The QEMU driver has a list of devices nodes that are whitelisted
for all guests. The kernel has recently started returning an
error if you try to whitelist a device which does not exist.
This causes a warning in libvirt logs and an audit error for
any missing devices. eg

2013-02-27 16:08:26.515+0000: 29625: warning : virDomainAuditCgroup:451 : success=no virt=kvm resrc=cgroup reason=allow vm="vm031714" uuid=9d8f1de0-44f4-a0b1-7d50-e41ee6cd897b cgroup="/sys/fs/cgroup/devices/libvirt/qemu/vm031714/" class=path path=/dev/kqemu rdev=? acl=rw
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The code for putting the emulator threads in a separate cgroup
would spam the logs with warnings

2013-02-27 16:08:26.731+0000: 29624: warning : virCgroupMoveTask:887 : no vm cgroup in controller 3
2013-02-27 16:08:26.731+0000: 29624: warning : virCgroupMoveTask:887 : no vm cgroup in controller 4
2013-02-27 16:08:26.732+0000: 29624: warning : virCgroupMoveTask:887 : no vm cgroup in controller 6

This is because it has only created child cgroups for 3 of the
controllers, but was trying to move the processes from all the
controllers. The fix is to only try to move threads in the
controllers we actually created. Also remove the warning and
make it return a hard error to avoid such lazy callers in the
future.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

https://bugzilla.redhat.com/show_bug.cgi?id=896685 points out
a regression caused by commit 38c4a9cc - libvirt only labels
the backing chain if the backing chain cache is populated, but
the code to populate the cache was only conditionally performed
if cgroup labeling was necessary.

* src/qemu/qemu_cgroup.c (qemuSetupCgroup): Hoist cache setup...
* src/qemu/qemu_process.c (qemuProcessStart): ...earlier into
caller, where it is now unconditional.

Rename all the usbDeviceXXX and usbXXXDevice APIs to have a
fixed virUSBDevice name prefix

When iterating over USB host devices to setup cgroups, the
usbDevice object was leaked in both LXC and QEMU driers
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>

While OOM can have knock-on effects that trash a system, generally
the first symptom is one of memory thrashing.

* src/qemu/qemu_cgroup.c (qemuSetupCgroup): Reword slightly.

Currently, if there's no hard memory limit defined for a domain,
libvirt tries to calculate one, based on domain definition and magic
equation and set it upon the domain startup. The rationale behind was,
if there's a memory leak or exploit in qemu, we should prevent the
host system trashing. However, the equation was too tightening, as it
didn't reflect what the kernel counts into the memory used by a
process. Since many hosts do have a swap, nobody hasn't noticed
anything, because if hard memory limit is reached, process can
continue allocating memory on a swap. However, if there is no swap on
the host, the process gets killed by OOM killer. In our case, the qemu
process it is.

To prevent this, we need to relax the hard RSS limit. Moreover, we
should reflect more precisely the kernel way of accounting the memory
for process. That is, even the kernel caches are counted within the
memory used by a process (within cgroups at least). Hence the magic
equation has to be changed:

  limit = 1.5 * (domain memory + total video memory) + (32MB for cache
          per each disk) + 200MB

To bring in line with new naming practice, rename the=
src/util/cgroup.{h,c} files to vircgroup.{h,c}
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When LXC labels USB devices during hotplug, it is running in
host context, so it needs to pass in a vroot path to the
container root.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Remove the obsolete 'qemud' naming prefix and underscore
based type name. Introduce virQEMUDriverPtr as the replacement,
in common with LXC driver naming style

The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When the cpu placement model is "auto", it sets the affinity for
domain process with the advisory nodeset from numad, however,
creating cgroup for the domain process (called emulator thread
in some contexts) later overrides that with pinning it to all
available pCPUs.

How to reproduce:

  * Configure the domain with "auto" placement for <vcpu>, e.g.
    <vcpu placement='auto'>4</vcpu>
  * % virsh start dom
  * % cat /proc/$dompid/status

Though the emulator cgroup cause conflicts, but we can't simply
prohibit creating it, as other tunables are still useful, such
as "emulator_period", which is used by API
virDomainSetSchedulerParameter. So this patch doesn't prohibit
creating the emulator cgroup, but inherit the nodeset from numad,
and reset the affinity for domain process.

* src/qemu/qemu_cgroup.h: Modify definition of qemuSetupCgroupForEmulator
                          to accept the passed nodenet
* src/qemu/qemu_cgroup.c: Set the affinity with the passed nodeset

Minor cleanup made possible by previous simplifications.

* src/qemu/qemu_cgroup.h (qemuSetupDiskCgroup)
(qemuTeardownDiskCgroup): Alter signature.
* src/qemu/qemu_cgroup.c (qemuSetupDiskCgroup)
(qemuTeardownDiskCgroup, qemuSetupCgroup): Update all uses.
* src/qemu/qemu_hotplug.c (qemuDomainDetachPciDiskDevice)
(qemuDomainDetachDiskDevice): Likewise.
* src/qemu/qemu_driver.c (qemuDomainAttachDeviceDiskLive)
(qemuDomainChangeDiskMediaLive)
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotUndoSingleDiskActive): Likewise.

We used to walk the backing file chain at least twice per disk,
once to set up cgroup device whitelisting, and once to set up
security labeling.  Rather than walk the chain every iteration,
which possibly includes calls to fork() in order to open root-squashed
NFS files, we can exploit the cache of the previous patch.

* src/conf/domain_conf.h (virDomainDiskDefForeachPath): Alter
signature.
* src/conf/domain_conf.c (virDomainDiskDefForeachPath): Require caller
to supply backing chain via disk, if recursion is desired.
* src/security/security_dac.c
(virSecurityDACSetSecurityImageLabel): Adjust caller.
* src/security/security_selinux.c
(virSecuritySELinuxSetSecurityImageLabel): Likewise.
* src/security/virt-aa-helper.c (get_files): Likewise.
* src/qemu/qemu_cgroup.c (qemuSetupDiskCgroup)
(qemuTeardownDiskCgroup): Likewise.
(qemuSetupCgroup): Pre-populate chain.

According to our recent changes (clarifications), we should be pinning
qemu's emulator processes using the <vcpu> 'cpuset' attribute in case
there is no <emulatorpin> specified.  This however doesn't work
entirely as expected and this patch should resolve all the remaining
issues.

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Should not return 0 when failed to setup cgroup.

This is another fix for the emulator-pin series. When going through
the cputune pinning settings, the current code is trying to pin all
the CPUs, even when not all of them are specified. This causes error
in the subsequent function which, of course, cannot find the cpu to
pin. Since it's enough to pass the correct VCPU ID to the function,
the fix is trivial.

When domain XML contains any of the elements for setting up CPU
scheduling parameters (period, quota, emulator_period, or
emulator_quota) we need cpu cgroup to enforce the configuration.
However, the existing code would just ignore silently such settings if
either cgroups were not available at all cpu cgroup was not available.
Moreover, APIs for manipulating CPU scheduler parameters were already
failing if cpu cgroup was not available. This patch makes cpu cgroup
mandatory for all domains that use CPU scheduling elements in their XML.

If cgroups are enabled in general but cpu cgroup is disabled in
qemu.conf or not mounted at all, libvirt would refuse to start any
domain even though scheduler parameters are not set in domain XML.

This patch makes cpu cgroup mandatory only for domains that actually
want to use it.

Commit 4b03d591 changed the pinning
behavior in a way that makes some machines non-startable.

The comment mentioning that we cannot control each vcpu when there is
not VCPU<-> PID mapping available is true, however, this isn't
necessarily an error, because this can be caused by old QEMU without
support for "query-cpus" command as well as a software emulated
machines that don't create more than one process.

This patch introduces support of setting emulator's period and
quota to limit cpu bandwidth when the vm starts.  Also updates
XML Schema for new entries and docs.

This patch changes the behaviour of xml element cputune.period
and cputune.quota to limit cpu bandwidth only for vcpus, and no
longer limit cpu bandwidth for the whole guest.

The reasons to do this are:

  - This matches docs of cputune.period and cputune.quota.
  - The other parts excepting vcpus are treated as "emulator",
    and there are separate period/quota settings for emulator
    in the subsequent patches

Introduce qemuSetupCgroupEmulatorPin() function to add emulator
threads pin info to cpuset cgroup, the same as vcpupin.
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: NHu Tao <hutao@cn.fujitsu.com>

vcpu threads pin are implemented using sched_setaffinity(), but
not controlled by cgroup. This patch does the following things:

    1) enable cpuset cgroup
    2) reflect all the vcpu threads pin info to cgroup
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: NHu Tao <hutao@cn.fujitsu.com>

Create a new cgroup and move all emulator threads to the new cgroup.
And then we can do the other things:
1. limit only vcpu usage rather than the whole qemu
2. limit for emulator threads(include vhost-net threads)
Signed-off-by: NWen Congyang <wency@cn.fujitsu.com>
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: NHu Tao <hutao@cn.fujitsu.com>

If there's a memory leak in qemu or qemu is exploited the host's
system will sooner or later start trashing instead of killing
the bad process. This however has impact on performance and other
guests as well. Therefore we should set a reasonable RSS limit
even when user hasn't set any. It's better to be secure by default.

Any time we have a string with no % passed through gettext, a
translator can inject a % to cause a stack overread.  When there
is nothing to format, it's easier to ask for a string that cannot
be used as a formatter, by using a trivial "%s" format instead.

In the past, we have used --disable-nls to catch some of the
offenders, but that doesn't get run very often, and many more
uses have crept in.  Syntax check to the rescue!

The syntax check can catch uses such as
virReportError(code,
               _("split "
                 "string"));
by using a sed script to fold context lines into one pattern
space before checking for a string without %.

This patch is just mechanical insertion of %s; there are probably
several messages touched by this patch where we would be better
off giving the user more information than a fixed string.

* cfg.mk (sc_prohibit_diagnostic_without_format): New rule.
* src/datatypes.c (virUnrefConnect, virGetDomain)
(virUnrefDomain, virGetNetwork, virUnrefNetwork, virGetInterface)
(virUnrefInterface, virGetStoragePool, virUnrefStoragePool)
(virGetStorageVol, virUnrefStorageVol, virGetNodeDevice)
(virGetSecret, virUnrefSecret, virGetNWFilter, virUnrefNWFilter)
(virGetDomainSnapshot, virUnrefDomainSnapshot): Add %s wrapper.
* src/lxc/lxc_driver.c (lxcDomainSetBlkioParameters)
(lxcDomainGetBlkioParameters): Likewise.
* src/conf/domain_conf.c (virSecurityDeviceLabelDefParseXML)
(virDomainDiskDefParseXML, virDomainGraphicsDefParseXML):
Likewise.
* src/conf/network_conf.c (virNetworkDNSHostsDefParseXML)
(virNetworkDefParseXML): Likewise.
* src/conf/nwfilter_conf.c (virNWFilterIsValidChainName):
Likewise.
* src/conf/nwfilter_params.c (virNWFilterVarValueCreateSimple)
(virNWFilterVarAccessParse): Likewise.
* src/libvirt.c (virDomainSave, virDomainSaveFlags)
(virDomainRestore, virDomainRestoreFlags)
(virDomainSaveImageGetXMLDesc, virDomainSaveImageDefineXML)
(virDomainCoreDump, virDomainGetXMLDesc)
(virDomainMigrateVersion1, virDomainMigrateVersion2)
(virDomainMigrateVersion3, virDomainMigrate, virDomainMigrate2)
(virStreamSendAll, virStreamRecvAll)
(virDomainSnapshotGetXMLDesc): Likewise.
* src/nwfilter/nwfilter_dhcpsnoop.c (virNWFilterSnoopReqLeaseDel)
(virNWFilterDHCPSnoopReq): Likewise.
* src/openvz/openvz_driver.c (openvzUpdateDevice): Likewise.
* src/openvz/openvz_util.c (openvzKBPerPages): Likewise.
* src/qemu/qemu_cgroup.c (qemuSetupCgroup): Likewise.
* src/qemu/qemu_command.c (qemuBuildHubDevStr, qemuBuildChrChardevStr)
(qemuBuildCommandLine): Likewise.
* src/qemu/qemu_driver.c (qemuDomainGetPercpuStats): Likewise.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Likewise.
* src/rpc/virnetsaslcontext.c (virNetSASLSessionGetIdentity):
Likewise.
* src/rpc/virnetsocket.c (virNetSocketNewConnectUNIX)
(virNetSocketSendFD, virNetSocketRecvFD): Likewise.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskBuildPool): Likewise.
* src/storage/storage_backend_fs.c
(virStorageBackendFileSystemProbe)
(virStorageBackendFileSystemBuild): Likewise.
* src/storage/storage_backend_rbd.c
(virStorageBackendRBDOpenRADOSConn): Likewise.
* src/storage/storage_driver.c (storageVolumeResize): Likewise.
* src/test/test_driver.c (testInterfaceChangeBegin)
(testInterfaceChangeCommit, testInterfaceChangeRollback):
Likewise.
* src/vbox/vbox_tmpl.c (vboxListAllDomains): Likewise.
* src/xenxs/xen_sxpr.c (xenFormatSxprDisk, xenFormatSxpr):
Likewise.
* src/xenxs/xen_xm.c (xenXMConfigGetUUID, xenFormatXMDisk)
(xenFormatXM): Likewise.

Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c

Update the QEMU driver to use virReportError instead of
the qemuReportError custom macro
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

This patch cleans up some missing "%s" before translation macros,
for strings which are const without format specifiers

The only useful translation of "%s" as a format string is "%s" (I
suppose you could claim "%1$s" is also valid, but why bother).  So
it is not worth translating; fixing this exposes some instances
where we were failing to translate real error messages.  This makes
the fix of commit 097da1ab more generic, as well as ensuring no
future regressions.

* cfg.mk (sc_prohibit_useless_translation): New rule.
* src/lxc/lxc_driver.c (lxcSetVcpuBWLive): Fix offender.
* src/openvz/openvz_conf.c (openvzReadFSConf): Likewise.
* src/qemu/qemu_cgroup.c (qemuSetupCgroupForVcpu): Likewise.
* src/qemu/qemu_driver.c (qemuSetVcpusBWLive): Likewise.
* src/xenapi/xenapi_utils.c (xenapiSessionErrorHandle): Likewise.