We should not destroy the state of SVM (Secondary VM) until we receive
the complete data of PVM's state, in case the primary fails in the process
of sending the state, so we cache the VM's state in secondary side before
load it into SVM.
Besides, we should call qemu_system_reset() before load VM state,
which can ensure the data is intact.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit@amitshah.net>
VM checkpointing is to synchronize the state of PVM to SVM, just
like migration does, we re-use save helpers to achieve migrating
PVM's state to Secondary side.
COLO need to cache the data of VM's state in the secondary side before
synchronize it to SVM. COLO need the size of the data to determine
how much data should be read in the secondary side.
So here, we can get the size of the data by saving it into I/O channel
before send it to the secondary side.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit@amitshah.net>
We need communications protocol of user-defined to control
the checkpointing process.
The new checkpointing request is started by Primary VM,
and the interactive process like below:
Checkpoint synchronizing points:
Primary Secondary
initial work
'checkpoint-ready' <-------------------- @
'checkpoint-request' @ -------------------->
Suspend (Only in hybrid mode)
'checkpoint-reply' <-------------------- @
Suspend&Save state
'vmstate-send' @ -------------------->
Send state Receive state
'vmstate-received' <-------------------- @
Release packets Load state
'vmstate-load' <-------------------- @
Resume Resume (Only in hybrid mode)
Start Comparing (Only in hybrid mode)
NOTE:
1) '@' who sends the message
2) Every sync-point is synchronized by two sides with only
one handshake(single direction) for low-latency.
If more strict synchronization is required, a opposite direction
sync-point should be added.
3) Since sync-points are single direction, the remote side may
go forward a lot when this side just receives the sync-point.
4) For now, we only support 'periodic' checkpoint, for which
the Secondary VM is not running, later we will support 'hybrid' mode.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit@amitshah.net>
This new communication path will be used for returning messages
from Secondary side to Primary side.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit@amitshah.net>
Switch from normal migration loadvm process into COLO checkpoint process if
COLO mode is enabled.
We add three new members to struct MigrationIncomingState,
'have_colo_incoming_thread' and 'colo_incoming_thread' record the COLO
related thread for secondary VM, 'migration_incoming_co' records the
original migration incoming coroutine.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit@amitshah.net>
Add a new migration state: MIGRATION_STATUS_COLO. Migration source side
enters this state after the first live migration successfully finished
if COLO is enabled by command 'migrate_set_capability x-colo on'.
We reuse migration thread, so the process of checkpointing will be handled
in migration thread.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit@amitshah.net>
We add helper function colo_supported() to indicate whether
colo is supported or not, with which we use to control whether or not
showing 'x-colo' string to users, they can use qmp command
'query-migrate-capabilities' or hmp command 'info migrate_capabilities'
to learn if colo is supported.
The default value for COLO (COarse-Grain LOck Stepping) is disabled.
Cc: Juan Quintela <quintela@redhat.com>
Cc: Amit Shah <amit.shah@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit@amitshah.net>
zhanghailiang