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.

Instead of returning a CPUs list, numad returns NUMA node
list instead, this patch is to convert the node list to
cpumap before affinity setting. Otherwise, the domain
processes will be pinned only to CPU[$numa_cell_num],
which will cause significiant performance losses.

Also because numad will balance the affinity dynamically,
reflecting the cpuset from numad back doesn't make much
sense then, and it may just could produce confusion for
the users. Thus the better way is not to reflect it back
to XML. And in this case, it's better to ignore the cpuset
when parsing XML.

The codes to update the cpuset is removed in this patch
incidentally, and there will be a follow up patch to ignore
the manually specified "cpuset" if "placement" is "auto",
and document will be updated too.

If placement mode is AUTO, on some return paths char *cpumap or
char *nodeset are leaked.

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>

If dynamic_ownership is off and we are creating a file on NFS
we force chown. This will fail as chown/chmod are not supported
on NFS. However, with no dynamic_ownership we are not required
to do any chown.

In my testing, I was able to provoke an odd block pull failure:

$ virsh blockpull dom vda --bandwidth 10000
error: Requested operation is not valid: No active operation on device: drive-virtio-disk0

merely by using gdb to artifically wait to do the block job set speed
until after the pull had already finished.  But in reality, that should
be a success, since the pull finished before we had a chance to set
speed.  Furthermore, using a double job lock is not only annoying, but
a bug in itself - if you do parallel virDomainBlockRebase, and hit
the race window just right, the first call grabs the VM job to start
a fast block job, then the second call grabs the VM job to start
a long-running job with unspecified speed, then the first call finally
regrabs the VM job and sets the speed, which ends up running the
second job under the speed from the first call.  By consolidating
things into a single job, we avoid opening that race, as well as reduce
the time between starting the job and changing the speed, for less
likelihood of the speed change happening after block job completion
in the first place.

* src/qemu/qemu_monitor.h (BLOCK_JOB_CMD): Add new mode.
* src/qemu/qemu_driver.c (qemuDomainBlockRebase): Move secondary
job call...
(qemuDomainBlockJobImpl): ...here, for fewer locks.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Change
return value on new internal mode.

Without the VIR_DOMAIN_BLOCK_JOB_ABORT_ASYNC flag, libvirt will internally
poll using qemu's "query-block-jobs" API and will not return until the
operation has been completed.  API users are advised that this operation
is unbounded and further interaction with the domain during this period
may block.  Future patches may refactor things to allow other queries in
parallel with this polling.  For older qemu, we synthesize the cancellation
event, since qemu won't generate it.

The choice of polling duration copies from the code in qemu_migration.c.
Signed-off-by: NAdam Litke <agl@us.ibm.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Probably in the noise, but this will let us scale more efficiently
as we learn to recognize even more qemu events.

* src/qemu/qemu_monitor_json.c (eventHandlers): Sort.
(qemuMonitorEventCompare): New helper function.
(qemuMonitorJSONIOProcessEvent): Optimize event lookup.

RHEL 6.2 was released with an early version of block jobs, which only
worked on the qed file format, where the commands were spelled with
underscore (contrary to QMP style), and where 'block_job_cancel' was
synchronous and did not trigger an event.

The upcoming qemu 1.1 release has fixed these short-comings [1][2]:
the commands now work on multiple file types, are spelled with dash,
and 'block-job-cancel' is asynchronous and emits an event upon conclusion.

[1]qemu commit 370521a1d6f5537ea7271c119f3fbb7b0fa57063
[2]https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg01248.html

This patch recognizes the new spellings, and fixes virDomainBlockRebase
to give a graceful error when talking to a too-old qemu on a partial
rebase attempt.  Fixes for the new semantics will come later.  This
patch also removes a bogus ATTRIBUTE_NONNULL mistakenly added in
commit 10ec36e2.

* src/qemu/qemu_capabilities.h (QEMU_CAPS_BLOCKJOB_SYNC)
(QEMU_CAPS_BLOCKJOB_ASYNC): New bits.
* src/qemu/qemu_capabilities.c (qemuCaps): Name them.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONCheckCommands): Set
them.
(qemuMonitorJSONBlockJob): Manage both command names.
(qemuMonitorJSONDiskSnapshot): Minor formatting fix.
* src/qemu/qemu_monitor.h (qemuMonitorBlockJob): Alter signature.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONBlockJob): Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Pass through
capability bit.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Update callers.

The new safe console handling introduced a possibility to deadlock the
qemu driver when a new console connection forcibly disconnects a
previous console stream that belongs to an already closed connection.

The virStreamFree function calls subsequently a the virReleaseConnect
function that tries to lock the driver while discarding the connection,
but the driver was already locked in qemuDomainOpenConsole.

Backtrace of the deadlocked thread:
0  0x00007f66e5aa7f14 in __lll_lock_wait () from /lib64/libpthread.so.0
1  0x00007f66e5aa3411 in _L_lock_500 () from /lib64/libpthread.so.0
2  0x00007f66e5aa322a in pthread_mutex_lock () from/lib64/libpthread.so.0
3  0x0000000000462bbd in qemudClose ()
4  0x00007f66e6e178eb in virReleaseConnect () from/usr/lib64/libvirt.so.0
5  0x00007f66e6e19c8c in virUnrefStream () from /usr/lib64/libvirt.so.0
6  0x00007f66e6e3d1de in virStreamFree () from /usr/lib64/libvirt.so.0
7  0x00007f66e6e09a5d in virConsoleHashEntryFree () from/usr/lib64/libvirt.so.0
8  0x00007f66e6db7282 in virHashRemoveEntry () from/usr/lib64/libvirt.so.0
9  0x00007f66e6e09c4e in virConsoleOpen () from /usr/lib64/libvirt.so.0
10 0x00000000004526e9 in qemuDomainOpenConsole ()
11 0x00007f66e6e421f1 in virDomainOpenConsole () from/usr/lib64/libvirt.so.0
12 0x00000000004361e4 in remoteDispatchDomainOpenConsoleHelper ()
13 0x00007f66e6e80375 in virNetServerProgramDispatch () from/usr/lib64/libvirt.so.0
14 0x00007f66e6e7ae11 in virNetServerHandleJob () from/usr/lib64/libvirt.so.0
15 0x00007f66e6da897d in virThreadPoolWorker () from/usr/lib64/libvirt.so.0
16 0x00007f66e6da7ff6 in virThreadHelper () from/usr/lib64/libvirt.so.0
17 0x00007f66e5aa0c5c in start_thread () from /lib64/libpthread.so.0
18 0x00007f66e57e7fcd in clone () from /lib64/libc.so.6

* src/qemu/qemu_driver.c: qemuDomainOpenConsole()
        -- unlock the qemu driver right after acquiring the domain
        object

qemuDomainObjEnterMonitor{,WithDriver} should not be called from async
jobs, only EnterMonitorAsync variant is allowed.

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.

* src/qemu/qemu_command.c: Wire up -bios with <loader>
* tests/qemuxml2argvdata/qemuxml2argv-bios.args,
  tests/qemuxml2argvdata/qemuxml2argv-bios.xml: Expand
  existing BIOS test case to cover <loader>

Leak introduced in commit 0436d328.  If we allocate an actions array,
but fail early enough to never consume it with the qemu monitor
transaction call, we leaked memory.

But our semantics of making the transaction command free the caller's
memory is awkward; avoiding the memory leak requires making every
intermediate function in the call chain check for error.  It is much
easier to fix things so that the function that allocates also frees,
while the call chain leaves the caller's data intact.  To do that,
I had to hack our JSON data structure to make it easy to protect a
portion of an arbitrary JSON tree from being freed.

* src/util/json.h (virJSONType): Name the enum.
(_virJSONValue): New field.
* src/util/json.c (virJSONValueFree): Use it to protect a portion
of an array.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONTransaction): Avoid
freeing caller's data.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateDiskActive):
Free actions array on failure.

We can tell qemuDomainSnapshotFSThaw if we want it to report errors or
not. However, if we don't want to and an error has been already set by
previous qemuReportError() we must keep copy of that error not just a
pointer to it. Otherwise, it get overwritten if FSThaw reports an error.

If the daemon is restarted it will lose list of active
USB devices assigned to active domains. Therefore we need
to rebuild this list on qemuProcessReconnect().

To prevent assigning one USB device to two domains,
we keep a list of assigned USB devices. On domain
startup - qemuProcessStart() - we insert devices
used by domain into the list but remove them only
on detach-device. Devices are, however, released
on qemuProcessStop() as well.

and add debug message when adding USB device
to the list of active devices.

Originally, qemuDomainCheckEjectableMedia was entering monitor with qemu
driver lock. Commit 2067e31b, which I
made to fix that, revealed another issue we had (but didn't notice it
since the driver was locked): we didn't set nested job when
qemuDomainCheckEjectableMedia is called during migration. Thus the
original fix I made was wrong.

Since Xen 3.1 the clock=variable semantic is supported. In addition to
qemu/kvm Xen also knows about a variant where the offset is relative to
'localtime' instead of 'utc'.

Extends the libvirt structure with a flag 'basis' to specify, if the
offset is relative to 'localtime' or 'utc'.

Extends the libvirt structure with a flag 'reset' to force the reset
behaviour of 'localtime' and 'utc'; this is needed for backward
compatibility with previous versions of libvirt, since they report
incorrect XML.

Adapt the only user 'qemu' to the new name.
Extend the RelaxNG schema accordingly.
Document the new 'basis' attribute in the HTML documentation.
Adapt test for the new attribute.
Signed-off-by: NPhilipp Hahn <hahn@univention.de>

If we round up a user's memory request, we should update the XML
to reflect the actual value in use by the VM, rather than giving
an artificially small value back to the user.

* src/qemu/qemu_command.c (qemuBuildNumaArgStr)
(qemuBuildCommandLine): Reflect rounding back to XML.

This patch was created to resolve this upstream bug:

  https://bugzilla.redhat.com/show_bug.cgi?id=784767

and is at least a partial solution to this RHEL RFE:

  https://bugzilla.redhat.com/show_bug.cgi?id=805071

Previously the only attribute of a network device that could be
modified by virUpdateDeviceFlags() ("virsh update-device") was the
link state; attempts to change any other attribute would log an error
and fail.

This patch adds recognition of a change in bridge device name, and
supports reconnecting the guest's interface to the new device.
Standard audit logs for detaching and attaching a network device are
also generated. Although the current auditing function doesn't log the
bridge being attached to, this will later be changed in a separate
patch.

qemuBuildHostNetStr had a switch-within-a-switch where both were
looking at the same variable. This was apparently to take advantage of
code common to three different cases (while also taking care of some
code that was different). However, there were only 2 lines common to
all, one of those can be eliminated by merging it into the
virAsprintfs that are in each case. On top of that, all the extra
empty cases cause Coverity complaints (because they are unreachable),
but absence of the empty cases causes a compile error due to
"enumeration value not handled in switch".

The solution is to just make each toplevel case independent, folding
in the common code to each.

commit b0e2bb33 set a default value for the SPICE agent channel by
inserting it during parsing of the channel XML. That method of setting
a default is problematic because it makes a format/parse roundtrip
unclean, and experience with setting other values as a side effect of
parsing has led to headaches (e.g. automatically setting a MAC address
in the parser when one isn't specified in the input XML).

This patch does not revert commit b0e2bb33 (it will be reverted in a
separate patch) but adds the alternate implementation of simply
inserting the default value in the appropriate place on the qemu
commandline when no value is provided.

If we issue guest command and GA is not running, the issuing thread
will block endlessly. We can check for GA presence by issuing
guest-sync with unique ID (timestamp). We don't want to issue real
command as even if GA is not running, once it is started, it process
all commands written to GA socket.

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>

When qemu cannot start, we may call qemuProcessStop() twice.
We have check whether the vm is running at the beginning of
qemuProcessStop() to avoid libvirt deadlock. We call
qemuProcessStop() with driver and vm locked. It seems that
we can avoid libvirt deadlock. But unfortunately we may
unlock driver and vm in the function qemuProcessKill() while
vm->def->id is not -1. So qemuProcessStop() will be run twice,
and monitor will be freed unexpectedly. So we should set
vm->def->id to -1 at the beginning of qemuProcessStop().

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>

Commit d42a2ffc caused a regression in creating a disk-only snapshot
of a qcow2 disk; by passing the wrong variable to the monitor call,
libvirt ended up creating JSON that looked like "format":null instead
of the intended "format":"qcow2".

To make it easier to diagnose this in the future, make JSON creation
error out if "s:arg" is paired with NULL (it is still possible to
use "n:arg" in the rare cases where qemu will accept a null).

* src/qemu/qemu_driver.c
(qemuDomainSnapshotCreateSingleDiskActive): Pass correct value.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONMakeCommandRaw):
Improve error message.

When libvirtd is restarted, also restart the netlink event
message callbacks for existing VEPA connections and send
a message to lldpad for these existing links, so it learns
the new libvirtd pid.
Signed-off-by: ND. Herrendoerfer <d.herrendoerfer@herrendoerfer.name>

This avoids possible deadlock of the qemu driver in case a domain is
begin migrated (in Begin phase) and unrelated connection to qemu driver
is closed at the right time.

I checked all callers of qemuDomainCheckEjectableMedia() and they are
calling this function with qemu driver locked.

Found when attempting to build on Fedora 17 alpha with:

   ./autogen.sh --system --enable-compile-warnings=error

(this same build command works without problem on Fedora 16). Since
the consumer of the qemuProcessReconnectData doesn't assume that the
other fields of the struct are initialized (although it uses them
internally), the simpler solution is to just switch to C99-style
struct initialization (which doesn't require specification of all
fields).

libvirt always adds -Werror-frame-larger-than=4096 to the flags when
it builds. When building on Fedora 17, two functions with multiple
1024 buffers declared inside if {} blocks would generate frame size
errors; apparently the version of gcc on Fedora 16 will merge these
multiple buffers into a single buffer even when optimization is off,
but Fedora 17 won't.

The fix is to declare a single 1024 buffer at the top of the two
offending functions, and reuse the single buffer throughout the
functions.

Return statements with parameter enclosed in parentheses were modified
and parentheses were removed. The whole change was scripted, here is how:

List of files was obtained using this command:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' |             \
grep -e '\.[ch]$' -e '\.py$'

Found files were modified with this command:
sed -i -e                                                                 \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'

Then checked for nonsense.

The whole command looks like this:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' |             \
grep -e '\.[ch]$' -e '\.py$' | xargs sed -i -e                            \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'

numad is available since Fedora 17 and RHEL6.X. And it's not supported
on s390[x] and ARM.

The oVirt developers have stated that the real reasons they want
to have qemu reuse existing volumes when creating a snapshot are:
1. the management framework is set up so that creation has to be
done from a central node for proper resource tracking, and having
libvirt and/or qemu create things violates the framework, and
2. qemu defaults to creating snapshots with an absolute path to
the backing file, but oVirt wants to manage a backing chain that
uses just relative names, to allow for easier migration of a chain
across storage locations.

When 0.9.10 added VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT (commit
4e9953a4), it only addressed point 1, but libvirt was still using
O_TRUNC which violates point 2.  Meanwhile, the new qemu
'transaction' monitor command includes a new optional mode argument
that will force qemu to reuse the metadata of the file it just
opened (with the burden on the caller to have valid metadata there
in the first place).  So, this tweaks the meaning of the flag to
cover both points as intended for use by oVirt.  It is not strictly
backward-compatible to 0.9.10 behavior, but it can be argued that
the O_TRUNC of 0.9.10 was a bug.

Note that this flag is all-or-nothing, and only selects between
'existing' and the default 'absolute-paths'.  A more flexible
approach that would allow per-disk selections, as well as adding
support for the 'no-backing-file' mode, would be possible by
extending the <domainsnapshot> xml to have a per-disk mode, but
until we have a management application expressing a need for that
additional complexity, it is not worth doing.

* src/libvirt.c (virDomainSnapshotCreateXML): Tweak documentation.
* src/qemu/qemu_monitor.h (qemuMonitorDiskSnapshot): Add
parameters.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDiskSnapshot):
Likewise.
* src/qemu/qemu_monitor.c (qemuMonitorDiskSnapshot): Pass them
through.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONDiskSnapshot): Use
new monitor command arguments.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateDiskActive)
(qemuDomainSnapshotCreateSingleDiskActive): Adjust callers.
(qemuDomainSnapshotDiskPrepare): Allow qed, modify rules on reuse.

The hardest part about adding transactions is not using the new
monitor command, but undoing the partial changes we made prior
to a failed transaction.

* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateDiskActive): Use
transaction when available.
(qemuDomainSnapshotUndoSingleDiskActive): New function.
(qemuDomainSnapshotCreateSingleDiskActive): Pass through actions.
(qemuDomainSnapshotCreateXML): Adjust caller.

QEmu 1.1 is adding a 'transaction' command to the JSON monitor.
Each element of a transaction corresponds to a top-level command,
with the additional guarantee that the transaction flushes all
pending I/O, then guarantees that all actions will be successful
as a group or that failure will roll back the state to what it
was before the monitor command.  The difference between a
top-level command:

{ "execute": "blockdev-snapshot-sync", "arguments":
  { "device": "virtio0", ... } }

and a transaction:

{ "execute": "transaction", "arguments":
  { "actions": [
    { "type": "blockdev-snapshot-sync", "data":
      { "device": "virtio0", ... } } ] } }

is just a couple of changed key names and nesting the shorter
command inside a JSON array to the longer command.  This patch
just adds the framework; the next patch will actually use a
transaction.

* src/qemu/qemu_monitor_json.c (qemuMonitorJSONMakeCommand): Move
guts...
(qemuMonitorJSONMakeCommandRaw): ...into new helper.  Add support
for array element.
(qemuMonitorJSONTransaction): New command.
(qemuMonitorJSONDiskSnapshot): Support use in a transaction.
* src/qemu/qemu_monitor_json.h (qemuMonitorJSONDiskSnapshot): Add
argument.
(qemuMonitorJSONTransaction): New declaration.
* src/qemu/qemu_monitor.h (qemuMonitorTransaction): Likewise.
(qemuMonitorDiskSnapshot): Add argument.
* src/qemu/qemu_monitor.c (qemuMonitorTransaction): New wrapper.
(qemuMonitorDiskSnapshot): Pass argument on.
* src/qemu/qemu_driver.c
(qemuDomainSnapshotCreateSingleDiskActive): Update caller.