We will not allow failures to happen when sending data from destination
to source via the return path. However it is possible that there can be
errors along the way. This patch allows the migrate_send_rp_message()
to return error when it happens, and further extended it to
migrate_send_rp_req_pages().
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180208103132.28452-9-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
It was only used for quitting the page fault thread before. Let it be
something more useful - now we can use it to notify a "wake" for the
page fault thread (for any reason), and it only means "quit" if the
fault_thread_quit is set.
Since we changed what it does, renaming it to userfault_event_fd.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180208103132.28452-3-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-4-armbru@redhat.com>
Allow whatever is performing the connection to pass migrate_fd_connect
an error to indicate there was a problem during connection, an allow
us to clean up.
The caller must free the error.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
This reverts commits
ca6011c migration: add postcopy total blocktime into query-migrate
5f32dc8 migration: add blocktime calculation into migration-test
2f7dae9 migration: postcopy_blocktime documentation
3be98be migration: calculate vCPU blocktime on dst side
01a87f0 migration: add postcopy blocktime ctx into MigrationIncomingState
31bf06a migration: introduce postcopy-blocktime capability
as they don't build on ppc32 due to trying to do atomic accesses
on types that are larger than the host pointer type.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We have quite a few lines in migration_thread() that calculates some
statistics for the migration interations. Isolate it into a single
function to improve readability.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Introduce MigrationState.downtime_start to replace the local variable
"start_time" in migration_thread to avoid passing things around.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Firstly, it was passed around. Let's just move it into MigrationState
just like many other variables as state of migration, renaming it to
vm_was_running.
One thing to mention is that for postcopy, we actually don't need this
knowledge at all since postcopy can't resume a VM even if it fails (we
can see that from the old code too: when we try to resume we also check
against "entered_postcopy" variable). So further we do this:
- in postcopy_start(), we don't update vm_old_running since useless
- in migration_thread(), we don't need to check entered_postcopy when
resume, since it's only used for precopy.
Comment this out too for that variable definition.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
It was used either to:
1. store initial timestamp of migration start, and
2. store total time used by last migration
Let's provide two parameters for each of them. Mix use of the two is
slightly misleading.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Postcopy total blocktime is available on destination side only.
But query-migrate was possible only for source. This patch
adds ability to call query-migrate on destination.
To be able to see postcopy blocktime, need to request postcopy-blocktime
capability.
The query-migrate command will show following sample result:
{"return":
"postcopy-vcpu-blocktime": [115, 100],
"status": "completed",
"postcopy-blocktime": 100
}}
postcopy_vcpu_blocktime contains list, where the first item is the first
vCPU in QEMU.
This patch has a drawback, it combines states of incoming and
outgoing migration. Ongoing migration state will overwrite incoming
state. Looks like better to separate query-migrate for incoming and
outgoing migration or add parameter to indicate type of migration.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This patch adds request to kernel space for UFFD_FEATURE_THREAD_ID, in
case this feature is provided by kernel.
PostcopyBlocktimeContext is encapsulated inside postcopy-ram.c,
due to it being a postcopy-only feature.
Also it defines PostcopyBlocktimeContext's instance live time.
Information from PostcopyBlocktimeContext instance will be provided
much after postcopy migration end, instance of PostcopyBlocktimeContext
will live till QEMU exit, but part of it (vcpu_addr,
page_fault_vcpu_time) used only during calculation, will be released
when postcopy ended or failed.
To enable postcopy blocktime calculation on destination, need to
request proper compatibility (Patch for documentation will be at the
tail of the patch set).
As an example following command enable that capability, assume QEMU was
started with
-chardev socket,id=charmonitor,path=/var/lib/migrate-vm-monitor.sock
option to control it
[root@host]#printf "{\"execute\" : \"qmp_capabilities\"}\r\n \
{\"execute\": \"migrate-set-capabilities\" , \"arguments\": {
\"capabilities\": [ { \"capability\": \"postcopy-blocktime\", \"state\":
true } ] } }" | nc -U /var/lib/migrate-vm-monitor.sock
Or just with HMP
(qemu) migrate_set_capability postcopy-blocktime on
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Right now it could be used on destination side to
enable vCPU blocktime calculation for postcopy live migration.
vCPU blocktime - it's time since vCPU thread was put into
interruptible sleep, till memory page was copied and thread awake.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Right now it is a variable in MigrationState instead of a
MigrationParameter. The change allows to set it as the rest of the
Migration parameters, from the command line, with
query_migration_paramters, set_migrate_parameters, etc.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We now report errors also when we finish migration, not only on info
migrate. We plan to use this error from several places, and we want
the first error to happen to win, so we add an mutex to order it.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Wait for a semaphore before completing the migration,
if the previously added capability was enabled.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
When 'pause-before-switchover' is enabled, the outgoing migration
will pause before invalidating the block devices and serializing
the device state.
At this point the management layer gets the chance to clean up any
device jobs or other device users before the migration completes.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Split common postcopy staff from ram postcopy staff.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Indicates how many pages we are going to send in each batch to a multifd
thread.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Be consistent with defaults and documentation
Use new DEFINE_PROP_*
Rename x-multifd-group to x-multifd-page-count
Indicates the number of channels that we will create. By default we
create 2 channels.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Catch inconsistent defaults (eric).
Improve comment stating that number of threads is the same than number
of sockets
Use new DEFIN_PROP_*
Rename x-multifd-threads to x-multifd-threads
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
--
Use new DEFINE_PROP
This function allows us to decide when to close the listener socket.
For now, we only need one connection.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
We pass the ioc instead of the fd. This will allow us to have more
than one channel open. We also make sure that we set the
from_src_file sooner, so we don't need to pass it as a parameter.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
--
Do not assing mis->from_src_file (peterxu)
When this capability is enabled, QEMU will use the return path even for
precopy migration. This is helpful at least in one case when destination
failed to load the image while source quited without confirmation. With
return path, source will wait for the last response from destination,
and if destination fails, it'll fail the migration on source, then the
guest can be run again on the source (rather than assuming to be good,
then the guest will be lost after source quits).
It needs to be enabled explicitly on source, otherwise disabled.
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1498472935-14461-1-git-send-email-peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Move it into MigrationState, revert its meaning and renaming it to
send_section_footer, with a property bound to it. Same trick is played
like previous patches.
Removing savevm_skip_section_footers().
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-9-git-send-email-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
It was in SaveState but now moved to MigrationState altogether, reverted
its meaning, then renamed to "send_configuration". Again, using
HW_COMPAT_2_3 for old PC/SPAPR machines, and accel_register_prop() for
xen_init().
Removing savevm_skip_configuration().
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-8-git-send-email-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
One less global variable, and it does only matter with migration.
We keep the old "--only-migratable" option, but also now we support:
-global migration.only-migratable=true
Currently still keep the old interface.
Hmm, now vl.c has no way to access migrate_get_current(). Export a
function for it to setup only_migratable.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-7-git-send-email-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Put it into MigrationState then we can use the properties to specify
whether to enable storing global state.
Removing global_state_set_optional() since now we can use HW_COMPAT_2_3
for x86/power, and AccelClass.global_props for Xen.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-6-git-send-email-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Let the old man "MigrationState" join the object family. Direct benefit
is that we can start to use all the property features derived from
current QDev, like: HW_COMPAT_* bits, command line setup for migration
parameters (so will never need to set them up each time using HMP/QMP,
this is really, really attractive for test writters), etc.
I see no reason to disallow this happen yet. So let's start from this
one, to see whether it would be anything good.
Now we init the MigrationState struct statically in main() to make sure
it's initialized after global properties are applied, since we'll use
them during creation of the object.
No functional change at all.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <1498536619-14548-5-git-send-email-peterx@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Nothing uses it outside of migration.h
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
