qemu/migration/qemu-file.h
Juan Quintela 9c53d369e5 migration/rdma: Simplify the function that saves a page
When we sent a page through QEMUFile hooks (RDMA) there are three
posiblities:
- We are not using RDMA. return RAM_SAVE_CONTROL_DELAYED and
  control_save_page() returns false to let anything else to proceed.
- There is one error but we are using RDMA.  Then we return a negative
  value, control_save_page() needs to return true.
- Everything goes well and RDMA start the sent of the page
  asynchronously.  It returns RAM_SAVE_CONTROL_DELAYED and we need to
  return 1 for ram_save_page_legacy.

Clear?

I know, I know, the interface is as bad as it gets.  I think that now
it is a bit clearer, but this needs to be done some other way.

Reviewed-by: Leonardo Bras <leobras@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230515195709.63843-16-quintela@redhat.com>
2023-09-29 18:13:53 +02:00

149 lines
5.2 KiB
C

/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef MIGRATION_QEMU_FILE_H
#define MIGRATION_QEMU_FILE_H
#include <zlib.h>
#include "exec/cpu-common.h"
#include "io/channel.h"
/*
* This function provides hooks around different
* stages of RAM migration.
* 'data' is call specific data associated with the 'flags' value
*/
typedef int (QEMURamHookFunc)(QEMUFile *f, uint64_t flags, void *data);
/*
* Constants used by ram_control_* hooks
*/
#define RAM_CONTROL_SETUP 0
#define RAM_CONTROL_ROUND 1
#define RAM_CONTROL_HOOK 2
#define RAM_CONTROL_FINISH 3
#define RAM_CONTROL_BLOCK_REG 4
/*
* This function allows override of where the RAM page
* is saved (such as RDMA, for example.)
*/
typedef int (QEMURamSaveFunc)(QEMUFile *f,
ram_addr_t block_offset,
ram_addr_t offset,
size_t size);
typedef struct QEMUFileHooks {
QEMURamHookFunc *before_ram_iterate;
QEMURamHookFunc *after_ram_iterate;
QEMURamHookFunc *hook_ram_load;
QEMURamSaveFunc *save_page;
} QEMUFileHooks;
QEMUFile *qemu_file_new_input(QIOChannel *ioc);
QEMUFile *qemu_file_new_output(QIOChannel *ioc);
void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks);
int qemu_fclose(QEMUFile *f);
/*
* qemu_file_transferred:
*
* Report the total number of bytes transferred with
* this file.
*
* For writable files, any pending buffers will be
* flushed, so the reported value will be equal to
* the number of bytes transferred on the wire.
*
* For readable files, the reported value will be
* equal to the number of bytes transferred on the
* wire.
*
* Returns: the total bytes transferred
*/
uint64_t qemu_file_transferred(QEMUFile *f);
/*
* qemu_file_transferred_noflush:
*
* As qemu_file_transferred except for writable files, where no flush
* is performed and the reported amount will include the size of any
* queued buffers, on top of the amount actually transferred.
*
* Returns: the total bytes transferred and queued
*/
uint64_t qemu_file_transferred_noflush(QEMUFile *f);
/*
* put_buffer without copying the buffer.
* The buffer should be available till it is sent asynchronously.
*/
void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
bool may_free);
#include "migration/qemu-file-types.h"
size_t coroutine_mixed_fn qemu_peek_buffer(QEMUFile *f, uint8_t **buf, size_t size, size_t offset);
size_t coroutine_mixed_fn qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size);
ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream,
const uint8_t *p, size_t size);
int qemu_put_qemu_file(QEMUFile *f_des, QEMUFile *f_src);
bool qemu_file_buffer_empty(QEMUFile *file);
/*
* Note that you can only peek continuous bytes from where the current pointer
* is; you aren't guaranteed to be able to peak to +n bytes unless you've
* previously peeked +n-1.
*/
int coroutine_mixed_fn qemu_peek_byte(QEMUFile *f, int offset);
void qemu_file_skip(QEMUFile *f, int size);
int qemu_file_get_error_obj_any(QEMUFile *f1, QEMUFile *f2, Error **errp);
void qemu_file_set_error_obj(QEMUFile *f, int ret, Error *err);
void qemu_file_set_error(QEMUFile *f, int ret);
int qemu_file_shutdown(QEMUFile *f);
QEMUFile *qemu_file_get_return_path(QEMUFile *f);
void qemu_fflush(QEMUFile *f);
void qemu_file_set_blocking(QEMUFile *f, bool block);
int qemu_file_get_to_fd(QEMUFile *f, int fd, size_t size);
void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
void ram_control_load_hook(QEMUFile *f, uint64_t flags, void *data);
/* Whenever this is found in the data stream, the flags
* will be passed to ram_control_load_hook in the incoming-migration
* side. This lets before_ram_iterate/after_ram_iterate add
* transport-specific sections to the RAM migration data.
*/
#define RAM_SAVE_FLAG_HOOK 0x80
#define RAM_SAVE_CONTROL_NOT_SUPP -1000
#define RAM_SAVE_CONTROL_DELAYED -2000
int ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
ram_addr_t offset, size_t size);
QIOChannel *qemu_file_get_ioc(QEMUFile *file);
#endif