[libvirt-users] RLIMIT_MEMLOCK in container environment

[Daniel P. Berrangé]

On Wed, Aug 21, 2019 at 01:37:21PM -0700, Ihar Hrachyshka wrote:
> Hi all,
> 
> KubeVirt uses libvirtd to manage qemu VMs represented as Kubernetes
> API resources. In this case, libvirtd is running inside an
> unprivileged pod, with some host mounts / capabilities added to the
> pod, needed by libvirtd and other services.
> 
> One of the capabilities libvirtd requires for successful startup
> inside a pod is SYS_RESOURCE. This capability is used to adjust
> RLIMIT_MEMLOCK ulimit value depending on devices attached to the
> managed guest, both on startup and during hotplug. AFAIU the need to
> lock the memory is to avoid pages being pushed out from RAM into swap.

Libvirt shouldn't set RLIMIT_MEMLOCK by default, unless there's
something in the XML that requires it - one of

 - hard limit memory value is present
 - host PCI device passthrough is requested
 - memory is locked into RAM

which of these are you actually using ?

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|