State deletion can be performed on running VM which reduces VM downtime
This approach looks a bit more natural.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

to create snapshot for all loaded block drivers.

The patch also ensures proper locking.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

There is no much sense to do the check and write warning.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

to check that snapshot is available for all loaded block drivers.
The check bs != bs1 in hmp_info_snapshots is an optimization. The check
for availability of this snapshot will return always true as the list
of snapshots was collected from that image.

The patch also ensures proper locking.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

We should check that all inserted and not read-only images support
snapshotting. This could be made using already invented helper
bdrv_all_can_snapshot().
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

to switch to snapshot on all loaded block drivers.

The patch also ensures proper locking.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

to delete snapshots from all loaded block drivers.

The patch also ensures proper locking.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

The patch enforces proper locking for this operation.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: NGreg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Where we have iterable, but non-postcopiable devices (e.g. htab
or block migration), complete them before forming the 'package'
but with the CPUs stopped.  This stops them filling up the package.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

since commit
    commit 94f5a437
    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: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NLiang Li <liang.z.li@intel.com>
Reviewed-by: NJuan 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: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

Modify save_live_pending to return separate postcopiable and
non-postcopiable counts.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewd-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

'cleanup' seems more appropriate than 'cancel'.
Signed-off-by: NLiang 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

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: NLiang 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

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 b45c03f5.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <1442231491-23352-1-git-send-email-armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1439463094-5394-5-git-send-email-dgilbert@redhat.com>
Reviewed-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>

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: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

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: NAnthony PERARD <anthony.perard@citrix.com>
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>

Commit df4b1024 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: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NAmit Shah <amit.shah@redhat.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>

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: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reported-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

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: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

To make sections optional, we need to do it at the beggining of the code.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>