Google Summer of Code 2016


Like in the previous years, libvirt is willing to apply for Google Summer of Code 2016. This page serves to collect ideas and informations for both students and mentors. But this year we have decided to try applying as a separate organization, because the number of libvirt applicants simply grew higher than qemu or kvm combined. So it wouldn't be fair if we continued outsourcing program management onto qemu project. Hopefully, this has no effect on students nor mentors.

NOTE: The mentoring organizations have NOT been chosen yet, so please take this list as non guaranteed yet.


Firstly, there were some important changes in rules. Be sure to read them first. On the top of those we have some additional guidelines as follows.

Each student can sign up for as many ideas listed here as they want. With each candidate respective mentor will do an interview (usually through IRC) consisting of a coding exercise and some follow up questions to evaluate their ability to code. Some examples of exercises from previous years can be found here.

Additional information

This page is meant to extend qemu page dedicated to GSoC: [1].


  • IRC (GSoC specific): #qemu-gsoc on

  • IRC (development and general): #virt on

  • libvir-list

Please contact the respective mentor for the idea you are interested in. For general questions feel free to contact me: Michal Prívozník (IRC nick: mprivozn).

Project ideas

Here is the list of libvirt ideas. If an idea involving work in both libvirt and qemu appears it should be listed here and on qemu list too.

Introducing job control to the storage driver

Summary: Implement abstract job control and use it to improve storage driver.

Currently, libvirt support job cancellation and progress reporting on domains. That is, if there's a long running job on a domain, e.g. migration, libvirt reports how much data has already been transferred to the destination and how much still needs to be transferred. However, libvirt lacks such information reporting in storage area, to which libvirt developers refer to as the storage driver. The aim is to report progress on several storage tasks, like volume wiping, file allocation an others.

Making virsh more bash like

Summary: If you have ever used virsh, you certainly reached the point where you stuggle with its user friendliness. Or unfriendliness I should rather say. Virsh is missing a lot of bash functionality that users consider natural: from automatic completion of object names, through redirecting command outputs through piping commands together. The aim would be to make these functions available in virsh and thus make user experience better.

Abstracting device address allocation

Summary: There are many types of addresses that devices can have in libvirt's XML description. Not all address types are properly assigned and checked for duplicates. The goal of this is to have an abstract data structure that would handle assigning all kinds of addresses, handle duplicates, etc.

libvirt bindings for node.js

Summary: There are few libvirt bindings for node.js available via npm. However none of them expose all libvirt APIs. That is mainly because they are manually written and not automatically generated. The aim is to utilize same information that python bindings do and automatically generate node libvirt bindings based on that information so that they don't need to be modified for every new API.

  • Component: libvirt

  • Skill level: advanced

  • Language: C, C++, node-gyp, scripting language of your choice

  • Mentor: Martin Kletzander <>

  • Suggested by: Martin Kletzander <>


QEMU command line generator XML fuzzing

Summary: Using fuzzing techniques to generate unusual XML to feed to QEMU command line generator

There are a huge number of potential variants of XML documents that can be fed into libvirt. Only a subset of these are valid for generating QEMU command lines. It is likely that there are cases where omitting certain attributes or XML elements will cause the QEMU command line generator to crash. Using fuzzing techniques to generate unusual XML documents which could then be fed through the test suite may identify crashes.


  • Component: libvirt

  • Skill level: intermediate

  • Language: C

  • Mentor: Martin Kletzander <>

  • Suggested by: Daniel Berrange

Asynchronous lifecycle events for storage objects

Summary: Implement asynchronous lifecycle events for libvirt's storage APIs. Lifecycle events allow apps to get notifications about object creation, deletion, and state change with out having to poll libvirt at regular intervals.

There are already lifecycle event APIs for domains/VMs and network objects, and generic infrastructure handling a lot of the heavy lifting, so there's plenty of examples to follow to implement much of this.

Time permitting, there's lots of additional work that can be done:

  • Add support for these events in virt-manager UI tool. In fact this is probably the best way to actually test the APIs

  • Extend libvirt (and virt-manager) with async events support for nodedev objects (physical host devices). This will likely be a simple task after the storage APIs are added.

  • Investigate adding event support for interface objects (host network devices). Implementing this for libvirt's udev driver is probably straightforward, but the netcf driver may be more complicated.



Conversion to and from OCI-formatted containers

Summary: Container formats is being standardized by Open Container Initiative. libvirt-lxc support for them would be awesome.

virsh has domxml-from-native and domxml-to-native to help converting between libvirt configuration and another one. In the libvirt-lxc driver the domxml-from-native command already supports converting from lxc (yes, naming is confusing). The goal is not only to implement it also for OCI format but also to implement export to OCI format.

Some code pointers to get started:

  • src/lxc/lxc_native.c is the place where the lxc import is implemented.

  • The starting point in the lxc driver is the connectDomainXMLFromNative function pointer.

  • To add export capabilities, the connectDomainXMLToNative will have to be defined.

Note that there may be tricky things to handle, like disk images conversion to a rootfs, but this project aims at implementing the simple cases first. If time permits, the corner cases could be handled as well.


  • Component: libvirt

  • Skill level: intermediate

  • Language: C

  • Mentor: Cédric Bosdonnat <>

  • Suggested by: Cédric Bosdonnat

Introduce libiscsi pool

Summary: Currently there is an iSCSI storage pool in libvirt. However, all the management communication is done by spawning iscsiadm binary. The aim of this project would be to rework the storage driver backend so that is uses libiscsi directly.

Libvirt has many drivers to address various parts of virtualization infrastructure. For example, it has so called domain driver which is responsible for managing virtual machines, network driver for providing connectivity to virtual machines and it has storage driver for managing storage pools and volumes. The enumeration is not complete, of course. The aim of the storage driver is to provide units of storage to virtual machines. In order to achieve that goal, the storage driver offers several APIs for management applications to use, e.g. creating a pool of volumes, creating a single volume within that pool and so on. Because of the nature of storage world, the driver has many backends which implement the APIs based on underlying storage technology used. Thus there's an LVM backend for managing LVs, FS backend for working with files and directories, and there's iSCSI backend too. This backend, however, uses iscsiadm binary to execute the desired operation. The binary can be spawned multiple times during single execution of an API. This is suboptimal esp. if there exists a better solution - libiscsi. This should be 1:1 replacement, but that's only an uneducated guess. Student working on this project should explore the possibilities of doing the replacement and implement it as well.



Enhancing libvirt-designer

Summary: The project is in its very early stage of life. The libvirt-designer tries to ease generation of libvirt XML with coworking with libosinfo project. See for a more detailed description.

During Summer of Code 2015, new API was added to make it possible to configure more VM details. This project would be a follow-up on that work, this could be :

  • switch GNOME Boxes to using libvirt-designer instead of its own code when creating a VM. This involves work in Vala for the Boxes side, and in C on the libvirt-designer side

  • improve libvirt-designer to make it appropriate for use by virt-manager/virt-install (written in Python)

  • work on both libvirt-designer and libvirt-builder, with the aim of creating a command-line tool to automatically create and install a VM (through libosinfo).

Contact me and we can refine these potential tasks and find something suitable.


  • Skill level: beginner

  • Language: C, (potentially Python, Vala)

  • Mentor: Christophe Fergeau <>, teuf on IRC (#qemu-gsoc OFTC)

  • Suggested by: Christophe Fergeau <>

Integrate secrets driver with DEO

Summary: Provide encryption of secrets stored by libvirt, optionally using DEO to unlock the master key

The libvirt secrets driver currently stores secrets in base64 plain text files with the recommendation that the filesystem be backed by a LUKS encrypted block volume. This provides protection against offline compromise, but is far from ideal. Libvirt should have its own master AES key that it uses to encrypt the individual secrets files, instead of storing them in base64.

Of course there is a chicken & egg problem of how to store the master AES key itself. For this we should have the ability to integrate with DEO to allow the master key to be password protected on local node, having DEO decrypt it at libvirtd startup.



  • Skill level: intermediate

  • Language: C

  • Mentor: Email address and IRC nick

  • Suggested by: Daniel Berrange


=== TITLE ===

 '''Summary:''' Short description of the project

 Detailed description of the project.

 * Wiki links to relevant material
 * External links to mailing lists or web sites

 * Skill level: beginner or intermediate or advanced
 * Language: C
 * Mentor: Email address and IRC nick
 * Suggested by: Person who suggested the idea