Commit Graph

1692 Commits

Author SHA1 Message Date
Juan Quintela
7b548761e5 ram: Document migration ram flags
0x80 is RAM_SAVE_FLAG_HOOK, it is in qemu-file now.
Bigger usable flag is 0x200, noticing that.
We can reuse RAM_SAVe_FLAG_FULL.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-13 03:45:47 +01:00
Leonardo Bras
cfc3bcf373 migration/multifd: Move load_cleanup inside incoming_state_destroy
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>
2023-02-13 03:45:40 +01:00
Leonardo Bras
10351fbad1 migration/multifd: Join all multifd threads in order to avoid leaks
Current approach will only join threads that are still running.

For the threads not joined, resources or private memory are always kept in
the process space and never reclaimed before process end, and this risks
serious memory leaks.

This should usually not represent a big problem, since multifd migration
is usually just ran at most a few times, and after it succeeds there is
not much to be done before exiting the process.

Yet still, it should not hurt performance to join all of them.

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>
2023-02-13 03:45:34 +01:00
Leonardo Bras
d926f3bb2a migration/multifd: Remove unnecessary assignment on multifd_load_cleanup()
Before assigning "p->quit = true" for every multifd channel,
multifd_load_cleanup() will call multifd_recv_terminate_threads() which
already does the same assignment, while protected by a mutex.

So there is no point doing the same assignment again.

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>
2023-02-13 03:45:28 +01:00
Leonardo Bras
e5bac1f525 migration/multifd: Change multifd_load_cleanup() signature and usage
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>
2023-02-13 03:44:44 +01:00
Peter Xu
5655aab079 migration: Postpone postcopy preempt channel to be after main
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>
2023-02-11 16:51:09 +01:00
Peter Xu
b28fb58227 migration: Add a semaphore to count PONGs
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>
2023-02-11 16:51:09 +01:00
Peter Xu
fc063a7b8a migration: Cleanup postcopy_preempt_setup()
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>
2023-02-11 16:51:09 +01:00
Peter Xu
d6f74fd12e migration: Rework multi-channel checks on URI
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>
2023-02-11 16:51:09 +01:00
ling xu
04ffce137b AVX512 support for xbzrle_encode_buffer
This commit is the same with [PATCH v6 1/2], and provides avx512 support for xbzrle_encode_buffer
function to accelerate xbzrle encoding speed. Runtime check of avx512
support and benchmark for this feature are added. Compared with C
version of xbzrle_encode_buffer function, avx512 version can achieve
50%-70% performance improvement on benchmarking. In addition, if dirty
data is randomly located in 4K page, the avx512 version can achieve
almost 140% performance gain.

Signed-off-by: ling xu <ling1.xu@intel.com>
Co-authored-by: Zhou Zhao <zhou.zhao@intel.com>
Co-authored-by: Jun Jin <jun.i.jin@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
e264705012 migration: I messed state_pending_exact/estimate
I called the helper function from the wrong top level function.

This code was introduced in:

commit c8df4a7aef
Author: Juan Quintela <quintela@redhat.com>
Date:   Mon Oct 3 02:00:03 2022 +0200

    migration: Split save_live_pending() into state_pending_*

    We split the function into to:

    - state_pending_estimate: We estimate the remaining state size without
      stopping the machine.

    - state pending_exact: We calculate the exact amount of remaining
      state.

Thanks to Avihai Horon <avihaih@nvidia.com> for finding it.

Fixes:c8df4a7aeffcb46020f610526eea621fa5b0cd47

When we introduced that patch, we enden calling

state_pending_estimate() helper from qemu_savevm_statepending_exact()
and
state_pending_exact() helper from qemu_savevm_statepending_estimate()

This patch fixes it.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
4010ba388d migration: Make ram_save_target_page() a pointer
We are going to create a new function for multifd latest in the series.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
8d80e1951e migration: Calculate ram size once
We are recalculating ram size continously, when we know that it don't
change during migration.  Create a field in RAMState to track it.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2023-02-11 16:51:09 +01:00
Juan Quintela
8008a272d6 migration: Split ram_bytes_total_common() in two functions
It is just a big if in the middle of the function, and we need two
functions anways.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>

---

Reindent to make Phillipe happy (and CODING_STYLE)
2023-02-11 16:51:09 +01:00
Juan Quintela
31e2ac742b migration: Make find_dirty_block() return a single parameter
We used to return two bools, just return a single int with the
following meaning:

old return / again / new return
false        false   PAGE_ALL_CLEAN
false        true    PAGE_TRY_AGAIN
true         true    PAGE_DIRTY_FOUND  /* We don't care about again at all */

Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
51efd36faf migration: Simplify ram_find_and_save_block()
We will need later that find_dirty_block() return errors, so
simplify the loop.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Li Zhang
bca762c2b9 multifd: Remove some redundant code
Clean up some unnecessary code

Signed-off-by: Li Zhang <lizhang@suse.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Li Zhang
e3f37b2ce6 multifd: cleanup the function multifd_channel_connect
Cleanup multifd_channel_connect

Signed-off-by: Li Zhang <lizhang@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Juan Quintela
b530ccde5d migration: Remove spurious files
I introduced spurious files on my tree during a rebase:

commit ebfc578715
Author: Zhenzhong Duan <zhenzhong.duan@intel.com>
Date:   Mon Oct 17 15:53:51 2022 +0800

    multifd: Fix flush of zero copy page send request

    Make IO channel flush call after the inflight request has been drained
    in multifd thread, or else we may missed to flush the inflight request.

    Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
    Reviewed-by: Juan Quintela <quintela@redhat.com>
    Signed-off-by: Juan Quintela <quintela@redhat.com>

To make things worse, it appears like Zhenzhong is the one to blame.

for(int i=0; i < 1000000; i++) {
	printf("I will not do rebases when I am tired\n");
}

Sorry, Juan.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-11 16:51:09 +01:00
Markus Armbruster
a67dfa660b Drop duplicate #include
Tracked down with the help of scripts/clean-includes.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230202133830.2152150-21-armbru@redhat.com>
2023-02-08 07:28:05 +01:00
Jiang Jiacheng
1b1f4ab69c migration: save/delete migration thread info
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>
2023-02-06 19:22:57 +01:00
Jiang Jiacheng
671326201d migration: Introduce interface query-migrationthreads
Introduce interface query-migrationthreads. The interface is used
to query information about migration threads and returns with
migration thread's name and its id.
Introduce threadinfo.c to manage threads with migration.

Signed-off-by: Jiang Jiacheng <jiangjiacheng@huawei.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:57 +01:00
Zhenzhong Duan
ebfc578715 multifd: Fix flush of zero copy page send request
Make IO channel flush call after the inflight request has been drained
in multifd thread, or else we may missed to flush the inflight request.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:57 +01:00
Zhenzhong Duan
ddbe628c97 multifd: Fix a race on reading MultiFDPages_t.block
In multifd_queue_page() MultiFDPages_t.block is checked twice.
Between the two checks, MultiFDPages_t.block may be reset to NULL
by multifd thread. This lead to the 2nd check always true then a
redundant page submitted to multifd thread again.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:57 +01:00
manish.mishra
6720c2b327 migration: check magic value for deciding the mapping of channels
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>
2023-02-06 19:22:57 +01:00
manish.mishra
84615a19dd io: Add support for MSG_PEEK for socket channel
MSG_PEEK peeks at the channel, The data is treated as unread and
the next read shall still return this data. This support is
currently added only for socket class. Extra parameter 'flags'
is added to io_readv calls to pass extra read flags like MSG_PEEK.

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>
2023-02-06 19:22:56 +01:00
Zhenzhong Duan
bd9510d385 migration/dirtyrate: Show sample pages only in page-sampling mode
The value of "Sample Pages" is confusing in mode other than page-sampling.
See below:

(qemu) calc_dirty_rate -b 10 520
(qemu) info dirty_rate
Status: measuring
Start Time: 11646834 (ms)
Sample Pages: 520 (per GB)
Period: 10 (sec)
Mode: dirty-bitmap
Dirty rate: (not ready)

(qemu) info dirty_rate
Status: measured
Start Time: 11646834 (ms)
Sample Pages: 0 (per GB)
Period: 10 (sec)
Mode: dirty-bitmap
Dirty rate: 2 (MB/s)

While it's totally useless in dirty-ring and dirty-bitmap mode, fix to
show it only in page-sampling mode.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
Dr. David Alan Gilbert
bb25a72895 migration: Perform vmsd structure check during tests
Perform a check on vmsd structures during test runs in the hope
of catching any missing terminators and other simple screwups.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
Dr. David Alan Gilbert
89c5684891 migration: Add canary to VMSTATE_END_OF_LIST
We fairly regularly forget VMSTATE_END_OF_LIST markers off descriptions;
given that the current check is only for ->name being NULL, sometimes
we get unlucky and the code apparently works and no one spots the error.

Explicitly add a flag, VMS_END that should be set, and assert it is
set during the traversal.

Note: This can't go in until we update the copy of vmstate.h in slirp.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
Fiona Ebner
74ecf6ac2b migration/rdma: fix return value for qio_channel_rdma_{readv,writev}
upon errors. As the documentation in include/io/channel.h states, only
-1 and QIO_CHANNEL_ERR_BLOCK should be returned upon error. Other
values have the potential to confuse the call sites.

error_setg is used rather than error_setg_errno, because there are
certain code paths where -1 (as a non-errno) is propagated up (e.g.
starting from qemu_rdma_block_for_wrid or qemu_rdma_post_recv_control)
all the way to qio_channel_rdma_{readv,writev}.

Similar to a216ec85b7 ("migration/channel-block: fix return value for
qio_channel_block_{readv,writev}").

Suggested-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
Peter Xu
db18dee7d7 migration: Show downtime during postcopy phase
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>
2023-02-06 19:22:56 +01:00
David Hildenbrand
80fe315c38 migration/ram: Factor out check for advised postcopy
Let's factor out this check, to be used in virtio-mem context next.

While at it, fix a spelling error in a related comment.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
David Hildenbrand
62f42625d4 migration/savevm: Allow immutable device state to be migrated early (i.e., before RAM)
For virtio-mem, we want to have the plugged/unplugged state of memory
blocks available before migrating any actual RAM content, and perform
sanity checks before touching anything on the destination. This
information is immutable on the migration source while migration is active,

We want to use this information for proper preallocation support with
migration: currently, we don't preallocate memory on the migration target,
and especially with hugetlb, we can easily run out of hugetlb pages during
RAM migration and will crash (SIGBUS) instead of catching this gracefully
via preallocation.

Migrating device state via a VMSD before we start iterating is currently
impossible: the only approach that would be possible is avoiding a VMSD
and migrating state manually during save_setup(), to be restored during
load_state().

Let's allow for migrating device state via a VMSD early, during the
setup phase in qemu_savevm_state_setup(). To keep it simple, we
indicate applicable VMSD's using an "early_setup" flag.

Note that only very selected devices (i.e., ones seriously messing with
RAM setup) are supposed to make use of such early state migration.

While at it, also use a bool for the "unmigratable" member.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
David Hildenbrand
e3bf5e68e2 migration/savevm: Prepare vmdesc json writer in qemu_savevm_state_setup()
... and store it in the migration state. This is a preparation for
storing selected vmds's already in qemu_savevm_state_setup().

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
David Hildenbrand
5e104f24e7 migration/savevm: Move more savevm handling into vmstate_save()
Let's move more code into vmstate_save(), reducing code duplication and
preparing for reuse of vmstate_save() in qemu_savevm_state_setup(). We
have to move vmstate_save() to make the compiler happy.

We'll now also trace from qemu_save_device_state(), triggering the same
tracepoints as previously called from
qemu_savevm_state_complete_precopy_non_iterable() only. Note that
qemu_save_device_state() ignores iterable device state, such as RAM,
and consequently doesn't trigger some other trace points (e.g.,
trace_savevm_state_setup()).

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
David Hildenbrand
e41c57702e migration/ram: Optimize ram_write_tracking_start() for RamDiscardManager
ram_block_populate_read() already optimizes for RamDiscardManager.
However, ram_write_tracking_start() will still try protecting discarded
memory ranges.

Let's optimize, because discarded ranges don't map any pages and

(1) For anonymous memory, trying to protect using uffd-wp without a mapped
    page is ignored by the kernel and consequently a NOP.

(2) For shared/file-backed memory, we will fill present page tables in the
    range with PTE markers. However, we will even allocate page tables
    just to fill them with unnecessary PTE markers and effectively
    waste memory.

So let's exclude these ranges, just like ram_block_populate_read()
already does.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
David Hildenbrand
59bcc049c1 migration/ram: Rely on used_length for uffd_change_protection()
ram_mig_ram_block_resized() will abort migration (including background
snapshots) when resizing a RAMBlock. ram_block_populate_read() will only
populate RAM up to used_length, so at least for anonymous memory
protecting everything between used_length and max_length won't
actually be protected and is just a NOP.

So let's only protect everything up to used_length.

Note: it still makes sense to register uffd-wp for max_length, such
that RAM_UF_WRITEPROTECT is independent of a changing used_length.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
David Hildenbrand
7cc8e9e0fa migration/ram: Don't explicitly unprotect when unregistering uffd-wp
When unregistering uffd-wp, older kernels before commit f369b07c86143
("mm/uffd:reset write protection when unregister with wp-mode") won't
clear the uffd-wp PTE bit. When re-registering uffd-wp, the previous
uffd-wp PTE bits would trigger again. With above commit, the kernel will
clear the uffd-wp PTE bits when unregistering itself.

Consequently, we'll clear the uffd-wp PTE bits now twice -- whereby we
don't care about clearing them at all: a new background snapshot will
re-register uffd-wp and re-protect all memory either way.

So let's skip the manual clearing of uffd-wp. If ever relevant, we
could clear conditionally in uffd_unregister_memory() -- we just need a
way to figure out more recent kernels.

Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
David Hildenbrand
72ef3a3708 migration/ram: Fix error handling in ram_write_tracking_start()
If something goes wrong during uffd_change_protection(), we would miss
to unregister uffd-wp and not release our reference. Fix it by
performing the uffd_change_protection(true) last.

Note that a uffd_change_protection(false) on the recovery path without a
prior uffd_change_protection(false) is fine.

Fixes: 278e2f551a ("migration: support UFFD write fault processing in ram_save_iterate()")
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
David Hildenbrand
5f19a44919 migration/ram: Fix populate_read_range()
Unfortunately, commit f7b9dcfbcf broke populate_read_range(): the loop
end condition is very wrong, resulting in that function not populating the
full range. Lets' fix that.

Fixes: f7b9dcfbcf ("migration/ram: Factor out populating pages readable in ram_block_populate_pages()")
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
Peter Xu
d5890ea072 util/userfaultfd: Add uffd_open()
Add a helper to create the uffd handle.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
Juan Quintela
d9df92925e migration: simplify migration_iteration_run()
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2023-02-06 19:22:56 +01:00
Juan Quintela
fd70385d38 migration: Remove unused threshold_size parameter
Until previous commit, save_live_pending() was used for ram.  Now with
the split into state_pending_estimate() and state_pending_exact() it
is not needed anymore, so remove them.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2023-02-06 19:22:56 +01:00
Juan Quintela
c8df4a7aef migration: Split save_live_pending() into state_pending_*
We split the function into to:

- state_pending_estimate: We estimate the remaining state size without
  stopping the machine.

- state pending_exact: We calculate the exact amount of remaining
  state.

The only "device" that implements different functions for _estimate()
and _exact() is ram.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2023-02-06 19:22:56 +01:00
Juan Quintela
255dc7af7e migration: No save_live_pending() method uses the QEMUFile parameter
So remove it everywhere.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2023-02-06 19:22:56 +01:00
Peter Xu
301d7ffe5f migration: Fix migration crash when target psize larger than host
Commit d9e474ea56 overlooked the case where the target psize is even larger
than the host psize.  One example is Alpha has 8K page size and migration
will start to crash the source QEMU when running Alpha migration on x86.

Fix it by detecting that case and set host start/end just to cover the
single page to be migrated.

This will slightly optimize the common case where host psize equals to
guest psize so we don't even need to do the roundups, but that's trivial.

Cc: qemu-stable@nongnu.org
Reported-by: Thomas Huth <thuth@redhat.com>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1456
Fixes: d9e474ea56 ("migration: Teach PSS about host page")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-06 19:22:56 +01:00
Markus Armbruster
27be86351e migration: Move the QMP command from monitor/ to migration/
This moves the command from MAINTAINERS sections "Human Monitor (HMP)"
and "QMP" to "Migration".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230124121946.1139465-19-armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
2023-02-04 07:56:54 +01:00
Markus Armbruster
119f50ce30 migration: Move HMP commands from monitor/ to migration/
This moves these commands from MAINTAINERS sections "Human
Monitor (HMP)" and "QMP" to "Migration".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230124121946.1139465-18-armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
2023-02-04 07:56:54 +01:00
Markus Armbruster
e2c1c34f13 include/block: Untangle inclusion loops
We have two inclusion loops:

       block/block.h
    -> block/block-global-state.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

       block/block.h
    -> block/block-io.h
    -> block/block-common.h
    -> block/blockjob.h
    -> block/block.h

I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac.

Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
2023-01-20 07:24:28 +01:00
Peter Maydell
928eac9539 Migration patches for 8.0
Hi
 
 This are the patches that I had to drop form the last PULL request because they werent fixes:
 - AVX2 is dropped, intel posted a fix, I have to redo it
 - Fix for out of order channels is out
   Daniel nacked it and I need to redo it
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Merge tag 'next-8.0-pull-request' of https://gitlab.com/juan.quintela/qemu into staging

Migration patches for 8.0

Hi

This are the patches that I had to drop form the last PULL request because they werent fixes:
- AVX2 is dropped, intel posted a fix, I have to redo it
- Fix for out of order channels is out
  Daniel nacked it and I need to redo it

# gpg: Signature made Thu 15 Dec 2022 09:38:29 GMT
# gpg:                using RSA key 1899FF8EDEBF58CCEE034B82F487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>" [full]
# gpg:                 aka "Juan Quintela <quintela@trasno.org>" [full]
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* tag 'next-8.0-pull-request' of https://gitlab.com/juan.quintela/qemu:
  migration: Drop rs->f
  migration: Remove old preempt code around state maintainance
  migration: Send requested page directly in rp-return thread
  migration: Move last_sent_block into PageSearchStatus
  migration: Make PageSearchStatus part of RAMState
  migration: Add pss_init()
  migration: Introduce pss_channel
  migration: Teach PSS about host page
  migration: Use atomic ops properly for page accountings
  migration: Yield bitmap_mutex properly when sending/sleeping
  migration: Remove RAMState.f references in compression code
  migration: Trivial cleanup save_page_header() on same block check
  migration: Cleanup xbzrle zero page cache update logic
  migration: Add postcopy_preempt_active()
  migration: Take bitmap mutex when completing ram migration
  migration: Export ram_release_page()
  migration: Export ram_transferred_ram()
  multifd: Create page_count fields into both MultiFD{Recv,Send}Params
  multifd: Create page_size fields into both MultiFD{Recv,Send}Params

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-12-15 14:52:13 +00:00