- Announce - libvirt List Archives

Entering freeze for libvirt-12.6.0
by Jiri Denemark 27 Jul '26

27 Jul '26

I have just tagged v12.6.0-rc1 in the repository and pushed signed tarballs to https://download.libvirt.org/ Please give the release candidate some testing and in case you find a serious issue which should have a fix in the upcoming release, feel free to reply to this thread to make sure the issue is more visible. If you have not done so yet, please update NEWS.rst to document any significant change you made since the last release. Jirka

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Release of libvirt-12.5.0
by Jiri Denemark 01 Jul '26

01 Jul '26

The 12.5.0 release of both libvirt and libvirt-python is tagged and signed tarballs are available at https://download.libvirt.org/ https://download.libvirt.org/python/ Thanks everybody who helped with this release by sending patches, reviewing, testing, or providing feedback. Your work is greatly appreciated. * New features * bhyve: Extend the guest agent support The bhyve driver now supports several APIs on top of the guest agent: * Getting and setting guest OS SSH keys * Setting guest OS user's password * Getting and setting guest OS time Additionally, domain rebooting and shutting down using the agent is now supported. * bhyve: Support ``on_reboot`` and ``on_poweroff`` actions The bhyve driver now respects the domain's ``on_reboot`` and ``on_poweroff`` actions. * bhyve: Support populating SMBIOS fields Add support for populating the SMBIOS fields as defined by the ``<sysinfo type='smbios'>`` section of the domain's XML. * qemu: Add support for standalone VNC server Starting with this release, libvirt might spawn a standalone qemu-vnc process instead of QEMU's built-in VNC server, for enhanced security. * Improvements * Enable hyperv driver on RHEL The spec file now enables the Hyper-V driver when building on Red Hat Enterprise Linux. * remote: allow passing argv to the ext transport The ext transport not only allows spawning a process (via the ``command`` attribute), but as of this release also specifying additional arguments to it, via ``argv`` attribute. * Introduce ``VIR_CONNECT_GET_DOMAIN_CAPABILITIES_SUPPORTED_CPU_FEATURES`` flag Some CPU features may be enabled explicitly, but should not automatically become part of a host-model CPU and thus are not normally visible in domain capabilities. Users can now request such features to be shown in the host-model CPU in domain capabilities using the new flag. It is exposed as ``--supported-cpu-features`` option for ``virsh domcapabilities``. * Bug fixes * Ensure proper shutdown ordering of ``virtlogd`` and ``virtlockd`` The logging and locking helper daemons now shutdown after the daemon running the ``qemu`` hypervisor driver since their services may be needed to shutdown the VMs run by the qemu driver. * qemu: Record selected ``virtio`` video device model into the XML The ``qemu`` driver may depending on platform and installed QEMU modules pick one of two distinct virtio video device types for the primary device. The choice was not recorded in the XML and since the devices are incompatible it can cause failures on migration when the destination picks the wrong device. This version thus records the picked device both for running VMs on upgrade and for new devices to prevent this problem in the future. * bhyve: Guest agent related fixes A few bugs related to the guest agent communication are fixed, from not properly initializing an agent to crashing when the agent socket cannot be opened. * Fix domain capabilities on AMD CPUs QEMU 10.1 and newer does not automatically enable features from arch-capabilities MSR on AMD CPUs as they are specific for Intel CPUs and KVM is just emulating them on AMD. But advertising them on AMD CPUs can cause Windows guest OS to crash so they are hidden by default now. But the features are still supported and can be enabled explicitly, for example, when migrating existing domains. Libvirt now detects this scenario and properly shows the affected features as enabled in domain capabilities when requested by ``VIR_CONNECT_GET_DOMAIN_CAPABILITIES_SUPPORTED_CPU_FEATURES`` flag. * vmx: Properly show all 64 disks on a SCSI controller Due to an off-by-one error a last, 64th disk was not shown in a domain XML, which is now fixed. Enjoy. Jirka

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Entering freeze for libvirt-12.5.0
by Jiri Denemark 29 Jun '26

29 Jun '26

I have just tagged v12.5.0-rc1 in the repository and pushed signed tarballs to https://download.libvirt.org/ Please give the release candidate some testing and in case you find a serious issue which should have a fix in the upcoming release, feel free to reply to this thread to make sure the issue is more visible. If you have not done so yet, please update NEWS.rst to document any significant change you made since the last release. Jirka

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Release of libvirt-12.4.0
by Jiri Denemark 01 Jun '26

01 Jun '26

The 12.4.0 release of both libvirt and libvirt-python is tagged and signed tarballs are available at https://download.libvirt.org/ https://download.libvirt.org/python/ Thanks everybody who helped with this release by sending patches, reviewing, testing, or providing feedback. Your work is greatly appreciated. * Removed features * qemu: Bump minimum version to QEMU-7.2 The minimal required version of QEMU was bumped to 7.2.0. * New features * resctrl: Add energy monitoring via resctrl's PERF_PKG_MON Add support for Linux kernel 7.0 feature - energy monitoring via resctrl. This allows to monitor per-VM energy consumption on supported platforms. Implemented via ``energytune`` element in ``cputune`` . * Add channel lifecycle domain event Add support for a new domain event which can be used to track the state of any virtio channel. It is similar to guest agent lifecycle event. * bhyve: Add memory tuning support The bhyve driver now allows setting a domain's memory hard limit using the following syntax:: <memtune> <hard_limit unit='G'>1</hard_limit> </memtune> It also implements the ``virDomainGetMemoryParameters()`` and ``virDomainSetMemoryParameters()`` APIs for controlling the memory hard limit of a running domain. * bhyve: Add virtio-console device support Domain XML can now use ``virtio-console`` devices. Among other things, these devices can be used to configure a QEMU Guest Agent:: <devices> <channel type='unix'> <source mode='bind' path='/var/run/libvirt/bhyve/bhyve.agent'/> <target type='virtio' name='org.qemu.guest_agent.0'/> <address type='virtio-serial' controller='0' bus='0' port='1'/> </channel> </devices> Additionally, the ``virDomainQemuAgentCommand()`` API which allows running arbitrary guest agent commands is now supported. The ``virDomainGetHostname()`` API, used to query the hostname of a guest, now supports using the guest agent as a source of information. * Improvements * vircgroupv2: Implement freezer controller The CGroupV2 code now supports freezer controller which allows suspending and resuming of LXC domains. * virnetdevbandwidth: Only clear qdisc for defined directions Setting a QoS on a vNIC no longer leads to clearing (preconfigured) root queuing discipline ('qdisc`) in both directions (egress, ingress), only the affected one. * Bug fixes * storage: ZFS: Fix incorrect volsize and refreservation on zvol creation When creating a zvol, the ZFS driver listed all volumes in the pool and updated the new volume's size with data from the last volume in the list rather than the matching one. Now it correctly returns on valid one. * esx/vmware: VMs are tracked under different UUIDs by default The VMWare-related drivers were using allegedly unique IDs for domains, but it turned out they were not completely unique, even for the same host. That caused an issue where a different domain could have been acted upon then requested. Unfortunately, to make this work, the UUIDs of all VMWare-related domains will change from this release. In order to use the pre-v12.4.0 behaviour there is a new URI query parameter ``legacy_uuid`` which, if set to ``1``, will revert to the older way of working. * virsh: Provide no auth callbacks for bash completer The bash completer script calls virsh to provide completions. In some cases the underlying virsh might get stuck waiting on input (e.g. password for SSH session). Not anymore. * virauth: Verify virConnectAuth::cb is set in virAuthGetPasswordPath() A check was missing in ``virAuthGetPasswordPath()`` which might lead to crash of the client library when NULL callback was provided. This is now fixed. Enjoy. Jirka

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Entering freeze for libvirt-12.4.0
by Jiri Denemark 28 May '26

28 May '26

I have just tagged v12.4.0-rc1 in the repository and pushed signed tarballs to https://download.libvirt.org/ Please give the release candidate some testing and in case you find a serious issue which should have a fix in the upcoming release, feel free to reply to this thread to make sure the issue is more visible. If you have not done so yet, please update NEWS.rst to document any significant change you made since the last release. Jirka

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Release of libvirt-12.3.0
by Jiri Denemark 02 May '26

02 May '26

The 12.3.0 release of both libvirt and libvirt-python is tagged and signed tarballs are available at https://download.libvirt.org/ https://download.libvirt.org/python/ Thanks everybody who helped with this release by sending patches, reviewing, testing, or providing feedback. Your work is greatly appreciated. * New features * bhyve: Add blkiotune support The bhyve driver now supports guest I/O throttling configuration:: <blkiotune> <device> <path>*</path> <read_iops_sec>20000</read_iops_sec> <write_iops_sec>20000</write_iops_sec> <read_bytes_sec>10000</read_bytes_sec> <write_bytes_sec>10000</write_bytes_sec> </device> </blkiotune> It uses the ``rctl(4)`` framework to apply these limits. * bhyve: Implement ``virDomainInterfaceAddresses()`` and ``virDomainGetHostname()`` The bhyve driver now implements APIs allowing to fetch address of VM's interfaces (accessible via ``virsh domifaddr``) and the hostname of the VM (``virsh domhostname``). * hyperv: Implement ``virDomainGetGuestInfo()`` The hyperv driver now implements API for fetching guest information (``virsh guestinfo``). * Improvements * security: Don't error out on security labels of type='none' Previously, libvirt reported an error if a domain with seclabel of type='none' (meaning do not take this security model into account for this domain) was being started and the model wasn't available (for instance, in case of SELinux it was disabled at boot). * Allow for multiple PCI root buses, not just for a single one numbered '0' `virPCIDeviceReset()` and `virPCIDeviceIsBehindSwitchLackingACS()` no longer use a hardcoded check (e.g bus == 0 ) to determine if a device is attached to a "root bus". This allows for better support on more complex PCI topologies. * Add mechanism to prevent accidental shrink of device with ``virsh blockresize`` A new flag ``VIR_DOMAIN_BLOCK_RESIZE_EXTEND`` was introduced which prevents accidental shrinking of the block device of the VM. The flag is exposed as ``virsh blockresize --extend``. * Expose ``MemAvailable`` field from kernel's meminfo as ``VIR_NODE_MEMORY_STATS_AVAILABLE`` * Bug fixes * virnetdevmacvlan: Wait for udev to settle after creating macvtap When starting a domain with a macvtap device (or when hotplugging one), libvirt creates the device and opens its ``/dev`` representation in order to set it according to the ``<interface/>`` XML (e.g. MAC address, queues, etc.). But if the system is under heavy load, it might happen that after the device creation the udev daemon was triggered, but did not have enough time to set the ``/dev`` representation fully. This may result in various misconfiguration or even failed ``open()``. Therefore, libvirt waits after device creation for udev daemon to settle down. * apparmor: Don't drop macvtap devices from profile on blockjobs Enjoy. Jirka

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Entering freeze for libvirt-12.3.0
by Jiri Denemark 29 Apr '26

29 Apr '26

I have just tagged v12.3.0-rc1 in the repository and pushed signed tarballs to https://download.libvirt.org/ Please give the release candidate some testing and in case you find a serious issue which should have a fix in the upcoming release, feel free to reply to this thread to make sure the issue is more visible. If you have not done so yet, please update NEWS.rst to document any significant change you made since the last release. Jirka

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Release of libvirt-12.2.0
by Jiri Denemark 01 Apr '26

01 Apr '26

The 12.2.0 release of both libvirt and libvirt-python is tagged and signed tarballs are available at https://download.libvirt.org/ https://download.libvirt.org/python/ Thanks everybody who helped with this release by sending patches, reviewing, testing, or providing feedback. Your work is greatly appreciated. * Removed features * qemu: Stop advertising support for ``handle`` backend of 9p filesystems QEMU removed the feature in the 4.0 release, but our capability XML still reported it. * New features * qemu: Add support to configure IOMMUFD backend for whole VM In addition to setting IOMMUFD backend for each device it is possible to use the new ``<iommufd>`` element to enable IOMMUFD backend for all host devices. Users can still change it per device. * qemu: Add support to pass FD for IOMMUFD when starting VM Management applications running unprivileged libvirt can open /dev/iommu and pass FD to libvirt in order to change locked memory accounting. This is done via new ``<iommufd>`` element. * qemu: Add support for declaring that storage was zeroed for storage copy APIs The qemu driver now can skip zeroing of the storage during ``virDomainBlockCopy`` or migration with non-shared storage with the appropriate flags. This can be used for storage technologies which lack efficient zeroing support. * hyperv: Add basic snapshot functionality The hyperv driver now implements the following libvirt APIs: ``virDomainDefineXMLFlags()``, ``virDomainSnapshotLookupByName()``, ``virDomainListAllSnapshots()``, ``virDomainSnapshotNum()``, ``virDomainSnapshotGetXMLDesc()``, ``virDomainSnapshotCurrent()``, ``virDomainHasCurrentSnapshot()``, ``virDomainSnapshotGetParent()``. * Improvements * conf: support more than 255 vCPUs with amd-iommu With 256 or more vCPUs libvirt previously required EIM enabled for all models of IOMMU. This is not valid for AMD model and validation was changed so that XTSup is required there. Additionally, it is automatically enabled if needed. * Introduce VIR_CONNECT_GET_DOMAIN_CAPABILITIES_EXPAND_CPU_FEATURES flag This new flag for virConnectGetDomainCapabilities can be used to request the host-model CPU definition to include all supported features (normally only extra features relative to the selected CPU model are listed). * qemu: Add statistics for ``<dataStore>`` storage The bulk statistics (``virsh domstats --block --backing``) now report also information about the ``<dataStore>`` if given disk uses this feature. * hyperv: Hyper-V guests now report TPM device status in their domain xml definition. * Bug fixes * qemu: Fix crash when attaching network inteface with hostdev network Introduced in v12.1.0 by implementing IOMMUFD backend support for host devices. Enjoy. Jirka

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Entering freeze for libvirt-12.2.0
by Jiri Denemark 30 Mar '26

30 Mar '26

I have just tagged v12.2.0-rc1 in the repository and pushed signed tarballs to https://download.libvirt.org/ Please give the release candidate some testing and in case you find a serious issue which should have a fix in the upcoming release, feel free to reply to this thread to make sure the issue is more visible. If you have not done so yet, please update NEWS.rst to document any significant change you made since the last release. Jirka

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Release of libvirt-12.1.0
by Jiri Denemark 02 Mar '26

02 Mar '26

The 12.1.0 release of both libvirt and libvirt-python is tagged and signed tarballs are available at https://download.libvirt.org/ https://download.libvirt.org/python/ Thanks everybody who helped with this release by sending patches, reviewing, testing, or providing feedback. Your work is greatly appreciated. * New features * qemu: Advertise firmware features in domain capabilities XML The contents of the ``<firmwareFeatures/>`` element can be used to determine ahead of time whether a firmware matching certain characteristics, for example Secure Boot support, is available for the selected architecture and machine type. * qemu: Add support for uefi-vars device and firmware builds using it This is particularly noteworthy for people running aarch64 VMs with the 'virt' machine type, as it makes it finally possible to use Secure Boot with that combination. In most cases, no special steps are needed to take advantage of this: assuming that you have installed a recent version of QEMU, as well as a build of edk2 that includes the necessary binaries, you can just `enable Secure Boot <kbase/secureboot.html>`__ as you normally would. To explicitly request that the uefi-vars device is used even for scenarios where that would normally not be the case, it's enough to add an empty ``<varstore/>`` element in the domain XML. More details are available in the `guest firmware configuration <formatdomain.html#guest-firmware>`__ section of the documentation. * hyperv: improve API coverage for the hyperv driver The `virDomainInterfaceAddresses()` and `virDomainGetBlockInfo()` APIs are now supported by the hyperv driver. In addition, the domain xml for hyperv domains will indicate via firmware features whether secure boot is enabled. It also honors these firmware features when creating new domains. * bhyve: Add support for vCPU pinning configuration Bhyve guests can now have vCPU pinning configured:: <cputune> <vcpupin vcpu="0" cpuset="1,2,3"/> </cputune> Additionally, the ``domainGetVcpuPinInfo`` API is implemented for querying vCPU pinning information. * qemu: Support block operation latency histograms Libvirt now allows configuring qemu's block latency histogram collection as well as returns them via the bulk stats API. * Improvements * Introduce granule attribute for virtio-iommu In case when guest page size doesn't match the host page size (typically aarch64) the ``virtio-iommu`` needs to know the guest page size so it can allocate memory aligned to guest page size. * Parse hyperv features even for host-model Two releases ago, in v11.9.0 new ``host-model`` mode for Hyper-V enlightenments was introduced. Starting with this release, users can additionally override the defaults that are picked when domain is started and features are expanded. * bhyve: Improve loader configuration for arm64 guests If loader is not explicitly configured, use the loader from the ``sysutils/u-boot-bhyve-arm64`` port/package for the arm64 guests. * Bug fixes * Fix build with remote driver disabled Some parts of code were wrongly annotated as depended on remote driver. But they were used even from client side drivers. This is now fixed and libvirt builds properly even with remote driver disabled. * Various fixes to libvirt-guests.sh Firstly, the exit code of various commands was ignored (which may lead the script to wrongly determine persistent/transient domain state, for instance). Secondly, due to logical error, the script might have incorrectly asses state a domain is in. * AppArmor: Ask for no deny rule for readonly disk elements For read only disks, libvirt created an AppArmor profile which disallowed any future write rules. But when doing a blockcommit, libvirt needs to allow hypervisor to write to even readonly disks. The rule in the profile was changed so that future write rules can be added, temporarily. * esx: Allow connecting to IPv6 server Due to a bug in our code, if an IPv6 address was provided in connection URI, libvirt would fail to connect to VMWare server. This is now fixed. * qemu: Use device alias if interface has no name The ``virDomainInterfaceAddresses()`` API (or ``virsh domifaddr``) returns an array interfaces among with their addresses. But some interface names might be unknown, for instance if the API is told to parse host's ARP table then PCI assigned NICs or slirp/passt lack interface name. If that's the case, let the API return domain's ``<interface/>`` alias. * bhyve: hyperv: Various memory leak fixes * qemu: Fix failures when restoring save/managed-save images with upcoming qemu versions Current git version of qemu would return an error when attempting to load an existing (managed) save image as we relied on deprecated features that were now removed. Enjoy. Jirka

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