0895a0e75d
In the 'topology' element it is mentioned, regarding the sockets
value, "They refer to the total number of CPU sockets".
This is not accurate. What we're doing is calculating the number
of sockets per NUMA node, which can be checked in the current
implementation of virHostCPUGetInfoPopulateLinux(). Calculating
the total number of sockets would break the topology sanity
check nodes*sockets*cores*threads=online_cpus.
This documentation fix is important to avoid user confusion when
seeing the output of 'virsh capabilities' and expecting it to be
equal to the output of 'lscpu'. E.g in a Power 9 host this 'lscpu'
output:
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 160
On-line CPU(s) list: 0-159
Thread(s) per core: 4
Core(s) per socket: 20
Socket(s): 2
NUMA node(s): 2
Model: 2.2 (pvr 004e 1202)
Model name: POWER9, altivec supported
And this XML output from virsh capabilities:
<cpu>
<arch>ppc64le</arch>
<model>POWER9</model>
<vendor>IBM</vendor>
<topology sockets='1' dies='1' cores='20' threads='4'/>
(...)
</cpu>
Both are correct, as long as we mention in the Libvirt documentation
that 'sockets' in the topology element represents the number of sockets
per NUMA node.
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@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
Libvirt uses the GNU Autotools build system, so in general can be built and installed with the usual commands, however, we mandate to have the build directory different than the source directory. For example, to build in a manner that is suitable for installing as root, use:
$ mkdir build && cd build
$ ../configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
$ make
$ sudo make install
While to build & install as an unprivileged user
$ mkdir build && cd build
$ ../configure --prefix=$HOME/usr
$ make
$ make install
The libvirt code relies on a large number of 3rd party libraries. These will
be detected during execution of the configure script and a summary printed
which lists any missing (optional) dependencies.
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: