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#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 */
  34typedef 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 */
  41typedef 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 */
  51typedef int (QEMUFileCloseFunc)(void *opaque);
  52
  53/* Called to return the OS file descriptor associated to the QEMUFile.
  54 */
  55typedef int (QEMUFileGetFD)(void *opaque);
  56
  57/*
  58 * This function writes an iovec to file.
  59 */
  60typedef 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 */
  67typedef 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 */
  81typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
  82                               ram_addr_t block_offset,
  83                               ram_addr_t offset,
  84                               size_t size,
  85                               int *bytes_sent);
  86
  87typedef struct QEMUFileOps {
  88    QEMUFilePutBufferFunc *put_buffer;
  89    QEMUFileGetBufferFunc *get_buffer;
  90    QEMUFileCloseFunc *close;
  91    QEMUFileGetFD *get_fd;
  92    QEMUFileWritevBufferFunc *writev_buffer;
  93    QEMURamHookFunc *before_ram_iterate;
  94    QEMURamHookFunc *after_ram_iterate;
  95    QEMURamHookFunc *hook_ram_load;
  96    QEMURamSaveFunc *save_page;
  97} QEMUFileOps;
  98
  99struct QEMUSizedBuffer {
 100    struct iovec *iov;
 101    size_t n_iov;
 102    size_t size; /* total allocated size in all iov's */
 103    size_t used; /* number of used bytes */
 104};
 105
 106QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 107QEMUFile *qemu_fopen(const char *filename, const char *mode);
 108QEMUFile *qemu_fdopen(int fd, const char *mode);
 109QEMUFile *qemu_fopen_socket(int fd, const char *mode);
 110QEMUFile *qemu_popen_cmd(const char *command, const char *mode);
 111QEMUFile *qemu_bufopen(const char *mode, QEMUSizedBuffer *input);
 112int qemu_get_fd(QEMUFile *f);
 113int qemu_fclose(QEMUFile *f);
 114int64_t qemu_ftell(QEMUFile *f);
 115void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size);
 116void qemu_put_byte(QEMUFile *f, int v);
 117/*
 118 * put_buffer without copying the buffer.
 119 * The buffer should be available till it is sent asynchronously.
 120 */
 121void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, int size);
 122bool qemu_file_mode_is_not_valid(const char *mode);
 123bool qemu_file_is_writable(QEMUFile *f);
 124
 125QEMUSizedBuffer *qsb_create(const uint8_t *buffer, size_t len);
 126QEMUSizedBuffer *qsb_clone(const QEMUSizedBuffer *);
 127void qsb_free(QEMUSizedBuffer *);
 128size_t qsb_set_length(QEMUSizedBuffer *qsb, size_t length);
 129size_t qsb_get_length(const QEMUSizedBuffer *qsb);
 130ssize_t qsb_get_buffer(const QEMUSizedBuffer *, off_t start, size_t count,
 131                       uint8_t *buf);
 132ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *buf,
 133                     off_t pos, size_t count);
 134
 135
 136/*
 137 * For use on files opened with qemu_bufopen
 138 */
 139const QEMUSizedBuffer *qemu_buf_get(QEMUFile *f);
 140
 141static inline void qemu_put_ubyte(QEMUFile *f, unsigned int v)
 142{
 143    qemu_put_byte(f, (int)v);
 144}
 145
 146#define qemu_put_sbyte qemu_put_byte
 147
 148void qemu_put_be16(QEMUFile *f, unsigned int v);
 149void qemu_put_be32(QEMUFile *f, unsigned int v);
 150void qemu_put_be64(QEMUFile *f, uint64_t v);
 151int qemu_peek_buffer(QEMUFile *f, uint8_t *buf, int size, size_t offset);
 152int qemu_get_buffer(QEMUFile *f, uint8_t *buf, int size);
 153/*
 154 * Note that you can only peek continuous bytes from where the current pointer
 155 * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 156 * previously peeked +n-1.
 157 */
 158int qemu_peek_byte(QEMUFile *f, int offset);
 159int qemu_get_byte(QEMUFile *f);
 160void qemu_file_skip(QEMUFile *f, int size);
 161void qemu_update_position(QEMUFile *f, size_t size);
 162
 163static inline unsigned int qemu_get_ubyte(QEMUFile *f)
 164{
 165    return (unsigned int)qemu_get_byte(f);
 166}
 167
 168#define qemu_get_sbyte qemu_get_byte
 169
 170unsigned int qemu_get_be16(QEMUFile *f);
 171unsigned int qemu_get_be32(QEMUFile *f);
 172uint64_t qemu_get_be64(QEMUFile *f);
 173
 174int qemu_file_rate_limit(QEMUFile *f);
 175void qemu_file_reset_rate_limit(QEMUFile *f);
 176void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 177int64_t qemu_file_get_rate_limit(QEMUFile *f);
 178int qemu_file_get_error(QEMUFile *f);
 179void qemu_file_set_error(QEMUFile *f, int ret);
 180void qemu_fflush(QEMUFile *f);
 181
 182static inline void qemu_put_be64s(QEMUFile *f, const uint64_t *pv)
 183{
 184    qemu_put_be64(f, *pv);
 185}
 186
 187static inline void qemu_put_be32s(QEMUFile *f, const uint32_t *pv)
 188{
 189    qemu_put_be32(f, *pv);
 190}
 191
 192static inline void qemu_put_be16s(QEMUFile *f, const uint16_t *pv)
 193{
 194    qemu_put_be16(f, *pv);
 195}
 196
 197static inline void qemu_put_8s(QEMUFile *f, const uint8_t *pv)
 198{
 199    qemu_put_byte(f, *pv);
 200}
 201
 202static inline void qemu_get_be64s(QEMUFile *f, uint64_t *pv)
 203{
 204    *pv = qemu_get_be64(f);
 205}
 206
 207static inline void qemu_get_be32s(QEMUFile *f, uint32_t *pv)
 208{
 209    *pv = qemu_get_be32(f);
 210}
 211
 212static inline void qemu_get_be16s(QEMUFile *f, uint16_t *pv)
 213{
 214    *pv = qemu_get_be16(f);
 215}
 216
 217static inline void qemu_get_8s(QEMUFile *f, uint8_t *pv)
 218{
 219    *pv = qemu_get_byte(f);
 220}
 221
 222// Signed versions for type safety
 223static inline void qemu_put_sbuffer(QEMUFile *f, const int8_t *buf, int size)
 224{
 225    qemu_put_buffer(f, (const uint8_t *)buf, size);
 226}
 227
 228static inline void qemu_put_sbe16(QEMUFile *f, int v)
 229{
 230    qemu_put_be16(f, (unsigned int)v);
 231}
 232
 233static inline void qemu_put_sbe32(QEMUFile *f, int v)
 234{
 235    qemu_put_be32(f, (unsigned int)v);
 236}
 237
 238static inline void qemu_put_sbe64(QEMUFile *f, int64_t v)
 239{
 240    qemu_put_be64(f, (uint64_t)v);
 241}
 242
 243static inline size_t qemu_get_sbuffer(QEMUFile *f, int8_t *buf, int size)
 244{
 245    return qemu_get_buffer(f, (uint8_t *)buf, size);
 246}
 247
 248static inline int qemu_get_sbe16(QEMUFile *f)
 249{
 250    return (int)qemu_get_be16(f);
 251}
 252
 253static inline int qemu_get_sbe32(QEMUFile *f)
 254{
 255    return (int)qemu_get_be32(f);
 256}
 257
 258static inline int64_t qemu_get_sbe64(QEMUFile *f)
 259{
 260    return (int64_t)qemu_get_be64(f);
 261}
 262
 263static inline void qemu_put_s8s(QEMUFile *f, const int8_t *pv)
 264{
 265    qemu_put_8s(f, (const uint8_t *)pv);
 266}
 267
 268static inline void qemu_put_sbe16s(QEMUFile *f, const int16_t *pv)
 269{
 270    qemu_put_be16s(f, (const uint16_t *)pv);
 271}
 272
 273static inline void qemu_put_sbe32s(QEMUFile *f, const int32_t *pv)
 274{
 275    qemu_put_be32s(f, (const uint32_t *)pv);
 276}
 277
 278static inline void qemu_put_sbe64s(QEMUFile *f, const int64_t *pv)
 279{
 280    qemu_put_be64s(f, (const uint64_t *)pv);
 281}
 282
 283static inline void qemu_get_s8s(QEMUFile *f, int8_t *pv)
 284{
 285    qemu_get_8s(f, (uint8_t *)pv);
 286}
 287
 288static inline void qemu_get_sbe16s(QEMUFile *f, int16_t *pv)
 289{
 290    qemu_get_be16s(f, (uint16_t *)pv);
 291}
 292
 293static inline void qemu_get_sbe32s(QEMUFile *f, int32_t *pv)
 294{
 295    qemu_get_be32s(f, (uint32_t *)pv);
 296}
 297
 298static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
 299{
 300    qemu_get_be64s(f, (uint64_t *)pv);
 301}
 302#endif
 303