Commit Graph

394 Commits

Author SHA1 Message Date
Fiona Ebner
930e239d11 migration: hold the BQL during setup
This is intended to be a semantic revert of commit 9b09503752
("migration: run setup callbacks out of big lock"). There have been so
many changes since that commit (e.g. a new setup callback
dirty_bitmap_save_setup() that also needs to be adapted now), it's
easier to do the revert manually.

For snapshots, the bdrv_writev_vmstate() function is used during setup
(in QIOChannelBlock backing the QEMUFile), but not holding the BQL
while calling it could lead to an assertion failure. To understand
how, first note the following:

1. Generated coroutine wrappers for block layer functions spawn the
coroutine and use AIO_WAIT_WHILE()/aio_poll() to wait for it.
2. If the host OS switches threads at an inconvenient time, it can
happen that a bottom half scheduled for the main thread's AioContext
is executed as part of a vCPU thread's aio_poll().

An example leading to the assertion failure is as follows:

main thread:
1. A snapshot-save QMP command gets issued.
2. snapshot_save_job_bh() is scheduled.

vCPU thread:
3. aio_poll() for the main thread's AioContext is called (e.g. when
the guest writes to a pflash device, as part of blk_pwrite which is a
generated coroutine wrapper).
4. snapshot_save_job_bh() is executed as part of aio_poll().
3. qemu_savevm_state() is called.
4. qemu_mutex_unlock_iothread() is called. Now
qemu_get_current_aio_context() returns 0x0.
5. bdrv_writev_vmstate() is executed during the usual savevm setup
via qemu_fflush(). But this function is a generated coroutine wrapper,
so it uses AIO_WAIT_WHILE. There, the assertion
assert(qemu_get_current_aio_context() == qemu_get_aio_context());
will fail.

To fix it, ensure that the BQL is held during setup. While it would
only be needed for snapshots, adapting migration too avoids additional
logic for conditional locking/unlocking in the setup callbacks.
Writing the header could (in theory) also trigger qemu_fflush() and
thus bdrv_writev_vmstate(), so the locked section also covers the
qemu_savevm_state_header() call, even for migration for consistency.

The section around multifd_send_sync_main() needs to be unlocked to
avoid a deadlock. In particular, the multifd_save_setup() function calls
socket_send_channel_create() using multifd_new_send_channel_async() as a
callback and then waits for the callback to signal via the
channels_ready semaphore. The connection happens via
qio_task_run_in_thread(), but the callback is only executed via
qio_task_thread_result() which is scheduled for the main event loop.
Without unlocking the section, the main thread would never get to
process the task result and the callback meaning there would be no
signal via the channels_ready semaphore.

The comment in ram_init_bitmaps() was introduced by 4987783400
("migration: fix incorrect memory_global_dirty_log_start outside BQL")
and is removed, because it referred to the qemu_mutex_lock_iothread()
call.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231013105839.415989-1-f.ebner@proxmox.com>
2023-10-17 09:25:13 +02:00
Tejus GK
969298f9d7 migration/vmstate: Introduce vmstate_save_state_with_err
Currently, a few code paths exist in the function vmstate_save_state_v,
which ultimately leads to a migration failure. However, an update in the
current MigrationState for the error description is never done.

vmstate.c somehow doesn't seem to allow	the use	of migrate_set_error due
to some	dependencies for unit tests. Hence, this patch introduces a new
function vmstate_save_state_with_err, which will eventually propagate
the error message to savevm.c where a migrate_set_error	call can be
eventually done.

Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Tejus GK <tejus.gk@nutanix.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231003065538.244752-2-tejus.gk@nutanix.com>
2023-10-04 10:54:40 +02:00
Stefan Hajnoczi
9ef497755a vfio queue:
* Small downtime optimisation for VFIO migration
 * P2P support for VFIO migration
 * Introduction of a save_prepare() handler to fail VFIO migration
 * Fix on DMA logging ranges calculation for OVMF enabling dynamic window
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEoPZlSPBIlev+awtgUaNDx8/77KEFAmT+uZQACgkQUaNDx8/7
 7KGFSw//UIqSet6MUxZZh/t7yfNFUTnxx6iPdChC3BphBaDDh99FCQrw5mPZ8ImF
 4rz0cIwSaHXraugEsC42TDaGjEmcAmYD0Crz+pSpLU21nKtYyWtZy6+9kyYslMNF
 bUq0UwD0RGTP+ZZi6GBy1hM30y/JbNAGeC6uX8kyJRuK5Korfzoa/X5h+B2XfouW
 78G1mARHq5eOkGy91+rAJowdjqtkpKrzkfCJu83330Bb035qAT/PEzGs5LxdfTla
 ORNqWHy3W+d8ZBicBQ5vwrk6D5JIZWma7vdXJRhs1wGO615cuyt1L8nWLFr8klW5
 MJl+wM7DZ6UlSODq7r839GtSuWAnQc2j7JKc+iqZuBBk1v9fGXv2tZmtuTGkG2hN
 nYXSQfuq1igu1nGVdxJv6WorDxsK9wzLNO2ckrOcKTT28RFl8oCDNSPPTKpwmfb5
 i5RrGreeXXqRXIw0VHhq5EqpROLjAFwE9tkJndO8765Ag154plxssaKTUWo5wm7/
 kjQVuRuhs5nnMXfL9ixLZkwD1aFn5fWAIaR0psH5vGD0fnB1Pba+Ux9ZzHvxp5D8
 Kg3H6dKlht6VXdQ/qb0Up1LXCGEa70QM6Th2iO924ydZkkmqrSj+CFwGHvBsINa4
 89fYd77nbRbdwWurj3JIznJYVipau2PmfbjZ/jTed4RxjBQ+fPA=
 =44e0
 -----END PGP SIGNATURE-----

Merge tag 'pull-vfio-20230911' of https://github.com/legoater/qemu into staging

vfio queue:

* Small downtime optimisation for VFIO migration
* P2P support for VFIO migration
* Introduction of a save_prepare() handler to fail VFIO migration
* Fix on DMA logging ranges calculation for OVMF enabling dynamic window

# -----BEGIN PGP SIGNATURE-----
#
# iQIzBAABCAAdFiEEoPZlSPBIlev+awtgUaNDx8/77KEFAmT+uZQACgkQUaNDx8/7
# 7KGFSw//UIqSet6MUxZZh/t7yfNFUTnxx6iPdChC3BphBaDDh99FCQrw5mPZ8ImF
# 4rz0cIwSaHXraugEsC42TDaGjEmcAmYD0Crz+pSpLU21nKtYyWtZy6+9kyYslMNF
# bUq0UwD0RGTP+ZZi6GBy1hM30y/JbNAGeC6uX8kyJRuK5Korfzoa/X5h+B2XfouW
# 78G1mARHq5eOkGy91+rAJowdjqtkpKrzkfCJu83330Bb035qAT/PEzGs5LxdfTla
# ORNqWHy3W+d8ZBicBQ5vwrk6D5JIZWma7vdXJRhs1wGO615cuyt1L8nWLFr8klW5
# MJl+wM7DZ6UlSODq7r839GtSuWAnQc2j7JKc+iqZuBBk1v9fGXv2tZmtuTGkG2hN
# nYXSQfuq1igu1nGVdxJv6WorDxsK9wzLNO2ckrOcKTT28RFl8oCDNSPPTKpwmfb5
# i5RrGreeXXqRXIw0VHhq5EqpROLjAFwE9tkJndO8765Ag154plxssaKTUWo5wm7/
# kjQVuRuhs5nnMXfL9ixLZkwD1aFn5fWAIaR0psH5vGD0fnB1Pba+Ux9ZzHvxp5D8
# Kg3H6dKlht6VXdQ/qb0Up1LXCGEa70QM6Th2iO924ydZkkmqrSj+CFwGHvBsINa4
# 89fYd77nbRbdwWurj3JIznJYVipau2PmfbjZ/jTed4RxjBQ+fPA=
# =44e0
# -----END PGP SIGNATURE-----
# gpg: Signature made Mon 11 Sep 2023 02:54:12 EDT
# gpg:                using RSA key A0F66548F04895EBFE6B0B6051A343C7CFFBECA1
# gpg: Good signature from "Cédric Le Goater <clg@redhat.com>" [unknown]
# gpg:                 aka "Cédric Le Goater <clg@kaod.org>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: A0F6 6548 F048 95EB FE6B  0B60 51A3 43C7 CFFB ECA1

* tag 'pull-vfio-20230911' of https://github.com/legoater/qemu:
  vfio/common: Separate vfio-pci ranges
  vfio/migration: Block VFIO migration with background snapshot
  vfio/migration: Block VFIO migration with postcopy migration
  migration: Add .save_prepare() handler to struct SaveVMHandlers
  migration: Move more initializations to migrate_init()
  vfio/migration: Fail adding device with enable-migration=on and existing blocker
  migration: Add migration prefix to functions in target.c
  vfio/migration: Allow migration of multiple P2P supporting devices
  vfio/migration: Add P2P support for VFIO migration
  vfio/migration: Refactor PRE_COPY and RUNNING state checks
  qdev: Add qdev_add_vm_change_state_handler_full()
  sysemu: Add prepare callback to struct VMChangeStateEntry
  vfio/migration: Move from STOP_COPY to STOP in vfio_save_cleanup()

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-09-11 09:13:08 -04:00
Avihai Horon
08fc4cb517 migration: Add .save_prepare() handler to struct SaveVMHandlers
Add a new .save_prepare() handler to struct SaveVMHandlers. This handler
is called early, even before migration starts, and can be used by
devices to perform early checks.

Refactor migrate_init() to be able to return errors and call
.save_prepare() from there.

Suggested-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
2023-09-11 08:34:06 +02:00
Kevin Wolf
8686a689e5 vmstate: Mark VMStateInfo.get/put() coroutine_mixed_fn
Migration code can run both in coroutine context (the usual case) and
non-coroutine context (at least savevm/loadvm for snapshots). This also
affects the VMState callbacks, and devices must consider this. Change
the callback definition in VMStateInfo to be explicit about it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230905145002.46391-2-kwolf@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-09-08 17:03:09 +02:00
David Hildenbrand
f161c88a03 migration/ram: Expose ramblock_is_ignored() as migrate_ram_is_ignored()
virtio-mem wants to know whether it should not mess with the RAMBlock
content (e.g., discard RAM, preallocate memory) on incoming migration.

So let's expose that function as migrate_ram_is_ignored() in
migration/misc.h

Message-ID: <20230706075612.67404-4-david@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
2023-07-12 09:25:37 +02:00
Alex Bennée
6caf1571a9 include/migration: mark vmstate_register() as a legacy function
Mention that QOM-ified devices already have support for registering
the description.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-24-alex.bennee@linaro.org>
2023-07-03 12:52:11 +01:00
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
Vladimir Sementsov-Ogievskiy
d0a14a2ba0 migration: process_incoming_migration_co(): move colo part to colo
Let's make better public interface for COLO: instead of
colo_process_incoming_thread and not trivial logic around creating the
thread let's make simple colo_incoming_co(), hiding implementation from
generic code.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20230515130640.46035-4-vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-05-18 18:40:51 +02:00
Vladimir Sementsov-Ogievskiy
4332ffcd7b colo: make colo_checkpoint_notify static and provide simpler API
colo_checkpoint_notify() is mostly used in colo.c. Outside we use it
once when x-checkpoint-delay migration parameter is set. So, let's
simplify the external API to only that function - notify COLO that
parameter was set. This make external API more robust and hides
implementation details from external callers. Also this helps us to
make COLO module optional in further patch (i.e. we are going to add
possibility not build the COLO module).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Message-Id: <20230428194928.1426370-3-vsementsov@yandex-team.ru>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2023-05-10 18:48:11 +02:00
Juan Quintela
c938157713 migration: move migration_global_dump() to migration-hmp-cmds.c
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
2023-04-24 15:01:46 +02:00
Paolo Bonzini
394b9407e4 migration: mark mixed functions that can suspend
There should be no paths from a coroutine_fn to aio_poll, however in
practice coroutine_mixed_fn will call aio_poll in the !qemu_in_coroutine()
path.  By marking mixed functions, we can track accurately the call paths
that execute entirely in coroutine context, and find more missing
coroutine_fn markers.  This results in more accurate checks that
coroutine code does not end up blocking.

If the marking were extended transitively to all functions that call
these ones, static analysis could be done much more efficiently.
However, this is a start and makes it possible to use vrc's path-based
searches to find potential bugs where coroutine_fns call blocking functions.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-04-20 11:17:35 +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
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
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
508f7988fd migration/vmstate: Introduce VMSTATE_WITH_TMP_TEST() and VMSTATE_BITMAP_TEST()
We'll make use of both next in the context of virtio-mem.

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>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
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 Maydell
1862198702 migration: Remove load_state_old and minimum_version_id_old
There are no longer any VMStateDescription structs in the tree which
use the load_state_old support for custom handling of incoming
migration from very old QEMU.  Remove the mechanism entirely.

This includes removing one stray useless setting of
minimum_version_id_old in a VMStateDescription with no load_state_old
function, which crept in after the global weeding-out of them in
commit 17e3134061.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20220215175705.3846411-1-peter.maydell@linaro.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Francisco Iglesias <francisco.iglesias@xilinx.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:20:45 +00:00
Rao, Lei
795969ab1f Fixed a QEMU hang when guest poweroff in COLO mode
When the PVM guest poweroff, the COLO thread may wait a semaphore
in colo_process_checkpoint().So, we should wake up the COLO thread
before migration shutdown.

Signed-off-by: Lei Rao <lei.rao@intel.com>
Reviewed-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2021-12-15 10:31:42 +01:00
Peter Xu
60fd680193 migration: Add migrate_add_blocker_internal()
An internal version that removes -only-migratable implications.  It can be used
for temporary migration blockers like dump-guest-memory.

Reviewed-by: Marc-André Lureau <marcandre.lureau@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>
2021-11-01 22:56:44 +01:00
David Hildenbrand
0fd7616e0f vfio: Support for RamDiscardManager in the vIOMMU case
vIOMMU support works already with RamDiscardManager as long as guests only
map populated memory. Both, populated and discarded memory is mapped
into &address_space_memory, where vfio_get_xlat_addr() will find that
memory, to create the vfio mapping.

Sane guests will never map discarded memory (e.g., unplugged memory
blocks in virtio-mem) into an IOMMU - or keep it mapped into an IOMMU while
memory is getting discarded. However, there are two cases where a malicious
guests could trigger pinning of more memory than intended.

One case is easy to handle: the guest trying to map discarded memory
into an IOMMU.

The other case is harder to handle: the guest keeping memory mapped in
the IOMMU while it is getting discarded. We would have to walk over all
mappings when discarding memory and identify if any mapping would be a
violation. Let's keep it simple for now and print a warning, indicating
that setting RLIMIT_MEMLOCK can mitigate such attacks.

We have to take care of incoming migration: at the point the
IOMMUs get restored and start creating mappings in vfio, RamDiscardManager
implementations might not be back up and running yet: let's add runstate
priorities to enforce the order when restoring.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210413095531.25603-10-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2021-07-08 15:54:45 -04:00
Philippe Mathieu-Daudé
feece4d070 cpu: Move CPUClass::vmsd to SysemuCPUOps
Migration is specific to system emulation.

- Move the CPUClass::vmsd field to SysemuCPUOps,
- restrict VMSTATE_CPU() macro to sysemu,
- vmstate_dummy is now unused, remove it.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210517105140.1062037-16-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-05-26 15:33:59 -07:00
David Hildenbrand
1a37352277 migrate/ram: remove "ram_bulk_stage" and "fpo_enabled"
The bulk stage is kind of weird: migration_bitmap_find_dirty() will
indicate a dirty page, however, ram_save_host_page() will never save it, as
migration_bitmap_clear_dirty() detects that it is not dirty.

We already fill the bitmap in ram_list_init_bitmaps() with ones, marking
everything dirty - it didn't used to be that way, which is why we needed
an explicit first bulk stage.

Let's simplify: make the bitmap the single source of thuth. Explicitly
handle the "xbzrle_enabled after first round" case.

Regarding XBZRLE (implicitly handled via "ram_bulk_stage = false" right
now), there is now a slight change in behavior:
- Colo: When starting, it will be disabled (was implicitly enabled)
  until the first round actually finishes.
- Free page hinting: When starting, XBZRLE will be disabled (was implicitly
  enabled) until the first round actually finished.
- Snapshots: When starting, XBZRLE will be disabled. We essentially only
  do a single run, so I guess it will never actually get disabled.

Postcopy seems to indirectly disable it in ram_save_page(), so there
shouldn't be really any change.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Andrey Gruzdev <andrey.gruzdev@virtuozzo.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210216105039.40680-1-david@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-05-13 18:21:13 +01:00
Andrey Gruzdev
1a8e44a89f migration: Inhibit virtio-balloon for the duration of background snapshot
The same thing as for incoming postcopy - we cannot deal with concurrent
RAM discards when using background snapshot feature in outgoing migration.

Fixes: 8518278a6a (migration: implementation
  of background snapshot thread)
Signed-off-by: Andrey Gruzdev <andrey.gruzdev@virtuozzo.com>
Reported-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210401092226.102804-3-andrey.gruzdev@virtuozzo.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-04-06 18:56:01 +01:00
Daniel P. Berrangé
bef7e9e2c7 migration: introduce a delete_snapshot wrapper
Make snapshot deletion consistent with the snapshot save
and load commands by using a wrapper around the blockdev
layer. The main difference is that we get upfront validation
of the passed in device list (if any).

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210204124834.774401-10-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-02-08 11:19:51 +00:00
Daniel P. Berrangé
f1a9fcdd01 migration: wire up support for snapshot device selection
Modify load_snapshot/save_snapshot to accept the device list and vmstate
node name parameters previously added to the block layer.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210204124834.774401-9-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-02-08 11:19:51 +00:00
Daniel P. Berrangé
f781f84189 migration: control whether snapshots are ovewritten
The traditional HMP "savevm" command will overwrite an existing snapshot
if it already exists with the requested name. This new flag allows this
to be controlled allowing for safer behaviour with a future QMP command.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210204124834.774401-8-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-02-08 11:19:51 +00:00
Daniel P. Berrangé
f61fe11aa6 migration: stop returning errno from load_snapshot()
None of the callers care about the errno value since there is a full
Error object populated. This gives consistency with save_snapshot()
which already just returns a boolean value.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
[PMD: Return false/true instead of -1/0, document function]
Acked-by: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210204124834.774401-4-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-02-08 11:19:51 +00:00
Philippe Mathieu-Daudé
7ea14df230 migration: Make save_snapshot() return bool, not 0/-1
Just for consistency, following the example documented since
commit e3fe3988d7 ("error: Document Error API usage rules"),
return a boolean value indicating an error is set or not.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210204124834.774401-3-berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2021-02-08 11:19:51 +00:00
Markus Armbruster
3ddba9a9e9 migration: Replace migration's JSON writer by the general one
Commit 8118f0950f "migration: Append JSON description of migration
stream" needs a JSON writer.  The existing qobject_to_json() wasn't a
good fit, because it requires building a QObject to convert.  Instead,
migration got its very own JSON writer, in commit 190c882ce2 "QJSON:
Add JSON writer".  It tacitly limits numbers to int64_t, and strings
contents to characters that don't need escaping, unlike
qobject_to_json().

The previous commit factored the JSON writer out of qobject_to_json().
Replace migration's JSON writer by it.

Cc: Juan Quintela <quintela@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-17-armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-12-19 10:39:16 +01:00
Paolo Bonzini
e69d50d621 migration, vl: start migration via qmp_migrate_incoming
Make qemu_start_incoming_migration local to migration/migration.c.
By using the runstate instead of a separate flag, vl need not do
anything to setup deferred incoming migration.

qmp_migrate_incoming also does not need the deferred_incoming flag
anymore, because "-incoming PROTOCOL" will clear the "once" flag
before the main loop starts.  Therefore, later invocations of
the migrate-incoming command will fail with the existing
"The incoming migration has already been started" error message.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-12-10 12:15:14 -05:00
Peter Maydell
9fe7ef8b66 migration: Drop unused VMSTATE_FLOAT64 support
Commit ef96e3ae96 in January 2019 removed the last user of the
VMSTATE_FLOAT64* macros. These were used by targets which defined
their floating point register file as an array of 'float64'.

We used to try to maintain a stricter distinction between
'float64' (a type for holding an integer representing an IEEE float)
and 'uint64_t', including having a debug option for 'float64' being
a struct and supposedly mandatory macros for converting between
float64 and uint64_t. We no longer think that's a usefully
strong distinction to draw and we allow ourselves to freely
assume that float64 really is just a 64-bit integer type, so
for new targets we would simply recommend use of the uint64_t type
for a floating point register file. The float64 type remains
as a useful way of documenting in the type signature of helper
functions and the like that they expect to receive an IEEE float
from the TCG generated code rather than an arbitrary integer.

Since the VMSTATE_FLOAT64* macros have no remaining users and
we don't recommend new code uses them, delete them.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20201022120830.5938-1-peter.maydell@linaro.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-10-26 16:15:04 +00:00
David Hildenbrand
18b1d3c952 migration/colo: Use ram_block_discard_disable()
COLO will copy all memory in a RAM block, disable discarding of RAM.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Lukas Straub <lukasstraub2@web.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Hailiang Zhang <zhang.zhanghailiang@huawei.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200626072248.78761-10-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-07-02 05:54:59 -04:00
David Hildenbrand
06df2e692a virtio-balloon: Rip out qemu_balloon_inhibit()
The only remaining special case is postcopy. It cannot handle
concurrent discards yet, which would result in requesting already sent
pages from the source. Special-case it in virtio-balloon instead.

Introduce migration_in_incoming_postcopy(), to find out if incoming
postcopy is active.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200626072248.78761-7-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-07-02 05:54:59 -04:00
Yuri Benditovich
ff4e6d545d vmstate.h: provide VMSTATE_VARRAY_UINT16_ALLOC macro
Similar to VMSTATE_VARRAY_UINT32_ALLOC, but the size is
16-bit field.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2020-06-18 21:05:50 +08:00
Philippe Mathieu-Daudé
e0d138aa9b migration/vmstate: Remove unnecessary MemoryRegion forward declaration
"migration/vmstate.h" only uses pointer to MemoryRegion, which
is already forward declared in "qemu/typedefs.h".

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200530165512.15225-1-f4bug@amsat.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-06-01 18:44:27 +01:00
Eric Auger
4746dbf8a9 migration: Support QLIST migration
Support QLIST migration using the same principle as QTAILQ:
94869d5c52 ("migration: migrate QTAILQ").

The VMSTATE_QLIST_V macro has the same proto as VMSTATE_QTAILQ_V.
The change mainly resides in QLIST RAW macros: QLIST_RAW_INSERT_HEAD
and QLIST_RAW_REVERSE.

Tests also are provided.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:23 +01:00
Peter Xu
93062e2361 migration: Change SaveStateEntry.instance_id into uint32_t
It was always used as 32bit, so define it as used to be clear.
Instead of using -1 as the auto-gen magic value, we switch to
UINT32_MAX.  We also make sure that we don't auto-gen this value to
avoid overflowed instance IDs without being noticed.

Suggested-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:23 +01:00
Peter Xu
1df2c9a26f migration: Define VMSTATE_INSTANCE_ID_ANY
Define the new macro VMSTATE_INSTANCE_ID_ANY for callers who wants to
auto-generate the vmstate instance ID.  Previously it was hard coded
as -1 instead of this macro.  It helps to change this default value in
the follow up patches.  No functional change.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2020-01-20 09:10:23 +01:00
Marc-André Lureau
3cad405bab vmstate: replace DeviceState with VMStateIf
Replace DeviceState dependency with VMStateIf on vmstate API.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
2020-01-06 18:41:32 +04:00
Marc-André Lureau
107b59698f vmstate: add qom interface to get id
Add an interface to get the instance id, instead of depending on
Device and qdev_get_dev_path().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2020-01-06 18:41:32 +04:00
Jens Freimann
c7e0acd5a3 migration: add new migration state wait-unplug
This patch adds a new migration state called wait-unplug.  It is entered
after the SETUP state if failover devices are present. It will transition
into ACTIVE once all devices were succesfully unplugged from the guest.

So if a guest doesn't respond or takes long to honor the unplug request
the user will see the migration state 'wait-unplug'.

In the migration thread we query failover devices if they're are still
pending the guest unplug. When all are unplugged the migration
continues. If one device won't unplug migration will stay in wait_unplug
state.

Signed-off-by: Jens Freimann <jfreimann@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20191029114905.6856-9-jfreimann@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-10-29 18:55:26 -04:00
Eric Auger
9a85e4b8f6 migration: Support gtree migration
Introduce support for GTree migration. A custom save/restore
is implemented. Each item is made of a key and a data.

If the key is a pointer to an object, 2 VMSDs are passed into
the GTree VMStateField.

When putting the items, the tree is traversed in sorted order by
g_tree_foreach.

On the get() path, gtrees must be allocated using the proper
key compare, key destroy and value destroy. This must be handled
beforehand, for example in a pre_load method.

Tests are added to test save/dump of structs containing gtrees
including the virtio-iommu domain/mappings scenario.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

Message-Id: <20191011121724.433-1-eric.auger@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  uintptr_t fixup for test on 32bit
2019-10-11 17:52:31 +01:00
Wei Yang
8f8d528e73 migration: use migration_is_active to represent active state
Wrap the check into a function to make it easy to read.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190717005341.14140-1-richardw.yang@linux.intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-10-11 14:18:13 +01:00