[Libvirt-announce] Release of libvirt-5.6.0

Daniel Veillard veillard at redhat.com
Mon Aug 5 17:36:25 UTC 2019

  It's out ! Tagged in git and with signed tarball and source rpm at the usual


I also released the 5.6.0 python bindings for the release that can be found


This release includes a number of new features, notably the checkpoint APIs
removes the sxpr xen support and carries a set of improvement and bug fixes
as usual:

New features:

- qemu: Introduce a new video model of type 'bochs'
Introduce a new video model type that supports the bochs-display device
that was added in qemu version 3.0.

- api: new virDomainCheckpoint APIs
Introduce several new APIs for creating and managing checkpoints in the
test and qemu drivers (the latter requires qcow2 images). Checkpoints
serve as a way to tell which portions of a disk have changed since a
point in time.

- qemu: Add support for overriding max threads per process limit
systemd-based systems impose a limit on the number of threads a process
can spawn, which in some cases can be exceeded by QEMU processes
running VMs. Add a max_threads_per_process option to qemu.conf to
override the system default.

- Remember original owners and SELinux labels of files
When a domain is starting up libvirt changes DAC and SELinux labels so
that domain can access it. However, it never remembered the original
labels and therefore the file was returned back to root:root. With this
release, the original labels are remembered and restored properly.

- network: Allow passing arbitrary options to dnsmasq
This works similarly to the existing support for passing arbitary
options to QEMU, and just like that feature it comes with no support

Removed features:

- xen: Remove sxpr config support
Remove the sxpr style config parser and formatter a year after the xend
driver was removed.


- qemu: Allow XML validation for snapshot creation
Add flag VIR_DOMAIN_SNAPSHOT_CREATE_VALIDATE to validate snapshot input
XML. For virsh, users can use it as virsh snapshot-create --validate.

- Support encrypted soft TPM
A soft TPM backend could be encrypted with passphrase. Now libvirt
supports using a secret object to hold the passphrase, and referring to
it via the encryption element of the TPM device.

- test driver: Expand API coverage
Additional APIs have been implemented in the test driver.

- Implement per-driver locking
Drivers now acquire a lock when they're loaded, ensuring that there can
never be two instances of the same driver active at a time.

- nss: Report newer addresses first
In some cases, a guest might be assigned a new IP address by DHCP
before the previous lease has expired, in which case the NSS plugin
will correctly report both addresses; many applications, however,
ignore all addresses but the first, and may thus end up trying to
connect using a stale address. To prevent that from happening, the NSS
plugin will now always report the newest address first.

- util: Optimize mass closing of FDs when spawning child processes
When the limit on the number of FDs is very high, closing all unwanted
FDs after calling fork() can take a lot of time and delay the start of
the child process. libvirt will now use an optimized algorithm that
minimizes such delays.

Bug fixes:

- logging: Ensure virtlogd rollover takes priority over logrotate
virtlogd implements its own rollover mechanism, but until now logrotate
could end up acting on the logs before virtlogd had a chance to do so

    Thanks everybody who helped with this release, be it with bug reports,
patches, reviews, documenation, localization, etc ...

  Enjoy the release,


Daniel Veillard      | Red Hat Developers Tools http://developer.redhat.com/
veillard at redhat.com  | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
http://veillard.com/ | virtualization library  http://libvirt.org/

More information about the Libvirt-announce mailing list