbuffer(QEMUFile *f, int8_t *buf, int size)
 251 {
 252     return qemu_get_buffer(f, (uint8_t *)buf, size);
 253 }
 254
 255 static inline int qemu_get_sbe16(QEMUFile *f)
 256 {
 257     return (int)qemu_get_be16(f);
 258 }
 259
 260 static inline int qemu_get_sbe32(QEMUFile *f)
 261 {
 262     return (int)qemu_get_be32(f);
 263 }
 264
 265 static inline int64_t qemu_get_sbe64(QEMUFile *f)
 266 {
 267     return (int64_t)qemu_get_be64(f);
 268 }
 269
 270 static inline void qemu_put_s8s(QEMUFile *f, const int8_t *pv)
 271 {
 272     qemu_put_8s(f, (const uint8_t *)pv);
 273 }
 274
 275 static inline void qemu_put_sbe16s(QEMUFile *f, const int16_t *pv)
 276 {
 277     qemu_put_be16s(f, (const uint16_t *)pv);
 278 }
 279
 280 static inline void qemu_put_sbe32s(QEMUFile *f, const int32_t *pv)
 281 {
 282     qemu_put_be32s(f, (const uint32_t *)pv);
 283 }
 284
 285 static inline void qemu_put_sbe64s(QEMUFile *f, const int64_t *pv)
 286 {
 287     qemu_put_be64s(f, (const uint64_t *)pv);
 288 }
 289
 290 static inline void qemu_get_s8s(QEMUFile *f, int8_t *pv)
 291 {
 292     qemu_get_8s(f, (uint8_t *)pv);
 293 }
 294
 295 static inline void qemu_get_sbe16s(QEMUFile *f, int16_t *pv)
 296 {
 297     qemu_get_be16s(f, (uint16_t *)pv);
 298 }
 299
 300 static inline void qemu_get_sbe32s(QEMUFile *f, int32_t *pv)
 301 {
 302     qemu_get_be32s(f, (uint32_t *)pv);
 303 }
 304
 305 static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
 306 {
 307     qemu_get_be64s(f, (uint64_t *)pv);
 308 }
 309
 310 size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
 311
 312 #endif