Commit Graph

228 Commits

Author SHA1 Message Date
Denis V. Lunev
15b3b8eaae migration: qemu_savevm_state_cleanup becomes mandatory operation
since commit
    commit 94f5a43704
    Author: Liang Li <liang.z.li@intel.com>
    Date:   Mon Nov 2 15:37:00 2015 +0800

    migration: defer migration_end & blk_mig_cleanup

when actual .cleanup callbacks calling was removed from complete operations.

The patch fixes regression introduced by the commit above results in
100% reliable assert for virtio-scsi VM with iothreads enabled during
'virsh create-snapshot' operation:
    assert(i != mr->ioeventfd_nb);
    memory_region_del_eventfd
    virtio_pci_set_host_notifier_internal
    virtio_pci_set_host_notifier
    virtio_scsi_dataplane_start
    virtio_scsi_handle_cmd
    virtio_queue_notify_vq
    virtio_queue_host_notifier_read
    aio_dispatch

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
371ff5a3f0 Inhibit ballooning during postcopy
Postcopy detects accesses to pages that haven't been transferred yet
using userfaultfd, and it causes exceptions on pages that are 'not
present'.
Ballooning also causes pages to be marked as 'not present' when the
guest inflates the balloon.
Potentially a balloon could be inflated to discard pages that are
currently inflight during postcopy and that may be arriving at about
the same time.

To avoid this confusion, disable ballooning during postcopy.

When disabled we drop balloon requests from the guest.  Since ballooning
is generally initiated by the host, the management system should avoid
initiating any balloon instructions to the guest during migration,
although it's not possible to know how long it would take a guest to
process a request made prior to the start of migration.
Guest initiated ballooning will not know if it's really freed a page
of host memory or not.

Queueing the requests until after migration would be nice, but is
non-trivial, since the set of inflate/deflate requests have to
be compared with the state of the page to know what the final
outcome is allowed to be.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
58b7c17e22 Disable mlock around incoming postcopy
Userfault doesn't work with mlock; mlock is designed to nail down pages
so they don't move, userfault is designed to tell you when they're not
there.

munlock the pages we userfault protect before postcopy.
mlock everything again at the end if mlock is enabled.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
e9bef235d9 End of migration for postcopy
Tweak the end of migration cleanup; we don't want to close stuff down
at the end of the main stream, since the postcopy is still sending pages
on the other thread.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
f952710757 Postcopy: Mark nohugepage before discard
Prior to servicing userfault requests we must ensure we've not got
huge pages in the area that might include non-transferred memory,
since a hugepage could incorrectly mark the whole huge page as present.

We mark the area as non-huge page (nhp) just before we perform
discards; the discard code now tells us to discard any areas
that haven't been sent (as well as any that are redirtied);
any already formed transparent-huge-pages get fragmented
by this discard process if they cotnain any discards.

Transparent huge pages that have been entirely transferred
and don't contain any discards are not broken by this mechanism;
they stay as huge pages.

By starting postcopy after a full precopy pass, many of the pages
then stay as huge pages; this is important for maintaining performance
after the end of the migration.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
27c6825bd3 postcopy: Wire up loadvm_postcopy_handle_ commands
Wire up more of the handlers for the commands on the destination side,
in particular loadvm_postcopy_handle_run now has enough to start the
guest running.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
c76201ab52 Start up a postcopy/listener thread ready for incoming page data
The loading of a device state (during postcopy) may access guest
memory that's still on the source machine and thus might need
a page fill; split off a separate thread that handles the incoming
page data so that the original incoming migration code can finish
off the device data.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
c4faeed231 Postcopy; Handle userfault requests
userfaultfd is a Linux syscall that gives an fd that receives a stream
of notifications of accesses to pages registered with it and allows
the program to acknowledge those stalls and tell the accessing
thread to carry on.

We convert the requests from the kernel into messages back to the
source asking for the pages.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
99e314ebca Host page!=target page: Cleanup bitmaps
Prior to the start of postcopy, ensure that everything that will
be transferred later is a whole host-page in size.

This is accomplished by discarding partially transferred host pages
and marking any that are partially dirty as fully dirty.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
35ecd943e7 Don't iterate on precopy-only devices during postcopy
During the postcopy phase we must not call the iterate method on
precopy-only devices, since they may have done some cleanup during
the _complete call at the end of the precopy phase.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
663e6c1df8 Don't sync dirty bitmaps in postcopy
Once we're in postcopy the source processors are stopped and memory
shouldn't change any more, so there's no need to look at the dirty
map.

There are two notes to this:
  1) If we do resync and a page had changed then the page would get
     sent again, which the destination wouldn't allow (since it might
     have also modified the page)
  2) Before disabling this I'd seen very rare cases where a page had been
     marked dirtied although the memory contents are apparently identical

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:28 +01:00
Dr. David Alan Gilbert
c53b7ddc61 postcopy: Check order of received target pages
Ensure that target pages received within a host page are in order.
This shouldn't trigger, but in the cases where the sender goes
wrong and sends stuff out of order it produces a corruption that's
really nasty to debug.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
a71808772a Postcopy: Use helpers to map pages during migration
In postcopy, the destination guest is running at the same time
as it's receiving pages; as we receive new pages we must put
them into the guests address space atomically to avoid a running
CPU accessing a partially written page.

Use the helpers in postcopy-ram.c to map these pages.

qemu_get_buffer_in_place is used to avoid a copy out of qemu_file
in the case that postcopy is going to do a copy anyway.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
696ed9a9b3 postcopy_ram.c: place_page and helpers
postcopy_place_page (etc) provide a way for postcopy to place a page
into guests memory atomically (using the copy ioctl on the ufd).

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
a82d593b61 Page request: Consume pages off the post-copy queue
When transmitting RAM pages, consume pages that have been queued by
MIG_RPCOMM_REQPAGE commands and send them ahead of normal page scanning.

Note:
  a) After a queued page the linear walk carries on from after the
unqueued page; there is a reasonable chance that the destination
was about to ask for other closeby pages anyway.

  b) We have to be careful of any assumptions that the page walking
code makes, in particular it does some short cuts on its first linear
walk that break as soon as we do a queued page.

  c) We have to be careful to not break up host-page size chunks, since
this makes it harder to place the pages on the destination.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
6c595cdee1 Page request: Process incoming page request
On receiving MIG_RPCOMM_REQ_PAGES look up the address and
queue the page.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
1e2d90ebc5 Page request: Add MIG_RP_MSG_REQ_PAGES reverse command
Add MIG_RP_MSG_REQ_PAGES command on Return path for the postcopy
destination to request a page from the source.

Two versions exist:
   MIG_RP_MSG_REQ_PAGES_ID that includes a RAMBlock name and start/len
   MIG_RP_MSG_REQ_PAGES that just has start/len for use with the same
                        RAMBlock as a previous MIG_RP_MSG_REQ_PAGES_ID

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
b10ac0c42c Postcopy: End of iteration
The end of migration in postcopy is a bit different since some of
the things normally done at the end of migration have already been
done on the transition to postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
1d34e4bf6a Postcopy: Postcopy startup in migration thread
Rework the migration thread to setup and start postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
f0a227ade4 postcopy: ram_enable_notify to switch on userfault
Mark the area of RAM as 'userfault'
Start up a fault-thread to handle any userfaults we might receive
from it (to be filled in later)

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
1caddf8a81 postcopy: Incoming initialisation
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
e0b266f01d migration_completion: Take current state
Soon we'll be in either ACTIVE or POSTCOPY_ACTIVE when we
complete migration, and we need to know which we expect to be
in to change state safely.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
f3f491fcd6 Postcopy: Maintain unsentmap
Maintain an 'unsentmap' of pages that have yet to be sent.
This is used in the following patches to discard some set of
the pages already sent as we enter postcopy mode.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
763c906b0e Add qemu_savevm_state_complete_postcopy
Add qemu_savevm_state_complete_postcopy to complement
qemu_savevm_state_complete_precopy together with a new
save_live_complete_postcopy method on devices.

The save_live_complete_precopy method is called on
all devices during a precopy migration, and all non-postcopy
devices during a postcopy migration at the transition.

The save_live_complete_postcopy method is called at
the end of postcopy for all postcopiable devices.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:27 +01:00
Dr. David Alan Gilbert
8421b205dd Avoid sending vmdescription during postcopy
VMDescription is normally sent at the end, after all
of the devices; however that's not the end for postcopy,
so just don't send it when in postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
9ec055ae29 MIGRATION_STATUS_POSTCOPY_ACTIVE: Add new migration state
'MIGRATION_STATUS_POSTCOPY_ACTIVE' is entered after migrate_start_postcopy

'migration_in_postcopy' is provided for other sections to know if
they're in postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
36f48567b8 migration_completion: Take current state
Soon we'll be in either ACTIVE or POSTCOPY_ACTIVE when we
complete migration, and we need to know which we expect to be
in to change state safely.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
4886a1bcb7 migrate_start_postcopy: Command to trigger transition to postcopy
Once postcopy is enabled (with migrate_set_capability), the migration
will still start on precopy mode.  To cause a transition into postcopy
the:

  migrate_start_postcopy

command must be issued.  Postcopy will start sometime after this
(when it's next checked in the migration loop).

Issuing the command before migration has started will error,
and issuing after it has finished is ignored.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
eb59db53a4 postcopy: OS support test
Provide a check to see if the OS we're running on has all the bits
needed for postcopy.

Creates postcopy-ram.c which will get most of the other helpers we need.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
c31b098f64 Modify save_live_pending for postcopy
Modify save_live_pending to return separate postcopiable and
non-postcopiable counts.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
11cf1d984b MIG_CMD_PACKAGED: Send a packaged chunk of migration stream
MIG_CMD_PACKAGED is a migration command that wraps a chunk of migration
stream inside a package whose length can be determined purely by reading
its header.  The destination guarantees that the whole MIG_CMD_PACKAGED
is read off the stream prior to parsing the contents.

This is used by postcopy to load device state (from the package)
while leaving the main stream free to receive memory pages.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
093e3c4296 Add wrappers and handlers for sending/receiving the postcopy-ram migration messages.
The state of the postcopy process is managed via a series of messages;
   * Add wrappers and handlers for sending/receiving these messages
   * Add state variable that track the current state of postcopy

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
53dd370ced Add migration-capability boolean for postcopy-ram.
The 'postcopy ram' capability allows postcopy migration of RAM;
note that the migration starts off in precopy mode until
postcopy mode is triggered (see the migrate_start_postcopy
patch later in the series).

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
7b89bf279f Rework loadvm path for subloops
Postcopy needs to have two migration streams loading concurrently;
one from memory (with the device state) and the other from the fd
with the memory transactions.

Split the core of qemu_loadvm_state out so we can use it for both.

Allow the inner loadvm loop to quit and cause the parent loops to
exit as well.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
70b2047774 Return path: Source handling of return path
Open a return path, and handle messages that are received upon it.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
f6844b99ce migration_is_setup_or_active
Add 'migration_is_setup_or_active' utility function to check state.
(It gets postcopy added to it's list later on in the series)

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
6decec9311 Return path: Send responses from destination to source
Add migrate_send_rp_message to send a message from destination to source along the return path.
  (It uses a mutex to let it be called from multiple threads)
Add migrate_send_rp_shut to send a 'shut' message to indicate
  the destination is finished with the RP.
Add migrate_send_rp_ack to send a 'PONG' message in response to a PING
  Use it in the MSG_RP_PING handler

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:26 +01:00
Dr. David Alan Gilbert
2e37701efd Return path: Control commands
Add two src->dest commands:
   * OPEN_RETURN_PATH - To request that the destination open the return path
   * PING - Request an acknowledge from the destination

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:25 +01:00
Dr. David Alan Gilbert
c76ca1888f Migration commands
Create QEMU_VM_COMMAND section type for sending commands from
source to destination.  These commands are not intended to convey
guest state but to control the migration process.

For use in postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:25 +01:00
Dr. David Alan Gilbert
3e4097b564 Return path: socket_writev_buffer: Block even on non-blocking fd's
The destination sets the fd to non-blocking on incoming migrations;
this also affects the return path from the destination, and thus we
need to make sure we can safely write to the return path.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 15:00:25 +01:00
Dr. David Alan Gilbert
adc468e9b9 Return path: Open a return path on QEMUFile for sockets
Postcopy needs a method to send messages from the destination back to
the source, this is the 'return path'.

Wire it up for 'socket' QEMUFile's.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:49 +01:00
Dr. David Alan Gilbert
a3e06c3d13 Rename save_live_complete to save_live_complete_precopy
In postcopy we're going to need to perform the complete phase
for postcopiable devices at a different point, start out by
renaming all of the 'complete's to make the difference obvious.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:49 +01:00
Dr. David Alan Gilbert
aefeb18bde migrate_init: Call from savevm
Suspend to file is very much like a migrate, and it makes life
easier if we have the Migration state available, so initialise it
in the savevm.c code for suspending.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewd-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:49 +01:00
Dr. David Alan Gilbert
a776aa15a7 ram_load: Factor out host_from_stream_offset call and check
The main RAM load loop has a call to host_from_stream_offset for
each page type that actually loads data with the same test;
factor it out before the switch.

The host = NULL is to silence a bogus gcc warning of
an unitialised in the RAM_SAVE_COMPRESS_PAGE case, it
doesn't seem to realise that host is always initialised by the if at
the top in the cases the switch takes.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:49 +01:00
Dr. David Alan Gilbert
4f2e425267 ram_debug_dump_bitmap: Dump a migration bitmap as text
Useful for debugging the migration bitmap and other bitmaps
of the same format (including the sentmap in postcopy).

The bitmap is printed to stderr.
Lines that are all the expected value are excluded so the output
can be quite compact for many bitmaps.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Dr. David Alan Gilbert
a800cd5c38 Add wrapper for setting blocking status on a QEMUFile
Add a wrapper to change the blocking status on a QEMUFile
rather than having to use qemu_set_block(qemu_get_fd(f));
it seems best to avoid exposing the fd since not all QEMUFile's
really have one.  With this wrapper we could move the implementation
down to be different on different transports.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Dr. David Alan Gilbert
9504fb510c Add qemu_get_buffer_in_place to avoid copies some of the time
qemu_get_buffer always copies the data it reads to a users buffer,
however in many cases the file buffer inside qemu_file could be given
back to the caller, avoiding the copy.  This isn't always possible
depending on the size and alignment of the data.

Thus 'qemu_get_buffer_in_place' either copies the data to a supplied
buffer or updates a pointer to the internal buffer if convenient.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Dr. David Alan Gilbert
42e2aa5637 Rename mis->file to from_src_file
'file' becomes confusing when you have flows in each direction;
rename to make it clear.
This leaves just the main forward direction ms->file, which is used
in a lot of places and is probably not worth renaming given the churn.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Dr. David Alan Gilbert
e3dd74934f qemu_ram_block_by_name
Add a function to find a RAMBlock by name; use it in two
of the places that already open code that loop; we've
got another use later in postcopy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Dr. David Alan Gilbert
172dfd4faf Move configuration section writing
The vmstate_configuration is currently written
in 'qemu_savevm_state_begin', move it to
'qemu_savevm_state_header' since it's got a hard
requirement that it must be the 1st thing after
the header.
(In postcopy some 'command' sections get sent
early before the saving of the main sections
and hence before qemu_savevm_state_begin).

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-11-10 14:51:48 +01:00
Liang Li
6ad2a215e7 migration: code clean up
Just clean up code, no behavior change.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>al3
Reviewed-by: Amit Shah <amit.shah@redhat.com>al3
Signed-off-by: Juan Quintela <quintela@redhat.com>al3
2015-11-04 13:40:13 +01:00
Liang Li
d1a8548c10 migration: rename cancel to cleanup in SaveVMHandles
'cleanup' seems more appropriate than 'cancel'.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>al3
Reviewed-by: Amit Shah <amit.shah@redhat.com>al3
Signed-off-by: Juan Quintela <quintela@redhat.com>al3
2015-11-04 13:40:13 +01:00
Liang Li
ea7415fac6 migration: rename qemu_savevm_state_cancel
The function qemu_savevm_state_cancel is called after the migration
in migration_thread, it seems strange to 'cancel' it after completion,
rename it to qemu_savevm_state_cleanup looks better.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>al3
Reviewed-by: Amit Shah <amit.shah@redhat.com>al3
Signed-off-by: Juan Quintela <quintela@redhat.com>al3
2015-11-04 13:40:13 +01:00
Liang Li
94f5a43704 migration: defer migration_end & blk_mig_cleanup
Because of the patch 3ea3b7fa9af067982f34b of kvm, which introduces a
lazy collapsing of small sptes into large sptes mechanism, now
migration_end() is a time consuming operation because it calls
memroy_global_dirty_log_stop(), which will trigger the dropping of small
sptes operation and takes about dozens of milliseconds, so call
migration_end() before all the vmsate data has already been transferred
to the destination will prolong VM downtime. This operation should be
deferred after all the data has been transferred to the destination.

blk_mig_cleanup() can be deferred too.

For a VM with 8G RAM, this patch can reduce the VM downtime about 30 ms.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>al3
Reviewed-by: Amit Shah <amit.shah@redhat.com>al3
Signed-off-by: Juan Quintela <quintela@redhat.com>al3
2015-11-04 13:40:13 +01:00
Max Reitz
5433c24f0f block: Prepare for NULL BDS
blk_bs() will not necessarily return a non-NULL value any more (unless
blk_is_available() is true or it can be assumed to otherwise, e.g.
because it is called immediately after a successful blk_new_with_bs() or
blk_new_open()).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23 18:18:23 +02:00
Daniel P. Berrange
10817bf09d coroutine: move into libqemuutil.a library
The coroutine files are currently referenced by the block-obj-y
variable. The coroutine functionality though is already used by
more than just the block code. eg migration code uses coroutine
yield. In the future the I/O channel code will also use the
coroutine yield functionality. Since the coroutine code is nicely
self-contained it can be easily built as part of the libqemuutil.a
library, making it widely available.

The headers are also moved into include/qemu, instead of the
include/block directory, since they are now part of the util
codebase, and the impl was never in the block/ directory
either.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-10-20 14:59:04 +01:00
Denis V. Lunev
60be634079 migration: fix deadlock
Release qemu global mutex before call synchronize_rcu().
synchronize_rcu() waiting for all readers to finish their critical
sections. There is at least one critical section in which we try
to get QGM (critical section is in address_space_rw() and
prepare_mmio_access() is trying to aquire QGM).

Both functions (migration_end() and migration_bitmap_extend())
are called from main thread which is holding QGM.

Thus there is a race condition that ends up with deadlock:
main thread     working thread
Lock QGA                |
|             Call KVM_EXIT_IO handler
|                       |
|        Open rcu reader's critical section
Migration cleanup bh    |
|                       |
synchronize_rcu() is    |
waiting for readers     |
|            prepare_mmio_access() is waiting for QGM
  \                   /
         deadlock

The patch changes bitmap freeing from direct g_free after synchronize_rcu
to free inside call_rcu.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reported-by: Igor Redko <redkoi@virtuozzo.com>
Tested-by: Igor Redko <redkoi@virtuozzo.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

CC: Anna Melekhova <annam@virtuozzo.com>
CC: Juan Quintela <quintela@redhat.com>
CC: Amit Shah <amit.shah@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Wen Congyang <wency@cn.fujitsu.com>
2015-10-15 08:14:13 +02:00
Amit Shah
92e3762237 migration: announce VM's new home just before VM is runnable
We were announcing the dest host's IP as our new IP a bit too soon -- if
there were errors detected after this announcement was done, the
migration is failed and the VM could continue running on the src host --
causing problems later.

Move around the qemu_announce_self() call so it's done just before the
VM is runnable.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-10-15 08:13:03 +02:00
Dr. David Alan Gilbert
ed1f3e0090 Migration: Generate the completed event only when we complete
The current migration-completed event is generated a bit too early,
which means that an eager libvirt that's ready to go as soon
as it sees the event ends up racing with the actual end of migration.

This corresponds to RH bug:
https://bugzilla.redhat.com/show_bug.cgi?id=1271145

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
xSigned-off-by: Juan Quintela <quintela@redhat.com>
2015-10-15 08:12:02 +02:00
Jason J. Herne
dc3256272c migration: Disambiguate MAX_THROTTLE
Migration has a define for MAX_THROTTLE. Update comment to clarify that this is
used for throttling transfer speed. Hopefully this will prevent it from being
confused with a guest cpu throttling entity.

Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
2015-09-30 09:42:04 +02:00
Jason J. Herne
4782893e09 qmp/hmp: Add throttle ratio to query-migrate and info migrate
Report throttle percentage in info migrate and query-migrate responses when
cpu throttling is active.

Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
2015-09-30 09:42:04 +02:00
Jason J. Herne
070afca258 migration: Dynamic cpu throttling for auto-converge
Remove traditional auto-converge static 30ms throttling code and replace it
with a dynamic throttling algorithm.

Additionally, be more aggressive when deciding when to start throttling.
Previously we waited until four unproductive memory passes. Now we begin
throttling after only two unproductive memory passes. Four seemed quite
arbitrary and only waiting for two passes allows us to complete the migration
faster.

Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
2015-09-30 09:42:04 +02:00
Jason J. Herne
1626fee3bd migration: Parameters for auto-converge cpu throttling
Add migration parameters to allow the user to adjust the parameters
that control cpu throttling when auto-converge is in effect. The added
parameters are as follows:

x-cpu-throttle-initial : Initial percantage of time guest cpus are throttled
when migration auto-converge is activated.

x-cpu-throttle-increment: throttle percantage increase each time
auto-converge detects that migration is not making progress.

Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
2015-09-30 09:42:04 +02:00
Dr. David Alan Gilbert
b9e6092814 ram_find_and_save_block: Split out the finding
Split out the finding of the dirty page and all the wrap detection
into a separate function since it was getting a bit hairy.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1443018431-11170-3-git-send-email-dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>

[Fix comment -- Amit]
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:38:29 +05:30
Dr. David Alan Gilbert
b8fb8cb748 Move dirty page search state into separate structure
Pull the search state for one iteration of the dirty page
search into a structure.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Message-Id: <1443018431-11170-2-git-send-email-dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:37:07 +05:30
Markus Armbruster
97f3ad3551 migration: 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).  Same Coccinelle semantic patch as in commit b45c03f.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1442231491-23352-1-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:36:35 +05:30
Dr. David Alan Gilbert
56f3835ff1 migration: qemu-file more size_t'ifying
This time convert the external functions:
  qemu_get_buffer, qemu_peek_buffer
  qemu_put_buffer and qemu_put_buffer_async

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1439463094-5394-6-git-send-email-dgilbert@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:33:02 +05:30
Dr. David Alan Gilbert
a202a4c001 migration: size_t'ify some of qemu-file
This is a start on using size_t more in qemu-file and friends;
it fixes up QEMUFilePutBufferFunc and QEMUFileGetBufferFunc
to take size_t lengths and return ssize_t return values (like read(2))
and fixes up all the different implementations of them.

Note that I've not yet followed this deeply into bdrv_ implementations.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1439463094-5394-5-git-send-email-dgilbert@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:33:02 +05:30
Dr. David Alan Gilbert
09f6c85e39 Split out end of migration code from migration_thread
The code that gets run at the end of the migration process
is getting large, and I'm about to add more for postcopy.
Split it into a separate function.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1439463094-5394-3-git-send-email-dgilbert@redhat.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:33:02 +05:30
Dr. David Alan Gilbert
2f68e39956 migration/ram.c: Use RAMBlock rather than MemoryRegion
RAM migration mainly works on RAMBlocks but in a few places
uses data from MemoryRegions to access the same information that's
already held in RAMBlocks; clean it up just to avoid the
MemoryRegion use.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1439463094-5394-2-git-send-email-dgilbert@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-09-29 11:33:02 +05:30
Daniel P. Berrange
ef1e1e0782 maint: avoid useless "if (foo) free(foo)" pattern
The free() and g_free() functions both happily accept
NULL on any platform QEMU builds on. As such putting a
conditional 'if (foo)' check before calls to 'free(foo)'
merely serves to bloat the lines of code.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-09-11 10:21:38 +03:00
Daniel P. Berrange
b6af097528 maint: remove / fix many doubled words
Many source files have doubled words (eg "the the", "to to",
and so on). Most of these can simply be removed, but a couple
were actual mis-spellings (eg "to to" instead of "to do").
There was even one triple word score "to to to" :-)

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-09-11 10:21:38 +03:00
Anthony PERARD
c69adea462 migration: Fix global state with Xen.
When doing migration via the QMP command xen_save_devices_state, the
current runstate is not store into the global state section. Also the
current runstate is not the one we want on the receiver side.

During migration, the Xen toolstack paused QEMU before save the devices
state. Also, the toolstack expect QEMU to autostart when the migration is
finished.
So this patch store "running" as it's current runstate.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2015-08-03 16:13:23 +00:00
Paolo Bonzini
ab28bd2312 rcu: actually register threads that have RCU read-side critical sections
Otherwise, grace periods are detected too early!

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-24 13:57:45 +02:00
Dr. David Alan Gilbert
24b41d66c8 RDMA: Fix error exits
The error checks I added used 'break' after the error, but I'm
in a switch inside the while loop, so they need to be 'goto out'.

Spotted by coverity; entries 1311368 and 1311369

Fixes: afcddefd

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1436555332-19076-1-git-send-email-dgilbert@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-16 20:00:20 +02:00
Juan Quintela
560d027b54 migration: We also want to store the global state for savevm
Commit df4b102452 introduced global_state
section.  But it only filled the state while doing migration.  While
doing a savevm, we stored an empty string as state.  So when we did a
loadvm, it complained that state was invalid.

Fedora 21, 4.1.1, qemu 2.4.0-rc0
> ../../configure --target-list="x86_64-softmmu"

068 2s ... - output mismatch (see 068.out.bad)
--- /home/bos/jhuston/src/qemu/tests/qemu-iotests/068.out	2015-07-08
17:56:18.588164979 -0400
+++ 068.out.bad	2015-07-09 17:39:58.636651317 -0400
@@ -6,6 +6,8 @@
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm 0
 (qemu) quit
+qemu-system-x86_64: Unknown savevm section or instance 'globalstate' 0
+qemu-system-x86_64: Error -22 while loading VM state
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 *** done
Failures: 068
Failed 1 of 1 tests

Actually, there were two problems here:
- we registered global_state too late for load_vm (fixed on another
  patch on the list)
- we didn't store a valid state for savevm (fixed by this patch).

Reported-by: John Snow <jsnow@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Tested-by:  Christian Borntraeger <borntraeger@de.ibm.com>
2015-07-15 12:22:54 +02:00
Liang Li
9f5f380b54 migration: reduce the count of strlen call
'strlen' is called three times in 'save_page_header', it's
inefficient.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-15 12:21:28 +02:00
Juan Quintela
4ba4bc5e9b migration: Trace event and migration event are different things
We can want the trace event even without migration events enabled.

Reported-by:  Wen Congyang <ghostwcy@gmail.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-15 09:07:54 +02:00
Juan Quintela
172c4356f3 migration: Only change state after migration has finished
On previous change, we changed state at post load time if it was not
running, special casing the "running" change.  Now, we change any states
at the end of the migration.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
2015-07-15 09:07:54 +02:00
Paolo Bonzini
d09a6fde15 migration: fix RCU deadlock
migration_end calls synchronize_rcu() within a critical section.
That causes a deadlock; move the call after rcu_read_unlock().

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-09 08:47:58 +02:00
Peter Maydell
30c6672aa4 Pull request
v2:
  * Drop block/nfs patch since it exposes an unfinished QAPI interface [kwolf]
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJVm9RLAAoJEJykq7OBq3PIpzcH/3PPHjCcBIvokfdUK5v+ZKwl
 Ng450lHrJI0aIB9oFYlXeEbYQeE6DU7jfLAKGxnzC5YlIfqo73d+u8dEBFc13sCo
 td/unU57tujxYj4zhzd47D9CiAPvSLWEuET9EfBEQsd/2Aus8ncJTh+RJ7ff9J2B
 bTYrrcd+34gGzlUUHHyD25qXuMJP5KVu5JxlcFvgoOi0CHd1gcKe/xT4GV0bM2CZ
 Spk+Q2F01Y6ERRS54Tx8PO066Tlj/chlnl5dnplHo3PjPuTWHg4cP5cZCsevMwqf
 RjmlYzwUa/B0qI7GZYbF9L4e86Z1U77IGmVa45lZ2vXQNxjsAD5s9+Wb2DBWswI=
 =gaXG
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

Pull request

v2:
 * Drop block/nfs patch since it exposes an unfinished QAPI interface [kwolf]

# gpg: Signature made Tue Jul  7 14:29:47 2015 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/block-pull-request:
  blockjob: add block_job_release function
  block/raw-posix: Don't think /dev/fd/<NN> is a floppy drive.
  block: Use bdrv_drain to replace uncessary bdrv_drain_all
  block: Initialize local_err in bdrv_append_temp_snapshot
  block: update bdrv_drain_all()/bdrv_drain() comments
  qcow2: remove unnecessary check

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-07-07 19:12:45 +01:00
Fam Zheng
53ec73e264 block: Use bdrv_drain to replace uncessary bdrv_drain_all
There callers work on a single BlockDriverState subtree, where using
bdrv_drain() is more accurate.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-07-07 14:27:14 +01:00
Li Zhijian
dd63169766 migration: extend migration_bitmap
Prevously, if we hotplug a device(e.g. device_add e1000) during
migration is processing in source side, qemu will add a new ram
block but migration_bitmap is not extended.
In this case, migration_bitmap will overflow and lead qemu abort
unexpectedly.

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:56 +02:00
Li Zhijian
2ff64038a5 migration: protect migration_bitmap
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:56 +02:00
Dr. David Alan Gilbert
59f39a4741 check_section_footers: Check the correct section_id
The section footers check was incorrectly checking the section_id
in the SaveStateEntry not the LoadStateEntry.  These can validly be different
if the two QEMU instances have instantiated their devices in a
different order.  The test only cares that we're finishing the same
section we started, and hence it's the LoadStateEntry that we care about.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:55 +02:00
Juan Quintela
7cf1fe6d68 migration: Add migration events on target side
We reuse the migration events from the source side, sending them on the
appropiate place.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:55 +02:00
Juan Quintela
b05dc72342 migration: Make events a capability
Make check fails with events.  THis is due to the parser/lexer that it
uses.  Just in case that they are more broken parsers, just only send
events when there are capabilities.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:55 +02:00
Juan Quintela
598cd2bda0 migration: create migration event
We have one argument that tells us what event has happened.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2015-07-07 14:54:55 +02:00
Juan Quintela
f2bb932491 migration: No need to call trace_migrate_set_state()
We now use the helper everywhere, so no need to call this on this two
places.  See on previous commit that there were a place where we missed
to mark the trace.  Now all tracing is done in migrate_set_state().

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:54 +02:00
Juan Quintela
7844337d1e migration: Use always helper to set state
There were three places that were not using the migrate_set_state()
helper, just fix that.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:54 +02:00
Juan Quintela
656a233440 migration: ensure we start in NONE state
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:53 +02:00
Juan Quintela
a5c17b5f68 migration: Use cmpxchg correctly
cmpxchg returns the old value

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:53 +02:00
Juan Quintela
61964c23e5 migration: Add configuration section
It needs to be the first one and it is not optional, that is the reason
why it is opencoded.  For new machine types, it is required that machine
type name is the same in both sides.

It is just done right now for pc's.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:53 +02:00
Juan Quintela
df8961522a vmstate: Create optional sections
To make sections optional, we need to do it at the beggining of the code.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:52 +02:00
Juan Quintela
13d16814d2 global_state: Make section optional
This section would be sent:

a- for all new machine types
b- for old machine types if section state is different form {running,paused}
   that were the only giving us troubles.

So, in new qemus: it is alwasy there.  In old qemus: they are only
there if it an error has happened, basically stoping on target.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:52 +02:00
Juan Quintela
df4b102452 migration: create new section to store global state
This includes a new section that for now just stores the current qemu state.

Right now, there are only one way to control what is the state of the
target after migration.

- If you run the target qemu with -S, it would start stopped.
- If you run the target qemu without -S, it would run just after migration finishes.

The problem here is what happens if we start the target without -S and
there happens one error during migration that puts current state as
-EIO.  Migration would ends (notice that the error happend doing block
IO, network IO, i.e. nothing related with migration), and when
migration finish, we would just "continue" running on destination,
probably hanging the guest/corruption data, whatever.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2015-07-07 14:54:51 +02:00
Dr. David Alan Gilbert
ef4b722d19 Fail more cleanly in mismatched RAM cases
If the number of RAMBlocks was different on the source from the
destination, QEMU would hang waiting for a disconnect on the source
and wouldn't release from that hang until the destination was manually
killed.

Mark the stream as being in error, this causes the destination to die
and the source to carry on.

(It still gets a whole bunch of warnings on the destination, and I've
not managed to complete another migration after the 1st one, still
progress).

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:50 +02:00
Dr. David Alan Gilbert
afcddefdbe Sanity check RDMA remote data
Perform some basic (but probably not complete) sanity checking on
requests from the RDMA source.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:49 +02:00
Dr. David Alan Gilbert
e4d633207c Sort destination RAMBlocks to be the same as the source
Use the order of incoming RAMBlocks from the source to record
an index number; that then allows us to sort the destination
local RAMBlock list to match the source.

Now that the RAMBlocks are known to be in the same order, this
simplifies the RDMA Registration step which previously tried to
match RAMBlocks based on offset (which isn't guaranteed to match).

Looking at the existing compress code, I think it was erroneously
relying on an assumption of matching ordering, which this fixes.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:49 +02:00
Dr. David Alan Gilbert
760ff4bebc Rework ram block hash
RDMA uses a hash from block offset->RAM Block; this isn't needed
on the destination, and it becomes harder to maintain after the next
patch in the series that sorts the block list.

Split the hash so that it's only generated on the source.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-07-07 14:54:49 +02:00