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 "qemu-common.h"
  27 #include "exec/cpu-common.h"
  28 #include "io/channel.h"
  29
  30
  31 /* Read a chunk of data from a file at the given position.  The pos argument
  32  * can be ignored if the file is only be used for streaming.  The number of
  33  * bytes actually read should be returned.
  34  */
  35 typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
  36                                         int64_t pos, size_t size);
  37
  38 /* Close a file
  39  *
  40  * Return negative error number on error, 0 or positive value on success.
  41  *
  42  * The meaning of return value on success depends on the specific back-end being
  43  * used.
  44  */
  45 typedef int (QEMUFileCloseFunc)(void *opaque);
  46
  47 /* Called to return the OS file descriptor associated to the QEMUFile.
  48  */
  49 typedef int (QEMUFileGetFD)(void *opaque);
  50
  51 /* Called to change the blocking mode of the file
  52  */
  53 typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled);
  54
  55 /*
  56  * This function writes an iovec to file. The handler must write all
  57  * of the data or return a negative errno value.
  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     QEMUFileGetBufferFunc *get_buffer;
 105     QEMUFileCloseFunc *close;
 106     QEMUFileSetBlocking *set_blocking;
 107     QEMUFileWritevBufferFunc *writev_buffer;
 108     QEMURetPathFunc *get_return_path;
 109     QEMUFileShutdownFunc *shut_down;
 110 } QEMUFileOps;
 111
 112 typedef struct QEMUFileHooks {
 113     QEMURamHookFunc *before_ram_iterate;
 114     QEMURamHookFunc *after_ram_iterate;
 115     QEMURamHookFunc *hook_ram_load;
 116     QEMURamSaveFunc *save_page;
 117 } QEMUFileHooks;
 118
 119 QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 120 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc);
 121 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc);
 122 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 123 int qemu_get_fd(QEMUFile *f);
 124 int qemu_fclose(QEMUFile *f);
 125 int64_t qemu_ftell(QEMUFile *f);
 126 int64_t qemu_ftell_fast(QEMUFile *f);
 127 void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size);
 128 void qemu_put_byte(QEMUFile *f, int v);
 129 /*
 130  * put_buffer without copying the buffer.
 131  * The buffer should be available till it is sent asynchronously.
 132  */
 133 void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size);
 134 bool qemu_file_mode_is_not_valid(const char *mode);
 135 bool qemu_file_is_writable(QEMUFile *f);
 136
 137
 138 static inline void qemu_put_ubyte(QEMUFile *f, unsigned int v)
 139 {
 140     qemu_put_byte(f, (int)v);
 141 }
 142
 143 #define qemu_put_sbyte qemu_put_byte
 144
 145 void qemu_put_be16(QEMUFile *f, unsigned int v);
 146 void qemu_put_be32(QEMUFile *f, unsigned int v);
 147 void qemu_put_be64(QEMUFile *f, uint64_t v);
 148 size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 149 size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size);
 150 size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 151 ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
 152                                   int level);
 153 int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
 154
 155 /*
 156  * Note that you can only peek continuous bytes from where the current pointer
 157  * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 158  * previously peeked +n-1.
 159  */
 160 int qemu_peek_byte(QEMUFile *f, int offset);
 161 int qemu_get_byte(QEMUFile *f);
 162 void qemu_file_skip(QEMUFile *f, int size);
 163 void qemu_update_position(QEMUFile *f, size_t size);
 164
 165 static inline unsigned int qemu_get_ubyte(QEMUFile *f)
 166 {
 167     return (unsigned int)qemu_get_byte(f);
 168 }
 169
 170 #define qemu_get_sbyte qemu_get_byte
 171
 172 unsigned int qemu_get_be16(QEMUFile *f);
 173 unsigned int qemu_get_be32(QEMUFile *f);
 174 uint64_t qemu_get_be64(QEMUFile *f);
 175
 176 int qemu_file_rate_limit(QEMUFile *f);
 177 void qemu_file_reset_rate_limit(QEMUFile *f);
 178 void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 179 int64_t qemu_file_get_rate_limit(QEMUFile *f);
 180 int qemu_file_get_error(QEMUFile *f);
 181 void qemu_file_set_error(QEMUFile *f, int ret);
 182 int qemu_file_shutdown(QEMUFile *f);
 183 QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 184 void qemu_fflush(QEMUFile *f);
 185 void qemu_file_set_blocking(QEMUFile *f, bool block);
 186
 187 static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
 188 {
 189     qemu_put_be64(f, *pv);
 190 }
 191
 192 static inline void qemu_put_be32s(QEMUFile *f, const uint32_t *pv)
 193 {
 194     qemu_put_be32(f, *pv);
 195 }
 196
 197 static inline void qemu_put_be16s(QEMUFile *f, const uint16_t *pv)
 198 {
 199     qemu_put_be16(f, *pv);
 200 }
 201
 202 static inline void qemu_put_8s(QEMUFile *f, const uint8_t *pv)
 203 {
 204     qemu_put_byte(f, *pv);
 205 }
 206
 207 static inline void qemu_get_be64s(QEMUFile *f, uint64_t *pv)
 208 {
 209     *pv = qemu_get_be64(f);
 210 }
 211
 212 static inline void qemu_get_be32s(QEMUFile *f, uint32_t *pv)
 213 {
 214     *pv = qemu_get_be32(f);
 215 }
 216
 217 static inline void qemu_get_be16s(QEMUFile *f, uint16_t *pv)
 218 {
 219     *pv = qemu_get_be16(f);
 220 }
 221
 222 static inline void qemu_get_8s(QEMUFile *f, uint8_t *pv)
 223 {
 224     *pv = qemu_get_byte(f);
 225 }
 226
 227 // Signed versions for type safety
 228 static inline void qemu_put_sbuffer(QEMUFile *f, const int8_t *buf, size_t size)
 229 {
 230     qemu_put_buffer(f, (const uint8_t *)buf, size);
 231 }
 232
 233 static inline void qemu_put_sbe16(QEMUFile *f, int v)
 234 {
 235     qemu_put_be16(f, (unsigned int)v);
 236 }
 237
 238 static inline void qemu_put_sbe32(QEMUFile *f, int v)
 239 {
 240     qemu_put_be32(f, (unsigned int)v);
 241 }
 242
 243 static inline void qemu_put_sbe64(QEMUFile *f, int64_t v)
 244 {
 245     qemu_put_be64(f, (uint64_t)v);
 246 }
 247
 248 static inline size_t qemu_get_sbuffer(QEMUFile *f, int8_t *buf, int size)
 249 {
 250     return qemu_get_buffer(f, (uint8_t *)buf, size);
 251 }
 252
 253 static inline int qemu_get_sbe16(QEMUFile *f)
 254 {
 255     return (int)qemu_get_be16(f);
 256 }
 257
 258 static inline int qemu_get_sbe32(QEMUFile *f)
 259 {
 260     return (int)qemu_get_be32(f);
 261 }
 262
 263 static inline int64_t qemu_get_sbe64(QEMUFile *f)
 264 {
 265     return (int64_t)qemu_get_be64(f);
 266 }
 267
 268 static inline void qemu_put_s8s(QEMUFile *f, const int8_t *pv)
 269 {
 270     qemu_put_8s(f, (const uint8_t *)pv);
 271 }
 272
 273 static inline void qemu_put_sbe16s(QEMUFile *f, const int16_t *pv)
 274 {
 275     qemu_put_be16s(f, (const uint16_t *)pv);
 276 }
 277
 278 static inline void qemu_put_sbe32s(QEMUFile *f, const int32_t *pv)
 279 {
 280     qemu_put_be32s(f, (const uint32_t *)pv);
 281 }
 282
 283 static inline void qemu_put_sbe64s(QEMUFile *f, const int64_t *pv)
 284 {
 285     qemu_put_be64s(f, (const uint64_t *)pv);
 286 }
 287
 288 static inline void qemu_get_s8s(QEMUFile *f, int8_t *pv)
 289 {
 290     qemu_get_8s(f, (uint8_t *)pv);
 291 }
 292
 293 static inline void qemu_get_sbe16s(QEMUFile *f, int16_t *pv)
 294 {
 295     qemu_get_be16s(f, (uint16_t *)pv);
 296 }
 297
 298 static inline void qemu_get_sbe32s(QEMUFile *f, int32_t *pv)
 299 {
 300     qemu_get_be32s(f, (uint32_t *)pv);
 301 }
 302
 303 static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
 304 {
 305     qemu_get_be64s(f, (uint64_t *)pv);
 306 }
 307
 308 size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
 309
 310 #endif