qemu/include/migration/qemu-file.h
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   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 */
  37typedef 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 */
  47typedef int (QEMUFileCloseFunc)(void *opaque);
  48
  49/* Called to return the OS file descriptor associated to the QEMUFile.
  50 */
  51typedef int (QEMUFileGetFD)(void *opaque);
  52
  53/* Called to change the blocking mode of the file
  54 */
  55typedef 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 */
  61typedef 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 */
  70typedef 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 */
  86typedef 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 */
  95typedef 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 */
 103typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr);
 104
 105typedef 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
 114typedef struct QEMUFileHooks {
 115    QEMURamHookFunc *before_ram_iterate;
 116    QEMURamHookFunc *after_ram_iterate;
 117    QEMURamHookFunc *hook_ram_load;
 118    QEMURamSaveFunc *save_page;
 119} QEMUFileHooks;
 120
 121QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 122QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc);
 123QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc);
 124void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 125int qemu_get_fd(QEMUFile *f);
 126int qemu_fclose(QEMUFile *f);
 127int64_t qemu_ftell(QEMUFile *f);
 128int64_t qemu_ftell_fast(QEMUFile *f);
 129void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size);
 130void 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 */
 135void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size);
 136bool qemu_file_mode_is_not_valid(const char *mode);
 137bool qemu_file_is_writable(QEMUFile *f);
 138
 139
 140static 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
 147void qemu_put_be16(QEMUFile *f, unsigned int v);
 148void qemu_put_be32(QEMUFile *f, unsigned int v);
 149void qemu_put_be64(QEMUFile *f, uint64_t v);
 150size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 151size_t qemu_get_buffer(QEMUFile *f, uint8_t *buf, size_t size);
 152size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 153ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
 154                                  int level);
 155int 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 */
 162int qemu_peek_byte(QEMUFile *f, int offset);
 163int qemu_get_byte(QEMUFile *f);
 164void qemu_file_skip(QEMUFile *f, int size);
 165void qemu_update_position(QEMUFile *f, size_t size);
 166
 167static 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
 174unsigned int qemu_get_be16(QEMUFile *f);
 175unsigned int qemu_get_be32(QEMUFile *f);
 176uint64_t qemu_get_be64(QEMUFile *f);
 177
 178int qemu_file_rate_limit(QEMUFile *f);
 179void qemu_file_reset_rate_limit(QEMUFile *f);
 180void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 181int64_t qemu_file_get_rate_limit(QEMUFile *f);
 182int qemu_file_get_error(QEMUFile *f);
 183void qemu_file_set_error(QEMUFile *f, int ret);
 184int qemu_file_shutdown(QEMUFile *f);
 185QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 186void qemu_fflush(QEMUFile *f);
 187void qemu_file_set_blocking(QEMUFile *f, bool block);
 188
 189static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
 190{
 191    qemu_put_be64(f, *pv);
 192}
 193
 194static inline void qemu_put_be32s(QEMUFile *f, const uint32_t *pv)
 195{
 196    qemu_put_be32(f, *pv);
 197}
 198
 199static inline void qemu_put_be16s(QEMUFile *f, const uint16_t *pv)
 200{
 201    qemu_put_be16(f, *pv);
 202}
 203
 204static inline void qemu_put_8s(QEMUFile *f, const uint8_t *pv)
 205{
 206    qemu_put_byte(f, *pv);
 207}
 208
 209static inline void qemu_get_be64s(QEMUFile *f, uint64_t *pv)
 210{
 211    *pv = qemu_get_be64(f);
 212}
 213
 214static inline void qemu_get_be32s(QEMUFile *f, uint32_t *pv)
 215{
 216    *pv = qemu_get_be32(f);
 217}
 218
 219static inline void qemu_get_be16s(QEMUFile *f, uint16_t *pv)
 220{
 221    *pv = qemu_get_be16(f);
 222}
 223
 224static 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
 230static 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
 235static inline void qemu_put_sbe16(QEMUFile *f, int v)
 236{
 237    qemu_put_be16(f, (unsigned int)v);
 238}
 239
 240static inline void qemu_put_sbe32(QEMUFile *f, int v)
 241{
 242    qemu_put_be32(f, (unsigned int)v);
 243}
 244
 245static inline void qemu_put_sbe64(QEMUFile *f, int64_t v)
 246{
 247    qemu_put_be64(f, (uint64_t)v);
 248}
 249
 250static 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
 255static inline int qemu_get_sbe16(QEMUFile *f)
 256{
 257    return (int)qemu_get_be16(f);
 258}
 259
 260static inline int qemu_get_sbe32(QEMUFile *f)
 261{
 262    return (int)qemu_get_be32(f);
 263}
 264
 265static inline int64_t qemu_get_sbe64(QEMUFile *f)
 266{
 267    return (int64_t)qemu_get_be64(f);
 268}
 269
 270static inline void qemu_put_s8s(QEMUFile *f, const int8_t *pv)
 271{
 272    qemu_put_8s(f, (const uint8_t *)pv);
 273}
 274
 275static inline void qemu_put_sbe16s(QEMUFile *f, const int16_t *pv)
 276{
 277    qemu_put_be16s(f, (const uint16_t *)pv);
 278}
 279
 280static inline void qemu_put_sbe32s(QEMUFile *f, const int32_t *pv)
 281{
 282    qemu_put_be32s(f, (const uint32_t *)pv);
 283}
 284
 285static inline void qemu_put_sbe64s(QEMUFile *f, const int64_t *pv)
 286{
 287    qemu_put_be64s(f, (const uint64_t *)pv);
 288}
 289
 290static inline void qemu_get_s8s(QEMUFile *f, int8_t *pv)
 291{
 292    qemu_get_8s(f, (uint8_t *)pv);
 293}
 294
 295static inline void qemu_get_sbe16s(QEMUFile *f, int16_t *pv)
 296{
 297    qemu_get_be16s(f, (uint16_t *)pv);
 298}
 299
 300static inline void qemu_get_sbe32s(QEMUFile *f, int32_t *pv)
 301{
 302    qemu_get_be32s(f, (uint32_t *)pv);
 303}
 304
 305static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
 306{
 307    qemu_get_be64s(f, (uint64_t *)pv);
 308}
 309
 310size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
 311
 312#endif
 313