Since 86d90b3a (yes, my patch; again) we are supporting NBD storage
migration. However, on error recovery path we got the steps reversed.
The correct order is: return NBD port to the virPortAllocator and then
either unlock the vm or remove it from the driver. Not vice versa.

==11192== Invalid write of size 4
==11192==    at 0x11488559: qemuMigrationPrepareAny (qemu_migration.c:2459)
==11192==    by 0x11488EA6: qemuMigrationPrepareDirect (qemu_migration.c:2652)
==11192==    by 0x114D1509: qemuDomainMigratePrepare3Params (qemu_driver.c:10332)
==11192==    by 0x519075D: virDomainMigratePrepare3Params (libvirt.c:7290)
==11192==    by 0x1502DA: remoteDispatchDomainMigratePrepare3Params (remote.c:4798)
==11192==    by 0x12DECA: remoteDispatchDomainMigratePrepare3ParamsHelper (remote_dispatch.h:5741)
==11192==    by 0x5212127: virNetServerProgramDispatchCall (virnetserverprogram.c:435)
==11192==    by 0x5211C86: virNetServerProgramDispatch (virnetserverprogram.c:305)
==11192==    by 0x520A8FD: virNetServerProcessMsg (virnetserver.c:165)
==11192==    by 0x520A9E1: virNetServerHandleJob (virnetserver.c:186)
==11192==    by 0x50DA78F: virThreadPoolWorker (virthreadpool.c:144)
==11192==    by 0x50DA11C: virThreadHelper (virthreadpthread.c:161)
==11192==  Address 0x1368baa0 is 576 bytes inside a block of size 688 free'd
==11192==    at 0x4A07F5C: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==11192==    by 0x5079A2F: virFree (viralloc.c:580)
==11192==    by 0x11456C34: qemuDomainObjPrivateFree (qemu_domain.c:267)
==11192==    by 0x50F41B4: virDomainObjDispose (domain_conf.c:2034)
==11192==    by 0x50C2991: virObjectUnref (virobject.c:262)
==11192==    by 0x50F4CFC: virDomainObjListRemove (domain_conf.c:2361)
==11192==    by 0x1145C125: qemuDomainRemoveInactive (qemu_domain.c:2087)
==11192==    by 0x11488520: qemuMigrationPrepareAny (qemu_migration.c:2456)
==11192==    by 0x11488EA6: qemuMigrationPrepareDirect (qemu_migration.c:2652)
==11192==    by 0x114D1509: qemuDomainMigratePrepare3Params (qemu_driver.c:10332)
==11192==    by 0x519075D: virDomainMigratePrepare3Params (libvirt.c:7290)
==11192==    by 0x1502DA: remoteDispatchDomainMigratePrepare3Params (remote.c:4798)
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

So far we are checking if qemu supports 'nbd-server-start'. This,
however, makes no sense on the source as nbd-server-* is used on the
destination. On the source the 'drive-mirror' is used instead.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

If there's a migration cancelled, the bitmap of migration port should be
cleaned up too.
Signed-off-by: NZeng Junliang <zengjunliang@huawei.com>
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Instead of using a port from the remote display range.

https://bugzilla.redhat.com/show_bug.cgi?id=1025699

When adding an automatically allocated port to a well-formed migration
URI, keep it well-formed:

  tcp://1.2.3.4/  ->  tcp://1.2.3.4/:12345   # wrong
  tcp://1.2.3.4/  ->  tcp://1.2.3.4:12345/   # fixed
  tcp://1.2.3.4   ->  tcp://1.2.3.4:12345    # still works
  tcp:1.2.3.4     ->  tcp:1.2.3.4:12345      # still works (old syntax)
Signed-off-by: NMichael Chapman <mike@very.puzzling.org>

https://bugzilla.redhat.com/show_bug.cgi?id=1019053

When we migrate vms concurrently, there's a chance that libvirtd on
destination assigns the same port for different migrations, which will
lead to migration failure during prepare phase on destination. So we use
virPortAllocator here to solve the problem.
Signed-off-by: NWang Yufei <james.wangyufei@huawei.com>
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

After my patches, some functions gained one more argument
(@listenAddress) which wasn't included in debug printing of
arguments they were called with. Functions in question are:
qemuMigrationPrepareDirect and qemuMigrationPerform.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=994364

Whenever we check for ABI stability, we have new xml (e.g. provided by
user, or obtained from snapshot, whatever) which we compare to old xml
and see if ABI won't break. However, if the new xml was produced via
virDomainGetXMLDesc(..., VIR_DOMAIN_XML_MIGRATABLE) it lacks some
devices, e.g. 'pci-root' controller. Hence, the ABI stability check
fails even though it is stable. Moreover, we can't simply fix
virDomainDefCheckABIStability because removing the correct devices is
task for the driver. For instance, qemu driver wants to remove the usb
controller too, while LXC driver doesn't. That's why we need special
qemu wrapper over virDomainDefCheckABIStability which removes the
correct devices from domain XML, produces MIGRATABLE xml and calls the
check ABI stability function.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Since the wait is done during migration (still inside
QEMU_ASYNC_JOB_MIGRATION_OUT), the code should enter the monitor as such
in order to prohibit all other jobs from interfering in the meantime.
This patch fixes bug #1009886 in which qemuDomainGetBlockInfo was
waiting on the monitor condition and after GetSpiceMigrationStatus
mangled its internal data, the daemon crashed.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1009886

qemuMigrationEatCookie has flags to control if these should
be parsed, but it does not fill mig->flags. These cookies might
get leaked if these flags are not set by qemuMigrationBakeCookie.

42 (32 direct, 10 indirect) bytes in 1 blocks are definitely lost in
loss record 361 of 662
==123== by 0x1BA33FCA: qemuMigrationEatCookie (qemu_migration.c:678)
==123== by 0x1BA34A1E: qemuMigrationRun (qemu_migration.c:3108)
==123== by 0x1BA3622B: doNativeMigrate (qemu_migration.c:3343)
==123== by 0x1BA3B408: qemuMigrationPerform (qemu_migration.c:4138)

Osier Yang pointed out that ever since commit 31cb030a, the
signature of qemuDomainObjEndJob was changed to return a bool.
While comparison against 0 or > 0 still gives the right results,
it looks fishy; we also had one place that was comparing < 0
which is effectively dead code.

* src/qemu/qemu_migration.c (qemuMigrationPrepareAny): Fix dead
code bug.
(qemuMigrationBegin): Use more canonical form of bool check.
* src/qemu/qemu_driver.c (qemuAutostartDomain)
(qemuDomainCreateXML, qemuDomainSuspend, qemuDomainResume)
(qemuDomainShutdownFlags, qemuDomainReboot, qemuDomainReset)
(qemuDomainDestroyFlags, qemuDomainSetMemoryFlags)
(qemuDomainSetMemoryStatsPeriod, qemuDomainInjectNMI)
(qemuDomainSendKey, qemuDomainGetInfo, qemuDomainScreenshot)
(qemuDomainSetVcpusFlags, qemuDomainGetVcpusFlags)
(qemuDomainRestoreFlags, qemuDomainGetXMLDesc)
(qemuDomainCreateWithFlags, qemuDomainAttachDeviceFlags)
(qemuDomainUpdateDeviceFlags, qemuDomainDetachDeviceFlags)
(qemuDomainBlockResize, qemuDomainBlockStats)
(qemuDomainBlockStatsFlags, qemuDomainMemoryStats)
(qemuDomainMemoryPeek, qemuDomainGetBlockInfo)
(qemuDomainAbortJob, qemuDomainMigrateSetMaxDowntime)
(qemuDomainMigrateGetCompressionCache)
(qemuDomainMigrateSetCompressionCache)
(qemuDomainMigrateSetMaxSpeed)
(qemuDomainSnapshotCreateActiveInternal)
(qemuDomainRevertToSnapshot, qemuDomainSnapshotDelete)
(qemuDomainQemuMonitorCommand, qemuDomainQemuAttach)
(qemuDomainBlockJobImpl, qemuDomainBlockCopy)
(qemuDomainBlockCommit, qemuDomainOpenGraphics)
(qemuDomainGetBlockIoTune, qemuDomainGetDiskErrors)
(qemuDomainPMSuspendForDuration, qemuDomainPMWakeup)
(qemuDomainQemuAgentCommand, qemuDomainFSTrim): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=999352

Since commit v1.0.5-56-g449e6b1b (Pull parsing of migration xml up into
QEMU driver APIs) any attempt to rename a domain during migration fails
with the following error message:

    internal error Incoming cookie data had unexpected name DOM vs DOM2

This is because migration cookies always use the original domain name
and the mentioned commit failed to propagate the name back to
qemuMigrationPrepareAny.

https://bugzilla.redhat.com/show_bug.cgi?id=979477

Since 1.0.3 we are using the new way to copy non shared storage during
migration (the NBD way). However, whether the new or old way is used is
not controllable by user but unconditionally turned on if both sides of
migration support it. Moreover, the implementation is not complete: the
combination for VIR_MIGRATE_TUNNELLED flag is missing (as we need to
open new port on the destination) in which case we just error out. This
is a deadly combination: not letting users choose their destiny and
erroring out. We should not do that but VIR_WARN and turn the NBD off
instead.

Convert the remaining methods in vircgroup.c to report errors
instead of returning errno values.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Remove assignment of the string freed by virURIFree
to hostname, since it's not used anywhere.

Double free introduced by ddf8ad82, useless code
introduced by f03dcc5d.

https://bugzilla.redhat.com/show_bug.cgi?id=977961

Whenever virPortAllocatorRelease is called with port == 0, it complains
that the port is not in an allowed range, which is expectable as the
port was never allocated. Let's make virPortAllocatorRelease ignore 0
ports in a similar way free() ignores NULL pointers.

https://bugzilla.redhat.com/show_bug.cgi?id=981139

If a domain is paused before migration starts, we need to tell that to
the destination libvirtd to prevent it from resuming the domain at the
end of migration. This regression was introduced by commit 5379bb0f.

Since commit 23e8b5d8, the code is refactored in a way that supports
domains with multiple graphics elements and commit 37b41520 allows
starting such domains.  However none of those commits take migration
into account.  Even though qemu doesn't support relocation for
anything else than SPICE and for no more than one graphics, there is no
reason to hardcode one graphics into this part of the code as well.

This flag is meant for errors happening on the source of the migration
and isn't used on the destination. To allow better migration
compatibility, don't propagate it to the destination.

Paolo Bonzini pointed out that it's actually possible to migrate a qemu
instance that was paused due to I/O error and it will be able to work on
the destination if the storage is accessible.

This patch introduces flag VIR_MIGRATE_ABORT_ON_ERROR that cancels the
migration in case an I/O error happens while it's being performed and
allows migration without this flag. This flag can be possibly used for
other error reasons that may be introduced in the future.

Currently, we wait for SPICE to migrate in the very same loop where we
wait for qemu to migrate. This has a disadvantage of slowing seamless
migration down. One one hand, we should not kill the domain until all
SPICE data has been migrated.  On the other hand, there is no need to
wait in the very same loop and hence slowing down 'cont' on the
destination. For instance, if users are watching a movie, they can
experience the movie to be stopped for a couple of seconds, as
processors are not running nor on src nor on dst as libvirt waits for
SPICE to migrate. We should move the waiting phase to migration CONFIRM
phase.

Such machine can't be successuflly migrated unles the I/O error has
recovered and might lead to data corruption. Forbid this kind of
migration.

During a live migration the guest may receive a disk access I/O error.
In this state the guest is unable to continue running on a remote host
after migration as some state may be present in the kernel and not
migrated.

With this patch, the migration is canceled in such case so it can either
continue on the source if the I/O issues are recovered or has to be
destroyed anyways.

Avoid leaking virDomainDef if Prepare phase fails before it gets to
qemuMigrationPrepareAny.

Since we have the new internal API to check for wildcard address,
we can use it instead of parsing and formatting.

Found with 'git grep "= 1"'.

Currently, a listen address for a SPICE server can be specified. Later,
when the domain is migrated, we need to relocate the graphics which
involves telling new destination to the SPICE server. However, we can't
just assume the listen address is the new location, because the listen
address can be ANYCAST (0.0.0.0 for IPv4, :: for IPv6). In which case,
we want to pass the remote hostname. But there are some troubles with
ANYCAST. In both IPv4 and IPv6 it has many ways for specifying such
address. For instance, in IPv4: 0, 0.0, 0.0.0, 0.0.0.0.  The number of
variations gets bigger in IPv6 world. Hence, in order to check for
ANYCAST address sanely, we should take the provided listen address,
parse it and format back in it's full form. Which is exactly what this
patch does.

A literal IPv6 must be escaped, otherwise migration fails with:
unable to execute QEMU command 'drive-mirror': address resolution failed
for f0::0d:5901: Servname not supported for ai_socktype
since QEMU treats everything after the first ':' as the port.

Since as the code indicates it doesn't work yet, so let's be
explicit about it.

By actually showing the Open() error to the user