Once there, rename it to migrate_tls() and make it return bool for
consistency.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
---
Fix typos found by fabiano
To be consistent with every other parameter, rename to
migrate_block_incremental().
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_return_path()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_block()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_xbzrle()
to be consistent with all other capabilities.
We change the type to return bool also for consistency.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to
migrate_zero_copy_send() to be consistent with all other capabilities.
We can remove the CONFIG_LINUX guard. We already check that we can't
setup this capability in migrate_caps_check().
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_multifd()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_events()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_compress()
to be consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Once that we are there, we rename the function to migrate_colo() to be
consistent with all other capabilities.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
We move there all capabilities helpers from migration.c.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
Following David advise:
- looked through the history, capabilities are newer than 2012, so we
can remove that bit of the header.
- This part is posterior to Anthony.
Original Author is Orit. Once there,
I put myself. Peter Xu also did quite a bit of work here.
Anyone else wants/needs to be there? I didn't search too hard
because nobody asked before to be added.
What do you think?
And remove the convoluted use of qmp_migrate_set_capabilities() to
enable disable MIGRATION_CAPABILITY_BLOCK.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
It has nothing to do with migration, except for the "migrate" in the
name of the command. Move it with the rest of the ui commands.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
It is only used there, so we can make it static.
Once there, remove spice.h that it is not used.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
fix David Edmonson ui/qemu-spice.h unintended removal
No need to declare a temporary variable.
Suggested-by: Juan Quintela <quintela@redhat.com>
Fixes: 1df36e8c6289 ("migration: Handle block device inactivation failures better")
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
We used to pass the old capabilities array and the new
capabilities as a list.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
It is clear from the context what that means, and such a long name
with the extra long names of the capabilities make very difficilut to
stay inside the 80 columns limit.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Consider what happens when performing a migration between two host
machines connected to an NFS server serving multiple block devices to
the guest, when the NFS server becomes unavailable. The migration
attempts to inactivate all block devices on the source (a necessary
step before the destination can take over); but if the NFS server is
non-responsive, the attempt to inactivate can itself fail. When that
happens, the destination fails to get the migrated guest (good,
because the source wasn't able to flush everything properly):
(qemu) qemu-kvm: load of migration failed: Input/output error
at which point, our only hope for the guest is for the source to take
back control. With the current code base, the host outputs a message, but then appears to resume:
(qemu) qemu-kvm: qemu_savevm_state_complete_precopy_non_iterable: bdrv_inactivate_all() failed (-1)
(src qemu)info status
VM status: running
but a second migration attempt now asserts:
(src qemu) qemu-kvm: ../block.c:6738: int bdrv_inactivate_recurse(BlockDriverState *): Assertion `!(bs->open_flags & BDRV_O_INACTIVE)' failed.
Whether the guest is recoverable on the source after the first failure
is debatable, but what we do not want is to have qemu itself fail due
to an assertion. It looks like the problem is as follows:
In migration.c:migration_completion(), the source sets 'inactivate' to
true (since COLO is not enabled), then tries
savevm.c:qemu_savevm_state_complete_precopy() with a request to
inactivate block devices. In turn, this calls
block.c:bdrv_inactivate_all(), which fails when flushing runs up
against the non-responsive NFS server. With savevm failing, we are
now left in a state where some, but not all, of the block devices have
been inactivated; but migration_completion() then jumps to 'fail'
rather than 'fail_invalidate' and skips an attempt to reclaim those
those disks by calling bdrv_activate_all(). Even if we do attempt to
reclaim disks, we aren't taking note of failure there, either.
Thus, we have reached a state where the migration engine has forgotten
all state about whether a block device is inactive, because we did not
set s->block_inactive in enough places; so migration allows the source
to reach vm_start() and resume execution, violating the block layer
invariant that the guest CPUs should not be restarted while a device
is inactive. Note that the code in migration.c:migrate_fd_cancel()
will also try to reactivate all block devices if s->block_inactive was
set, but because we failed to set that flag after the first failure,
the source assumes it has reclaimed all devices, even though it still
has remaining inactivated devices and does not try again. Normally,
qmp_cont() will also try to reactivate all disks (or correctly fail if
the disks are not reclaimable because NFS is not yet back up), but the
auto-resumption of the source after a migration failure does not go
through qmp_cont(). And because we have left the block layer in an
inconsistent state with devices still inactivated, the later migration
attempt is hitting the assertion failure.
Since it is important to not resume the source with inactive disks,
this patch marks s->block_inactive before attempting inactivation,
rather than after succeeding, in order to prevent any vm_start() until
it has successfully reactivated all devices.
See also https://bugzilla.redhat.com/show_bug.cgi?id=2058982
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Acked-by: Lukas Straub <lukasstraub2@web.de>
Tested-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Rest of counters that refer to pages has a _pages suffix.
And historically, this showed the number of full pages transferred.
The name "normal" refered to the fact that they were sent without any
optimization (compression, xbzrle, zero_page, ...).
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Rest of counters that refer to pages has a _pages suffix.
And historically, this showed the number of pages composed of the same
character, here comes the name "duplicated". But since years ago, it
refers to the number of zero_pages.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
In the spirit of:
commit 394d323bc3451e4d07f13341cb8817fac8dfbadd
Author: Peter Xu <peterx@redhat.com>
Date: Tue Oct 11 17:55:51 2022 -0400
migration: Use atomic ops properly for page accountings
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Using MgrationStats as type for ram_counters mean that we didn't have
to re-declare each value in another struct. The need of atomic
counters have make us to create MigrationAtomicStats for this atomic
counters.
Create RAMStats type which is a merge of MigrationStats and
MigrationAtomicStats removing unused members.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
Fix typos found by David Edmondson
In 8.0 devel window we reworked preempt channel creation, so that there'll
be no race condition when the migration channel and preempt channel got
established in the wrong order in commit 5655aab079.
However no one noticed that the change will also be not compatible with
older qemus, majorly 7.1/7.2 versions where preempt mode started to be
supported.
Leverage the same pre-7.2 flag introduced in the previous patch to recover
the behavior hopefully before 8.0 releases, so we don't break migration
when we migrate from 8.0 to older qemu binaries.
Fixes: 5655aab079 ("migration: Postpone postcopy preempt channel to be after main")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
postcopy_qemufile_src object should be owned by one thread, either the main
thread (e.g. when at the beginning, or at the end of migration), or by the
return path thread (when during a preempt enabled postcopy migration). If
that's not the case the access to the object might be racy.
postcopy_preempt_shutdown_file() can be potentially racy, because it's
called at the end phase of migration on the main thread, however during
which the return path thread hasn't yet been recycled; the recycle happens
in await_return_path_close_on_source() which is after this point.
It means, logically it's posslbe the main thread and the return path thread
are both operating on the same qemufile. While I don't think qemufile is
thread safe at all.
postcopy_preempt_shutdown_file() used to be needed because that's where we
send EOS to dest so that dest can safely shutdown the preempt thread.
To avoid the possible race, remove this only place that a race can happen.
Instead we figure out another way to safely close the preempt thread on
dest.
The core idea during postcopy on deciding "when to stop" is that dest will
send a postcopy SHUT message to src, telling src that all data is there.
Hence to shut the dest preempt thread maybe better to do it directly on
dest node.
This patch proposed such a way that we change postcopy_prio_thread_created
into PreemptThreadStatus, so that we kick the preempt thread on dest qemu
by a sequence of:
mis->preempt_thread_status = PREEMPT_THREAD_QUIT;
qemu_file_shutdown(mis->postcopy_qemufile_dst);
While here shutdown() is probably so far the easiest way to kick preempt
thread from a blocked qemu_get_be64(). Then it reads preempt_thread_status
to make sure it's not a network failure but a willingness to quit the
thread.
We could have avoided that extra status but just rely on migration status.
The problem is postcopy_ram_incoming_cleanup() is just called early enough
so we're still during POSTCOPY_ACTIVE no matter what.. So just make it
simple to have the status introduced.
One flag x-preempt-pre-7-2 is added to keep old pre-7.2 behaviors of
postcopy preempt.
Fixes: 9358982744 ("migration: Send requested page directly in rp-return thread")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Once that res_compatible is removed, they don't make sense anymore.
We remove the _only preffix. And to make things clearer we rename
them to must_precopy and can_postcopy.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Nothing assigns to it after previous commit.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Currently running migration_incoming_state_destroy() without first running
multifd_load_cleanup() will cause a yank error:
qemu-system-x86_64: ../util/yank.c:107: yank_unregister_instance:
Assertion `QLIST_EMPTY(&entry->yankfns)' failed.
(core dumped)
The above error happens in the target host, when multifd is being used
for precopy, and then postcopy is triggered and the migration finishes.
This will crash the VM in the target host.
To avoid that, move multifd_load_cleanup() inside
migration_incoming_state_destroy(), so that the load cleanup becomes part
of the incoming state destroying process.
Running multifd_load_cleanup() twice can become an issue, though, but the
only scenario it could be ran twice is on process_incoming_migration_bh().
So removing this extra call is necessary.
On the other hand, this multifd_load_cleanup() call happens way before the
migration_incoming_state_destroy() and having this happening before
dirty_bitmap_mig_before_vm_start() and vm_start() may be a need.
So introduce a new function multifd_load_shutdown() that will mainly stop
all multifd threads and close their QIOChannels. Then use this function
instead of multifd_load_cleanup() to make sure nothing else is received
before dirty_bitmap_mig_before_vm_start().
Fixes: b5eea99ec2 ("migration: Add yank feature")
Reported-by: Li Xiaohui <xiaohli@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Since it's introduction in commit f986c3d256 ("migration: Create multifd
migration threads"), multifd_load_cleanup() never returned any value
different than 0, neither set up any error on errp.
Even though, on process_incoming_migration_bh() an if clause uses it's
return value to decide on setting autostart = false, which will never
happen.
In order to simplify the codebase, change multifd_load_cleanup() signature
to 'void multifd_load_cleanup(void)', and for every usage remove error
handling or decision made based on return value != 0.
Fixes: b5eea99ec2 ("migration: Add yank feature")
Reported-by: Li Xiaohui <xiaohli@redhat.com>
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Postcopy with preempt-mode enabled needs two channels to communicate. The
order of channel establishment is not guaranteed. It can happen that the
dest QEMU got the preempt channel connection request before the main
channel is established, then the migration may make no progress even during
precopy due to the wrong order.
To fix it, create the preempt channel only if we know the main channel is
established.
For a general postcopy migration, we delay it until postcopy_start(),
that's where we already went through some part of precopy on the main
channel. To make sure dest QEMU has already established the channel, we
wait until we got the first PONG received. That's something we do at the
start of precopy when postcopy enabled so it's guaranteed to happen sooner
or later.
For a postcopy recovery, we delay it to qemu_savevm_state_resume_prepare()
where we'll have round trips of data on bitmap synchronizations, which
means the main channel must have been established.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This is mostly useless, but useful for us to know whether the main channel
is correctly established without changing the migration protocol.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Since we just dropped the only case where postcopy_preempt_setup() can
return an error, it doesn't need a retval anymore because it never fails.
Move the preempt check to the caller, preparing it to be used elsewhere to
do nothing but as simple as kicking the async connection.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The whole idea of multi-channel checks was not properly done, IMHO.
Currently we check multi-channel in a lot of places, but actually that's
not needed because we only need to check it right after we get the URI and
that should be it.
If the URI check succeeded, we should never need to check it again because
we must have it. If it check fails, we should fail immediately on either
the qmp_migrate or qmp_migrate_incoming, instead of failingg it later after
the connection established.
Neither should we fail any set capabiliities like what we used to do here:
5ad15e8614 ("migration: allow enabling mutilfd for specific protocol only", 2021-10-19)
Because logically the URI will only be set later after the capability is
set, so it doesn't make a lot of sense to check the URI type when setting
the capability, because we're checking the cap with an old URI passed in,
and that may not even be the URI we're going to use later.
This patch mostly reverted all such checks for before, dropping the
variable migrate_allow_multi_channels and helpers. Instead, add a common
helper to check URI for multi-channels for either qmp_migrate and
qmp_migrate_incoming and that should do all the proper checks. The failure
will only trigger with the "migrate" or "migrate_incoming" command, or when
user specified "-incoming xxx" where "xxx" is not "defer".
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
To support query migration thread infomation, save and delete
thread(live_migration and multifdsend) information at thread
creation and finish.
Signed-off-by: Jiang Jiacheng <jiangjiacheng@huawei.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Current logic assumes that channel connections on the destination side are
always established in the same order as the source and the first one will
always be the main channel followed by the multifid or post-copy
preemption channel. This may not be always true, as even if a channel has a
connection established on the source side it can be in the pending state on
the destination side and a newer connection can be established first.
Basically causing out of order mapping of channels on the destination side.
Currently, all channels except post-copy preempt send a magic number, this
patch uses that magic number to decide the type of channel. This logic is
applicable only for precopy(multifd) live migration, as mentioned, the
post-copy preempt channel does not send any magic number. Also, tls live
migrations already does tls handshake before creating other channels, so
this issue is not possible with tls, hence this logic is avoided for tls
live migrations. This patch uses read peek to check the magic number of
channels so that current data/control stream management remains
un-effected.
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: manish.mishra <manish.mishra@nutanix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The downtime should be displayed during postcopy phase because the
switchover phase is done. OTOH it's weird to show "expected downtime"
which can confuse what does that mean if the switchover has already
happened anyway.
This is a slight ABI change on QMP, but I assume it shouldn't affect
anyone.
Reviewed-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
