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
  30/* Read a chunk of data from a file at the given position.  The pos argument
  31 * can be ignored if the file is only be used for streaming.  The number of
  32 * bytes actually read should be returned.
  33 */
  34typedef ssize_t (QEMUFileGetBufferFunc)(void *opaque, uint8_t *buf,
  35                                        int64_t pos, size_t size);
  36
  37/* Close a file
  38 *
  39 * Return negative error number on error, 0 or positive value on success.
  40 *
  41 * The meaning of return value on success depends on the specific back-end being
  42 * used.
  43 */
  44typedef int (QEMUFileCloseFunc)(void *opaque);
  45
  46/* Called to return the OS file descriptor associated to the QEMUFile.
  47 */
  48typedef int (QEMUFileGetFD)(void *opaque);
  49
  50/* Called to change the blocking mode of the file
  51 */
  52typedef int (QEMUFileSetBlocking)(void *opaque, bool enabled);
  53
  54/*
  55 * This function writes an iovec to file. The handler must write all
  56 * of the data or return a negative errno value.
  57 */
  58typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque, struct iovec *iov,
  59                                           int iovcnt, int64_t pos);
  60
  61/*
  62 * This function provides hooks around different
  63 * stages of RAM migration.
  64 * 'opaque' is the backend specific data in QEMUFile
  65 * 'data' is call specific data associated with the 'flags' value
  66 */
  67typedef int (QEMURamHookFunc)(QEMUFile *f, void *opaque, uint64_t flags,
  68                              void *data);
  69
  70/*
  71 * Constants used by ram_control_* hooks
  72 */
  73#define RAM_CONTROL_SETUP     0
  74#define RAM_CONTROL_ROUND     1
  75#define RAM_CONTROL_HOOK      2
  76#define RAM_CONTROL_FINISH    3
  77#define RAM_CONTROL_BLOCK_REG 4
  78
  79/*
  80 * This function allows override of where the RAM page
  81 * is saved (such as RDMA, for example.)
  82 */
  83typedef size_t (QEMURamSaveFunc)(QEMUFile *f, void *opaque,
  84                               ram_addr_t block_offset,
  85                               ram_addr_t offset,
  86                               size_t size,
  87                               uint64_t *bytes_sent);
  88
  89/*
  90 * Return a QEMUFile for comms in the opposite direction
  91 */
  92typedef QEMUFile *(QEMURetPathFunc)(void *opaque);
  93
  94/*
  95 * Stop any read or write (depending on flags) on the underlying
  96 * transport on the QEMUFile.
  97 * Existing blocking reads/writes must be woken
  98 * Returns 0 on success, -err on error
  99 */
 100typedef int (QEMUFileShutdownFunc)(void *opaque, bool rd, bool wr);
 101
 102typedef struct QEMUFileOps {
 103    QEMUFileGetBufferFunc *get_buffer;
 104    QEMUFileCloseFunc *close;
 105    QEMUFileSetBlocking *set_blocking;
 106    QEMUFileWritevBufferFunc *writev_buffer;
 107    QEMURetPathFunc *get_return_path;
 108    QEMUFileShutdownFunc *shut_down;
 109} QEMUFileOps;
 110
 111typedef struct QEMUFileHooks {
 112    QEMURamHookFunc *before_ram_iterate;
 113    QEMURamHookFunc *after_ram_iterate;
 114    QEMURamHookFunc *hook_ram_load;
 115    QEMURamSaveFunc *save_page;
 116} QEMUFileHooks;
 117
 118QEMUFile *qemu_fopen_ops(void *opaque, const QEMUFileOps *ops);
 119void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
 120int qemu_get_fd(QEMUFile *f);
 121int qemu_fclose(QEMUFile *f);
 122int64_t qemu_ftell(QEMUFile *f);
 123int64_t qemu_ftell_fast(QEMUFile *f);
 124/*
 125 * put_buffer without copying the buffer.
 126 * The buffer should be available till it is sent asynchronously.
 127 */
 128void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
 129                           bool may_free);
 130bool qemu_file_mode_is_not_valid(const char *mode);
 131bool qemu_file_is_writable(QEMUFile *f);
 132
 133#include "migration/qemu-file-types.h"
 134
 135size_t qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
 136size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
 137ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
 138                                  const uint8_t *p, size_t size);
 139int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
 140
 141/*
 142 * Note that you can only peek continuous bytes from where the current pointer
 143 * is; you aren't guaranteed to be able to peak to +n bytes unless you've
 144 * previously peeked +n-1.
 145 */
 146int qemu_peek_byte(QEMUFile *f, int offset);
 147void qemu_file_skip(QEMUFile *f, int size);
 148void qemu_update_position(QEMUFile *f, size_t size);
 149void qemu_file_reset_rate_limit(QEMUFile *f);
 150void qemu_file_set_rate_limit(QEMUFile *f, int64_t new_rate);
 151int64_t qemu_file_get_rate_limit(QEMUFile *f);
 152void qemu_file_set_error(QEMUFile *f, int ret);
 153int qemu_file_shutdown(QEMUFile *f);
 154QEMUFile *qemu_file_get_return_path(QEMUFile *f);
 155void qemu_fflush(QEMUFile *f);
 156void qemu_file_set_blocking(QEMUFile *f, bool block);
 157
 158size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
 159
 160void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
 161void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
 162void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
 163
 164/* Whenever this is found in the data stream, the flags
 165 * will be passed to ram_control_load_hook in the incoming-migration
 166 * side. This lets before_ram_iterate/after_ram_iterate add
 167 * transport-specific sections to the RAM migration data.
 168 */
 169#define RAM_SAVE_FLAG_HOOK     0x80
 170
 171#define RAM_SAVE_CONTROL_NOT_SUPP -1000
 172#define RAM_SAVE_CONTROL_DELAYED  -2000
 173
 174size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
 175                             ram_addr_t offset, size_t size,
 176                             uint64_t *bytes_sent);
 177
 178void qemu_put_counted_string(QEMUFile *f, const char *name);
 179
 180#endif
 181