Bug reporting

Security Issues

If you think that an issue with libvirt may have security implications, please do not publicly report it in the bug tracker, mailing lists, or irc. Libvirt has a dedicated process for handling (potential) security issues that should be used instead. So if your issue has security implications, ignore the rest of this page and follow the security process instead.

Bug Tracking

If you are using libvirt binaries from a Linux distribution check below for distribution specific bug reporting policies first.

General libvirt bug reports

Bugs in upstream libvirt code should be reported as issues in the appropriate project on GitLab. Before submitting a ticket, check the existing tickets to see if the bug/feature is already tracked.

It's always a good idea to file bug reports, as the process of filing the report always makes it easier to describe the problem, and the bug number provides a quick way of referring to the problem. However, not everybody in the community pays frequent attention to issues, so after you file a bug, asking questions and submitting patches on the libvirt mailing lists will increase your bug's visibility and encourage people to think about your problem. Don't hesitate to ask questions on the list, as others may know of existing solutions or be interested in collaborating with you on finding a solution. Patches are always appreciated, and it's likely that someone else has the same problem you do!

If you decide to write code, though, before you begin please read the contributor guidelines, especially the first point: "Discuss any large changes on the mailing list first. Post patches early and listen to feedback." Few development experiences are more discouraging than spending a bunch of time writing a patch only to have someone point out a better approach on list.

Note bugs in language bindings and other sub-projects should be reported to their corresponding git repository rather than the main libvirt.git linked above.

Linux Distribution specific bug reports

  • If you are using binaries from Fedora, enter tickets against the Fedora product and the libvirt component.

  • If you are using binaries from Red Hat Enterprise Linux, enter tickets against the Red Hat Enterprise Linux product that you're using (e.g., Red Hat Enterprise Linux 6) and the libvirt component. Red Hat bugzilla has additional guidance about getting support if you are a Red Hat customer.

  • If you are using binaries from another Linux distribution first follow their own bug reporting guidelines.

  • Finally, if you are a contributor to another Linux distribution and would like to have your procedure for filing bugs mentioned here, please mail the libvirt development list.

How to file high quality bug reports

To increase the likelihood of your bug report being addressed it is important to provide as much information as possible. When filing libvirt bugs use this checklist to see if you are providing enough information:

  • The version number of the libvirt build, or SHA1 of the GIT commit

  • The hardware architecture being used

  • The name of the hypervisor (Xen, QEMU, KVM)

  • The XML config of the guest domain if relevant

  • For Xen hypervisor, the domain logfiles from /var/log/xen and /var/log/libvirt/libxl

  • For QEMU/KVM, the domain logfile from /var/log/libvirt/qemu

If the bug leads to a tool linked to libvirt crash, then the best is to provide a backtrace along with the scenario used to get the crash, the simplest is to run the program under gdb, reproduce the steps leading to the crash and then issue a gdb "bt -a" command to get the stack trace, attach it to the bug. Note that for the data to be really useful libvirt debug information must be present for example by installing libvirt debuginfo package on Fedora or Red Hat Enterprise Linux (with debuginfo-install libvirt) prior to running gdb.

It may also happen that the libvirt daemon itself crashes or gets stuck, in the first case run it (as root) under gdb, and reproduce the sequence leading to the crash, similarly to a normal program provide the "bt" backtrace information to where gdb will have stopped. But if libvirtd gets stuck, for example seems to stop processing commands, try to attach to the faulty daemon and issue a gdb command "thread apply all bt" to show all the threads backtraces, as in:

 #  ps -o etime,pid `pgrep libvirt`
... note the process id from the output
# gdb /usr/sbin/libvirtd
.... some information about gdb and loading debug data
(gdb) attach $the_daemon_process_id
(gdb) thread apply all bt
.... information to attach to the bug