MemLock is already used in other modules and, while still an
abbreviation, is not ambiguous.

When the function changes the memory lock limit for the first time,
it will retrieve the current value and store it inside the
virDomainObj for the domain.

When the function is called again, if memory locking is no longer
needed, it will be able to restore the memory locking limit to its
original value.

We increase the limit before plugging in a PCI hostdev or a memory
module because some memory might need to be locked due to eg. VFIO.

Of course we should do the opposite after unplugging a device: this
was already the case for memory modules, but not for PCI hostdevs.

Replace all uses of the qemuDomainRequiresMlock/virProcessSetMaxMemLock
combination with the equivalent qemuDomainAdjustMaxMemLock() call.

This function detects whether a domain needs RLIMIT_MEMLOCK
to be set, and if so, uses an appropriate value.

In commit 686eb7a2, the break was not considered part of the
condition, hence breaking after first node when searching.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

when appropriate, of course. If the config for a domain specifies boot
order with <boot dev='blah'/> elements, e.g.:

     <os>
       ...
       <boot dev='hd'/>
       <boot dev='network'/>
     </os>

Then the first disk device in the config will have ",bootindex=1"
appended to its qemu commandline -device options, and the first (and
*only* the first) network interface device will get ",bootindex=2".

However, if the first network interface device is a "hostdev" device
(an SRIOV Virtual Function (VF) being assigned to the domain with
vfio), then the bootindex option will *not* be appended. This happens
because the bootindex=n option corresponding to the order of "<boot
dev='network'/>" is added to the -device for the first network device
when network device commandline args are constructed, but if it's a
hostdev network device, its commandline arg is instead constructed in
the loop for hostdevs.

This patch fixes that omission by noticing (in bootHostdevNet) if the
first network device was a hostdev, and if so passing on the proper
bootindex to the commandline generator for hostdev devices - the
result is that ",bootindex=2" will be properly appended to the first
"network" device in the config even if it is really a hostdev
(including if it is assigned from a libvirt network pool). (note that
this is only the case if there is no <bootmenu enabled='yes'/> element
in the config ("-boot menu-on" in qemu) , since the two are mutually
exclusive - when the bootmenu is enabled, the individual per-device
bootindex options can't be used by qemu, and we revert to using "-boot
order=xyz" instead).

If a greater level of control over boot order is desired (e.g., more
than one network device should be tried, or a network device other
than the first one encountered in the config), then <boot
dev='network'/> in the <os> element should not be used; instead, the
individual device elements in the config should be given a "<boot
order='n'/>

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1278421

Commit 256496e1 introduced a detection if "is locked" in error replay
from qemu monitor. Commit c4073657 fixed a memory leak, but it was
pointed out by Peter, that this could be done cleaner without
stringifing the replay.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

The return value of virJSONValueToString() should be freed when
no longer needed. This is not the case after 256496e1.

==26902== 138 bytes in 2 blocks are definitely lost in loss record 1,051 of 1,239
==26902==    at 0x4C29F80: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==26902==    by 0xAA5F599: strdup (in /lib64/libc-2.21.so)
==26902==    by 0x552BAD9: virStrdup (virstring.c:726)
==26902==    by 0x54F60A7: virJSONValueToString (virjson.c:1790)
==26902==    by 0x1DF6EBB9: qemuMonitorJSONEjectMedia (qemu_monitor_json.c:2225)
==26902==    by 0x1DF57A4C: qemuMonitorEjectMedia (qemu_monitor.c:1985)
==26902==    by 0x1DF1EF2D: qemuDomainChangeEjectableMedia (qemu_hotplug.c:199)
==26902==    by 0x1DF90314: qemuDomainChangeDiskLive (qemu_driver.c:7985)
==26902==    by 0x1DF90476: qemuDomainUpdateDeviceLive (qemu_driver.c:8030)
==26902==    by 0x1DF91ED7: qemuDomainUpdateDeviceFlags (qemu_driver.c:8677)
==26902==    by 0x561785F: virDomainUpdateDeviceFlags (libvirt-domain.c:8559)
==26902==    by 0x134210: remoteDispatchDomainUpdateDeviceFlags (remote_dispatch.h:10966)

==26902== 106 bytes in 1 blocks are definitely lost in loss record 1,033 of 1,239
==26902==    at 0x4C29F80: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==26902==    by 0xAA5F599: strdup (in /lib64/libc-2.21.so)
==26902==    by 0x552BAD9: virStrdup (virstring.c:726)
==26902==    by 0x54F60A7: virJSONValueToString (virjson.c:1790)
==26902==    by 0x1DF6EC0C: qemuMonitorJSONEjectMedia (qemu_monitor_json.c:2227)
==26902==    by 0x1DF57A4C: qemuMonitorEjectMedia (qemu_monitor.c:1985)
==26902==    by 0x1DF1EF2D: qemuDomainChangeEjectableMedia (qemu_hotplug.c:199)
==26902==    by 0x1DF90314: qemuDomainChangeDiskLive (qemu_driver.c:7985)
==26902==    by 0x1DF90476: qemuDomainUpdateDeviceLive (qemu_driver.c:8030)
==26902==    by 0x1DF91ED7: qemuDomainUpdateDeviceFlags (qemu_driver.c:8677)
==26902==    by 0x561785F: virDomainUpdateDeviceFlags (libvirt-domain.c:8559)
==26902==    by 0x134210: remoteDispatchDomainUpdateDeviceFlags (remote_dispatch.h:10966)
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Moving tasks to cgroups implied sched_setaffinity. Changing the cpus in
a set implies the same for all tasks in the group.
The old code put the the thread into the cpuset inherited from the
machine cgroup, which allowed it to run outside of vcpupin for a short
while.
Signed-off-by: NHenning Schild <henning.schild@siemens.com>

The machine cgroup is a superset, a parent to the emulator and vcpuX
cgroups. The parent cgroup should never have any tasks directly in it.
In fact the parent cpuset might contain way more cpus than the sum of
emulatorpin and vcpupins. So putting tasks in the superset will allow
them to run outside of <cputune>.
Signed-off-by: NHenning Schild <henning.schild@siemens.com>

virCgroupNewMachine used to add the pidleader to the newly created
machine cgroup. Do not do this implicit anymore.
Signed-off-by: NHenning Schild <henning.schild@siemens.com>

When user configures vhost-user interface and forgets to also configure
any shared memory, the search for the root cause of non-operational
interface might take unpleasantly long time.  Let's enhance user
experience by emitting a warning in the logs.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1266982Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=1240439

Ta-da! Now that we know how to open a macvtap device multiple
times, we can finally enable the multiqueue feature. Everything
else is already prepared (e.g. command line generation) from the
previous iteration where the feature was implemented for
TUN/TAP devices.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

For the multiqueue on macvtaps we are going to need to open
the device multiple times. Currently, this is not supported.
Rework the function, so that upper layers can be reworked too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

So yet again one of integer arguments that we use as a boolean.
Since the argument count of the function is unbearably long
enough, lets turn those booleans into flags.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Use the proper data structures for the iteration since ncpupids will be
made private later.

Change some of the control structures and switch to using the new vcpu
structure.

Instead of directly accessing the array add a helper to do this.

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.

The vCPU threads make sense in the counterparts that set the vCPU
bandwidth/quota, not in the emulator one. The emulator tunables are set
all the time anyways.

Drop the extra check and remove the now unneeded vm argument.

Since commit 0c04906f the check for priv->cgroup doesn't make sense as
the calls to virCgroupHasController return the same information. Remove
it and move it's comment partially to the new check.

The already spurious check was also later copied to the iothreads code.

Refactor the code flow so that 'exit_monitor:' can be removed.

This patch moves the auditing functions into places where it's certain
that hotunplug was or was not successful and reports errors from
qemuMonitorGetCPUInfo properly.

Refactor the code flow so that 'exit_monitor:' can be removed.

This patch also moves the auditing and setting of the new vCPU count
right to the place where the hotplug happens, since it's possible that
the hotplug succeeds and adds a cpu while other stuff fails.

Lastly, failures of qemuMonitorGetCPUInfo are now reported rather than
ignored. The function retuns 0 if it "successfully" detected 0 threads.

qemuDomainHotplugVcpus/qemuDomainHotunplugVcpus are complex enough in
regards of adding one CPU. Additionally it will be desired to reuse
those functions later with specific vCPU hotplug.

Move the loops for adding vCPUs into qemuDomainSetVcpusFlags so that the
helpers can be made simpler and more straightforward.

Let the function report errors internally and change it to return
standard return codes.

The cpu hotplug helper functions used negative error handling in a part
of them, although some code that was added later didn't properly set the
error codes in some cases. This would cause improper error messages in
cases where we couldn't modify the numa cpu mask and a few other cases.

Fix the logic by converting it to the regularly used pattern.

There's only very little common code among the two operations. Split the
functions so that the internals are easier to understand and refactor
later.

With a very unfortunate timing, the agent might vanish before we do the
second call while the locks were down. Re-check that the agent is
available before attempting it again.

Separate the code so that qemuDomainSetVcpusFlags contains only code
relevant to hardware hotplug/unplug.

As in commit 88dc7e0c, the helper can be used in cases where the
function actually does not access anyting in the private data besides
the agent.

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

The new helper will simplify checking whether the domain config contains
inactive vCPUs.

The code can be unified into the new accessor rather than being
scattered accross the drivers.

To support further refactors replace all write access to def->maxvcpus
with a accessor function.

The current virtlogd RPC protocol provides the ability to
handle log files associated with QEMU stdout/err. The log
protocol messages take the virt driver, domain name and
use that to form a log file path. This is quite restrictive
as it prevents us re-using the same RPC protocol messages
for logging to char device backends where the filename
can be arbitrarily user specified. It is also bad because
it means we have 2 separate locations which have to decide
on logfile name.

This change alters the RPC protocol so that we pass the
desired log file path along when opening the log file
initially. Now the virt driver is exclusively in charge
of deciding the log filename
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The qemuDomainLogContextNew method leaks the "logfile" path
on the non-virtlogd code path.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When a SCSI disk is hotplugged to a domain that does not have the required
SCSI controller already defined and loaded the following internal error occurs

error: Failed to attach device from scsi_disk.xml
error: internal error: Could not find scsi controller with index 0 required for device

Commit 0260506c added in method qemuBuildDriveDevStr a lookup of the controller
alias. The internal error occurs because in method qemuDomainAttachSCSIDisk
the automatic creation of the potentially missing SCSI controller occurs after
calling qemuBuildDriveDevStr.

This patch reverses the calling sequence.
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>