Many drivers had a comment that they did not validate the incoming 'flags' to virDomainGetXMLDesc() because they were relying on virDomainDefFormat() to do it instead. This used to be the case (at least since 461e0f1a and friends in 0.9.4 added unknown flag checking in general), but regressed in commit 0ecd6851 (1.2.12), when all of the drivers were changed to pass 'flags' through the new helper virDomainDefFormatConvertXMLFlags(). Since this helper silently ignores unknown flags, we need to implement flag checking in each driver instead. Annoyingly, this means that any new flag values added will silently be ignored when targeting an older libvirt, rather than our usual practice of loudly diagnosing an unsupported flag. Add comments in domain_conf.[ch] to remind us to be extra vigilant about the impact when adding flags (a new flag to add data is safe if the older server omitting the requested data doesn't break things in the newer client; a new flag to suppress data rather than enhancing the existing VIR_DOMAIN_XML_SECURE may form a data leak or even a security hole). In the qemu driver, there are multiple callers all funnelling to qemuDomainDefFormatBufInternal(); many of them already validated flags (and often only a subset of the full set of possible flags), but for ease of maintenance, we can also check flags at the common helper function. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Ferlan <jferlan@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: