After removing capability check for fd migration the code that was left
behind didn't make quite sense. The old exec migration would be used in
case when pipe() failed. Remove the old code and make failure of pipe()
a hard error.

This additionally removes usage of virCgroupAllowDevicePath outside of
qemu_cgroup.c.

Traditionally, we pass incoming migration URI on QEMU command line,
which has some drawbacks. Depending on the URI QEMU may initialize its
migration state immediately without giving us a chance to set any
additional migration parameters (this applies mainly for fd: URIs). For
some URIs the monitor may be completely blocked from the beginning until
migration is finished, which means we may be stuck in qmp_capabilities
command without being able to send any QMP commands.

QEMU solved this by introducing "defer" parameter for -incoming command
line option. This will tell QEMU to prepare for an incoming migration
while the actual incoming URI is sent using migrate-incoming QMP
command. Before calling this command we can normally talk to the
monitor and even set any migration parameters which will be honored by
the incoming migration.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Use the migration @flags for checking various migration aspects rather
than picking them out as booleans. Document the new semantics in the
function header.

Now that qemuMigrationIsAllowed is always called with @vm, we can drop
the @def argument and simplify the control flow.

Additionally the comment is invalid so drop it.

If QEMU fails during incoming migration, the domain disappears including
a possibly useful error message read from QEMU log file. Let's remember
the error in virQEMUDriver so that Finish can report more than just "no
such domain".
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Once we start waiting for migration events instead of polling
query-migrate, priv->job.current will not be regularly updated anymore
because we will get the current status directly from the events. Thus
virDomainGetJob{Info,Stats} will have to query QEMU, but they can't just
blindly update priv->job.current structure. This patch introduces
qemuMigrationFetchJobStatus which just fills in a caller supplied
structure and makes qemuMigrationUpdateJobStatus a tiny wrapper around
it.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

When libvirtd is restarted during migration, we properly cancel the
ongoing migration (unless it managed to almost finished before the
restart). But if we were also migrating storage using NBD, we would
completely forget about the running disk mirrors.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1203032

Implement a `migrate_disks' parameters for the QEMU driver. This multi-
value parameter can be used to explicitly specify what block devices
are to be migrated using the NBD server. Tunnelled migration using NBD
is to be done.
Signed-off-by: NPavel Boldin <pboldin@mirantis.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

There is one problem that causes various errors in the daemon.  When
domain is waiting for a job, it is unlocked while waiting on the
condition.  However, if that domain is for example transient and being
removed in another API (e.g. cancelling incoming migration), it get's
unref'd.  If the first call, that was waiting, fails to get the job, it
unref's the domain object, and because it was the last reference, it
causes clearing of the whole domain object.  However, when finishing the
call, the domain must be unlocked, but there is no way for the API to
know whether it was cleaned or not (unless there is some ugly temporary
variable, but let's scratch that).

The root cause is that our APIs don't ref the objects they are using and
all use the implicit reference that the object has when it is in the
domain list.  That reference can be removed when the API is waiting for
a job.  And because each domain doesn't do its ref'ing, it results in
the ugly checking of the return value of virObjectUnref() that we have
everywhere.

This patch changes qemuDomObjFromDomain() to ref the domain (using
virDomainObjListFindByUUIDRef()) and adds qemuDomObjEndAPI() which
should be the only function in which the return value of
virObjectUnref() is checked.  This makes all reference counting
deterministic and makes the code a bit clearer.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

RDMA Live migration requires registering memory with the hardware, and
thus QEMU offers a new 'capability' to pre-register / mlock() the guest
memory in advance for higher RDMA performance before the migration
begins. This capability is disabled by default, which means QEMU will
register the memory with the hardware in an on-demand basis.

This patch exposes this capability with the following example usage:

virsh migrate --live --rdma-pin-all --migrateuri rdma://hostname domain qemu+ssh://hostname/systemSigned-off-by: NMichael R. Hines <mrhines@us.ibm.com>
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

As we are doing with the enum structures, a cleanup in "src/qemu/"
directory was done now. All the enums that were defined in the
header files were converted to typedefs in this directory. This
patch includes all the adjustments to remove conflicts when you do
this kind of change. "Enum-to-typedef"'s conversions were made in
"src/qemu/qemu_{capabilities, domain, migration, hotplug}.h".
Signed-off-by: NJulio Faracco <jcfaracco@gmail.com>

Busy enterprise workloads hosted on large sized VM's tend to dirty
memory faster than the transfer rate achieved via live guest migration.
Despite some good recent improvements (& using dedicated 10Gig NICs
between hosts) the live migration may NOT converge.

Recently support was added in qemu (version 1.6) to allow a user to
choose if they wish to force convergence of their migration via a
new migration capability : "auto-converge". This feature allows for qemu
to auto-detect lack of convergence and trigger a throttle-down of the
VCPUs.

This patch includes the libvirt support needed to trigger this
feature. (Testing is in progress)
Signed-off-by: NChegu Vinod <chegu_vinod@hp.com>
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Signed-off-by: NMichal Privoznik <mprivozn@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.

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.

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

Currently the parsing of XML is pushed down into the various
migration helper APIs. This makes it difficult to insert the
correct access control checks, since one helper API services
many public APIs. Pull the parsing of XML up to the top level
of the QEMU driver APIs

This patch exports qemuMigrationIsAllowed and adds a new parameter to it
to denote if it's a remote migration or a local migration. Local
migrations are used in snapshots and saving of the machine state and
have fewer restrictions. This patch also adjusts callers of the function
and tweaks some error messages to be more universal.

Offline migration transfers inactive definition of a domain (which may
or may not be active). After successful completion, the domain remains
in its current state on source host and is defined but inactive on
destination host. It's a bit more clever than virDomainGetXMLDesc() on
source host followed by virDomainDefineXML() on destination host, as
offline migration will run pre-migration hook to update the domain XML
on destination host. Currently, copying non-shared storage is not
supported during offline migration.

Offline migration can be requested with a new migration flag called
VIR_MIGRATE_OFFLINE (which has to be combined with
VIR_MIGRATE_PERSIST_DEST flag).

Remove the obsolete 'qemud' naming prefix and underscore
based type name. Introduce virQEMUDriverPtr as the replacement,
in common with LXC driver naming style

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Switch virDomainObjPtr to use the virObject APIs for reference
counting. The main change is that virObjectUnref does not return
the reference count, merely a bool indicating whether the object
still has any refs left. Checking the return value is also not
mandatory.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c

When a client which started non-p2p migration dies in a bad time, the
source libvirtd never clears the migration job and almost nothing can be
done with the domain without restarting the daemon. This patch makes use
of connection close callbacks and ensures that migration job is properly
discarded when the client disconnects.

Migrating domains with disks using cache != none is unsafe unless the
disk images are stored on coherent clustered filesystem. Thus we forbid
migrating such domains unless VIR_MIGRATE_UNSAFE flags is used.

Explicitly disallow conflicts between domain name from dxml and dname.

Migration is another case of stranding metadata.  And since
snapshot metadata is arbitrarily large, there's no way to
shoehorn it into the migration cookie of migration v3.

This patch consolidates two existing locations for migration
validation into one helper function, then enhances that function
to also do the new checks.  If we could always trust the source
to validate migration, then the destination would not have to
do anything; but since older servers that did not do checking
can migrate to newer destinations, we have to repeat some of
the same checks on the destination; meanwhile, we want to
detect failures as soon as possible.  With migration v2, this
means that validation will reject things at Prepare on the
destination if the XML exposes the problem, otherwise at Perform
on the source; with migration v3, this means that validation
will reject things at Begin on the source, or if the source
is old and the XML exposes the problem, then at Prepare on the
destination.

This patch is necessarily over-strict.  Once a later patch
properly handles auto-cleanup of snapshot metadata on the
death of a transient domain, then the only time we actually
need snapshots to prevent migration is when using the
--undefinesource flag on a persistent source domain.

It is possible to recreate snapshot metadata on the destination
with VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE and
VIR_DOMAIN_SNAPSHOT_CREATE_CURRENT.  But for now, that is limited,
since if we delete the snapshot metadata prior to migration,
then we won't know the name of the current snapshot to pass
along; and if we delete the snapshot metadata after migration
and use the v3 migration cookie to pass along the name of the
current snapshot, then we need a way to bypass the fact that
this patch refuses migration with snapshot metadata present.

So eventually, we may have to introduce migration protocol v4
that allows feature negotiation and an arbitrary number of
handshake exchanges, so as to pass as many rpc calls as needed
to transfer all the snapshot xml hierarchy.

But all of that is thoughts for the future; for now, the best
course of action is to quit early, rather than get into a
funky state of stale metadata; then relax restrictions later.

* src/qemu/qemu_migration.h (qemuMigrationIsAllowed): Make static.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Alter
signature, and allow checks for both outgoing and incoming.
(qemuMigrationBegin, qemuMigrationPrepareAny)
(qemuMigrationPerformJob): Update callers.

In a SELinux or root-squashing NFS environment, libvirt has to go
through some hoops to create a new file that qemu can then open()
by name.  Snapshots are a case where we want to guarantee an empty
file that qemu can open; also, reopening a save file to convert it
from being marked partial to complete requires a reopen to avoid
O_DIRECT headaches.  Refactor some existing code to make it easier
to reuse in later patches.

* src/qemu/qemu_migration.h (qemuMigrationToFile): Drop parameter.
* src/qemu/qemu_migration.c (qemuMigrationToFile): Let cgroup do
the stat, rather than asking caller to do it and pass info down.
* src/qemu/qemu_driver.c (qemuOpenFile): New function, pulled from...
(qemuDomainSaveInternal): ...here.
(doCoreDump, qemuDomainSaveImageOpen): Use it here as well.

Currently, we attempt to run sync job and async job at the same time. It
means that the monitor commands for two jobs can be run in any order.

In the function qemuDomainObjEnterMonitorInternal():
    if (priv->job.active == QEMU_JOB_NONE && priv->job.asyncJob) {
        if (qemuDomainObjBeginNestedJob(driver, obj) < 0)
We check whether the caller is an async job by priv->job.active and
priv->job.asynJob. But when an async job is running, and a sync job is
also running at the time of the check, then priv->job.active is not
QEMU_JOB_NONE. So we cannot check whether the caller is an async job
in the function qemuDomainObjEnterMonitorInternal(), and must instead
put the burden on the caller to tell us when an async command wants
to do a nested job.

Once the burden is on the caller, then only async monitor enters need
to worry about whether the VM is still running; for sync monitor enter,
the internal return is always 0, so lots of ignore_value can be dropped.

* src/qemu/THREADS.txt: Reflect new rules.
* src/qemu/qemu_domain.h (qemuDomainObjEnterMonitorAsync): New
prototype.
* src/qemu/qemu_process.h (qemuProcessStartCPUs)
(qemuProcessStopCPUs): Add parameter.
* src/qemu/qemu_migration.h (qemuMigrationToFile): Likewise.
(qemuMigrationWaitForCompletion): Make static.
* src/qemu/qemu_domain.c (qemuDomainObjEnterMonitorInternal): Add
parameter.
(qemuDomainObjEnterMonitorAsync): New function.
(qemuDomainObjEnterMonitor, qemuDomainObjEnterMonitorWithDriver):
Update callers.
* src/qemu/qemu_driver.c (qemuDomainSaveInternal)
(qemudDomainCoreDump, doCoreDump, processWatchdogEvent)
(qemudDomainSuspend, qemudDomainResume, qemuDomainSaveImageStartVM)
(qemuDomainSnapshotCreateActive, qemuDomainRevertToSnapshot):
Likewise.
* src/qemu/qemu_process.c (qemuProcessStopCPUs)
(qemuProcessFakeReboot, qemuProcessRecoverMigration)
(qemuProcessRecoverJob, qemuProcessStart): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationToFile)
(qemuMigrationWaitForCompletion, qemuMigrationUpdateJobStatus)
(qemuMigrationJobStart, qemuDomainMigrateGraphicsRelocate)
(doNativeMigrate, doTunnelMigrate, qemuMigrationPerformJob)
(qemuMigrationPerformPhase, qemuMigrationFinish)
(qemuMigrationConfirm): Likewise.
* src/qemu/qemu_hotplug.c: Drop unneeded ignore_value.

Make MIGRATION_OUT use the new helper methods.

This also introduces new protection to migration v3 process: the
migration job is held from Begin to Confirm to avoid changes to a domain
during migration (esp. between Begin and Perform phases). This change is
automatically applied to p2p and tunneled migrations. For normal
migration, this requires support from a client. In other words, if an
old (pre 0.9.4) client starts normal migration of a domain, the domain
will not be protected against changes between Begin and Perform steps.

This patch introduces several helper methods to deal with jobs and
phases during migration in a simpler manner.

Commit f548480b broke migration v3 on qemu, because the driver
passed flags on through to qemu_migration even though
qemu_migration wasn't using those flags.

* src/qemu/qemu_migration.h (QEMU_MIGRATION_FLAGS): New define.
* src/qemu/qemu_driver.c: Simplify all migration callbacks.
* src/qemu/qemu_migration.c (qemuMigrationConfirm): Fix regression.