news.xml

<?xml version="1.0"?>

<!-- libvirt release notes

     This file will be processed to produce both HTML and plain text versions
     of the release notes.

     Keep the style consistent with existing entries as much as possible:
     each change should be documented by a short, one-sentence summary
     and optionally a description where it's explained in more detail -->

<libvirt>
  <release version="v3.2.0" date="unreleased">
    <section title="New features">
      <change>
        <summary>
          The virt-host-validate tool now supports bhyve hypervisor
        </summary>
      </change>
      <change>
        <summary>
          Introduce NVDIMM memory model
        </summary>
        <description>
          NVDIMM is new type of memory introduced into QEMU 2.6. The idea is
          that we have a non-volatile memory module that keeps the data
          persistent across domain reboots and offers much faster data
          accesses.  However, due to a bug in QEMU, this feature is not enabled
          for QEMUs older than 2.9.0.
        </description>
      </change>
      <change>
        <summary>
          qemu: Introduce support for generic PCIe Root Ports
        </summary>
        <description>
          For new controllers, a generic device (pcie-root-port) will be used
          by default instead of the Intel-specific device (ioh3420), provided
          the QEMU binary supports it.
        </description>
      </change>
      <change>
        <summary>
          qemu: Add support for checking guest CPU ABI compatibility
        </summary>
        <description>
          When migrating a domain to a different host, restoring a domain from
          a file or reverting a snapshot libvirt will make sure the guest CPU
          QEMU presents to the guest OS exactly matches the one provided on
          the source host (or before the domain's state was saved). This
          enhanced check may also be requested when starting a new domain to
          ensure the virtual CPU exactly matches the one specified in the XML.
        </description>
      </change>
      <change>
        <summary>
          qemu: Add support to migrate using TLS
        </summary>
        <description>
          Add the ability to migrate QEMU guests using TLS via a new flag
          VIR_MIGRATE_TLS or virsh migrate '--tls' option. Requires using at
          least QEMU 2.9.0 in order to work properly.
        </description>
      </change>
      <change>
        <summary>
          qemu: add mediated devices framework support
        </summary>
        <description>
          Recent kernel version introduced new mediated device framework, so
          provide an initial support of this framework for libvirt, mainly by
          introducing a new host device type in the XML.
        </description>
      </change>
      <changes>
        <summary>
          qemu: Add support for setting TSC frequency
        </summary>
        <description>
          Setting TSC frequency is required to enable migration for domains
          with 'invtsc' CPU feature turned on.
        </description>
      </changes>
    </section>
    <section title="Improvements">
      <change>
        <summary>
          qemu: Detect host CPU model by asking QEMU on x86_64
        </summary>
        <description>
          Previously, libvirt detected the host CPU model using CPUID
          instruction, which caused libvirt to detect a lot of CPU features
          that are not supported by QEMU/KVM. Asking QEMU makes sure we
          don't start it with unsupported features.
        </description>
      </change>
      <change>
        <summary>
          perf: Add more perf statistics
        </summary>
        <description>
          Add support to get the count of cpu clock time, task clock time,
          page faults, context switches, cpu migrations, minor page faults,
          major page faults, alignment faults, emulation faults by
          applications running on the platform.
        </description>
      </change>
    </section>
    <section title="Bug fixes">
      <change>
        <summary>
          QEMU: Use adaptive timeout for connecting to monitor
        </summary>
        <description>
          When starting qemu, libvirt waits for qemu to create the monitor
          socket which libvirt connects to. Historically, there was sharp 30
          second timeout after which the qemu process was killed. This
          approach is suboptimal as in some scenarios with huge amounts of
          guest RAM it can take a minute or more for kernel to allocate and
          zero out pages for qemu. The timeout is now flexible and computed by
          libvirt at domain startup.
        </description>
        </change>
    </section>
  </release>
  <release version="v3.1.0" date="2017-03-03">
    <section title="New features">
      <change>
        <summary>
          storage: Add Virtuozzo storage backend storage pool
        </summary>
        <description>
          Add new storage backend to support pool and volume management
          within the Virtuozzo Storage environment. Virtuozzo Storage is
          a highly available distributed software defined storage with
          built-in replication and disaster recovery.
        </description>
      </change>
      <change>
        <summary>
          qemu: Add support for memory backing with file source
        </summary>
        <description>
          Add support in numa topology for file source inside memory backing
          (hugepages are not needed) Three new elements
          &lt;source/&gt;,&lt;access/&gt; and &lt;allocation/&gt; were added
          to &lt;memoryBacking/&gt; element. Also new configuration parameter
          <code>memory_backing_dir</code> was added to qemu.conf.
        </description>
      </change>
      <change>
        <summary>
          network: make openvswitch call timeout configurable
        </summary>
        <description>
          Adding the ability to specify the timeout value in seconds for
          openvswitch calls in the libvirtd configuration file.
        </description>
      </change>
      <change>
        <summary>
          bhyve: add e1000 NIC support
        </summary>
        <description>
          Add support for e1000 NIC. Previously, the only available option
          was <code>virtio-net</code>.
        </description>
      </change>
      <change>
        <summary>
          libxl: add tunneled migration support
        </summary>
        <description>
          Add tunneled migration to libxl driver, which is always capable of
          strong encryption and doesn't require any extra network connection
          other than what's required for remote access of libvirtd.
        </description>
      </change>
      <change>
        <summary>
          qemu: add rendernode argument
        </summary>
        <description>
          Add a new attribute 'rendernode' to &lt;gl&gt; spice element.
        </description>
      </change>
      <change>
        <summary>
          nodedev: add drm capability
        </summary>
        <description>
          Add a new 'drm' capability for Direct Rendering Manager (DRM)
          devices, providing device type information.
        </description>
      </change>
      <change>
        <summary>
          Add API for individual/specific vCPU hotplug
        </summary>
        <description>
          The new API allows selecting specific vCPUs to be added/removed from
          the VM. The existing APIs allowed only adding/removing from the end
          which did not play well with NUMA.
        </description>
      </change>
    </section>
    <section title="Improvements">
      <change>
        <summary>
           virsh: pool-list: allow both --uuid and --name in one command
        </summary>
        <description>
          Adjust the virsh-pool command to support the --uuid and/or --name
          options in order to print just the --name and/or --uuid of pools.
        </description>
      </change>
      <change>
        <summary>
          Introduce MTU to domain &lt;interface/&gt; and &lt;network&gt;
        </summary>
        <description>
          Allow setting MTU size for some types of domain interface
          and network.
        </description>
      </change>
      <change>
        <summary>
          libxl: improve support for &lt;timer&gt; configurations
        </summary>
        <description>
          Add support for multiple timers. Extend the tsc timer to
          support the emulate mode. Improve conversion of timer XML
          to/from xl.cfg.
        </description>
      </change>
      <change>
        <summary>
          storage: modularize the storage driver
        </summary>
        <description>
          Split up the storage driver backends into loadable modules so that
          binary distributions don't have to compromise on shipping the storage
          driver with all backends which may pull in too many dependencies.
        </description>
      </change>
    </section>
    <section title="Bug fixes">
      <change>
        <summary>
          nodedev: Fabric name must not be required for fc_host capability
        </summary>
        <description>
          fabric_name is one of many fc_host attributes in Linux that is
          optional and left to the low-level driver to decide if it is
          implemented. For example the zfcp device driver does not provide a
          fabric name for an fcp host. The requirement for the existence of
          a fabric name has been removed by making it optional.
        </description>
      </change>
      <change>
        <summary>
          bhyve: change address allocation schema for SATA disks
        </summary>
        <description>
          Previously, the bhyve driver assigned PCI addresses to SATA disks
          directly rather than assigning that to a controller and
          using SATA addresses for disks. It was implemented this way
          because bhyve has no notion of an explicit SATA controller.
          However, as this doesn't match libvirt's understanding of
          disk addresses, the bhyve driver was changed to follow
          the common schema and have PCI addresses for SATA controllers
          and SATA addresses for disks. If you're having issues
          because of this, it's recommended to edit the domain's XML
          and remove &lt;address type='pci'&gt; from the &lt;disk&gt;
          elements with &lt;target bus='sata'/&gt; and let libvirt
          regenerate it properly.
        </description>
      </change>
      <change>
        <summary>
          libxl: maximum memory fixes
        </summary>
        <description>
          Fix reporting of domain maximum memory. Fix setting dom0
          maximum memory.
        </description>
      </change>
      <change>
        <summary>
          libxl: fix disk detach when &lt;driver&gt; not specified
        </summary>
      </change>
      <change>
        <summary>
          libxl: fix dom0 autoballooning with Xen 4.8
        </summary>
      </change>
      <change>
        <summary>
          qemu: Allow empty script path to &lt;interface/&gt;
        </summary>
        <description>
          Historically, this was always allowed. Unfortunately, due to some
          rework done for 1.3.2 release a bug was dragged in which suddenly
          stop allowing domain with such configuration to start.
        </description>
      </change>
    </section>
  </release>
  <release version="v3.0.0" date="2017-01-17">
    <section title="New features">
      <change>
        <summary>
          Domain events for metadata content changes
        </summary>
        <description>
          The domain events framework has a new event ID that can
          be used to get notifications when domain metadata content
          changes.
        </description>
      </change>
      <change>
        <summary>
          Event notifications for the secret object
        </summary>
        <description>
          The secret object now supports event notifications, covering
          lifcycle changes and secret value changes.
        </description>
      </change>
      <change>
        <summary>
          New localPtr attribute for "ip" element in network XML
        </summary>
      </change>
      <change>
        <summary>
          qemu: Support QEMU group I/O throttling
        </summary>
        <description>
          Add the capability to allow group I/O throttling via a new
          domain &lt;disk&gt; &lt;iotune&gt; subelement "group_name"
          to allow sharing I/O throttling quota between multiple drives.
        </description>
      </change>
      <change>
        <summary>
          nss: Introduce <code>libvirt_guest</code>
        </summary>
        <description>
          New <code>libvirt_guest</code> nss module that translates libvirt
          guest names into IP addresses.
        </description>
      </change>
      <change>
        <summary>
          daemon: Add support for runtime logging settings adjustment
        </summary>
        <description>
          Logging-related settings like log outputs and filters can now be
          adjusted during runtime using the admin interface without the
          necessity of the daemon's restart.
        </description>
      </change>
      <change>
        <summary>
          storage: Add virStorageVolInfoFlags API
        </summary>
        <description>
          Add the API to support using the VIR_STORAGE_VOL_GET_PHYSICAL
          flag in order to return the host physical size in bytes
          of the image container in the allocation field of the
          _virStorageVolInfo structure. The --physical flag has been
          added to the virsh vol-info command to access the data.
        </description>
      </change>
      <change>
        <summary>
          libxl: Implement virDomainGetMaxVcpus API
        </summary>
      </change>
      <change>
        <summary>
          storage: Add overwrite flag checking for logical pool
        </summary>
        <description>
          Add support for the OVERWRITE flags for the logical storage
          backend including checking for existing data on the target
          volumes when building a new logical pool on target volume(s).
        </description>
      </change>
      <change>
        <summary>
          qemu: Add support for guest CPU configuration on s390(x)
        </summary>
      </change>
    </section>
    <section title="Improvements">
      <change>
        <summary>
          perf: Add more perf statistics
        </summary>
        <description>
          Add support to get the count of branch instructions
          executed, branch misses, bus cycles, stalled frontend
          cpu cycles, stalled backend cpu cycles, and ref cpu
          cycles by applications running on the platform.
        </description>
      </change>
      <change>
        <summary>
          conf: Display &lt;physical&gt; for volume xml
        </summary>
        <description>
          Add a display of the &lt;physical&gt; size of a disk
          volume in the output of the volume XML.
        </description>
      </change>
      <change>
        <summary>
          qemu: Use virtio-pci by default for aarch64 mach-virt guests
        </summary>
        <description>
          virtio-pci provides several advantages over virtio-mmio, such
          as the ability to hotplug devices and improved performance.
          While opting in to virtio-pci has been possible for a while,
          newly-defined guests will now use it automatically.
        </description>
      </change>
      <change>
        <summary>
          vbox: remove support for VirtualBox 3.x and older
        </summary>
        <description>
          Those old VirtualBox versions have been unsupported by
          upstream for a long time and the API of 4.0 and newer has
          diverged enough to require code abstractions to handle differences.
          Removing support for those old versions drops lots of code from
          the driver and simplifies the logic to ease implementation of new
          features going forward.
        </description>
      </change>
      <change>
        <summary>
          virsh: pool-info: introduce option --bytes
        </summary>
        <description>
          Add option --bytes to virsh pool-info in order ti allow display
          of units in bytes rather than default of human readable output.
        </description>
      </change>
      <change>
        <summary>
          scsi: Add parent wwnn/wwpn or fabric capability for createVport
        </summary>
        <description>
          Improve the algorithm searching for the parent scsi_host device
          for vHBA/NPIV scsi_host creation. Rather than supplying the
          "parent" by name, it's now possible to define the parent by
          it's wwnn/wwpn or fabric_wwn in the node device create XML or
          the storage pool XML.
        </description>
      </change>
      <change>
        <summary>
          qemu: aggregate pcie-root-ports onto multiple functions of a slot
        </summary>
        <description>
          When pcie-root-ports are added to pcie-root in order to
          provide a place to connect PCI Express endpoint devices,
          libvirt now aggregates multiple root ports together onto the
          same slot (up to 8 per slot) in order to conserve slots.
          Using this method, it's possible to connect more than 200
          endpoint devices to a guest that uses PCIe without requiring
          setup of any PCIe switches.
        </description>
      </change>
    </section>
    <section title="Bug fixes">
      <change>
        <summary>
          lxc: fix accidental killing of containers during libvirtd restart
        </summary>
        <description>
          The libvirt_lxc process was previously not moved into the
          container scope. As a result, if systemd reloads its config
          after a container is started, when libvirtd is later restarted
          it will accidentally kill the containers.
        </description>
      </change>
      <change>
        <summary>
          qemu: Correct GetBlockInfo values
        </summary>
        <description>
          For an active domain, correct the physical value provided for
          a raw sparse file backed storage and the allocation value provided
          for a qcow2 file backed storage that hasn't yet been opened on
          the domain.
        </description>
      </change>
      <change>
        <summary>
          qemu: Make virtio console usable on ppc64 guests
        </summary>
        <description>
          The chardev detection code has been improved and can now handle this
          configuration properly.
        </description>
      </change>
      <change>
        <summary>
          qemu: Enable mount namespace
        </summary>
        <description>
          To avoid funny races with udev relabelling devices under our hands and
          to enhance security, libvirt now spawns each qemu process with its own
          <code>/dev</code>.
        </description>
      </change>
      <change>
        <summary>
          storage: Fix implementation of no-overwrite for file system backend
        </summary>
        <description>
          Fix file system storage backend implementation of the OVERWRITE
          flags to be consistent between code and documentation. Add checks
          to ensure that when building a new file system on a target volume
          that there is not something already on the disk in a format that
          libvirt can recognize.
        </description>
      </change>
      <change>
        <summary>
          qemu: Create hugepage path on per domain basis
        </summary>
        <description>
          Historically, all hugepage enabled domains shared the same path under
          hugetlbfs. This left libvirt unable to correctly set security labels
          on it. With this release, however, each domain is put into a
          separate path which is also correctly labeled.
        </description>
      </change>
      <change>
        <summary>
          conf: Reject domains with duplicate drive addresses
        </summary>
        <description>
          Reject duplicate drive addresses for disks and hostdevs at
          domain definition.
        </description>
      </change>
      <change>
        <summary>
          libxl: reverse defaults on HVM net device attach
        </summary>
        <description>
          Fixes network interface attach for HVM domains when no model is
          specified. Emulated hotplug isn't yet supported and hence we should
          default to the general working scenario.
        </description>
      </change>
      <change>
        <summary>
          libxl: always enable pae for x86_64 HVM
        </summary>
        <description>
          By default pae is disabled in libxl. Without an explicit &lt;pae/&gt;
          setting in the domain &lt;features&gt; configuration, an x86_64 HVM
          domain would be get an i686 environment. pae should always be enabled
          for x86_64 HVM domains.
        </description>
      </change>
      <change>
        <summary>
          qemu: Fix XML dump of autogenerated websocket
        </summary>
        <description>
          As a result autogenerated websocket port is regenerated on domain restore,
          migration and such as it should be.
        </description>
      </change>
    </section>
  </release>
  <release version="v2.5.0" date="2016-12-04">
    <section title="New features">
      <change>
        <summary>
          shmem: Add support for additional models
        </summary>
        <description>
          The shmem device can now utilize QEMU's ivshmem-plain and
          ivshmem-doorbell, more modern versions of ivshmem.
        </description>
      </change>
      <change>
        <summary>
          vbox: Add VirtualBox 5.1 support
        </summary>
      </change>
      <change>
        <summary>
          libssh: New transport
        </summary>
        <description>
          The new libssh transport allows one to connect to a running
          libvirtd via SSH, using the libssh library; for example:
          <tt>qemu+libssh://<i>server</i>/system</tt>.
        </description>
      </change>
      <change>
        <summary>
          vhost-scsi: Add support scsi_host hostdev passthrough
        </summary>
        <description>
          Add the capability to pass through a scsi_host HBA and the
          associated LUNs to the guest.
        </description>
      </change>
      <change>
        <summary>
          qemu: Users can now enable debug logging for native gluster
          volumes in qemu using the "gluster_debug_level" option in qemu.conf
        </summary>
      </change>
      <change>
        <summary>
          memory hotplug: Slot numbers for memory devices are now
          automatically allocated and thus persistent. In addition slot numbers
          can be specified without providing a base address, which simplifies
          user configuration
        </summary>
      </change>
      <change>
        <summary>
          qemu: Express devices will be placed on PCIe bus by default
        </summary>
        <description>
          For machine types that use a PCI Express root bus
          (e.g. x86_64/Q35 and aarch64/virt), any unaddressed PCI
          device that is an Express device (all virtio-1.0 devices,
          e1000e, nec-xhci, vfio assigned devices) will be placed on
          an Express controller (i.e. a pcie-root-port) instead of a
          legacy PCI controller (i.e. pci-bridge) with the root ports
          added as needed.
        </description>
      </change>
    </section>
    <section title="Improvements">
      <change>
        <summary>
          docs: Better documentation for migration APIs and flags
        </summary>
      </change>
      <change>
        <summary>
          vbox: Address thread safety issues
        </summary>
      </change>
      <change>
        <summary>
          virsh: Add support for passing an alternative persistent XML
          to migrate command
        </summary>
      </change>
      <change>
        <summary>
          vhostuser: Allow hotplug of multiqueue devices
        </summary>
      </change>
      <change>
        <summary>
          NEWS: Switch to an improved format
        </summary>
        <description>
          List user-visible changes instead of single commits for a better
          high-level overview of differences between libvirt releases.
        </description>
      </change>
      <change>
        <summary>
          website: Modernize layout and branding
        </summary>
        <description>
          The libvirt website looked very cluttered and outdated; it has now
          been completely overhauled, resulting in a design that's better
          organized and more pleasant to look at.
        </description>
      </change>
    </section>
    <section title="Bug fixes">
      <change>
        <summary>
          vz: Fix migration in P2P mode
        </summary>
      </change>
      <change>
        <summary>
          Forbid newline character in names of some libvirt objects
        </summary>
      </change>
      <change>
        <summary>
          Fix compilation on macOS
        </summary>
      </change>
      <change>
        <summary>
          Overwrite (clear) 2 KB instead of just 512 bytes when initializing logical device
        </summary>
      </change>
      <change>
        <summary>
          Describe the logical backend requirements better for pool-create-as
        </summary>
      </change>
    </section>
  </release>
</libvirt>