- Announce - libvirt List Archives

Release of libvirt-12.7.0
by Jiri Denemark 01 Sep '26

01 Sep '26

The 12.7.0 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. * Security * CVE-2026-18917: Integer overflow in RPC handler for ``virNodeGetFreePages`` The RPC handler for ``virNodeGetFreePages`` didn't properly check for overflows in multiplication of integers when calculating the amount of returned data for validation and allocation of the return buffer. Specific values could thus pass validation and cause an undersized buffer to be allocated. The hypervisor driver would then fill the undersized buffer based on the values prior to multiplication and thus cause a write beyond the end of the allocated buffer. This bug can be triggered via a read-only connection. * CVE-2026-77158: Double free of disks array in ``qemuAgentGetDisks`` The qemu hypervisor driver would double-free the array of parsed disks, on error code paths leading to crash of the daemon. The error code path could be reached when the qemu guest agent provided malformed data as response to the ``guest-get-disks`` command. * CVE-2026-77159: ``chown()`` of swtpm log file follows symlinks When starting up a VM with a ``swtpm`` device configured, libvirt ``chown()``-s the log file of swtpm to the (unprivileged) user/group running the swtpm process. The problem is that the directory containing the log files is also owned by the same user/group, thus users with access to that directory could install a symlink to a privileged file that the libvirt daemon would follow and chown the file pointed to. * New features * bhyve: implement ``virDomainGetGuestInfo()`` and ``virDomainAgentSetResponseTimeout()`` APIs The bhyve driver now implements ``virDomainGetGuestInfo()`` which returns information about the guest, and ``virDomainAgentSetResponseTimeout()`` which sets the guest agent response timeout. * bhyve: allow setting disk serial numbers The bhyve driver now allows specifying ``<serial>`` for SATA disks and NVMe controllers:: <disk type='file'> <serial>BHYVE-SER01-0001</serial> <driver name='file' type='raw'/> <source file='/tmp/freebsd1.img'/> <target dev='hda' bus='sata' rotation_rate='7200'/> </disk> <controller type='nvme' index='0'> <serial>BHYVE-NVME0-01234</serial> </controller> It also supports specifying ``<wwn>`` for NVMe disks:: <disk type='file'> <driver name='file' type='raw'/> <source file='/path/to/some.img'/> <target dev='nvme0n1' bus='nvme'/> <wwn>01000000efbeadde</wwn> </disk> * qemu: Add poll-weight support for iothreads The qemu driver now supports the iothread poll-weight property, which controls the weight of the most recent event interval in the adaptive polling duration calculation. * Add guest device info to ``virDomainGetGuestInfo()`` QEMU guest agent has 'guest-get-devices` command, which returns information on guest devices (driver name, version, release date, and so on). This is now exposed via ``virDomainGetGuestInfo()`` API (accessible via ``guestinfo --devices`` virsh command). * Bug fixes * bhyve: fix domain API calls hanging after domain shutdown * remote: Fix stale virStream status In a few cases it might happen that daemon held incorrect state of a virStream leading to an infinite loop. This is now fixed. * esx: Don't crash when parsing unmounted datastore When libvirt constructs domain XML for an ESX domain it traverses through all datastores to find which one stores disks for the domain. But if a datastore wasn't mounted, then a crash would occur. This is now fixed. * virsh: Don't crash when certain error messages are printed A bug in the error printing function could cause ``virsh`` to crash when certain errors (e.g. disk not found in ``virsh detach-disk``) were being reported. Enjoy. Jirka

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Entering freeze for libvirt-12.7.0
by Jiri Denemark 27 Aug '26

27 Aug '26

I have just tagged v12.7.0-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-12.6.0
by Jiri Denemark 03 Aug '26

03 Aug '26

The 12.6.0 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: implement ``virDomainRename()`` The bhyve driver now implements the ``virDomainRename()`` API for renaming of a domain (``virsh domrename``). * build: Add option to control building libvirtd Meson option ``libvirtd`` has been added to control building the monolithic libvirtd, independent from the stateful, daemon-based drivers. * sanlock: Add option to check ownership of disk leases The sanlock lock driver plugin now supports the ``check_disk_lease_owner`` setting in sanlock.conf. When enabled, the sanlock plugin will check that leases are owned by the domain attempting to acquire them. * Improvements * qemu: Add ``preserve-running`` action for ``<on_crash>`` Allow qemu VMs to be kept running after they notify that they've crashed. This is useful for guests that can take their own crash dump and reboot. Enjoy. Jirka

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Entering freeze for libvirt-12.6.0
by Jiri Denemark 30 Jul '26

30 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 01 May '26

01 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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