Surprisingly we did not grab a VM job when a block job finished and we'd
happily rewrite the backing chain data. This made it possible to crash
libvirt when queueing two backing chains tightly and other badness.

To fix it, add yet another handler to the helper thread that handles
monitor events that require a job.

Not just the DomainObj's private data.

Depending on the context, either error out if the domain
has disappeared in the meantime, or just ignore the value
to allow marking the function as ATTRIBUTE_RETURN_CHECK.

The domain might disappear during the time in monitor when
the virDomainObjPtr is unlocked, so the caller needs to check
if it's still alive.

Since most of the callers are going to need it, put the
check inside qemuDomainObjExitMonitor and return -1 if
the domain died in the meantime.

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>

When requested in a later patch, the QMP command results are now
examined recursively.  As qemu_driver will eventually have to
read items out of the hash table as stored by this patch, the
computation of backing alias string is done in a shared location.

* src/qemu/qemu_domain.h (qemuDomainStorageAlias): New prototype.
* src/qemu/qemu_domain.c (qemuDomainStorageAlias): Implement it.
* src/qemu/qemu_monitor_json.c
(qemuMonitorJSONGetOneBlockStatsInfo)
(qemuMonitorJSONBlockStatsUpdateCapacityOne): Perform recursion.
(qemuMonitorJSONGetAllBlockStatsInfo)
(qemuMonitorJSONBlockStatsUpdateCapacity): Update callers.
Signed-off-by: NEric Blake <eblake@redhat.com>

Thanks to that we don't need to drag the pointer everywhere and future
code will get cleaner.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Move entering the job into the thread to simplify the program flow. Also
as the code holds a separate reference to the domain object some
conditions can be simplified.

After this patch qemuDomainObjTransferJob is no longer needed so this
patch removes it.

https://bugzilla.redhat.com/show_bug.cgi?id=1160084

As of b6d4dad1 (1.2.5) we are trying to keep the status of FSFreeze
in the guest. Even though I've tried to fixed couple of corner cases
(6ea54769), it occurred to me just recently, that the approach is
broken by design. Firstly, there are many other ways to talk to
qemu-ga (even through libvirt) that filesystems can be thawed (e.g.
qemu-agent-command) without libvirt noticing. Moreover, there are
plenty of ways to thaw filesystems without even qemu-ga noticing (yes,
qemu-ga keeps internal track of FSFreeze status). So, instead of
keeping the track ourselves, or asking qemu-ga for stale state, it's
the best to let qemu-ga deal with that (and possibly let guest kernel
propagate an error).

Moreover, there's one bug with the following approach, if fsfreeze
command failed, we've executed fsthaw subsequently. So issuing
domfsfreeze in virsh gave the following result:

virsh # domfsfreeze gentoo
Froze 1 filesystem(s)

virsh # domfsfreeze gentoo
error: Unable to freeze filesystems
error: internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': The command guest-fsfreeze-freeze has been disabled for this instance

virsh # domfsfreeze gentoo
Froze 1 filesystem(s)

virsh # domfsfreeze gentoo
error: Unable to freeze filesystems
error: internal error: unable to execute QEMU agent command 'guest-fsfreeze-freeze': The command guest-fsfreeze-freeze has been disabled for this instance
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

New qemu added a new event that is emitted when a virtio serial channel
is opened in the guest OS. This allows us to update the state of the
port in the output-only XML element.

This patch implements the monitor callbacks and necessary handlers to
update the state in the definition.

NIC_RX_FILTER_CHANGED is sent by qemu any time a NIC driver in the
guest modified the NIC's RX Filter (for example, if the MAC address of
the NIC is changed by the guest).

This patch doesn't do anything useful with that event; it just sets up
all the plumbing to get news of the event into a worker thread with
all proper locking/reference counting, and provide an easy place to
add in desired functionality.

See src/qemu/EVENTHANDLERS.txt for information/instructions on adding
a libvirt-internal handler for a qemu event (using
NIC_RX_FILTER_CHANGED as an example).

Request erroring out from the backing chain traveller and drop qemu's
internal backing chain integrity tester.

The backing chain traveller reports errors by itself with possibly more
detail than qemuDiskChainCheckBroken ever could.

We also need to make sure that we reconnect to existing qemu instances
even at the cost of losing the backing chain info (this really should be
stored in the XML rather than reloaded from disk, but that needs some
work).

Reuse virStorageSourceIsEmpty and rename "force" argument to
"force_probe".

Mimic the "Disk" processing for 'rawio', but for a scsi_host hostdev
lun device.

Add new 'niothreadpids' and 'iothreadpids' to mimic the 'ncpupids' and
'vcpupids' that already exist.

Total time of a migration and total downtime transfered from a source to
a destination host do not count with the transfer time to the
destination host and with the time elapsed before guest CPUs are
resumed. Thus, source libvirtd remembers when migration started and when
guest CPUs were paused. Both timestamps are transferred to destination
libvirtd which uses them to compute total migration time and total
downtime. Obviously, this requires the time to be synchronized between
the two hosts. The reported times are useless otherwise but they would
be equally useless if we didn't do this recomputation so don't lose
anything by doing it.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

virDomainGetJobStats gains new VIR_DOMAIN_JOB_STATS_COMPLETED flag that
can be used to fetch statistics of a completed job rather than a
currently running job.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Job statistics data were tracked in several structures and variables.
Let's make a new qemuDomainJobInfo structure which can be used as a
single source of statistics data as a preparation for storing data about
completed a job.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Be consistent with naming of private defines. Also line up code
correctly in few places where the macro is used.

During a QEMU live migration several warning messages about job
handling could be written to syslog on the destination host:

"entering monitor without asking for a nested job is dangerous"

The messages are written because the job handling during migration
uses hard coded asyncJob values in several places that are incorrect.

This patch passes the required asyncJob value around and prevents
the warnings as well as any issues that the warnings may be referring
to.

https://bugzilla.redhat.com/show_bug.cgi?id=1130089Signed-off-by: NSam Bobroff <sam.bobroff@au1.ibm.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Add a wrapper that determines the correct uid and gid for a certain
storage file and domain.

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>

Just code movement and rename.

In "src/conf/domain_conf.h" there are many enum declarations. The
cleanup in this header filer was started, but it wasn't enough and
there are many other files that has enum variables declared. So, the
commit was starting to be big. This commit finish the cleanup in this
header file and in other files that has enum variables, parameters,
or functions declared.
Signed-off-by: NJulio Faracco <jcfaracco@gmail.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Currently, we don not acquire any job when removing a device after
DEVICE_DELETED event was received from QEMU. This means that if there is
another API running at the time DEVICE_DELETED is delivered and the API
acquired a job, we may happily change the definition of the domain the
API is working with whenever it unlocks the domain object (e.g., to talk
with its monitor). That said, we have to acquire a job before finishing
device removal to make things safe. However, doing so in the main event
loop would cause a deadlock so we need to move most of the event handler
into a separate thread.

Another good reason for both acquiring a job and handling the event in a
separate thread is that we currently remove a device backend immediately
after removing its frontend while we should only remove the backend once
we already received DEVICE_DELETED event. That is, we will have to talk
to QEMU monitor from the event handler.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

It's only used within qemu_domain.c.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Introduce new files (domain_addr.[ch]) to provide
an API for domain device handling that could be
shared across the drivers.

A list of data types were extracted and moved there:

 qemuDomainPCIAddressBus -> virDomainPCIAddressBus
 qemuDomainPCIAddressBusPtr -> virDomainPCIAddressBusPtr
 _qemuDomainPCIAddressSet -> virDomainPCIAddressSet
 qemuDomainPCIAddressSetPtr -> virDomainPCIAddressSetPtr
 qemuDomainPCIConnectFlags -> virDomainPCIConnectFlags

Also, move the related definitions and macros.

Adds 'quiesced' status into qemuDomainObjPrivate that tracks whether
FSFreeze is requested in the domain.

It modifies error code from qemuDomainSnapshotFSFreeze and
qemuDomainSnapshotFSThaw, so that a caller can know whether the command is
actually sent to the guest agent. If the error is caused before sending a
freeze command, a counterpart thaw command shouldn't be sent either, not to
confuse fsfreeze status tracking.
Signed-off-by: NTomoki Sekiyama <tomoki.sekiyama@hds.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

The function isn't used in any other source file. Move it so that it
doesn't need a declaration.

Eliminate all the code re-use which checks for priv->agentError or
priv->agent.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Currently, there's just one place where we care if hook script is
changing the domain XML: migration hook for incoming migration. In
all other places where a hook script is executed, we don't read the
XML back from the script.

Anyway, the hook script can alter domain XML and hence we should taint
it if the script did.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The code took into account only the global permissions. The domains now
support per-vm DAC labels and per-image DAC labels. Use the most
specific label available.

Couple of codepaths shared the same code which can be moved out to a
function and on one of such places, qemuMigrationConfirmPhase(), the
domain was resumed even if it wasn't running before the migration
started.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1057407Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

The virDomainEvent class is kept as it indicates what meta informations
are valid for the children classes. This may be useful in the future.

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>

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>

This function is to guess the correct limit for maximal memory
usage by qemu for given domain. This can never be guessed
correctly, not to mention all the pains and sleepless nights this
code has caused. Once somebody discovers algorithm to solve the
Halting Problem, we can compute the limit algorithmically. But
till then, this code should never see the light of the release
again.

*src/util/virstoragefile.c: Add a helper function to get
the first name of missing backing files, if the name is NULL,
it means the diskchain is not broken.
*src/qemu/qemu_domain.c: qemuDiskChainCheckBroken(disk) to
check if its chain is broken

In case libvirtd is asked to unplug a device but the device is actually
unplugged later when libvirtd is not running, we need to detect that and
remove such device when libvirtd starts again and reconnects to running
domains.