f136b83139
https://bugzilla.redhat.com/show_bug.cgi?id=1503284 The way we currently start qemu from CPU affinity POV is as follows: 1) the child process is set affinity to all online CPUs (unless some vcpu pinning was given in the domain XML) 2) Once qemu is running, cpuset cgroup is configured taking memory pinning into account Problem is that we let qemu allocate its memory just anywhere in 1) and then rely in 2) to be able to move the memory to configured NUMA nodes. This might not be always possible (e.g. qemu might lock some parts of its memory) and is very suboptimal (copying large memory between NUMA nodes takes significant amount of time). The solution is to set affinity to one of (in priority order): - The CPUs associated with NUMA memory affinity mask - The CPUs associated with emulator pinning - All online host CPUs Later (once QEMU has allocated its memory) we then change this again to (again in priority order): - The CPUs associated with emulator pinning - The CPUs returned by numad - The CPUs associated with vCPU pinning - All online host CPUs Signed-off-by: Michal Privoznik <mprivozn@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@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: