Add qemuDomainHasVCpuPids to do the checking and replace in place checks
with it.

We no longer need checking whether the thread contains fake data
(vcpupids[0] == vm->pid) as in b07f3d82
and 65686e5a this was removed.

Finalize the refactor by adding the 'virDomainDefGetVCpusMax' getter and
reusing it accross libvirt.

Often when debugging bug reports one is given a copy of the file
from /var/log/libvirt/qemu/$NAME.log along with other supporting
files. In a number of cases I've been given sets of files which
were from different machines. Including the hostname in the QEMU
log file will help identify when the bug reporter is providing
bad information.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

If VM A is shutdown a by qemu agent at appoximately the same time
an agent EOF of VM A happened, there's a chance that deadlock may occur:

qemuProcessHandleAgentEOF in main thread
A)  priv->agent = NULL; //A happened before B

    //deadlock when we get agent lock which's held by worker thread
    qemuAgentClose(agent);

qemuDomainObjExitAgent called by qemuDomainShutdownFlags in worker thread
B)  hasRefs = virObjectUnref(priv->agent); // priv->agent is NULL,
                                           // return false
    if (hasRefs)
        virObjectUnlock(priv->agent); //agent lock will not be released here

In order to resolve, during EOF close the agent first, then set priv->agent
to NULL to fix the deadlock.

This essentially reverts commit id '1020a504'. It's also of note that commit
id '362d0477' notes a possible/rare deadlock similar to what was seen in
the monitor in commit id '25f582e3'. However, it seems interceding changes
including commit id 'd960d06f' should remove the deadlock issue.

With this change, if EOF is called:

    Get VM lock
    Check if !priv->agent || priv->beingDestroyed, then unlock VM
    Call qemuAgentClose
    Unlock VM

When qemuAgentClose is called
    Get Agent lock
    If Agent->fd open, close it
    Unlock Agent
    Unref Agent

qemuDomainObjEnterAgent
    Enter with VM lock
    Get Agent lock
    Increase Agent refcnt
    Unlock VM

After running agent command, calling qemuDomainObjExitAgent
    Enter with Agent lock
    Unref Agent
    If not last reference, unlock Agent
    Get VM lock

If we were in the middle of an EnterAgent, call Agent command, and
ExitAgent sequence and the EOF code is triggered, then the EOF code
can get the VM lock, make it's checks against !priv->agent ||
priv->beingDestroyed, and call qemuAgentClose. The CloseAgent
would wait to get agent lock. The other thread then will eventually
call ExitAgent, release the Agent lock and unref the Agent. Once
ExitAgent releases the Agent lock, AgentClose will get the Agent
Agent lock, close the fd, unlock the agent, and unref the agent.
The final unref would cause deletion of the agent.
Signed-off-by: NWang Yufei <james.wangyufei@huawei.com>
Reviewed-by: NRen Guannan <renguannan@huawei.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>

When the qemuProcessAttach/Stop methods write a marker into
the log file, they can use qemuDomainLogContextWrite to
write a formatted message.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Instead of writing directly to a log file descriptor, change
qemuLogOperation to use qemuDomainLogContextWrite().
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The qemuDomainTaint APIs currently expect to be passed a log file
descriptor. Change them to instead use a qemuDomainLogContextPtr
to hide the implementation details.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Convert the places which create/open log files to use the new
qemuDomainLogContextPtr object instead.
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>

Now that new domains are started inside a QEMU_ASYNC_JOB_START job,
we need to pass it down to qemuProcessStartCPUs too.

This removes the warning:
qemuDomainObjEnterMonitorInternal:1750 : This thread seems to be the
async job owner; entering monitor without asking for a nested job is
dangerous

Introduced by commit 04c721f2, before that this code path was only
executed with QEMU_ASYNC_JOB_NONE.

(This code is not executed on migration, because qemuMigrationPrepareAny
 sets the VIR_QEMU_PROCESS_START_PAUSED flag.)

Remembering to call qemuMonitorSetDomainLog in the right paths before
calling qemuProcessStop is annoying and easy to forget. And I already
forgot to do so in commit v1.2.8-52-g03890605: logfd may be leaked if
QEMU process dies between Prepare and Finish migration phases.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Every caller setting migrateFrom already sets
VIR_QEMU_PROCESS_START_PAUSED flag anyway.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

qemuProcessMakeDir is used for creating a per-domain directory in a
given parent directory.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

qemuProcessStart is so big that any nontrivial code should be moved to
dedicated functions to make the code easier to read and maintain.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Move {Enter,Exit}Monitor calls inside qemuProcessSetLinkStates to
simplify qemuProcessStart.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

qemuProcessStart is so big that any nontrivial code should be moved to
dedicated functions to make the code easier to read and maintain.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

qemuProcessStart is so big that any nontrivial code should be moved to
dedicated functions to make the code easier to read and maintain.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

qemuProcessStart is so big that any nontrivial code should be moved to
dedicated functions to make the code easier to read and maintain.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

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>

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

Make callers of qemuBuildCommandLine responsible for providing the URI
which should be passed as a parameter for -incoming.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

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

As of QEMU 0.11.0 the 'info chardev' monitor command can be
used to report on allocated chardev paths, so we can drop
support for parsing QEMU stderr to locate the PTY paths.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

nodeset should be freed in both success and failure paths.

While tmppath is freed immediately after it's consumed, moving it from
error to cleanup label is a bit more consistent and robust.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Remove code duplication by moving common cleanup code in a dedicated
label.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Generally, we use "ret" variable for storing the value we are going to
return at the and of a function, but this is not the case in
qemuProcessStart. Let's rename "ret" as "rv".
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Current "cleanup" label is only used in error path, thus it should
rather be called "error".
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

qemuProcessStart was passing char * migrateFrom as the third argument to
qemuPrepareNVRAM. We should explicitly convert the pointer to bool which
is what the function expects.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

This calls the PCI-, USB- and SCSI-specific functions just
like qemuHostdev{Prepare,ReAttach}DomainDevices() already do,
and was the missing piece for the qemuHostdev API to nicely
mirror the virHostdev API.

Update qemuProcessReconnect() to use the new function.

Adopt the same names used for virHostdevUpdateActive*Devices() for
consistency's sake and to make it easier to jump between the two.

No functional changes.

Adopt the same names used for virHostdevReAttach*Devices() for
consistency's sake and to make it easier to jump between the two.

No functional changes.

Adopt the same names used for virHostdevPrepare*Devices() for
consistency's sake and to make it easier to jump between the two.

No functional changes.