Rather than trying some magic calculations on our side query the monitor
for the current size of the memory balloon both on hotplug and
hotunplug.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1220702

This will skip few steps from qemuProcessStart in order to create only
qemu CMD.  Use a VIR_QEMU_PROCESS_START_PRETEND for all the qemuProcess*
functions called by this one to not modify or check host.

This new function will be used later on for XMLToNative API and also for
qemuxml2argvtest to make sure that both API and test uses the same code
as qemuProcessStart.

We need also update qemuProcessInit to wrap few lines of code with check
that VIR_QEMU_PROCESS_START_PRETEND that makes sense only for
qemuProcessStart.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

Move all code that checks host and domain.  Do not check host if we use
VIR_QEMU_PROCESS_START_PRETEND flag.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

Move all code that modifies host system to this function.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

Move all code that modifies only live XML to this function.  The new
VIR_QEMU_PROCESS_START_PRETEND flag will be used by qemuXMLToNative and
qemuxml2argvtest later in order to reuse the same code as
qemuProcessStart uses.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

Per-domain directories were introduced in order to be able to
completely separate security labels for each domain (commit
f1f68ca3).  However when the domain
name is long (let's say a ridiculous 110 characters), we cannot
connect to the monitor socket because on length of UNIX socket address
is limited.  In order to get around this, let's shorten it in similar
fashion and in order to avoid conflicts, throw in an ID there as well.
Also save that into the status XML and load the old status XMLs
properly (to clean up after older domains).  That way we can change it
in the future.

The shortening can be seen in qemuxml2argv tests, for example in the
hugepages-pages2 case.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Calling qemuProcessStop without a job opens a way to race conditions
with qemuDomainObjExitMonitor called in another thread. A real world
example of such a race condition:

  - migration thread (A) calls qemuMigrationWaitForSpice
  - another thread (B) starts processing qemuDomainAbortJob API
  - thread B signals thread A via qemuDomainObjAbortAsyncJob
  - thread B enters monitor (qemuDomainObjEnterMonitor)
  - thread B calls qemuMonitorSend
  - thread A awakens and calls qemuProcessStop
  - thread A calls qemuMonitorClose and sets priv->mon to NULL
  - thread B calls qemuDomainObjExitMonitor with priv->mon == NULL
  => monitor stays ref'ed and locked

Depending on how lucky we are, the race may result in a memory leak or
it can even deadlock libvirtd's event loop if it tries to lock the
monitor to process an event received before qemuMonitorClose was called.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

When destroying a domain we need to make sure we will be able to start a
job no matter what other operations are running or even stuck in a job.
This is done by killing the domain before starting the destroy job.

Let's introduce qemuProcessBeginStopJob which combines killing a domain
and starting a job in a single API which can be called everywhere we
need a job to stop a domain.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

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

https://bugzilla.redhat.com/show_bug.cgi?id=1293351

Since we already have virtio channel events, we know when guest
agent within guest has (dis-)connected. Instead of us blindly
connecting to a socket that no one is listening to, we can just
follow what qemu-ga does. This has a nice benefit that we don't
need to 'guest-ping' the agent just to timeout and find out
nobody is listening.

The way that this commit is implemented:
- don't connect in qemuProcessLaunch directly, defer that to event
  callback (which already follows the agent) -
  processSerialChangedEvent
- after migration is settled, before we resume vCPUs, ask qemu
  whether somebody is listening on the socket and if so, connect
  to it.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Rather than iterating 3 times for various settings this function
aggregates all the code into single place. One of the other advantages
is that it can then be reused for properly setting IOThread info on
hotplug.

Rather than iterating 3 times for various settings this function
aggregates all the code into single place. One of the other advantages
is that it can then be reused for properly setting vCPU info on hotplug.

With this approach autoCpuset is also used when setting the process
affinity rather than just via cgroups.

When starting a qemu process there are certain checks done to ensure
that the configuration makes sense. Extract them into a separate
function so that they can be reused in the test code.

My commit 674afcb0 moved computing the
default listen address from qemuMigrationPrepareAny to
qemuMigrationPrepareIncoming. However, I didn't notice listenAddress was
later passed to qemuMigrationStartNBDServer. Thus, it would be called
with the original value of listenAddress (NULL).

Let's add the updated listen address to qemuProcessIncomingDef and use
it when starting NBD servers.
Reported-by: NMichael Chapman <mike@very.puzzling.org>
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Currently the QEMU monitor is given an FD to the logfile. This
won't work in the future with virtlogd, so it needs to use the
qemuDomainLogContextPtr instead, but it shouldn't directly
access that object either. So define a callback that the
monitor can use for reporting errors from the log file.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

There are two pretty similar functions qemuProcessReadLog and
qemuProcessReadChildErrors. Both read from the QEMU log file
and try to strip out libvirt messages. The latter then reports
an error, while the former lets the callers report an error.

Re-write qemuProcessReadLog so that it uses a single read
into a dynamically allocated buffer. Then introduce a new
qemuProcessReportLogError that calls qemuProcessReadLog
and reports an error.

Convert all callers to use qemuProcessReportLogError.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Finishes starting a new domain launched by qemuProcessLaunch.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Once qemuProcessInit was called, qemuProcessLaunch will launch a new
QEMU process with stopped virtual CPUs.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

qemuProcessStart is going to be split in three parts: qemuProcessInit,
qemuProcessLaunch, and qemuProcessFinish so that migration Prepare phase
can insert additional code in the process. qemuProcessStart will be a
small wrapper for all other callers.

qemuProcessInit prepares the domain up to the point when priv->qemuCaps
is initialized.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

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>

We only started an async job for incoming migration from another host.
When we were starting a domain from scratch or restoring from a saved
state (migration from file) we didn't set any async job. Let's introduce
a new QEMU_ASYNC_JOB_START for these cases.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Incoming migration may require quite a few parameters (URI, fd, path) to
be considered while starting QEMU and we will soon add another one.
Let's group all of them in a single struct.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

If a user hot-attaches the guest agent channel libvirt would ignore it
until the restart of libvirtd or shutdown/destroy and start of the VM
itself.

This patch adds code that opens or closes the guest agent connection
according to the state of the guest agent channel according to
connect/disconnect events.

To allow opening the channel from the event handler qemuConnectAgent
needed to be exported.

Two places would call to qemuPrepareCpumap() with priv->autoNodeset to
convert it to a cpuset. Remove the function and use the prepared cpuset
automatically.

We have two different places that needs to be updated while touching
code for allocation spice ports.  Add a bool option to
'qemuProcessSPICEAllocatePorts' function to switch between true and fake
allocation so we can use this function also in qemu_driver to generate
native domain definition.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1178986Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

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>

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>

In "src/util/" there are many enumeration (enum) declarations.
Sometimes, it's better using a typedef for variable types,
function types and other usages. Other enumeration will be
changed to typedef's in the future.
Signed-off-by: NJulio Faracco <jcfaracco@gmail.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Teach the function to skip character device definitions printed by qemu
at startup in addition to libvirt log messages and make it usable from
outside of qemu_process.c. Also add documentation about the func.

Later code will need this outside of qemu_process.c

unpriv_sgio setting is tight with the shared device helpers, let's
put them together in qemu_conf.c

s/VIR_QEMU_PROCESS_START_AUTODESROY/VIR_QEMU_PROCESS_START_AUTODESTROY/
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Based on moving various checking into qemuAddSharedDisk, this
avoids the caller using it in wrong ways. Also this adds two
new checking for qemuCheckSharedDisk (disk device not 'lun'
and kernel doesn't support unpriv_sgio simply returns 0).

With the majority of fields in the virQEMUDriverPtr struct
now immutable or self-locking, there is no need for practically
any methods to be using the QEMU driver lock. Only a handful
of helper APIs in qemu_conf.c now need it

Currently the APIs for managing the shared disk list take
a virHashTablePtr as the primary argument. This is bad
because it requires the caller to deal with locking of
the QEMU driver. Switch the APIs to take the full
virQEMUDriverPtr instance
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the virQEMUDriverPtr struct contains an wide variety
of data with varying access needs. Move all the static config
data into a dedicated virQEMUDriverConfigPtr object. The only
locking requirement is to hold the driver lock, while obtaining
an instance of virQEMUDriverConfigPtr. Once a reference is held
on the config object, it can be used completely lockless since
it is immutable.

NB, not all APIs correctly hold the driver lock while getting
a reference to the config object in this patch. This is safe
for now since the config is never updated on the fly. Later
patches will address this fully.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>