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.
As reported by Daniel Berrangé, we have a huge performance regression
for virDomainGetInfo() due to the change which makes virDomainEndJob()
save the XML status file every time it is called. Previous to that
change, 2000 calls to virDomainGetInfo() took ~2.5 seconds. After that
change, 2000 calls to virDomainGetInfo() take 2 *minutes* 45 secs.
We made the change to be able to recover from libvirtd restart in the
middle of a job. However, only destroy and async jobs are taken care of.
Thus it makes more sense to only save domain state XML when these jobs
are started/stopped.
Offline internal snapshots can be rolled back with just a little
bit of refactoring, meaning that we are now automatically atomic.
* src/qemu/qemu_domain.c (qemuDomainSnapshotForEachQcow2): Move
guts...
(qemuDomainSnapshotForEachQcow2Raw): ...to new helper, to allow
rollbacks.
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.
With current code, we pass true iff domain is cold booting. However,
if disk is inaccessible and startupPolicy for that disk is set to
'requisite' we have to fail iff cold booting.
When host-model and host-passthrouh CPU modes were introduced, qemu
driver was properly modify to update guest CPU definition during
migration so that we use the right CPU at the destination. However,
similar treatment is needed for (managed)save and snapshots since they
need to save the exact CPU so that a domain can be properly restored.
To avoid repetition of such situation, all places that need live XML
share the code which generates it.
As a side effect, this patch fixes error reporting from
qemuDomainSnapshotWriteMetadata().
This patch fixes console corruption, that happens if two concurrent
sessions are opened for a single console on a domain. Result of this
corruption was that each of the console streams recieved just a part
of the data written to the pipe so every console rendered unusable.
New helper function for safe console handling is used to establish the
console stream connection. This function ensures that no other libvirt
client is using the console (with the ability to disconnect consoles of
libvirt clients) and that no UUCP style lockfile is placed on the PTY
device.
* src/qemu/qemu_domain.h
- add data structure to domain's private data dealing with
console connections
* src/qemu/qemu_domain.c:
- allocate/free domain's console data structure
* src/qemu/qemu_driver.c
- use the new helper function for console handling
Fix my typo at
commit 74e034964c32edb1732d0ff7642f3977f3587d72
"disk->rawio == -1" indicates that this value is not
specified. So in case of this, domain must not
be tainted.
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
This patch revises qemuProcessStart() function for qemu
processes to retain CAP_SYS_RAWIO if needed.
And in case of that, add taint flag to domain.
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Shota Hirae <m11g1401@hibikino.ne.jp>
There is now a standard QEMU guest agent that can be installed
and given a virtio serial channel
<channel type='unix'>
<source mode='bind' path='/var/lib/libvirt/qemu/f16x86_64.agent'/>
<target type='virtio' name='org.qemu.guest_agent.0'/>
</channel>
The protocol that runs over the guest agent is JSON based and
very similar to the JSON monitor. We can't use exactly the same
code because there are some odd differences in the way messages
and errors are structured. The qemu_agent.c file is based on
a combination and simplification of qemu_monitor.c and
qemu_monitor_json.c
* src/qemu/qemu_agent.c, src/qemu/qemu_agent.h: Support for
talking to the agent for shutdown
* src/qemu/qemu_domain.c, src/qemu/qemu_domain.h: Add thread
helpers for talking to the agent
* src/qemu/qemu_process.c: Connect to agent whenever starting
a guest
* src/qemu/qemu_monitor_json.c: Make variable static
There are several reasons for doing this:
- the CPU specification is out of libvirt's control so we cannot
guarantee stable guest ABI
- not every feature of a CPU may actually work as expected when
advertised directly to a guest
- migration between two machines with exactly the same CPU may work but
no guarantees can be made
- this mode is not supported and its use is at one's own risk
VIR_DOMAIN_XML_UPDATE_CPU flag for virDomainGetXMLDesc may be used to
get updated custom mode guest CPU definition in case it depends on host
CPU. This patch implements the same behavior for host-model and
host-passthrough CPU modes.
This fixes https://bugzilla.redhat.com/show_bug.cgi?id=638633
Although scripts are not used by interfaces of type other than
"ethernet" in qemu, due to the fact that the parser stores the script
name in a union that is only valid when type is ethernet or bridge,
there is no way for anyone except the parser itself to catch the
problem of specifying an interface script for an inappropriate
interface type (by the time the parsed data gets back to the code that
called the parser, all evidence that a script was specified is
forgotten).
Since the parser itself should be agnostic to which type of interface
allows scripts (an example of why: a script specified for an interface
of type bridge is valid for xen domains, but not for qemu domains),
the solution here is to move the script out of the union(s) in the
DomainNetDef, always populate it when specified (regardless of
interface type), and let the driver decide whether or not it is
appropriate.
Currently the qemu, xen, libxml, and uml drivers recognize the script
parameter and do something with it (the uml driver only to report that
it isn't supported). Those drivers have been updated to log a
CONFIG_UNSUPPORTED error when a script is specified for an interface
type that's inappropriate for that particular hypervisor.
(NB: There was earlier discussion of solving this problem by adding a
VALIDATE flag to all libvirt APIs that accept XML, which would cause
the XML to be validated against the RNG files. One statement during
that discussion was that the RNG shouldn't contain hypervisor-specific
things, though, and a proper solution to this problem would require
that (again, because a script for an interface of type "bridge" is
accepted by xen, but not by qemu).
Currently all drivers using domain events need to provide a callback
for handling a timer to dispatch events in a clean stack. There is
no technical reason for dispatch to go via driver specific code. It
could trivially be dispatched directly from the domain event code,
thus removing tedious boilerplate code from all drivers
Also fix the libxl & xen drivers to pass 'true' when creating the
virDomainEventState, since they run inside the daemon & thus always
expect events to be present.
* src/conf/domain_event.c, src/conf/domain_event.h: Internalize
dispatch of events from timer callback
* src/libxl/libxl_driver.c, src/lxc/lxc_driver.c,
src/qemu/qemu_domain.c, src/qemu/qemu_driver.c,
src/remote/remote_driver.c, src/test/test_driver.c,
src/uml/uml_driver.c, src/vbox/vbox_tmpl.c,
src/xen/xen_driver.c: Remove all timer dispatch functions
The virTimestamp and virTimeMs functions in src/util/util.h
duplicate functionality from virtime.h, in a non-async signal
safe manner. Remove them, and convert all code over to the new
APIs.
* src/util/util.c, src/util/util.h: Delete virTimeMs and virTimestamp
* src/lxc/lxc_driver.c, src/qemu/qemu_domain.c,
src/qemu/qemu_driver.c, src/qemu/qemu_migration.c,
src/qemu/qemu_process.c, src/util/event_poll.c: Convert to use
virtime APIs
If something fails while initializing qemu job object in
qemuDomainObjPrivateAlloc(), memory to the private pointer is freed, but
after that, the pointer is still dereferenced, which may result in a
segfault.
* qemuDomainObjPrivateAlloc() - Don't dereference NULL pointer.
All constants related to events should have a prefix of
VIR_DOMAIN_EVENT_
* include/libvirt/libvirt.h.in, src/qemu/qemu_domain.c:
Rename VIR_DOMAIN_DISK_CHANGE_MISSING_ON_START to
VIR_DOMAIN_EVENT_DISK_CHANGE_MISSING_ON_START
If a disk source gets dropped because it is not accessible,
mgmt application might want to be informed about this. Therefore
we need to emit an event. The event presented in this patch
is however a bit superset of what written above. The reason is simple:
an intention to be easily expanded, e.g. on 'user ejected disk
in guest' events. Therefore, callback gets source string and disk alias
(which should be unique among a domain) and reason (an integer);
This patch implements on_missing feature in qemu driver.
Upon qemu startup process an accessibility of CDROMs
and floppy disks is checked. The source might get dropped
if unavailable and on_missing is set accordingly.
No event is emit thought. Look for follow up patch.
The XML parser for the qemu specific extensions expects the qemu name-space
to be bound to the 'qemu' prefix. This is too strict, since the name of the
name-space-prefix is only meant as an internal lookup key. Only the associated
URI is relevant.
<domain>...
<qemu:commandline xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0">
...</qemu:commandline>
</domain>
<domain xmlns:ns0="http://libvirt.org/schemas/domain/qemu/1.0">...
<ns0:commandline>
...</ns0:commandline>
</domain>
<domain xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0">
<qemu:commandline xmlns:qemu="urn:foo">
...</qemu:commandline>
</domain>
Remove the test for checking the name-space binding on the top-level <domain>
element. Registering the name-space with XPath is enough.
Signed-off-by: Philipp Hahn <hahn@univention.de>
Once we know which set of disks belong to a snapshot, reverting or
deleting that snapshot should visit just those disks, rather than
also visiting disks that were hot-plugged in the meantime or
skipping disks that were hot-unplugged in the meantime.
* src/qemu/qemu_domain.c (qemuDomainSnapshotForEachQcow2): Use
snapshot domain details when available. Avoid NULL deref.
Destination libvirtd remembers the original name in the prepare phase
and clears it in the finish phase. The original name is used when
comparing domain name in migration cookie.
Currently, qemuDomainGetXMLDesc and qemudDomainGetInfo check for
outstanding synchronous job before (eventual) monitor entering.
However, there can be already async job set, e.g. migration.
The previous patch removed all snapshots, but not the directory
where the snapshots lived, which is still a form of stale data.
* src/qemu/qemu_domain.c (qemuDomainRemoveInactive): Wipe any
snapshot directory.
This patch is mostly code motion - moving some functions out
of qemu_driver and into qemu_domain so they can be reused by
multiple qemu_* files (since qemu_driver.h must not grow).
It also adds a new helper function, qemuDomainRemoveInactive,
which will be used in the next patch.
* src/qemu/qemu_domain.h (qemuFindQemuImgBinary)
(qemuDomainSnapshotWriteMetadata, qemuDomainSnapshotForEachQcow2)
(qemuDomainSnapshotDiscard, qemuDomainSnapshotDiscardAll)
(qemuDomainRemoveInactive): New prototypes.
(struct qemu_snap_remove): New struct.
* src/qemu/qemu_domain.c (qemuDomainRemoveInactive)
(qemuDomainSnapshotDiscardAllMetadata): New functions.
(qemuFindQemuImgBinary, qemuDomainSnapshotWriteMetadata)
(qemuDomainSnapshotForEachQcow2, qemuDomainSnapshotDiscard)
(qemuDomainSnapshotDiscardAll): Move here...
* src/qemu/qemu_driver.c (qemuFindQemuImgBinary)
(qemuDomainSnapshotWriteMetadata, qemuDomainSnapshotForEachQcow2)
(qemuDomainSnapshotDiscard, qemuDomainSnapshotDiscardAll): ...from
here.
(qemuDomainUndefineFlags): Update caller.
* src/conf/domain_conf.c (virDomainRemoveInactive): Doc fixes.
The maximum bandwidth that can be consumed when migrating a domain
is better classified as an operational vs configuration parameter of
the dommain. As such, store this parameter in qemuDomainObjPrivate
structure.
This patch creates an optional BeginJob queue size limit. When
active, all other attempts above level will fail. To set this
feature assign desired value to max_queued variable in qemu.conf.
Setting it to 0 turns it off.
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.
qemuMigrationUpdateJobStatus (called in a loop by migration
and save tasks) uses qemuDomainObjEnterMonitorWithDriver;
however, that function ended up starting a nested job without
releasing the driver.
Since no one else is making nested calls, we can inline the
internal functions to properly track driver_locked.
* src/qemu/qemu_domain.h (qemuDomainObjBeginNestedJob)
(qemuDomainObjBeginNestedJobWithDriver)
(qemuDomainObjEndNestedJob): Drop unused prototypes.
* src/qemu/qemu_domain.c (qemuDomainObjEnterMonitorInternal):
Reflect driver lock to nested job.
(qemuDomainObjBeginNestedJob)
(qemuDomainObjBeginNestedJobWithDriver)
(qemuDomainObjEndNestedJob): Drop unused functions.
Asynchronous jobs may take long time to finish and may consist of
several phases which we need to now about to help with recovery/rollback
after libvirtd restarts.
Query commands are safe to be called during long running jobs (such as
migration). This patch makes them all work without the need to
special-case every single one of them.
The patch introduces new job.asyncCond condition and associated
job.asyncJob which are dedicated to asynchronous (from qemu monitor
point of view) jobs that can take arbitrarily long time to finish while
qemu monitor is still usable for other commands.
The existing job.active (and job.cond condition) is used all other
synchronous jobs (including the commands run during async job).
Locking schema is changed to use these two conditions. While asyncJob is
active, only allowed set of synchronous jobs is allowed (the set can be
different according to a particular asyncJob) so any method that
communicates to qemu monitor needs to check if it is allowed to be
executed during current asyncJob (if any). Once the check passes, the
method needs to normally acquire job.cond to ensure no other command is
running. Since domain object lock is released during that time, asyncJob
could have been started in the meantime so the method needs to recheck
the first condition. Then, normal jobs set job.active and asynchronous
jobs set job.asyncJob and optionally change the list of allowed job
groups.
Since asynchronous jobs only set job.asyncJob, other allowed commands
can still be run when domain object is unlocked (when communicating to
remote libvirtd or sleeping). To protect its own internal synchronous
commands, the asynchronous job needs to start a special nested job
before entering qemu monitor. The nested job doesn't check asyncJob, it
only acquires job.cond and sets job.active to block other jobs.
EnterMonitor and ExitMonitor methods are very similar to their
*WithDriver variants; consolidate them into EnterMonitorInternal and
ExitMonitorInternal to avoid (mainly future) code duplication.
