qemu/migration/options.h
Avihai Horon 6574232fff migration: Add switchover ack capability
Migration downtime estimation is calculated based on bandwidth and
remaining migration data. This assumes that loading of migration data in
the destination takes a negligible amount of time and that downtime
depends only on network speed.

While this may be true for RAM, it's not necessarily true for other
migrated devices. For example, loading the data of a VFIO device in the
destination might require from the device to allocate resources, prepare
internal data structures and so on. These operations can take a
significant amount of time which can increase migration downtime.

This patch adds a new capability "switchover ack" that prevents the
source from stopping the VM and completing the migration until an ACK
is received from the destination that it's OK to do so.

This can be used by migrated devices in various ways to reduce downtime.
For example, a device can send initial precopy metadata to pre-allocate
resources in the destination and use this capability to make sure that
the pre-allocation is completed before the source VM is stopped, so it
will have full effect.

This new capability relies on the return path capability to communicate
from the destination back to the source.

The actual implementation of the capability will be added in the
following patches.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Tested-by: YangHang Liu <yanghliu@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
2023-06-30 06:02:51 +02:00

104 lines
2.9 KiB
C

/*
* QEMU migration capabilities
*
* Copyright (c) 2012-2023 Red Hat Inc
*
* Authors:
* Orit Wasserman <owasserm@redhat.com>
* Juan Quintela <quintela@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef QEMU_MIGRATION_OPTIONS_H
#define QEMU_MIGRATION_OPTIONS_H
#include "hw/qdev-properties.h"
#include "hw/qdev-properties-system.h"
/* migration properties */
extern Property migration_properties[];
/* capabilities */
bool migrate_auto_converge(void);
bool migrate_background_snapshot(void);
bool migrate_block(void);
bool migrate_colo(void);
bool migrate_compress(void);
bool migrate_dirty_bitmaps(void);
bool migrate_events(void);
bool migrate_ignore_shared(void);
bool migrate_late_block_activate(void);
bool migrate_multifd(void);
bool migrate_pause_before_switchover(void);
bool migrate_postcopy_blocktime(void);
bool migrate_postcopy_preempt(void);
bool migrate_postcopy_ram(void);
bool migrate_rdma_pin_all(void);
bool migrate_release_ram(void);
bool migrate_return_path(void);
bool migrate_switchover_ack(void);
bool migrate_validate_uuid(void);
bool migrate_xbzrle(void);
bool migrate_zero_blocks(void);
bool migrate_zero_copy_send(void);
/*
* pseudo capabilities
*
* These are functions that are used in a similar way to capabilities
* check, but they are not a capability.
*/
bool migrate_multifd_flush_after_each_section(void);
bool migrate_postcopy(void);
bool migrate_tls(void);
/* capabilities helpers */
bool migrate_caps_check(bool *old_caps, bool *new_caps, Error **errp);
bool migrate_cap_set(int cap, bool value, Error **errp);
/* parameters */
const BitmapMigrationNodeAliasList *migrate_block_bitmap_mapping(void);
bool migrate_has_block_bitmap_mapping(void);
bool migrate_block_incremental(void);
uint32_t migrate_checkpoint_delay(void);
int migrate_compress_level(void);
int migrate_compress_threads(void);
int migrate_compress_wait_thread(void);
uint8_t migrate_cpu_throttle_increment(void);
uint8_t migrate_cpu_throttle_initial(void);
bool migrate_cpu_throttle_tailslow(void);
int migrate_decompress_threads(void);
uint64_t migrate_downtime_limit(void);
uint8_t migrate_max_cpu_throttle(void);
uint64_t migrate_max_bandwidth(void);
uint64_t migrate_max_postcopy_bandwidth(void);
int migrate_multifd_channels(void);
MultiFDCompression migrate_multifd_compression(void);
int migrate_multifd_zlib_level(void);
int migrate_multifd_zstd_level(void);
uint8_t migrate_throttle_trigger_threshold(void);
const char *migrate_tls_authz(void);
const char *migrate_tls_creds(void);
const char *migrate_tls_hostname(void);
uint64_t migrate_xbzrle_cache_size(void);
/* parameters setters */
void migrate_set_block_incremental(bool value);
/* parameters helpers */
bool migrate_params_check(MigrationParameters *params, Error **errp);
void migrate_params_init(MigrationParameters *params);
void block_cleanup_parameters(void);
#endif