When we mount any cgroup without "-o devices", we will fail to start vms:
error: Failed to start domain vm1
error: Unable to deny all devices for vm1: No such file or directory
When we mount any cgroup without "-o cpu", we will fail to get schedinfo:
Scheduler : posix
error: unable to get cpu shares tunable: No such file or directory
We should only use the cgroup controllers which are mounted on host.
So I add virCgroupMounted() for qemuCgroupControllerActive()
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
As pointed out by Eric Blake, using dirent->d_type breaks
compilation on MinGW. This patch addresses this by using
'#if defined' as same as doing for virCgroupForDriver.
ENOENT happens normally when a subsystem is enabled with any other
subsystems and the directory of the target group has already removed
in a prior loop. In that case, the function should just return without
leaving an error message.
NB this is the same behavior as before introducing virCgroupRemoveRecursively.
When configuring serial, parallel, console or channel devices
with a file, dev or pipe backend type, it is necessary to label
the file path in the security drivers. For char devices of type
file, it is neccessary to pre-create (touch) the file if it does
not already exist since QEMU won't be allowed todo so itself.
dev/pipe configs already require the admin to pre-create before
starting the guest.
* src/qemu/qemu_security_dac.c: set file ownership for character
devices
* src/security/security_selinux.c: Set file labeling for character
devices
* src/qemu/qemu_driver.c: Add character devices to cgroup ACL
Through conversation with Kumar L Srikanth-B22348, I found
that the function of getting memory usage (e.g., virsh dominfo)
doesn't work for lxc with ns subsystem of cgroup enabled.
This is because of features of ns and memory subsystems.
Ns creates child cgroup on every process fork and as a result
processes in a container are not assigned in a cgroup for
domain (e.g., libvirt/lxc/test1/). For example, libvirt_lxc
and init (or somewhat specified in XML) are assigned into
libvirt/lxc/test1/8839/ and libvirt/lxc/test1/8839/8849/,
respectively. On the other hand, memory subsystem accounts
memory usage within a group of processes by default, i.e.,
it does not take any child (and descendant) groups into
account. With the two features, virsh dominfo which just
checks memory usage of a cgroup for domain always returns
zero because the cgroup has no process.
Setting memory.use_hierarchy of a group allows to account
(and limit) memory usage of every descendant groups of the group.
By setting it of a cgroup for domain, we can get proper memory
usage of lxc with ns subsystem enabled. (To be exact, the
setting is required only when memory and ns subsystems are
enabled at the same time, e.g., mount -t cgroup none /cgroup.)
As same as normal directories, a cgroup cannot be removed if it
contains sub groups. This patch changes virCgroupRemove to remove
all descendant groups (subdirectories) of a target group before
removing the target group.
The handling is required when we run lxc with ns subsystem of cgroup.
Ns subsystem automatically creates child cgroups on every process
forks, but unfortunately the groups are not removed on process exits,
so we have to remove them by ourselves.
With this patch, such child (and descendant) groups are surely removed
at lxc shutdown, i.e., lxcVmCleanup which calls virCgroupRemove.
The switch from %lli to %lld in virCgroupGetValueI64 is intended,
as virCgroupGetValueU64 uses base 10 too, and virCgroupSetValueI64
uses %lld to format the number to string.
Parsing is stricter now and doesn't accept trailing characters
after the actual value anymore.
Invoking virDomainSetMemory() on lxc driver results in libvirtd
segfault when cgroups has not been configured on the host.
Ensure driver->cgroup is non-null before invoking
virCgroupForDomain(). To prevent similar segfaults in the future,
ensure driver parameter to virCgroupForDomain() is non-null before
dereferencing.
When getting the driver/domain cgroup it is possible to specify
whether it should be auto created. If auto-creation was turned
off, libvirt still mistakenly created its own top level cgroup
* src/util/cgroup.c: Honour autocreate flag for top level cgroup
In the scenario where the cgroups were mounted but the
particular group did not exist, and the caller had not
requested auto-creation, the code would fail to return
an error condition. This caused the lxc_controller to
think the cgroup existed, and it then later failed when
attempting to use it
* src/util/cgroup.c: Raise an error if the cgroup path does not
exist
A cgroup file returns integer value terminated with '\n' and remaining
it has sometimes harmful effects, for example it leads virStrToLong_ull
to fail.
* src/util/cgroup.c: strip out terminating \n when reading a value
The patch implements the missing memory control APIs for lxc, i.e.,
domainGetMaxMemory, domainSetMaxMemory, domainSetMemory, and improves
domainGetInfo to return proper amount of used memory via cgroup.
* src/libvirt_private.syms: Export virCgroupGetMemoryUsage
and add missing virCgroupSetMemory
* src/lxc/lxc_driver.c: Implement missing memory functions
* src/util/cgroup.c, src/util/cgroup.h: Add the function
to get used memory
* src/conf/domain_conf.c: Don't assume all virDomainObjPtr have
a non-NULL monitor_chr field in virDomainObjFormat.
* src/lxc/lxc_driver.c: Implement suspend/resume driver APis
* src/util/cgroup.c, src/util/cgroup.h: Support the 'freezer'
cgroup controller
* src/libvirt_private.syms: Export virCgroupSetFreezerState
and virCgroupGetFreezerState
