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.

Similarly to previous commit change the way how iothread scheduler info
is stored and clean up a lot of unnecessary code.

Due to bad design the vcpu sched element is orthogonal to the way how
the data belongs to the corresponding objects. Now that vcpus are a
struct that allow to store other info too, let's convert the data to the
sane structure.

The helpers for the conversion are made universal so that they can be
reused for iothreads too.

This patch also resolves https://bugzilla.redhat.com/show_bug.cgi?id=1235180
since with the correct storage approach you can't have dangling data.

Now with the new struct the data can be stored in a much saner place.

This step can be omitted, so that drivers can decide what to do when the
user requests to use default vcpu pinning.

Now that qemuDomainDetectVcpuPids is able to refresh the vCPU pid
information it can be reused in the hotplug and hotunplug code paths
rather than open-coding a very similar algorithm.

A slight algorithm change is necessary for unplug since the vCPU needs
to be marked offline prior to calling the thread detector function and
eventually rolled back if something fails.

Some callers will need to behave differently when the detection failed
and when the VM crashed during the redetection. Return -2 if it crashed.

Pass a bitmap of enabled guest vCPUs to virCgroupGetPercpuStats so that
non-continuous vCPU topologies can be used.

Move the logic from virDomainDiskDefDstDuplicates into
virDomainDiskDefCheckDuplicateInfo so that we don't have to loop
multiple times through the array of disks. Since the original function
was called in qemuBuildDriveDevStr, it was actually called for every
single disk which was quite wasteful.

Additionally the target uniqueness check needed to be duplicated in
the disk hotplug case, since the disk was inserted into the domain
definition after the device string was formatted and thus
virDomainDiskDefDstDuplicates didn't do anything in that case.

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.

Retrieval of the driver capabilities as well as emulator capabilities
does not require the complete qemuProcessStop to be executed on
failure.

We do the check on VM start, but the user could still hotplug a disk
with a conflicting serial or WWN. Reuse the checker function to fix the
issue.

Target uniqueness check was duplicated in all of the three workers
called from it. Extract it to the parent.

Remove the default case since all cases are covered.

In b3d2a42e I've refactored the code and moved the 'cleanup' label.
Unfortunately the code that was originally in the 'endjob' label and
wanted to jump to cleanup is now in the cleanup label. Remove the jump
and let the function finish.

If we are attempting to thaw the filesystems on error, the code would
overwrite the error code that caused the snapshot to fail with the error
of thawing the filesystem. Since the thawing function allows control of
error reporting behavior we can use this feature.

So, systemd-machined has this philosophy that machine names are like
hostnames and hence should follow the same rules.  But we always allowed
international characters in domain names.  Thus we need to modify the
machine name we are passing to systemd.

In order to change some machine names that we will be passing to systemd,
we also need to call TerminateMachine at the end of a lifetime of a
domain.  Even for domains that were started with older libvirt.  That
can be achieved thanks to virSystemdGetMachineNameByPID().  And because
we can change machine names, we can get rid of the inconsistent and
pointless escaping of domain names when creating machine names.

So this patch modifies the naming in the following way.  It creates the
name as <drivername>-<id>-<name> where invalid hostname characters are
stripped out of the name and if the resulting name is longer, it
truncates it to 64 characters.  That way we can start domains we
couldn't start before.  Well, at least on systemd.

To make it work all together, the machineName (which is needed only with
systemd) is saved in domain's private data.  That way the generation is
moved to the driver and we don't need to pass various unnecessary
arguments to cgroup functions.

The only thing this complicates a bit is the scope generation when
validating a cgroup where we must check both old and new naming, so a
slight modification was needed there.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1282846Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

The virDomainSnapshotDefFormat calls into virDomainDefFormat,
so should be providing a non-NULL virCapsPtr instance. On the
qemu driver we change qemuDomainSnapshotWriteMetadata to also
include caps since it calls virDomainSnapshotDefFormat.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

The virDomainObjFormat and virDomainSaveStatus methods
both call into virDomainDefFormat, so should be providing
a non-NULL virCapsPtr instance.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>

virDomainSaveConfig calls virDomainDefFormat which was setting the caps
to NULL, thus keeping the old behaviour (i.e. not looking at
netprefix). This patch adds the virCapsPtr to the function and allows
the configuration to be saved and skipping interface names that were
registered with virCapabilitiesSetNetPrefix().
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

And use the newly added caps->host.netprefix (if it exists) for
interface names that match the autogenerated target names.
Signed-off-by: NJoao Martins <joao.m.martins@oracle.com>

A pretty nasty deadlock occurs while trying to rename a VM in parallel
with virDomainObjListNumOfDomains.
The short description of the problem is as follows:

Thread #1:

qemuDomainRename:
    ------> aquires domain lock by qemuDomObjFromDomain
       ---------> waits for domain list lock in any of the listed functions:
          - virDomainObjListFindByName
          - virDomainObjListRenameAddNew
          - virDomainObjListRenameRemove

Thread #2:

virDomainObjListNumOfDomains:
    ------> aquires domain list lock
       ---------> waits for domain lock in virDomainObjListCount

Introduce generic virDomainObjListRename function for renaming domains.
It aquires list lock in right order to avoid deadlock. Callback is used
to make driver specific domain updates.
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Free the old vcpupids array in case when this function is called again
during the run of the VM. It will be later reused in the vCPU hotplug
code. The function now returns the number of detected VCPUs.

Future patches will tweak and reuse the function in different places so
move it separately first.

Avoid using virDomainDefSetVcpus when we can set it directly in the
structure.

In case of guest panicked, preserved crashed domain has stopped CPUs.
It's not possible to use tools like WinDbg for the problem investigation
until we start CPUs back.

Error paths after sending the event that domain is started written as if ret = -1
which is set at the beginning of the function. It's common idioma to keep 'ret'
equal to -1 until the end of function where it is set to 0. But here we use ret
to keep result of restore operation too and thus breaks the idioma and its users :)

Let's use different variable to hold restore result.
Signed-off-by: NNikolay Shirokovskiy <nshirokovskiy@virtuozzo.com>

Having on_crash set to either coredump-destroy or coredump-restart
creates core dumps with option memory-only in the directory specified
by auto_dump_path. When a watchdog is triggered with the action dump
the core dump is also placed into the directory specified by auto_dump_path
but is created without the option memory-only.

This patch sets the option memory-only also for core dumps created by the
watchdog event.
Signed-off-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: NBjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: NStefan Zimmermann <stzi@linux.vnet.ibm.com>

This should be the last offender.

Iterate over all cpus skipping inactive ones.

This patch creates two bitmaps, one for macvlan device names and one
for macvtap. The bitmap position is used to indicate that libvirt is
currently using a device with the name macvtap%d/macvlan%d, where %d
is the position in the bitmap. When requested to create a new
macvtap/macvlan device, libvirt will now look for the first clear bit
in the appropriate bitmap and derive the device name from that rather
than just starting at 0 and counting up until one works.

When libvirtd is restarted, the qemu driver code that reattaches to
active domains calls the appropriate function to "re-reserve" the
device names as it is scanning the status of running domains.

Note that it may seem strange that the retry counter now starts at
8191 instead of 5. This is because we now don't do a "pre-check" for
the existence of a device once we've reserved it in the bitmap - we
move straight to creating it; although very unlikely, it's possible
that someone has a running system where they have a large number of
network devices *created outside libvirt* named "macvtap%d" or
"macvlan%d" - such a setup would still allow creating more devices
with the old code, while a low retry max in the new code would cause a
failure. Since the objective of the retry max is just to prevent an
infinite loop, and it's highly unlikely to do more than 1 iteration
anyway, having a high max is a reasonable concession in order to
prevent lots of new failures.

The current code was a little bit odd.  At first we've removed all
possible implicit input devices from domain definition to add them later
back if there was any graphics device defined while parsing XML
description.  That's not all, while formating domain definition to XML
description we at first ignore any input devices with bus different to
USB and VIRTIO and few lines later we add implicit input devices to XML.

This seems to me as a lot of code for nothing.  This patch may look
to be more complicated than original approach, but this is a preferred
way to modify/add driver specific stuff only in those drivers and not
deal with them in common parsing/formating functions.

The update is to add those implicit input devices into config XML to
follow the real HW configuration visible by guest OS.

There was also inconsistence between our behavior and QEMU's in the way,
that in QEMU there is no way how to disable those implicit input devices
for x86 architecture and they are available always, even without graphics
device.  This applies also to XEN hypervisor.  VZ driver already does its
part by putting correct implicit devices into live XML.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

The VIR_DOMAIN_STATS_VCPU flag to virDomainListGetStats
enables reporting of stats about vCPUs. Currently we
only report the cumulative CPU running time and the
execution state.

This adds reporting of the wait time - time the vCPU
wants to run, but the host scheduler has something else
running ahead of it.

The data is reported per-vCPU eg

$ virsh domstats --vcpu demo
 Domain: 'demo'
   vcpu.current=4
   vcpu.maximum=4
   vcpu.0.state=1
   vcpu.0.time=1420000000
   vcpu.0.wait=18403928
   vcpu.1.state=1
   vcpu.1.time=130000000
   vcpu.1.wait=10612111
   vcpu.2.state=1
   vcpu.2.time=110000000
   vcpu.2.wait=12759501
   vcpu.3.state=1
   vcpu.3.time=90000000
   vcpu.3.wait=21825087

In implementing this I notice our reporting of CPU execute
time has very poor granularity, since we are getting it
from /proc/$PID/stat. As a future enhancement we should
prefer to get CPU execute time from /proc/$PID/schedstat
or /proc/$PID/sched (if either exist on the running kernel)
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Remove unnecessary condition and variable.

Counterintuitively the user would end up with a VM with maximum number
of vCPUs available.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1290324