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Since its 5.14 release the Linux kernel allows userspace to define trusted groups of processes/threads that can run on sibling Hyper Threads (HT) at the same time. This is to mitigate side channel attacks like L1TF or MDS. If there are no tasks to fully utilize all HTs, then a HT will idle instead of running a task from another (un-)trusted group. On low level, this is implemented by cookies (effectively an UL value): processes in the same trusted group share the same cookie and cookie is unique to the group. There are four basic operations: 1) PR_SCHED_CORE_GET -- get cookie of given PID, 2) PR_SCHED_CORE_CREATE -- create a new unique cookie for PID, 3) PR_SCHED_CORE_SHARE_TO -- push cookie of the caller onto another PID, 4) PR_SCHED_CORE_SHARE_FROM -- pull cookie of another PID into the caller. Since a system where the code is built can be different to the one where the code is ran let's provide declaration of some values. It's not unusual for distros to ship older linux-headers than the actual kernel. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
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==============================
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:
https://libvirt.org
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:
https://libvirt.org/contact.html