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#include <zlib.h>
  29#include "exec/cpu-common.h"
  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 */
  35typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
  36                                        int64_t pos, size_t size,
  37                                        Error **errp);
  38
  39/* Close a file
  40 *
  41 * Return negative error number on error, 0 or positive value on success.
  42 *
  43 * The meaning of return value on success depends on the specific back-end being
  44 * used.
  45 */
  46typedef int (QEMUFileCloseFunc)(void *opaque, Error **errp);
  47
  48/* Called to return the OS file descriptor associated to the QEMUFile.
  49 */
  50typedef int (QEMUFileGetFD)(void *opaque);
  51
  52/* Called to change the blocking mode of the file
  53 */
  54typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled, Error **errp);
  55
  56/*
  57 * This function writes an iovec to file. The handler must write all
  58 * of the data or return a negative errno value.
  59 */
  60typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
  61                                           int iovcnt, int64_t pos,
  62                                           Error **errp);
  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                                   Error **errp);
 105
 106typedef struct QEMUFileOps {
 107    QEMUFileGetBufferFunc *get_buffer;
 108    QEMUFileCloseFunc *close;
 109    QEMUFileSetBlocking *set_blocking;
 110    QEMUFileWritevBufferFunc *writev_buffer;
 111    QEMURetPathFunc *get_return_path;
 112    QEMUFileShutdownFunc *shut_down;
 113} QEMUFileOps;
 114
 115typedef struct QEMUFileHooks {
 116    QEMURamHookFunc *before_ram_iterate;
 117    QEMURamHookFunc *after_ram_iterate;
 118    QEMURamHookFunc *hook_ram_load;
 119    QEMURamSaveFunc *save_page;
 120} QEMUFileHooks;
 121
 122QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 123void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 124int qemu_get_fd(QEMUFile *f);
 125int qemu_fclose(QEMUFile *f);
 126int64_t qemu_ftell(QEMUFile *f);
 127int64_t qemu_ftell_fast(QEMUFile *f);
 128/*
 129 * put_buffer without copying the buffer.
 130 * The buffer should be available till it is sent asynchronously.
 131 */
 132void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
 133                           bool may_free);
 134bool qemu_file_mode_is_not_valid(const char *mode);
 135bool qemu_file_is_writable(QEMUFile *f);
 136
 137#include "migration/qemu-file-types.h"
 138
 139size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 140size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 141ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
 142                                  const uint8_t *p, size_t size);
 143int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
 144
 145/*
 146 * Note that you can only peek continuous bytes from where the current pointer
 147 * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 148 * previously peeked +n-1.
 149 */
 150int qemu_peek_byte(QEMUFile *f, int offset);
 151void qemu_file_skip(QEMUFile *f, int size);
 152void qemu_update_position(QEMUFile *f, size_t size);
 153void qemu_file_reset_rate_limit(QEMUFile *f);
 154void qemu_file_update_transfer(QEMUFile *f, int64_t len);
 155void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 156int64_t qemu_file_get_rate_limit(QEMUFile *f);
 157int qemu_file_get_error_obj(QEMUFile *f, Error **errp);
 158void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
 159void qemu_file_set_error(QEMUFile *f, int ret);
 160int qemu_file_shutdown(QEMUFile *f);
 161QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 162void qemu_fflush(QEMUFile *f);
 163void qemu_file_set_blocking(QEMUFile *f, bool block);
 164
 165void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 166void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 167void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 168
 169/* Whenever this is found in the data stream, the flags
 170 * will be passed to ram_control_load_hook in the incoming-migration
 171 * side. This lets before_ram_iterate/after_ram_iterate add
 172 * transport-specific sections to the RAM migration data.
 173 */
 174#define RAM_SAVE_FLAG_HOOK     0x80
 175
 176#define RAM_SAVE_CONTROL_NOT_SUPP -1000
 177#define RAM_SAVE_CONTROL_DELAYED  -2000
 178
 179size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 180                             ram_addr_t offset, size_t size,
 181                             uint64_t *bytes_sent);
 182
 183#endif
 184