LXR qemu/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 MIGRATION_QEMU_FILE_H
  26#define MIGRATION_QEMU_FILE_H
  27
  28/* Read a chunk of data from a file at the given position.  The pos argument
  29 * can be ignored if the file is only be used for streaming.  The number of
  30 * bytes actually read should be returned.
  31 */
  32typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
  33                                        int64_t pos, size_t size);
  34
  35/* Close a file
  36 *
  37 * Return negative error number on error, 0 or positive value on success.
  38 *
  39 * The meaning of return value on success depends on the specific back-end being
  40 * used.
  41 */
  42typedef int (QEMUFileCloseFunc)(void *opaque);
  43
  44/* Called to return the OS file descriptor associated to the QEMUFile.
  45 */
  46typedef int (QEMUFileGetFD)(void *opaque);
  47
  48/* Called to change the blocking mode of the file
  49 */
  50typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled);
  51
  52/*
  53 * This function writes an iovec to file. The handler must write all
  54 * of the data or return a negative errno value.
  55 */
  56typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
  57                                           int iovcnt, int64_t pos);
  58
  59/*
  60 * This function provides hooks around different
  61 * stages of RAM migration.
  62 * 'opaque' is the backend specific data in QEMUFile
  63 * 'data' is call specific data associated with the 'flags' value
  64 */
  65typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
  66                              void *data);
  67
  68/*
  69 * Constants used by ram_control_* hooks
  70 */
  71#define RAM_CONTROL_SETUP     0
  72#define RAM_CONTROL_ROUND     1
  73#define RAM_CONTROL_HOOK      2
  74#define RAM_CONTROL_FINISH    3
  75#define RAM_CONTROL_BLOCK_REG 4
  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                               uint64_t *bytes_sent);
  86
  87/*
  88 * Return a QEMUFile for comms in the opposite direction
  89 */
  90typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
  91
  92/*
  93 * Stop any read or write (depending on flags) on the underlying
  94 * transport on the QEMUFile.
  95 * Existing blocking reads/writes must be woken
  96 * Returns 0 on success, -err on error
  97 */
  98typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr);
  99
 100typedef struct QEMUFileOps {
 101    QEMUFileGetBufferFunc *get_buffer;
 102    QEMUFileCloseFunc *close;
 103    QEMUFileSetBlocking *set_blocking;
 104    QEMUFileWritevBufferFunc *writev_buffer;
 105    QEMURetPathFunc *get_return_path;
 106    QEMUFileShutdownFunc *shut_down;
 107} QEMUFileOps;
 108
 109typedef struct QEMUFileHooks {
 110    QEMURamHookFunc *before_ram_iterate;
 111    QEMURamHookFunc *after_ram_iterate;
 112    QEMURamHookFunc *hook_ram_load;
 113    QEMURamSaveFunc *save_page;
 114} QEMUFileHooks;
 115
 116QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 117void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 118int qemu_get_fd(QEMUFile *f);
 119int qemu_fclose(QEMUFile *f);
 120int64_t qemu_ftell(QEMUFile *f);
 121int64_t qemu_ftell_fast(QEMUFile *f);
 122/*
 123 * put_buffer without copying the buffer.
 124 * The buffer should be available till it is sent asynchronously.
 125 */
 126void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
 127                           bool may_free);
 128bool qemu_file_mode_is_not_valid(const char *mode);
 129bool qemu_file_is_writable(QEMUFile *f);
 130
 131#include "migration/qemu-file-types.h"
 132
 133size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 134size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 135ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size,
 136                                  int level);
 137int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
 138
 139/*
 140 * Note that you can only peek continuous bytes from where the current pointer
 141 * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 142 * previously peeked +n-1.
 143 */
 144int qemu_peek_byte(QEMUFile *f, int offset);
 145void qemu_file_skip(QEMUFile *f, int size);
 146void qemu_update_position(QEMUFile *f, size_t size);
 147void qemu_file_reset_rate_limit(QEMUFile *f);
 148void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 149int64_t qemu_file_get_rate_limit(QEMUFile *f);
 150int qemu_file_get_error(QEMUFile *f);
 151void qemu_file_set_error(QEMUFile *f, int ret);
 152int qemu_file_shutdown(QEMUFile *f);
 153QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 154void qemu_fflush(QEMUFile *f);
 155void qemu_file_set_blocking(QEMUFile *f, bool block);
 156
 157size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
 158
 159void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 160void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 161void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 162
 163/* Whenever this is found in the data stream, the flags
 164 * will be passed to ram_control_load_hook in the incoming-migration
 165 * side. This lets before_ram_iterate/after_ram_iterate add
 166 * transport-specific sections to the RAM migration data.
 167 */
 168#define RAM_SAVE_FLAG_HOOK     0x80
 169
 170#define RAM_SAVE_CONTROL_NOT_SUPP -1000
 171#define RAM_SAVE_CONTROL_DELAYED  -2000
 172
 173size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 174                             ram_addr_t offset, size_t size,
 175                             uint64_t *bytes_sent);
 176
 177#endif
 178