total_cpus is the total number of CPUs on the host
need_cpus is the number of CPUs we need to look at

(need_cpus can be larger than ncpus, because we need to look
 at CPUs before the startcpu too, even if we aren't reporting
 their stats)

Currently, virCgroupGetPercpuStats is only used by the LXC driver,
filling out the CPUTIME stats. qemuDomainGetPercpuStats does this
and also filles out VCPUTIME stats.

Extend virCgroupGetPercpuStats to also report VCPUTIME stats if
nvcpupids is non-zero. In the LXC driver, we don't have cpupids.
In the QEMU driver, there is at least one cpupid for a running domain,
so the behavior shouldn't change for QEMU either.

Also rename getSumVcpuPercpuStats to virCgroupGetPercpuVcpuSum.

We need to return the number of successfully populated stats,
not the nparams supplied by the user.

Signed-off-by: NHongwei Bi <hwbi2008@gmail.com>

When I start multi VMs coincidently and any of the cgroup directories
named machine doesn't exist. There's a chance that VM start failed because
of creating directory failed:
Unable to initialize /machine cgroup: File exists
When the errno returned by mkdir in virCgroupMakeGroup is EEXIST,
we should pass it through and continue to start the VM.
Signed-off-by: NWang Yufei <james.wangyufei@huawei.com>

Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Commit a1cbe4b5 added a check for spaces around assignments and this
patch extends it to checks for spaces around '=='.  One exception is
virAssertCmpInt where comma after '==' is acceptable (since it is a
macro and '==' is its argument).
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Running ./autobuild.sh detected a mingw failure:

  CCLD     libvirt.la
Cannot export virCgroupGetPercpuStats: symbol not defined
Cannot export virCgroupSetOwner: symbol not defined

* src/util/vircgroup.c (virCgroupGetPercpuStats)
(virCgroupSetOwner): Implement stubs.
Signed-off-by: NEric Blake <eblake@redhat.com>

This function is needed for user namespaces, where we need to chmod()
the cgroup to the initial uid/gid such that systemd is allowed to
use the cgroup.
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Commit 65158899 broke the build on FreeBSD:
In function `qemuDomainGetCPUStats':
/../../src/qemu/qemu_driver.c:16102:
undefined reference to `virCgroupGetDomainTotalCpuStats'

To reuse this from other drivers, like lxc.

This reads blkio stats from blkio.throttle.io_service_bytes and
blkio.throttle.io_serviced.

This patch introduces virCgroupSetBlkioDeviceReadIops,
virCgroupSetBlkioDeviceWriteIops,
virCgroupSetBlkioDeviceReadBps and
virCgroupSetBlkioDeviceWriteBps,

we can use these interfaces to set up throttle
blkio cgroup for domain.

This patch also adds the new throttle blkio cgroup
elements to the test xml.
Signed-off-by: NGuan Qiang <hzguanqiang@corp.netease.com>
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>

Since kernel 3.12 (commit 34ff8dc08956098563989d8599840b130be81252 in
linux-stable.git in particular) the value for 'unlimited' in cgroup
memory limits changed from LLONG_MAX to ULLONG_MAX.  Due to rather
unfortunate choice of our VIR_DOMAIN_MEMORY_PARAM_UNLIMITED constant
(which we transfer as an unsigned long long in Kibibytes), we ended up
with the situation described below (applies to x86_64):

 - 2^64-1 (ULLONG_MAX) -- "unlimited" in kernel = 3.12

 - 2^63-1 (LLONG_MAX) -- "unlimited" in kernel < 3.12
 - 2^63-1024 -- our PARAM_UNLIMITED scaled to Bytes

 - 2^53-1 -- our PARAM_UNLIMITED unscaled (in Kibibytes)

This means that when any number within (2^63-1, 2^64-1] is read from
memory cgroup, we are transferring that number instead of "unlimited".
Unfortunately, changing VIR_DOMAIN_MEMORY_PARAM_UNLIMITED would break
ABI compatibility and thus we have to resort to a different solution.

With this patch every value greater than PARAM_UNLIMITED means
"unlimited".  Even though this may seem misleading, we are already in
such unclear situation when running 3.12 kernel with memory limits set
to 2^63.

One example showing most of the problems at once (with kernel 3.12.2):
 # virsh memtune asdf --hard-limit 9007199254740991 --swap-hard-limit -1
 # echo 12345678901234567890 >\
/sys/fs/cgroup/memory/machine/asdf.libvirt-qemu/memory.soft_limit_in_bytes
 # virsh memtune asdf
 hard_limit     : 18014398509481983
 soft_limit     : 12056327051986884
 swap_hard_limit: 18014398509481983
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Unifying codding style, replace 'newpath' with 'newPath'.

From: Zhou Yimin <zhouyimin@huawei.com>

The range of valid values for cgroup tunables has
changed in the past and may change again in future
kernels. Avoid hardcoding range checks in libvirt
code, delegating range checking to the kernel itself.
Signed-off-by: NChen Hanxiao <chenhanxiao@cn.fujitsu.com>

When EINVAL is returned while changing a cgroups value, tell
user that what values are invalid for the field.
Signed-off-by: NChen Hanxiao <chenhanxiao@cn.fujitsu.com>

s/shoule/should
Signed-off-by: NChen Hanxiao <chenhanxiao@cn.fujitsu.com>

The function existed in two identical instances in lxc and qemu. Move it
to vircgroup.c and simplify it. Refactor the callers too.

Semantics of the libvirt helper are more clear. This change also allows
to clean up some pieces of code.

Debian systems may run the 'systemd-logind' daemon, which causes the
/sys/fs/cgroup/systemd  mount to be setup, but no other cgroup
controllers are created. While the LXC driver considers cgroups to
be mandatory, the QEMU driver is supposed to accept them as optional.

We detect whether they are present by looking in /proc/mounts for
any mounts of type 'cgroups', but this is not sufficient. We need to
skip any named mounts (as seen by a name=XXX string in the mount
options), so that we only detect actual resource controllers.

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=721979Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Some users in Ubuntu/Debian seem to have a setup where all the
cgroup controllers are mounted on /sys/fs/cgroup rather than
any /sys/fs/cgroup/<controller> name. In the loop which detects
which controllers are present for a mount point we were modifying
'mnt_dir' field in the 'struct mntent' var, but not always restoring
the original value. This caused detection to break in the all-in-one
mount setup.

Fix that logic bug and add test case coverage for this mount
setup.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Complete the refactoring by adding missing stubs so it compiles on
platform without cgroup support.
Signed-off-by: NEric Blake <eblake@redhat.com>

Complete moving to VIR_CGROUP_SUPPORTED
Signed-off-by: NEric Blake <eblake@redhat.com>

Continue converting to VIR_CGROUP_SUPPORTED
Signed-off-by: NEric Blake <eblake@redhat.com>

- Convert virCgroupGet* to VIR_CGROUP_SUPPORTED
- Convert virCgroup(Get|Set)FreezerState to VIR_CGROUP_SUPPORTED
Signed-off-by: NEric Blake <eblake@redhat.com>

- Introduce VIR_CGROUP_SUPPORTED conditional
- Convert virCgroupKill* to use it
- Convert virCgroupIsolateMount() to use it
- Convert virCgroupRemoveRecursively to VIR_CGROUP_SUPPORTED
Signed-off-by: NEric Blake <eblake@redhat.com>

Make future patches smaller by matching a sane header listing in
the first place.  No semantic change.

* src/util/vircgroup.h: Move free next to new, and controller
functions next to each other.
* src/util/vircgroup.c (virCgroupFree, virCgroupHasController)
(virCgroupPathOfController, virCgroupRemoveRecursively)
(virCgroupRemove): Sort implementation to be closer to header.
Signed-off-by: NEric Blake <eblake@redhat.com>

Avoid a forward declaration of a static function.

* src/util/vircgroup.c (virCgroupPartitionNeedsEscaping)
(virCgroupParticionEscape): Move up.
Signed-off-by: NEric Blake <eblake@redhat.com>

Format all functions with two blank lines between, and return type
on separate line from function name.  Also break some lines longer
than 80 columns.  This makes the subsequent macro refactoring
less noisy.

* src/util/vircgroup.c: Match prevailing style.
Signed-off-by: NEric Blake <eblake@redhat.com>

Make the virCgroupNewMachine method try to use systemd-machined
first. If that fails, then fallback to using the traditional
cgroup setup code path.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When systemd is involved in managing processes, it may start
killing off & tearing down croups associated with the process
while we're still doing virCgroupKillPainfully. We must
explicitly check for ENOENT and treat it as if we had finished
killing processes
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Systemd uses a named cgroup mount for tracking processes. Add
it as another type of controller, albeit one which we have to
special case in a number of places. In particular we must
never create/delete directories there, nor add tasks. Essentially
the systemd mount is to be considered read-only for libvirt.

With this change both the virCgroupDetectPlacement and
virCgroupCopyPlacement methods must be invoked. The copy
placement method will copy setup for resource controllers
only. The detect placement method will probe for any
named controllers, or resource controllers not already
setup.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The previous patch was incomplete.

  CC       libvirt_util_la-vircgroup.lo
../../src/util/vircgroup.c:70:12: error: 'virCgroupPartitionEscape' declared 'static' but never defined [-Werror=unused-function]
 static int virCgroupPartitionEscape(char **path);
            ^

* src/util/vircgroup.c (virCgroupPartitionEscape): Move forward
declaration inside conditional.
Signed-off-by: NEric Blake <eblake@redhat.com>

The virCgroupValidateMachineGroup method calls some functions
which are only conditionally compiled, thus it too must be
made conditional. This fixes the build on non-Linux hosts.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

If the app has provided a whitelist of controllers to be used,
we skip detecting its mount point. We still, however, fill in
the placement info which later confuses the machine name
validation code. Skip detecting placement if the controller
mount point is not set
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When detecting cgroups we must honour any controllers
whitelist the driver may have.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When a VM has an 'emulator' child cgroup present, we must
strip off that suffix when detecting the cgroup for a
machine

Rename the virCgroupIsValidMachineGroup method to
virCgroupValidateMachineGroup to make a bit clearer
that this isn't simply a boolean check, it will make
changes to the object.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>