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#include "io/channel.h"
  31
  32/* Read a chunk of data from a file at the given position.  The pos argument
  33 * can be ignored if the file is only be used for streaming.  The number of
  34 * bytes actually read should be returned.
  35 */
  36typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
  37                                        int64_t pos, size_t size,
  38                                        Error **errp);
  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, Error **errp);
  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, Error **errp);
  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                                           Error **errp);
  64
  65/*
  66 * This function provides hooks around different
  67 * stages of RAM migration.
  68 * 'opaque' is the backend specific data in QEMUFile
  69 * 'data' is call specific data associated with the 'flags' value
  70 */
  71typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
  72                              void *data);
  73
  74/*
  75 * Constants used by ram_control_* hooks
  76 */
  77#define RAM_CONTROL_SETUP     0
  78#define RAM_CONTROL_ROUND     1
  79#define RAM_CONTROL_HOOK      2
  80#define RAM_CONTROL_FINISH    3
  81#define RAM_CONTROL_BLOCK_REG 4
  82
  83/*
  84 * This function allows override of where the RAM page
  85 * is saved (such as RDMA, for example.)
  86 */
  87typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
  88                               ram_addr_t block_offset,
  89                               ram_addr_t offset,
  90                               size_t size,
  91                               uint64_t *bytes_sent);
  92
  93/*
  94 * Return a QEMUFile for comms in the opposite direction
  95 */
  96typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
  97
  98/*
  99 * Stop any read or write (depending on flags) on the underlying
 100 * transport on the QEMUFile.
 101 * Existing blocking reads/writes must be woken
 102 * Returns 0 on success, -err on error
 103 */
 104typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr,
 105                                   Error **errp);
 106
 107typedef struct QEMUFileOps {
 108    QEMUFileGetBufferFunc *get_buffer;
 109    QEMUFileCloseFunc *close;
 110    QEMUFileSetBlocking *set_blocking;
 111    QEMUFileWritevBufferFunc *writev_buffer;
 112    QEMURetPathFunc *get_return_path;
 113    QEMUFileShutdownFunc *shut_down;
 114} QEMUFileOps;
 115
 116typedef struct QEMUFileHooks {
 117    QEMURamHookFunc *before_ram_iterate;
 118    QEMURamHookFunc *after_ram_iterate;
 119    QEMURamHookFunc *hook_ram_load;
 120    QEMURamSaveFunc *save_page;
 121} QEMUFileHooks;
 122
 123QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops, bool has_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);
 129/*
 130 * put_buffer without copying the buffer.
 131 * The buffer should be available till it is sent asynchronously.
 132 */
 133void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
 134                           bool may_free);
 135bool qemu_file_mode_is_not_valid(const char *mode);
 136bool qemu_file_is_writable(QEMUFile *f);
 137
 138#include "migration/qemu-file-types.h"
 139
 140size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 141size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 142ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
 143                                  const uint8_t *p, size_t size);
 144int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
 145
 146/*
 147 * Note that you can only peek continuous bytes from where the current pointer
 148 * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 149 * previously peeked +n-1.
 150 */
 151int qemu_peek_byte(QEMUFile *f, int offset);
 152void qemu_file_skip(QEMUFile *f, int size);
 153void qemu_update_position(QEMUFile *f, size_t size);
 154void qemu_file_reset_rate_limit(QEMUFile *f);
 155void qemu_file_update_transfer(QEMUFile *f, int64_t len);
 156void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 157int64_t qemu_file_get_rate_limit(QEMUFile *f);
 158int qemu_file_get_error_obj(QEMUFile *f, Error **errp);
 159void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
 160void qemu_file_set_error(QEMUFile *f, int ret);
 161int qemu_file_shutdown(QEMUFile *f);
 162QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 163void qemu_fflush(QEMUFile *f);
 164void qemu_file_set_blocking(QEMUFile *f, bool block);
 165
 166void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 167void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 168void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 169
 170/* Whenever this is found in the data stream, the flags
 171 * will be passed to ram_control_load_hook in the incoming-migration
 172 * side. This lets before_ram_iterate/after_ram_iterate add
 173 * transport-specific sections to the RAM migration data.
 174 */
 175#define RAM_SAVE_FLAG_HOOK     0x80
 176
 177#define RAM_SAVE_CONTROL_NOT_SUPP -1000
 178#define RAM_SAVE_CONTROL_DELAYED  -2000
 179
 180size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 181                             ram_addr_t offset, size_t size,
 182                             uint64_t *bytes_sent);
 183QIOChannel *qemu_file_get_ioc(QEMUFile *file);
 184
 185#endif
 186