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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

This reverts commits
ca6011c2 migration: add postcopy total blocktime into query-migrate
5f32dc8e migration: add blocktime calculation into migration-test
2f7dae9d migration: postcopy_blocktime documentation
3be98be4 migration: calculate vCPU blocktime on dst side
01a87f0b migration: add postcopy blocktime ctx into MigrationIncomingState
31bf06a9 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: NPeter Maydell <peter.maydell@linaro.org>

It is already called in migrate_fd_cleanup.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Keep the one in migrate_fd_cleanup() would be enough.  Removing the other
two.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

This patch only moved the last part of migration_thread() into a new
function migration_iteration_finish() to make it much shorter.  With
previous works to remove some local variables, now it's fairly easy to
do that.
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

The major work for migration iterations are to move RAM/block/... data
via qemu_savevm_state_iterate().  Generalize those part into a single
function.
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

It converts the old if clauses into switch, explicitly mentions the
possible migration states.  The old nested "if"s are not clear on what
we do on different states.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Generalize the calculation part when migration complete into a
function to simplify migration_thread().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan 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: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NJuan 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: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NJuan 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: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

It's only used once, clean it up a bit.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Moving existing callers all into migrate_fd_cleanup().  It simplifies
migration_thread() a bit.
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

When reaching here if we are still "active" it means we must be in colo
state.  After a quick discussion offlist, we decided to use the safer
error_report().

Finally I want to use "switch" here rather than lots of complicated if
clauses.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

current_migration has .instance_finalize callback, but it is not
called, because nobody unrefs current_migration. Fix that.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan 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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NAlexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan 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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NAlexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Once there, do one thing for line
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>

We use int for everything (int64_t), and then we check that value is
between 0 and 255.  Change it to the valid types.

This change only happens for HMP.  QMP always use bytes and similar.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NEric Blake <eblake@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: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

After the previous commits, we make sure that the value passed is
right, or we just drop an error.  So now we return if there is one
error or we have setup correctly the value passed.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

--

Improve error messasge
Return 0 always for success

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: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

Add pause-before-switchover support for postcopy.
After starting postcopy it will transition
    active->pre-switchover->postcopy_active
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

If a migration_cancel is issued during the new paused state,
kick the pause_sem to get to unpause so it can cancel.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

A new qmp command allows the caller to continue from a given
paused state.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Wait for a semaphore before completing the migration,
if the previously added capability was enabled.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Add two statuses for use when the 'pause-before-switchover'
capability is enabled.

'pre-switchover' is the state that we wait in for management
to allow us to continue.
'device' is the state we enter while serialising the devices
after management gives us the OK.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan 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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>

They were missing when introduced on the tree
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>

That tiny refactoring is necessary to be able to set
UFFD_FEATURE_THREAD_ID while requesting features, and then
to create downtime context in case when kernel supports it.
Signed-off-by: NAlexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Split common postcopy staff from ram postcopy staff.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

We need that on later patches.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>

Creation of the threads, nothing inside yet.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

--

Use pointers instead of long array names
Move to use semaphores instead of conditions as paolo suggestion

Put all the state inside one struct.
Use a counter for the number of threads created.  Needed during cancellation.

Add error return to thread creation

Add id field

Rename functions to multifd_save/load_setup/cleanup
Change recv parameters to a pointer to struct
Change back to a struct
Use Error * for _cleanup

Indicates how many pages we are going to send in each batch to a multifd
thread.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter 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: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter 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: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Reviewed-by: NDaniel 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: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDaniel 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: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDaniel P. Berrange <berrange@redhat.com>

--

Do not assing mis->from_src_file (peterxu)