c159db4cc0
It all started as a simple bug: trying to move domain memory between NUMA nodes (e.g. via virsh numatune) did not work. I've traced the problem to qemuProcessHook() because that's where we decide whether to rely on CGroups or use numactl APIs to satisfy <numatune/>. The problem was that virCgroupControllerAvailable() was telling us that cpuset controller is unavailable. This is CGroupsV2, and pretty weird because CGroupsV2 definitely do support cpuset controller and I had them mounted in a standard way. What I found out (with Pavel's help) was that virCgroupNewSelf() was looking into the following path to detect supported controllers: /sys/fs/cgroup/system.slice/cgroup.controllers However, if there's no other VM running then the system.slice only has 'memory' and 'pids' controllers. Therefore, we saw 'cpuset' as not available. The fix is to look at the top most path, which has the full set of controllers: /sys/fs/cgroup/cgroup.controllers Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1976690 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser
General Public License, version 2.1 (or later). Some parts of the code
that are not part of the C library may have the more restrictive GNU
General Public License, version 2.0 (or later). See the files
COPYING.LESSER and COPYING for full license
terms & conditions.
Installation
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: