Ever since the feature was introduced with commit 0f8e7ae33ace, it has contained a logic error in that it attempted to use a NUMA node map where a CPU map was expected. Because of that, guests using <numatune> might fail to start: # virsh start guest error: Failed to start domain guest error: cannot set CPU affinity on process 40055: Invalid argument This was particularly easy to trigger on POWER 8 machines, where secondary threads always show up as offline in the host: having <numatune> <memory mode='strict' placement='static' nodeset='1'/> </numatune> in the guest configuration, for example, would result in libvirt trying to set the process affinity so that it would prefer running on CPU 1, but since that's a secondary thread and thus shows up as offline, the operation would fail, and so would starting the guest. Use the newly introduced virNumaNodesetToCPUset() to convert the NUMA node map to a CPU map, which in the example above would be 48,56,64,72,80,88 - a valid input for virProcessSetAffinity(). https://bugzilla.redhat.com/show_bug.cgi?id=1703661 Signed-off-by: Andrea Bolognani <abologna@redhat.com> Reviewed-by: Ján Tomko <jtomko@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 2.1 (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. For example, to build in a manner that is suitable for installing as root, use:
$ ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
$ make
$ sudo make install
While to build & install as an unprivileged user
$ ./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: