For now, disk migration via block copy job is not implemented in
libvirt.  But when we do implement it, we have to deal with the
fact that qemu does not yet provide an easy way to re-start a qemu
process with mirroring still intact.  Paolo has proposed an idea
for a persistent dirty bitmap that might make this possible, but
until that design is complete, it's hard to say what changes
libvirt would need.  Even something like 'virDomainSave' becomes
hairy, if you realize the implications that 'virDomainRestore'
would be stuck with recreating the same mirror layout.

But if we step back and look at the bigger picture, we realize that
the initial client of live storage migration via disk mirroring is
oVirt, which always uses transient domains, and that if a transient
domain is destroyed while a mirror exists, oVirt can easily restart
the storage migration by creating a new domain that visits just the
source storage, with no loss in data.

We can make life a lot easier by being cowards for now, forbidding
certain operations on a domain.  This patch guarantees that we
never get in a state where we would have to restart a domain with
a mirroring block copy, by preventing saves, snapshots, migration,
hot unplug of a disk in use, and conversion to a persistent domain
(thankfully, it is still relatively easy to 'virsh undefine' a
running domain to temporarily make it transient, run tests on
'virsh blockcopy', then 'virsh define' to restore the persistence).
Later, if the qemu design is enhanced, we can relax our code.

The change to qemudDomainDefine looks a bit odd for undoing an
assignment, rather than probing up front to avoid the assignment,
but this is because of how virDomainAssignDef combines both a
lookup and assignment into a single function call.

* src/conf/domain_conf.h (virDomainHasDiskMirror): New prototype.
* src/conf/domain_conf.c (virDomainHasDiskMirror): New function.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/qemu/qemu_driver.c (qemuDomainSaveInternal)
(qemuDomainSnapshotCreateXML, qemuDomainRevertToSnapshot)
(qemuDomainBlockJobImpl, qemudDomainDefine): Prevent dangerous
actions while block copy is already in action.
* src/qemu/qemu_hotplug.c (qemuDomainDetachDiskDevice): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Likewise.

Transport Open vSwitch per-port data during live
migration by using the utility functions
virNetDevOpenvswitchGetMigrateData() and
virNetDevOpenvswitchSetMigrateData().
Signed-off-by: NKyle Mestery <kmestery@cisco.com>

Add the ability for the Qemu V3 migration protocol to
include transporting network configuration. A generic
framework is proposed with this patch to allow for the
transfer of opaque data.
Signed-off-by: NKyle Mestery <kmestery@cisco.com>
Signed-off-by: NLaine Stump <laine@laine.org>

Having hostuuid in migration cookie is a nice bonus since it provides an
easy way of detecting migration to the same host. However, requiring it
breaks backward compatibility with older libvirt releases.

Recently, patches were added support for (managed)saving, restoring, and
migrating domains with host USB devices. However, qemu driver would
still forbid migration of such domains because qemuMigrationIsAllowed
was not updated.

When p2p migration fails early because qemuMigrationIsAllowed or
qemuMigrationIsSafe say migration should be cancelled, we fail to clear
the migration-out async job. As a result of that, further APIs called
for the same domain may fail with Timed out during operation: cannot
acquire state change lock.

Reported by Guido Winkelmann.

Save/restore with passed through USB devices currently only works if the
USB device can be found at the same USB address where it used to be
before saving a domain. This makes sense in case a user explicitly
configure the USB address in domain XML. However, if the device was
found automatically by vendor/product identification, we should try to
search for that device when restoring the domain and use any device we
find as long as there is only one available. In other words, the USB
device can now be removed and plugged again or the host can be rebooted
between saving and restoring the domain.

Using VIR_DOMAIN_XML_MIGRATABLE flag, one can request domain's XML
configuration that is suitable for migration or save/restore. Such XML
may contain extra run-time stuff internal to libvirt and some default
configuration may be removed for better compatibility of the XML with
older libvirt releases.

This flag may serve as an easy way to get the XML that can be passed
(after desired modifications) to APIs that accept custom XMLs, such as
virDomainMigrate{,ToURI}2 or virDomainSaveFlags.

Recently, there have been some improvements made to qemu so it
supports seamless migration or something very close to it.
However, it requires libvirt interaction. Once qemu is migrated,
the SPICE server needs to send its internal state to the destination.
Once it's done, it fires SPICE_MIGRATE_COMPLETED event and this
fact is advertised in 'query-spice' output as well.
We must not kill qemu until SPICE server finishes the transfer.

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/

The current qemu capabilities are stored in a virBitmapPtr
object, whose type is exposed to callers. We want to store
more data besides just the flags, so we need to move to a
struct type. This object will also need to be reference
counted, since we'll be maintaining a cache of data per
binary. This change introduces a 'qemuCapsPtr' virObject
class. Most of the change is just renaming types and
variables in all the callers
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

We were failing to react to allocation failure when initializing
a snapshot object list.  Changing things to store a pointer
instead of a complete object adds one more possible point of
allocation failure, but at the same time, will make it easier to
react to failure now, as well as making it easier for a future
patch to split all virDomainSnapshotPtr handling into a separate
file, as I continue to add even more snapshot code.

Luckily, there was only one client outside of domain_conf.c that
was actually peeking inside the object, and a new wrapper function
was easy.

* src/conf/domain_conf.h (_virDomainObj): Use a pointer.
(virDomainSnapshotObjListInit): Rename.
(virDomainSnapshotObjListFree, virDomainSnapshotForEach): New
declarations.
(_virDomainSnapshotObjList): Move definitions...
* src/conf/domain_conf.c: ...here.
(virDomainSnapshotObjListInit, virDomainSnapshotObjListDeinit):
Rename...
(virDomainSnapshotObjListNew, virDomainSnapshotObjListFree): ...to
these.
(virDomainSnapshotForEach): New function.
(virDomainObjDispose, virDomainListPopulate): Adjust callers.
* src/qemu/qemu_domain.c (qemuDomainSnapshotDiscard)
(qemuDomainSnapshotDiscardAllMetadata): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotLoad)
(qemuDomainUndefineFlags, qemuDomainSnapshotCreateXML)
(qemuDomainSnapshotListNames, qemuDomainSnapshotNum)
(qemuDomainListAllSnapshots)
(qemuDomainSnapshotListChildrenNames)
(qemuDomainSnapshotNumChildren)
(qemuDomainSnapshotListAllChildren)
(qemuDomainSnapshotLookupByName, qemuDomainSnapshotGetParent)
(qemuDomainSnapshotGetXMLDesc, qemuDomainSnapshotIsCurrent)
(qemuDomainSnapshotHasMetadata, qemuDomainRevertToSnapshot)
(qemuDomainSnapshotDelete): Likewise.
* src/libvirt_private.syms (domain_conf.h): Export new function.

When entering "confirm" phase, we are interested in the value of
cancelled rather then ret variable which was interesting before "finish"
phase and didn't change since then.

Previously, qemu did not respond to monitor commands during migration if
the limit was too high. This prevented us from raising the limit
earlier. The qemu issue seems to be fixed (according to my testing) and
we may remove the 32Mb/s limit.

Make virSocket use the virObject APIs for reference counting
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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>

This converts the following public API datatypes to use the
virObject infrastructure:

  virConnectPtr
  virDomainPtr
  virDomainSnapshotPtr
  virInterfacePtr
  virNetworkPtr
  virNodeDevicePtr
  virNWFilterPtr
  virSecretPtr
  virStreamPtr
  virStorageVolPtr
  virStoragePoolPtr

The code is significantly simplified, since the mutex in the
virConnectPtr object now only needs to be held when accessing
the per-connection virError object instance. All other operations
are completely lock free.

* src/datatypes.c, src/datatypes.h, src/libvirt.c: Convert
  public datatypes to use virObject
* src/conf/domain_event.c, src/phyp/phyp_driver.c,
  src/qemu/qemu_command.c, src/qemu/qemu_migration.c,
  src/qemu/qemu_process.c, src/storage/storage_driver.c,
  src/vbox/vbox_tmpl.c, src/xen/xend_internal.c,
  tests/qemuxml2argvtest.c, tests/qemuxmlnstest.c,
  tests/sexpr2xmltest.c, tests/xmconfigtest.c: Convert
  to use virObjectUnref/virObjectRef
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

Update the QEMU driver to use virReportError instead of
the qemuReportError custom macro
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch cleans up some missing "%s" before translation macros,
for strings which are const without format specifiers

Introduce new members in the virMacAddr 'class'
- virMacAddrSet: set virMacAddr from a virMacAddr
- virMacAddrSetRaw: setting virMacAddr from raw 6 byte MAC address buffer
- virMacAddrGetRaw: writing virMacAddr into raw 6 byte MAC address buffer
- virMacAddrCmp: comparing two virMacAddr
- virMacAddrCmpRaw: comparing a virMacAddr with a raw 6 byte MAC address buffer

then replace raw MAC addresses by replacing

- 'unsigned char *' with virMacAddrPtr
- 'unsigned char ... [VIR_MAC_BUFLEN]' with virMacAddr

and introduce usage of above functions where necessary.

QEMU (and librbd) flush the cache on the source before the
destination starts, and the destination does not read any
changeable data before that, so live migration with rbd caching
is safe.

This makes 'virsh migrate' work with rbd and caching without the
--unsafe flag.
Reported-by: NVladimir Bashkirtsev <vladimir@bashkirtsev.com>
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

Now that domain listing is a thin wrapper around child listing,
it's easier to have a common entry point.  This restores the
hashForEach optimization lost in the previous patch when there
are no snapshots being filtered out of the entire list.

* src/conf/domain_conf.h (virDomainSnapshotObjListGetNames)
(virDomainSnapshotObjListNum): Add parameter.
(virDomainSnapshotObjListGetNamesFrom)
(virDomainSnapshotObjListNumFrom): Delete.
* src/libvirt_private.syms (domain_conf.h): Drop deleted functions.
* src/conf/domain_conf.c (virDomainSnapshotObjListGetNames):
Merge, and (re)add an optimization.
* src/qemu/qemu_driver.c (qemuDomainUndefineFlags)
(qemuDomainSnapshotListNames, qemuDomainSnapshotNum)
(qemuDomainSnapshotListChildrenNames)
(qemuDomainSnapshotNumChildren): Update callers.
* src/qemu/qemu_migration.c (qemuMigrationIsAllowed): Likewise.
* src/conf/virdomainlist.c (virDomainListPopulate): Likewise.

Currently, we are passing only one boolean (migrated) so there is
no real profit in this. But it creates starting position for
next patch.

otherwise migration fails for e.g. network filesystems like sheepdog
with:

   error: Invalid relative path 'virt-name': Invalid argument

while we should fail with:

    Migration may lead to data corruption if disks use cache != none

References:

    http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=676328
    https://www.redhat.com/archives/libvirt-users/2012-May/msg00088.html

If we migrate to fd, spec->fwdType is not MIGRATION_FWD_DIRECT,
we will close spec->dest.fd.local in qemuMigrationRun(). So we
should set spec->dest.fd.local to -1 in qemuMigrationRun().

Bug present since 0.9.5 (commit 32617617).

When we added the default USB controller into domain XML, we efficiently
broke migration to older versions of libvirt that didn't support USB
controllers at all (0.9.4 and earlier) even for domains that don't use
anything that the older libvirt can't provide. We still want to present
the default USB controller in any XML seen by a user/app but we can
safely remove it from the domain XML used during migration. If we are
migrating to a new enough libvirt, it will add the controller XML back,
while older libvirt won't be confused with it although it will still
tell qemu to create the controller.

Similar approach can be used in the future whenever we find out we
always enabled some kind of device without properly advertising it in
domain XML.

Always use appropriate qemuDomain{,Def}Format wrapper since it may do
some additional magic based on the flags.

Once qemu monitor reports migration has completed, we just closed our
end of the pipe and let migration tunnel die. This generated bogus error
in case we did so before the thread saw EOF on the pipe and migration
was aborted even though it was in fact successful.

With this patch we first wake up the tunnel thread and once it has read
all data from the pipe and finished the stream we close the
filedescriptor.

A small additional bonus of this patch is that real errors reported
inside qemuMigrationIOFunc are not overwritten by virStreamAbort any
more.

When QEMU reported failed or canceled migration, we correctly detected
it but didn't really consider it as an error condition and migration
protocol just went on. Luckily, some of the subsequent steps eventually
failed end we reported an (unrelated and mostly random) error back to
the caller.

In some cases (spotted with broken connection during tunneled migration)
we were overwriting the original error with worse or even misleading
errors generated when we were cleaning up after failed migration.

Currently, we have 3 boolean arguments we have to pass
to qemuProcessStart(). As libvirt grows it is harder and harder
to remember them and their position. Therefore we should
switch to flags instead.

This patch adds a netlink callback when migrating a VEPA enabled
virtual machine.  It fixes a Bug where a VM would not request a port
association when it was cleared by lldpad.

This patch requires the latest git version of lldpad to work.
Signed-off-by: ND. Herrendoerfer <d.herrendoerfer@herrendoerfer.name>

In case an API fails with "cannot acquire state change lock", searching
for the API that possibly forgot to end its job is not always easy.
Let's keep track of the job owner and print it out for easier
identification.

The code is splattered with a mix of

  sizeof foo
  sizeof (foo)
  sizeof(foo)

Standardize on sizeof(foo) and add a syntax check rule to
enforce it
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

In the current V3 migration protocol, Libvirt does not
check the result of the function

  qemuMigrationVPAssociatePortProfiles

This means that it is possible for a migration to complete
successfully even when the VM loses network connectivity on
the destination host.

With this change libvirt aborts the migration
(during the "finish" step) when the above function fails, that
is to say when at least one of the port profile associations fails.

Signed-off by: Christian Benvenuti <benve@cisco.com>

Move error reporting out of the callers, into virURIParse
and virURIFormat, to get consistency.

* include/libvirt/virterror.h, src/util/virterror.c: Add VIR_FROM_URI
* src/util/viruri.c, src/util/viruri.h: Add error reporting
* src/esx/esx_driver.c, src/libvirt.c, src/libxl/libxl_driver.c,
  src/lxc/lxc_driver.c, src/openvz/openvz_driver.c,
  src/qemu/qemu_driver.c, src/qemu/qemu_migration.c,
  src/remote/remote_driver.c, src/uml/uml_driver.c,
  src/vbox/vbox_tmpl.c, src/vmx/vmx.c, src/xen/xen_driver.c,
  src/xen/xend_internal.c, tests/viruritest.c: Remove error
  reporting
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Since we defined a custom virURIPtr type, we should use a
virURIFree method instead of assuming it will always be
a typedef for xmlURIPtr

* src/util/viruri.c, src/util/viruri.h, src/libvirt_private.syms:
  Add a virURIFree method
* src/datatypes.c, src/esx/esx_driver.c, src/libvirt.c,
  src/qemu/qemu_migration.c, src/vmx/vmx.c, src/xen/xend_internal.c,
  tests/viruritest.c: s/xmlFreeURI/virURIFree/
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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.

Destination daemon should not rely on the client or source daemon
(depending on the type of migration) to call Finish when migration
fails, because the client may crash before it can do so. The domain
prepared for incoming migration is set to be destroyed (and migration
job cleaned up) when connection with the client closes but this is not
enough. If the associated qemu process crashes after Prepare step and
the domain is cleaned up before the connection gets closed, autodestroy
is not called for the domain and migration jobs remains set. In case the
domain is defined on destination host (i.e., it is not completely
removed once destroyed) we keep the job set for ever. To fix this, we
register a cleanup callback which is responsible to clean migration-in
job when a domain dies anywhere between Prepare and Finish steps. Note
that we can't blindly clean any job when spotting EOF on monitor since
normally an API is running at that time.