Commit Graph

1587 Commits

Author SHA1 Message Date
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
02bdbe172d migration: remove the QEMUFileOps 'get_return_path' callback
This directly implements the get_return_path logic using QIOChannel APIs.

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
ec2135eec8 migration: remove the QEMUFileOps 'writev_buffer' callback
This directly implements the writev_buffer logic using QIOChannel APIs.

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
f759d7050b migration: remove the QEMUFileOps 'get_buffer' callback
This directly implements the get_buffer logic using QIOChannel APIs.

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: Fixup len = *-*EIO as spotted by Peter Xu
2022-06-23 10:17:58 +01:00
Daniel P. Berrangé
0ae1f7f055 migration: remove the QEMUFileOps 'close' callback
This directly implements the close logic using QIOChannel APIs.

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>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
80ad97069c migration: remove the QEMUFileOps 'set_blocking' callback
This directly implements the set_blocking logic using QIOChannel APIs.

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>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
d3c581b750 migration: remove the QEMUFileOps 'shut_down' callback
This directly implements the shutdown logic using QIOChannel APIs.

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>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
0f58c3fcc7 migration: remove unused QEMUFileGetFD typedef / qemu_get_fd method
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>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
c0c6e1e2dd migration: introduce new constructors for QEMUFile
Prepare for the elimination of QEMUFileOps by introducing a pair of new
constructors. This lets us distinguish between an input and output file
object explicitly rather than via the existance of specific callbacks.

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>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
2893a2884b migration: hardcode assumption that QEMUFile is backed with QIOChannel
The only callers of qemu_fopen_ops pass 'true' for the 'has_ioc'
parameter, so hardcode this assumption in QEMUFile, by passing in
the QIOChannel object as a non-opaque parameter.

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: Fixed long line
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
365c0463db migration: stop passing 'opaque' parameter to QEMUFile hooks
The only user of the hooks is RDMA which provides a QIOChannel backed
impl of QEMUFile. It can thus use the qemu_file_get_ioc() method.

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>
2022-06-22 19:33:43 +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
65cf200a51 migration: introduce a QIOChannel impl for BlockDriverState VMState
Introduce a QIOChannelBlock class that exposes the BlockDriverState
VMState region for I/O.

This is kept in the migration/ directory rather than io/, to avoid
a mutual dependancy between block/ <-> io/ directories. Also the
VMState should only be used by the migration code.

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: Fixed coding style in qio_channel_block_close
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
bc698c367d migration: rename qemu_file_update_transfer to qemu_file_acct_rate_limit
The qemu_file_update_transfer name doesn't give a clear guide on what
its purpose is, and how it differs from the qemu_file_credit_transfer
method. The latter is specifically for accumulating for total migration
traffic, while the former is specifically for accounting in thue rate
limit calculations. The new name give better guidance on its usage.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.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>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-06-22 19:33:43 +01:00
Daniel P. Berrangé
1a93bd2f60 migration: rename qemu_update_position to qemu_file_credit_transfer
The qemu_update_position method name gives the misleading impression
that it is changing the current file offset. Most of the files are
just streams, however, so there's no concept of a file offset in the
general case.

What this method is actually used for is to report on the number of
bytes that have been transferred out of band from the main I/O methods.
This new name better reflects this purpose.

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>
2022-06-22 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
Daniel P. Berrangé
154d87b4ef migration: rename 'pos' field in QEMUFile to 'bytes_processed'
The field name 'pos' 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.

Every QIOChannel backed impl of QEMUFile is currently ignoring the
'pos' field.

The only QEMUFile impl using 'pos' as an offset for I/O is the block
device vmstate. A later patch is introducing a QIOChannel impl for the
vmstate, and to handle this it is tracking a file offset itself
internally to the QIOChannel impl. So when we later eliminate the
QEMUFileOps callbacks later, the 'pos' field will no longer be used
from any I/O read/write methods.

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: Fixed long line
2022-06-22 18:59:38 +01:00
Daniel P. Berrangé
c7fc8d323a migration: rename rate limiting fields in QEMUFile
This renames the following QEMUFile fields

 * bytes_xfer -> rate_limit_used
 * xfer_limit -> rate_limit_max

The intent is to make it clear that 'bytes_xfer' is specifically related
to rate limiting of data and applies to data queued, which need not have
been transferred on the wire yet if a flush hasn't taken place.

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>
2022-06-22 18:11:21 +01:00
Daniel P. Berrangé
246683c22f migration: remove unreachble RDMA code in save_hook impl
The QEMUFile 'save_hook' callback has a 'size_t size' parameter.

The RDMA impl of this has logic that takes different actions
depending on whether the value is zero or non-zero. It has
commented out logic that would have taken further actions
if the value was negative.

The only place where the 'save_hook' callback is invoked is
the ram_control_save_page() method, which passes 'size'
through from its caller. The only caller of this method is
in turn control_save_page(). This method unconditionally
passes the 'TARGET_PAGE_SIZE' constant for the 'size' parameter.

IOW, the only scenario for 'size' that can execute in the
qemu_rdma_save_page method is 'size > 0'. The remaining code
has been unreachable since RDMA support was first introduced
9 years ago.

Reviewed-by: Eric Blake <eblake@redhat.com>
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>
2022-06-22 18:11:21 +01:00
Daniel P. Berrangé
c0e0825c98 migration: switch to use QIOChannelNull for dummy channel
This removes one further custom impl of QEMUFile, in favour of a
QIOChannel based impl.

Reviewed-by: Eric Blake <eblake@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>
2022-06-22 18:11:21 +01:00
Leonardo Bras
1abaec9a1b migration: Change zero_copy_send from migration parameter to migration capability
When originally implemented, zero_copy_send was designed as a Migration
paramenter.

But taking into account how is that supposed to work, and how
the difference between a capability and a parameter, it only makes sense
that zero-copy-send would work better as a capability.

Taking into account how recently the change got merged, it was decided
that it's still time to make it right, and convert zero_copy_send into
a Migration capability.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: always define the capability, even on non-Linux but error if
set; avoids build problems with the capability
2022-06-22 18:11:17 +01:00
Juan Quintela
f6f213e4c7 migration: Remove RDMA_UNREGISTRATION_EXAMPLE
Nobody has ever showed up to unregister individual pages, and another
set of patches written by Daniel P. Berrangé <berrange@redhat.com>
just remove qemu_rdma_signal_unregister() function needed here.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-06-22 17:02:37 +01:00
Leonardo Bras
5b1d9bab2d multifd: Implement zero copy write in multifd migration (multifd-zero-copy)
Implement zero copy send on nocomp_send_write(), by making use of QIOChannel
writev + flags & flush interface.

Change multifd_send_sync_main() so flush_zero_copy() can be called
after each iteration in order to make sure all dirty pages are sent before
a new iteration is started. It will also flush at the beginning and at the
end of migration.

Also make it return -1 if flush_zero_copy() fails, in order to cancel
the migration process, and avoid resuming the guest in the target host
without receiving all current RAM.

This will work fine on RAM migration because the RAM pages are not usually freed,
and there is no problem on changing the pages content between writev_zero_copy() and
the actual sending of the buffer, because this change will dirty the page and
cause it to be re-sent on a next iteration anyway.

A lot of locked memory may be needed in order to use multifd migration
with zero-copy enabled, so disabling the feature should be necessary for
low-privileged users trying to perform multifd migrations.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220513062836.965425-9-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-16 13:56:24 +01:00
Leonardo Bras
b7dbdd8e76 multifd: Send header packet without flags if zero-copy-send is enabled
Since d48c3a0445 ("multifd: Use a single writev on the send side"),
sending the header packet and the memory pages happens in the same
writev, which can potentially make the migration faster.

Using channel-socket as example, this works well with the default copying
mechanism of sendmsg(), but with zero-copy-send=true, it will cause
the migration to often break.

This happens because the header packet buffer gets reused quite often,
and there is a high chance that by the time the MSG_ZEROCOPY mechanism get
to send the buffer, it has already changed, sending the wrong data and
causing the migration to abort.

It means that, as it is, the buffer for the header packet is not suitable
for sending with MSG_ZEROCOPY.

In order to enable zero copy for multifd, send the header packet on an
individual write(), without any flags, and the remanining pages with a
writev(), as it was happening before. This only changes how a migration
with zero-copy-send=true works, not changing any current behavior for
migrations with zero-copy-send=false.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220513062836.965425-8-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-16 13:56:24 +01:00
Leonardo Bras
33d70973a3 multifd: multifd_send_sync_main now returns negative on error
Even though multifd_send_sync_main() currently emits error_reports, it's
callers don't really check it before continuing.

Change multifd_send_sync_main() to return -1 on error and 0 on success.
Also change all it's callers to make use of this change and possibly fail
earlier.

(This change is important to next patch on  multifd zero copy
implementation, to make it sure an error in zero-copy flush does not go
unnoticed.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220513062836.965425-7-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-16 13:56:24 +01:00
Leonardo Bras
d2fafb6a68 migration: Add migrate_use_tls() helper
A lot of places check parameters.tls_creds in order to evaluate if TLS is
in use, and sometimes call migrate_get_current() just for that test.

Add new helper function migrate_use_tls() in order to simplify testing
for TLS usage.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220513062836.965425-6-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-16 13:56:24 +01:00
Leonardo Bras
abb6295b3a migration: Add zero-copy-send parameter for QMP/HMP for Linux
Add property that allows zero-copy migration of memory pages
on the sending side, and also includes a helper function
migrate_use_zero_copy_send() to check if it's enabled.

No code is introduced to actually do the migration, but it allow
future implementations to enable/disable this feature.

On non-Linux builds this parameter is compiled-out.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220513062836.965425-5-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-16 13:56:24 +01:00
Leonardo Bras
b88651cb4d QIOChannel: Add flags on io_writev and introduce io_flush callback
Add flags to io_writev and introduce io_flush as optional callback to
QIOChannelClass, allowing the implementation of zero copy writes by
subclasses.

How to use them:
- Write data using qio_channel_writev*(...,QIO_CHANNEL_WRITE_FLAG_ZERO_COPY),
- Wait write completion with qio_channel_flush().

Notes:
As some zero copy write implementations work asynchronously, it's
recommended to keep the write buffer untouched until the return of
qio_channel_flush(), to avoid the risk of sending an updated buffer
instead of the buffer state during write.

As io_flush callback is optional, if a subclass does not implement it, then:
- io_flush will return 0 without changing anything.

Also, some functions like qio_channel_writev_full_all() were adapted to
receive a flag parameter. That allows shared code between zero copy and
non-zero copy writev, and also an easier implementation on new flags.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20220513062836.965425-3-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-05-16 13:56:24 +01:00
Paolo Bonzini
3730a7341f meson, configure: move RDMA options to meson
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-28 08:52:20 +02:00
Dr. David Alan Gilbert
552de79bfd migration: Read state once
The 'status' field for the migration is updated normally using
an atomic operation from the migration thread.
Most readers of it aren't that careful, and in most cases it doesn't
matter.

In query_migrate->fill_source_migration_info the 'state'
is read twice; the first time to decide which state fields to fill in,
and then secondly to copy the state to the status field; that can end up
with a status that's inconsistent; e.g. setting up the fields
for 'setup' and then having an 'active' status.  In that case
libvirt gets upset by the lack of ram info.
The symptom is:
   libvirt.libvirtError: internal error: migration was active, but no RAM info was set

Read the state exactly once in fill_source_migration_info.

This is a possible fix for:
https://bugzilla.redhat.com/show_bug.cgi?id=2074205

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220413113329.103696-1-dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-04-21 19:36:46 +01:00
Dr. David Alan Gilbert
f912ec5b2d migration: Fix operator type
Clang spotted an & that should have been an &&; fix it.

Reported by: David Binderman / https://gitlab.com/dcb
Fixes: 65dacaa04f ("migration: introduce save_normal_page()")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/963
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220406102515.96320-1-dgilbert@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-04-21 19:36:46 +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
Peter Xu
a39e933962 migration: Move channel setup out of postcopy_try_recover()
We used to use postcopy_try_recover() to replace migration_incoming_setup() to
setup incoming channels.  That's fine for the old world, but in the new world
there can be more than one channels that need setup.  Better move the channel
setup out of it so that postcopy_try_recover() only handles the last phase of
switching to the recovery phase.

To do that in migration_fd_process_incoming(), move the postcopy_try_recover()
call to be after migration_incoming_setup(), which will setup the channels.
While in migration_ioc_process_incoming(), postpone the recover() routine right
before we'll jump into migration_incoming_process().

A side benefit is we don't need to pass in QEMUFile* to postcopy_try_recover()
anymore.  Remove it.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220331150857.74406-7-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
Peter Xu
929068ec2f migration: Export ram_load_postcopy()
Will be reused in postcopy fast load thread.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220331150857.74406-6-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
Peter Xu
f444eeda71 migration: Move migrate_allow_multifd and helpers into migration.c
This variable, along with its helpers, is used to detect whether multiple
channel will be supported for migration.  In follow up patches, there'll be
other capability that requires multi-channels.  Hence move it outside multifd
specific code and make it public.  Meanwhile rename it from "multifd" to
"multi_channels" to show its real meaning.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220331150857.74406-5-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
Peter Xu
ea2faf0c35 migration: Add pss.postcopy_requested status
This boolean flag shows whether the current page during migration is triggered
by postcopy or not.  Then in ram_save_host_page() and deeper stack we'll be
able to have a reference on the priority of this page.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220331150857.74406-4-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
Peter Xu
7f692ec79a migration: Drop multifd tls_hostname cache
The hostname is cached N times, N equals to the multifd channels.

Drop that cache because after previous patch we've got s->hostname
being alive for the whole lifecycle of migration procedure.

Cc: Juan Quintela <quintela@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220331150857.74406-3-peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@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
Peter Xu
83174765da migration: Postpone releasing MigrationState.hostname
We used to release it right after migrate_fd_connect().  That's not good
enough when there're more than one socket pair required, because it'll be
needed to establish TLS connection for the rest channels.

One example is multifd, where we copied over the hostname for each channel
but that's actually not needed.

Keeping the hostname until the cleanup phase of migration.

Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220331150857.74406-2-peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  dgilbert: Fixup checkpatch error; don't need to check for NULL
  around g_free
2022-04-21 19:36:46 +01:00
Daniel P. Berrangé
4b2bbca7a0 migration: fix use of TLS PSK credentials with a UNIX socket
The migration TLS code has a check mandating that a hostname be
available when starting a TLS session. This is expected when using
x509 credentials, but is bogus for PSK and anonymous credentials
as neither involve hostname validation.

The TLS crdentials object gained suitable error reporting in the
case of TLS with x509 credentials, so there is no longer any need
for the migration code to do its own (incorrect) validation.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220310171821.3724080-7-berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-04-21 19:36:46 +01:00
Marc-André Lureau
69242e7e7e Move CPU softfloat unions to cpu-float.h
The types are no longer used in bswap.h since commit
f930224fff ("bswap.h: Remove unused float-access functions"), there
isn't much sense in keeping it there and having a dependency on fpu/.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-29-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 14:31:43 +02:00
Marc-André Lureau
8e3b0cbb72 Replace qemu_real_host_page variables with inlined functions
Replace the global variables with inlined helper functions. getpagesize() is very
likely annotated with a "const" function attribute (at least with glibc), and thus
optimization should apply even better.

This avoids the need for a constructor initialization too.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 10:50:38 +02:00
Markus Armbruster
b21e238037 Use g_new() & friends where that makes obvious sense
g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).

Patch created mechanically with:

    $ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
	     --macro-file scripts/cocci-macro-file.h FILES...

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220315144156.1595462-4-armbru@redhat.com>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
2022-03-21 15:44:44 +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 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
Peter Xu
e031149c78 migration: Add migration_incoming_transport_cleanup()
Add a helper to cleanup the transport listener.

When do it, we should also null-ify the cleanup hook and the data, then it's
even safe to call it multiple times.

Move the socket_address_list cleanup altogether, because that's a mirror of the
listener channels and only for the purpose of query-migrate.  Hence when
someone wants to cleanup the listener transport, it should also want to cleanup
the socket list too, always.

No functional change intended.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-15-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:20:45 +00:00
Peter Xu
27dd21b461 migration: postcopy_pause_fault_thread() never fails
Per the title, remove the return code and simplify the callers as the errors
will never be triggered.  No functional change intended.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-12-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:20:45 +00:00
Peter Xu
d5c8f2afe8 migration: Enlarge postcopy recovery to capture !-EIO too
We used to have quite a few places making sure -EIO happened and that's the
only way to trigger postcopy recovery.  That's based on the assumption that
we'll only return -EIO for channel issues.

It'll work in 99.99% cases but logically that won't cover some corner cases.
One example is e.g. ram_block_from_stream() could fail with an interrupted
network, then -EINVAL will be returned instead of -EIO.

I remembered Dave Gilbert pointed that out before, but somehow this is
overlooked.  Neither did I encounter anything outside the -EIO error.

However we'd better touch that up before it triggers a rare VM data loss during
live migrating.

To cover as much those cases as possible, remove the -EIO restriction on
triggering the postcopy recovery, because even if it's not a channel failure,
we can't do anything better than halting QEMU anyway - the corpse of the
process may even be used by a good hand to dig out useful memory regions, or
the admin could simply kill the process later on.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-11-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:20:45 +00:00
Peter Xu
755e8d7cb6 migration: Move static var in ram_block_from_stream() into global
Static variable is very unfriendly to threading of ram_block_from_stream().
Move it into MigrationIncomingState.

Make the incoming state pointer to be passed over to ram_block_from_stream() on
both caller sites.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20220301083925.33483-8-peterx@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2022-03-02 18:20:45 +00:00
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