Commit Graph

324 Commits (f4f71363fcdb1092ff64d2bba6f9af39570c2f2b)

Author SHA1 Message Date
Juan Quintela cf786549ce migration: Change qemu_file_transferred to noflush
We do a qemu_fclose() just after that, that also does a qemu_fflush(),
so remove one qemu_fflush().

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20230530183941.7223-3-quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-07-26 10:55:56 +02:00
Juan Quintela fc95c63b60 qemu-file: Rename qemu_file_transferred_ fast -> noflush
Fast don't say much.  Noflush indicates more clearly that it is like
qemu_file_transferred but without the flush.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20230530183941.7223-2-quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-07-26 10:55:56 +02:00
Michael Tokarev d8b71d96b3 migration: spelling fixes
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
2023-07-25 17:13:20 +03:00
Avihai Horon 808642a2f6 vfio/migration: Reset bytes_transferred properly
Currently, VFIO bytes_transferred is not reset properly:
1. bytes_transferred is not reset after a VM snapshot (so a migration
   following a snapshot will report incorrect value).
2. bytes_transferred is a single counter for all VFIO devices, however
   upon migration failure it is reset multiple times, by each VFIO
   device.

Fix it by introducing a new function vfio_reset_bytes_transferred() and
calling it during migration and snapshot start.

Remove existing bytes_transferred reset in VFIO migration state
notifier, which is not needed anymore.

Fixes: 3710586caa ("qapi: Add VFIO devices migration stats in Migration stats")
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
2023-06-30 06:02:51 +02:00
Avihai Horon 1b4adb10f8 migration: Implement switchover ack logic
Implement switchover ack logic. This prevents the source from stopping
the VM and completing the migration until an ACK is received from the
destination that it's OK to do so.

To achieve this, a new SaveVMHandlers handler switchover_ack_needed()
and a new return path message MIG_RP_MSG_SWITCHOVER_ACK are added.

The switchover_ack_needed() handler is called during migration setup in
the destination to check if switchover ack is used by the migrated
device.

When switchover is approved by all migrated devices in the destination
that support this capability, the MIG_RP_MSG_SWITCHOVER_ACK return path
message is sent to the source to notify it that it's OK to do
switchover.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: YangHang Liu <yanghliu@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
2023-06-30 06:02:51 +02:00
Vladimir Sementsov-Ogievskiy c33f1829f8 migration: never fail in global_state_store()
Actually global_state_store() can never fail. Let's get rid of extra
error paths.

To make things clear, use new runstate_get() and use same approach for
global_state_store() and global_state_store_running().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230517123752.21615-3-vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-06-02 01:03:19 +02:00
Juan Quintela e1fde0e038 migration: Move rate_limit_max and rate_limit_used to migration_stats
These way we can make them atomic and use this functions from any
place.  I also moved all functions that use rate_limit to
migration-stats.

Functions got renamed, they are not qemu_file anymore.

qemu_file_rate_limit -> migration_rate_exceeded
qemu_file_set_rate_limit -> migration_rate_set
qemu_file_get_rate_limit -> migration_rate_get
qemu_file_reset_rate_limit -> migration_rate_reset
qemu_file_acct_rate_limit -> migration_rate_account.

Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230515195709.63843-6-quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-05-18 18:40:51 +02:00
Juan Quintela 6da835d42a qemu-file: Remove total from qemu_file_total_transferred_*()
Function is already quite long.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20230508130909.65420-7-quintela@redhat.com>
2023-05-15 13:46:14 +02:00
Juan Quintela 61abf1ebdc qemu-file: Make total_transferred an uint64_t
Change all the functions that use it.  It was already passed as
uint64_t.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20230504113841.23130-8-quintela@redhat.com>
2023-05-05 02:01:59 +02:00
Juan Quintela aff3f6606d migration: Rename ram_counters to mig_stats
migration_stats is just too long, and it is going to have more than
ram counters in the near future.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
2023-05-03 11:24:20 +02:00
Juan Quintela 947701cc1a migration: Move ram_stats to its own file migration-stats.[ch]
There is already include/qemu/stats.h, so stats.h was a bad idea.
We want this file to not depend on anything else, we will move all the
migration counters/stats to this struct.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
2023-05-03 11:24:19 +02:00
Peter Xu 12c81e5ae9 migration/vmstate-dump: Dump array size too as "num"
For VMS_ARRAY typed vmsd fields, also dump the number of entries in the
array in -vmstate-dump.

Without such information, vmstate static checker can report false negatives
of incompatible vmsd on VMS_ARRAY typed fields, when the src/dst do not
have the same type of array defined.  It's because in the checker we only
check against size of fields within a VMSD field.

One example: e1000e used to have a field defined as a boolean array with 5
entries, then removed it and replaced it with UNUSED (in 31e3f318c8):

-        VMSTATE_BOOL_ARRAY(core.eitr_intr_pending, E1000EState,
-                           E1000E_MSIX_VEC_NUM),
+        VMSTATE_UNUSED(E1000E_MSIX_VEC_NUM),

It's a legal replacement but vmstate static checker is not happy with it,
because it checks only against the "size" field between the two
fields (here one is BOOL_ARRAY, the other is UNUSED):

For BOOL_ARRAY:

      {
        "field": "core.eitr_intr_pending",
        "version_id": 0,
        "field_exists": false,
        "size": 1
      },

For UNUSED:

      {
        "field": "unused",
        "version_id": 0,
        "field_exists": false,
        "size": 5
      },

It's not the script to blame because there's just not enough information
dumped to show the total size of the entry for an array.  Add it.

Note that this will not break old vmstate checker because the field will
just be ignored.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-04-27 10:18:25 +02:00
Peter Xu 74c38cf7fd migration: Allow postcopy_ram_supported_by_host() to report err
Instead of print it to STDERR, bring the error upwards so that it can be
reported via QMP responses.

E.g.:

{ "execute": "migrate-set-capabilities" ,
  "arguments": { "capabilities":
  [ { "capability": "postcopy-ram", "state": true } ] } }

{ "error":
  { "class": "GenericError",
    "desc": "Postcopy is not supported: Host backend files need to be TMPFS
    or HUGETLBFS only" } }

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-04-27 10:18:25 +02:00
Juan Quintela 9d4b1e5f22 migration: Move migrate_use_block() to options.c
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>
2023-04-24 15:01:46 +02:00
Juan Quintela 1f0776f1c0 migration: Create options.c
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?
2023-04-24 15:01:46 +02:00
Juan Quintela 0cec2056ff migration: rename enabled_capabilities to capabilities
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>
2023-04-24 11:29:01 +02:00
Juan Quintela 24beea4efe migration: Rename res_{postcopy,precopy}_only
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>
2023-02-15 20:04:30 +01:00
Juan Quintela 24f254ed79 migration: Remove unused res_compatible
Nothing assigns to it after previous commit.

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-02-15 20:04:30 +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
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
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
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
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
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
Jason A. Donenfeld 7966d70f6f reset: allow registering handlers that aren't called by snapshot loading
Snapshot loading only expects to call deterministic handlers, not
non-deterministic ones. So introduce a way of registering handlers that
won't be called when reseting for snapshots.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-id: 20221025004327.568476-2-Jason@zx2c4.com
[PMM: updated json doc comment with Markus' text; fixed
 checkpatch style nit]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2022-10-27 11:34:31 +01:00
Peter Xu 60bb3c5871 migration: Postcopy recover with preempt enabled
To allow postcopy recovery, the ram fast load (preempt-only) dest QEMU thread
needs similar handling on fault tolerance.  When ram_load_postcopy() fails,
instead of stopping the thread it halts with a semaphore, preparing to be
kicked again when recovery is detected.

A mutex is introduced to make sure there's no concurrent operation upon the
socket.  To make it simple, the fast ram load thread will take the mutex during
its whole procedure, and only release it if it's paused.  The fast-path socket
will be properly released by the main loading thread safely when there's
network failures during postcopy with that mutex held.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185506.27257-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-07-20 12:15:08 +01:00
Peter Xu 36f62f11e4 migration: Postcopy preemption preparation on channel creation
Create a new socket for postcopy to be prepared to send postcopy requested
pages via this specific channel, so as to not get blocked by precopy pages.

A new thread is also created on dest qemu to receive data from this new channel
based on the ram_load_postcopy() routine.

The ram_load_postcopy(POSTCOPY) branch and the thread has not started to
function, and that'll be done in follow up patches.

Cleanup the new sockets on both src/dst QEMUs, meanwhile look after the new
thread too to make sure it'll be recycled properly.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220707185502.27149-1-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: With Peter's fix to quieten compiler warning on
       start_migration
2022-07-20 12:15:08 +01:00
Daniel P. Berrangé 77ef2dc1c8 migration: remove the QEMUFileOps abstraction
Now that all QEMUFile callbacks are removed, the entire concept can be
deleted.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@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>
2022-06-23 10:18:13 +01:00
Daniel P. Berrangé 67bdabe2af migration: convert savevm to use QIOChannelBlock for VMState
With this change, all QEMUFile usage is backed by QIOChannel at
last.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@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>
  dgilbert: Wrap long lines
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé fbfa6404e5 migration: rename qemu_ftell to qemu_file_total_transferred
The name 'ftell' gives the misleading impression that the QEMUFile
objects are seekable. This is not the case, as in general we just
have an opaque stream. The users of this method are only interested
in the total bytes processed. This switches to a new name that
reflects the intended usage.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@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>
   dgilbert: Wrapped long line
2022-06-22 19:33:36 +01:00
Peter Xu 08401c0426 migration: Allow migrate-recover to run multiple times
Previously migration didn't have an easy way to cleanup the listening
transport, migrate recovery only allows to execute once.  That's done with a
trick flag in postcopy_recover_triggered.

Now the facility is already there.

Drop postcopy_recover_triggered and instead allows a new migrate-recover to
release the previous listener transport.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220331150857.74406-8-peterx@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-04-21 19:36:46 +01:00
Emanuele Giuseppe Esposito 6b573efec8 include/block/snapshot: global state API + assertions
Snapshots run also under the BQL, so they all are
in the global state API. The aiocontext lock that they hold
is currently an overkill and in future could be removed.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20220303151616.325444-23-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-03-04 18:18:25 +01:00
Emanuele Giuseppe Esposito 3b71719462 block: rename bdrv_invalidate_cache_all, blk_invalidate_cache and test_sync_op_invalidate_cache
Following the bdrv_activate renaming, change also the name
of the respective callers.

bdrv_invalidate_cache_all -> bdrv_activate_all
blk_invalidate_cache -> blk_activate
test_sync_op_invalidate_cache -> test_sync_op_activate

No functional change intended.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220209105452.1694545-5-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2022-03-04 18:14:40 +01:00
Peter Xu 095c12a4a2 migration: Add postcopy_thread_create()
Postcopy create threads. A common manner is we init a sem and use it to sync
with the thread.  Namely, we have fault_thread_sem and listen_thread_sem and
they're only used for this.

Make it a shared infrastructure so it's easier to create yet another thread.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-7-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:20:45 +00:00
Peter Xu 77dadc3f83 migration: Introduce postcopy channels on dest node
Postcopy handles huge pages in a special way that currently we can only have
one "channel" to transfer the page.

It's because when we install pages using UFFDIO_COPY, we need to have the whole
huge page ready, it also means we need to have a temp huge page when trying to
receive the whole content of the page.

Currently all maintainance around this tmp page is global: firstly we'll
allocate a temp huge page, then we maintain its status mostly within
ram_load_postcopy().

To enable multiple channels for postcopy, the first thing we need to do is to
prepare N temp huge pages as caching, one for each channel.

Meanwhile we need to maintain the tmp huge page status per-channel too.

To give some example, some local variables maintained in ram_load_postcopy()
are listed; they are responsible for maintaining temp huge page status:

  - all_zero:     this keeps whether this huge page contains all zeros
  - target_pages: this counts how many target pages have been copied
  - host_page:    this keeps the host ptr for the page to install

Move all these fields to be together with the temp huge pages to form a new
structure called PostcopyTmpPage.  Then for each (future) postcopy channel, we
need one structure to keep the state around.

For vanilla postcopy, obviously there's only one channel.  It contains both
precopy and postcopy pages.

This patch teaches the dest migration node to start realize the possible number
of postcopy channels by introducing the "postcopy_channels" variable.  Its
value is calculated when setup postcopy on dest node (during POSTCOPY_LISTEN
phase).

Vanilla postcopy will have channels=1, but when postcopy-preempt capability is
enabled (in the future), we will boost it to 2 because even during partial
sending of a precopy huge page we still want to preempt it and start sending
the postcopy requested page right away (so we start to keep two temp huge
pages; more if we want to enable multifd).  In this patch there's a TODO marked
for that; so far the channels is always set to 1.

We need to send one "host huge page" on one channel only and we cannot split
them, because otherwise the data upon the same huge page can locate on more
than one channel so we need more complicated logic to manage.  One temp host
huge page for each channel will be enough for us for now.

Postcopy will still always use the index=0 huge page even after this patch.
However it prepares for the latter patches where it can start to use multiple
channels (which needs src intervention, because only src knows which channel we
should use).

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-5-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: Fixed up long line
2022-03-02 18:19:31 +00:00
Peter Xu b9a040b935 migration: Tracepoint change in postcopy-run bottom half
Remove the old two tracepoints and they're even near each other:

    trace_loadvm_postcopy_handle_run_cpu_sync()
    trace_loadvm_postcopy_handle_run_vmstart()

Add trace_loadvm_postcopy_handle_run_bh() with a finer granule trace.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-4-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:17:56 +00:00
Peter Xu c84f976e91 migration: Finer grained tracepoints for POSTCOPY_LISTEN
The enablement of postcopy listening has a few steps, add a few tracepoints to
be there ready for some basic measurements for them.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-3-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:17:56 +00:00
Peter Xu a7060ba3cc migration: Dump sub-cmd name in loadvm_process_command tp
It'll be easier to read the name rather than index of sub-cmd when debugging.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-2-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:17:56 +00:00
David Edmondson 9200265838 migration: Report the error returned when save_live_iterate fails
Should qemu_savevm_state_iterate() encounter a failure when calling a
particular save_live_iterate function, report the error code returned
by the function.

Signed-off-by: David Edmondson <david.edmondson@oracle.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>
2022-01-28 15:38:23 +01:00
Juan Quintela 144fa06b34 migration: Never call twice qemu_target_page_size()
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-12-15 10:31:42 +01:00
Juan Quintela 02abee3d51 migration: Zero migration compression counters
Based on previous patch from yuxiating <yuxiating@huawei.com>

Signed-off-by: Juan Quintela <quintela@redhat.com>
2021-11-03 09:38:53 +01:00
Peter Xu 39675ffffb migration: Move the yank unregister of channel_close out
It's efficient, but hackish to call yank unregister calls in channel_close(),
especially it'll be hard to debug when qemu crashed with some yank function
leaked.

Remove that hack, but instead explicitly unregister yank functions at the
places where needed, they are:

  (on src)
  - migrate_fd_cleanup
  - postcopy_pause

  (on dst)
  - migration_incoming_state_destroy
  - postcopy_pause_incoming

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210722175841.938739-6-peterx@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-07-26 12:45:03 +01:00
Peter Xu c6ad5be7ae migration: Teach QEMUFile to be QIOChannel-aware
migration uses QIOChannel typed qemufiles.  In follow up patches, we'll need
the capability to identify this fact, so that we can get the backing QIOChannel
from a QEMUFile.

We can also define types for QEMUFile but so far since we only need to be able
to identify QIOChannel, introduce a boolean which is simpler.

Introduce another helper qemu_file_get_ioc() to return the ioc backend of a
qemufile if has_ioc is set.

No functional change.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20210722175841.938739-5-peterx@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-07-26 12:44:59 +01:00
Daniel P. Berrangé 85cd1cc668 migration: use GDateTime for formatting timestamp in snapshot names
The GDateTime APIs provided by GLib avoid portability pitfalls, such
as some platforms where 'struct timeval.tv_sec' field is still 'long'
instead of 'time_t'. When combined with automatic cleanup, GDateTime
often results in simpler code too.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2021-06-14 13:28:50 +01:00
Daniel P. Berrangé 0f0d83a456 migration: introduce snapshot-{save, load, delete} QMP commands
savevm, loadvm and delvm are some of the few HMP commands that have never
been converted to use QMP. The reasons for the lack of conversion are
that they blocked execution of the event thread, and the semantics
around choice of disks were ill-defined.

Despite this downside, however, libvirt and applications using libvirt
have used these commands for as long as QMP has existed, via the
"human-monitor-command" passthrough command. IOW, while it is clearly
desirable to be able to fix the problems, they are not a blocker to
all real world usage.

Meanwhile there is a need for other features which involve adding new
parameters to the commands. This is possible with HMP passthrough, but
it provides no reliable way for apps to introspect features, so using
QAPI modelling is highly desirable.

This patch thus introduces new snapshot-{load,save,delete} commands to
QMP that are intended to replace the old HMP counterparts. The new
commands are given different names, because they will be using the new
QEMU job framework and thus will have diverging behaviour from the HMP
originals. It would thus be misleading to keep the same name.

While this design uses the generic job framework, the current impl is
still blocking. The intention that the blocking problem is fixed later.
None the less applications using these new commands should assume that
they are asynchronous and thus wait for the job status change event to
indicate completion.

In addition to using the job framework, the new commands require the
caller to be explicit about all the block device nodes used in the
snapshot operations, with no built-in default heuristics in use.

Note that the existing "query-named-block-nodes" can be used to query
what snapshots currently exist for block nodes.

Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210204124834.774401-13-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: removed tests for now, the output ordering isn't
deterministic
2021-02-08 11:19:52 +00:00