libvirt releases
================

# v3.4.0 (2017-06-02)

  * New features

    - Improved streams to efficiently transfer sparseness
        New extension to virStream was implemented so that
        virStorageVolDownload and virStorageVolUpload can preserve file
        sparseness.

    - I/O APIC type can be specified for QEMU/KVM domains
        The ioapic tag was added to domain features, so the type of the I/O
        APIC can now be specified (e.g. putting it in userspace for KVM
        domains).

    - The reason for VM shutdown is reported, if known
        QEMU 2.10 will be able to report the reason for shutting down (whether
        that was caused by the guest or not), and libvirt is prepared for that
        and reports that information in its shutdown event as well, if it is
        known.

  * Improvements

    - Repository now has new README.md file
        The new file uses markdown syntax, so it looks better on github and
        possibly other web pages, but it has also more useful information. The
        old README is now symlink to the new file.

    - qemu: Use GICv2 by default for aarch64/virt TCG guests
        The emulated GICv3 has some limitations that make it unusable as a
        default; use GICv2 until they're sorted out. This change makes it once
        again possible to run aarch64/virt guests on a x86_64 host without
        having to tweak their configuration.

    - Additional capabilities for the node_device module
        Introduce two new capabilities to the node_device module. The first is
        for CCW devices, most common on the S390 architecture. The second is
        for fibre channel-backed SCSI devices and exposes the fc_remote_port
        sub-capability to SCSI target devices.

    - Node devices now report Mediated device capabilities
        Endpoint devices support new mdev capability and their parents now
        report the supported types in new mdev_types capability.

    - Capabilities now report information about host caches
        If supported in the kernel, host capabilities will now list L3 caches.
        The code for other levels was added as well, but only L3 caches are
        reported currently.

    - POWER9 CPU model was added
        It is now properly reported in host capabilities.

    - libxl: NUMA sibling distances are now reported in host capabilities

    - VMDK version 3 files are now properly detected

    - Interrupt remapping and Extended interrupt mode for IOMMU devices
        These two new features can now be controlled with new <driver
        intremap='on/off' eim='on/off'/> tag for iommu devices.

    - Graphics in libxl domains now have default addresses
        Even though there were default addresses before this change, they were
        not saved in the XML. It is now possible to see and control the listen
        addresses properly.

    - Default USB controllers are now added for devices in libxl domains
        Even though they were added automatically when USB device was attached,
        they could've been missing in some other cases. The logic is now fixed
        so there are always USB controllers, even if there was none of them in
        the specified XML.

    - Limits for RPC messages were increased
        Hitting the RPC limits we have is easier every day, so they were
        increased once again and some guessing logic was improved as well. It
        is now possible to get more stats than ever using the
        virConnectGetAllDomainStats() call and push through even bigger
        requests and replies for all APIs.

  * Bug fixes

    - qemu: Create memory_backing_dir on startup
        Libvirt's policy is that directories are created on startup if they
        don't exist. We've missed this one.

    - PCIe 4.0 cards now report proper link speeds
        It could happen that the link speed for PCIe devices was not properly
        reported or the nodedev-dumpxml just failed. That was due to mistake in
        the field width, but should now work properly.

    - qemu: Do not report errors on shutdown
        For some users, in some rare cases, it could happen that there was an
        error message "internal error: End of file from qemu monitor" in the
        logs even though no problem happened. The detection of these false
        positives was improved and such errors should not show any more.

    - User-specified UNIX socket paths for virtio channels should not be reset
        It could happen, in some cases, that libvirt would mistake a
        user-specified path for its own generated one and thus remove it from
        the XML. The detection of such addresses was improved now.

    - Fix address reservation during RNG hot-plug
        When error occurred in a specific point in time during the hot-plug of
        an RNG device, it could happen that an address was released even though
        another device was already using it, making it possible to hot-plug
        another device with that address, effectively having duplicated
        addresses in the XML.

# v3.3.0 (2017-05-05)

  * New features

    - net: Add support for coalesce settings
        Enabling data batching through these settings can improve network
        performance for guests.

    - qemu: Add support for guest CPU cache specification
        This features allows fine-grained control of the cache behavior of the
        guest CPU.

    - qemu: Add support for the qemu-xhci USB controller

  * Improvements

    - hyperv: Support Hyper-V 2012 and newer
        Starting with Hyper-V 2012 the API has changed causing the existing
        driver to be unable to send and process requests properly. This has
        been resolved by adding abstractions to handle the differences and ease
        handling such breaks if they happen in the future.

    - libxl: Add support for nested HVM domains
        Xen has supported nested HVM domains since version 4.4. The libvirt
        libxl driver now supports nested HVM domains by specifying the
        host-passthrough CPU mode when defining a domain.

    - qemu: Implement ACPI support for aarch64 guests
        Up until this point, ACPI support was only advertised for x86_64 guests
        and disabling it for aarch64 guests was not possible at all.

    - vz: Add support for changing the number of vCPUs

    - qemu: Automatically choose the best USB controller for guests
        The recently introduced qemu-xhci USB controller is the best choice for
        both ppc64 and aarch64 guests, so use it by default on those
        architectures if available.

    - daemon: Increase default task limit for libvirtd
        The default number of tasks for the pids cgroup controller is 512,
        which libvirtd can quickly bump into when starting lots of guests.
        Raise the limit to a more reasonable 32768.

    - docs: Include man pages describing key code names and values

    - virsh: Report initialization errors
        Sometimes virsh might be unable to start: when that happens, report
        useful diagnostics instead of failing silently.

  * Bug fixes

    - nss: Don't require a network restart for libvirt_guest
        Previously, the libvirt_guest NSS module would only work properly after
        the corresponding network had been restarted; now newly started guests
        will be reported correctly right away.

    - storage: Remove unavailable transient pools after restart
        Solve an issue where transient storage pools would be stuck in an
        unmanageable state if the source disappeared and libvirtd was
        subsequently restarted.

    - storage: Fix capacity value for LUKS encrypted volumes
        The 'capacity' value (e.g. guest logical size) for a LUKS volume is
        smaller than the 'physical' value of the file in the file system, so we
        need to account for that.

    - qemu: Fix regression when hyperv/vendor_id feature is used
        Guests using the feature would not be started at all; it is now
        possible to start them as expected.

    - qemu: Do not crash on USB address with no port and invalid bus

    - crypto: Always pad data before encrypting it
        If this step is not performed, when the data length matches the chunk
        size the decryption routines will misinterpret the last byte of data as
        the padding length and fail to decode it correctly.

# v3.2.0 (2017-04-02)

  * New features

    - The virt-host-validate tool now supports bhyve hypervisor

    - Introduce NVDIMM memory model
        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.

    - qemu: Introduce support for generic PCIe Root Ports
        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.

    - qemu: Add support for checking guest CPU ABI compatibility
        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.

    - qemu: Add support to migrate using TLS
        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.

    - qemu: add mediated devices framework support
        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.

    - qemu: Add support for setting TSC frequency
        Setting TSC frequency is required to enable migration for domains with
        'invtsc' CPU feature turned on.

    - Add support for block device threshold event
        When using thin provisioning, management tools need to resize the disk
        in certain cases. To avoid having them to poll disk usage this version
        introduces an event which will be fired when a given offset of the
        storage is written by the hypervisor. Together with the API it allows
        registering thresholds for given storage backing volumes and this event
        will then notify management if the threshold is exceeded. Currently
        only the qemu driver supports this.

    - bhyve: Add support for UEFI boot ROM, VNC, and USB tablet
        The bhyve driver now supports booting using the UEFI boot ROM, so
        non-FreeBSD guests that support UEFI could be booted without using an
        external boot loader like grub-bhyve. Video is also supported now,
        allowing to connect to guests via VNC and use an USB tablet as an input
        device. Please refer to the driver page for domain XML examples.

  * Improvements

    - qemu: Detect host CPU model by asking QEMU on x86_64
        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.

    - perf: Add more perf statistics
        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.

    - Write hyperv crash information into vm log
        qemu's implementation of the hyperv panic notifier now reports
        information about the crash from the guest os. Starting with this
        version, libvirt logs the information to the vm log file for possible
        debugging.

  * Bug fixes

    - QEMU: Use adaptive timeout for connecting to monitor
        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.

    - Overwrite (clear) 2 KB instead of just 512 bytes when initializing
      logical device

    - Describe the logical backend requirements better for pool-create-as

# v3.1.0 (2017-03-03)

  * New features

    - storage: Add Virtuozzo storage backend storage pool
        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.

    - qemu: Add support for memory backing with file source
        Add support in numa topology for file source inside memory backing
        (hugepages are not needed) Three new elements <source/>,<access/> and
        <allocation/> were added to <memoryBacking/> element. Also new
        configuration parameter memory_backing_dir was added to qemu.conf.

    - network: make openvswitch call timeout configurable
        Adding the ability to specify the timeout value in seconds for
        openvswitch calls in the libvirtd configuration file.

    - bhyve: add e1000 NIC support
        Add support for e1000 NIC. Previously, the only available option was
        virtio-net.

    - libxl: add tunneled migration support
        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.

    - qemu: add rendernode argument
        Add a new attribute 'rendernode' to <gl> spice element.

    - nodedev: add drm capability
        Add a new 'drm' capability for Direct Rendering Manager (DRM) devices,
        providing device type information.

    - Add API for individual/specific vCPU hotplug
        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.

  * Improvements

    - virsh: pool-list: allow both --uuid and --name in one command
        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.

    - Introduce MTU to domain <interface/> and <network>
        Allow setting MTU size for some types of domain interface and network.

    - libxl: improve support for <timer> configurations
        Add support for multiple timers. Extend the tsc timer to support the
        emulate mode. Improve conversion of timer XML to/from xl.cfg.

    - storage: modularize the storage driver
        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.

  * Bug fixes

    - nodedev: Fabric name must not be required for fc_host capability
        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.

    - bhyve: change address allocation schema for SATA disks
        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 <address
        type='pci'> from the <disk> elements with <target bus='sata'/> and let
        libvirt regenerate it properly.

    - libxl: maximum memory fixes
        Fix reporting of domain maximum memory. Fix setting dom0 maximum
        memory.

    - libxl: fix disk detach when <driver> not specified

    - libxl: fix dom0 autoballooning with Xen 4.8

    - qemu: Allow empty script path to <interface/>
        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.

# v3.0.0 (2017-01-17)

  * New features

    - Domain events for metadata content changes
        The domain events framework has a new event ID that can be used to get
        notifications when domain metadata content changes.

    - Event notifications for the secret object
        The secret object now supports event notifications, covering lifcycle
        changes and secret value changes.

    - New localPtr attribute for "ip" element in network XML

    - qemu: Support QEMU group I/O throttling
        Add the capability to allow group I/O throttling via a new domain
        <disk> <iotune> subelement "group_name" to allow sharing I/O throttling
        quota between multiple drives.

    - nss: Introduce libvirt_guest
        New libvirt_guest nss module that translates libvirt guest names into
        IP addresses.

    - daemon: Add support for runtime logging settings adjustment
        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.

    - storage: Add virStorageVolInfoFlags API
        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.

    - libxl: Implement virDomainGetMaxVcpus API

    - storage: Add overwrite flag checking for logical pool
        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).

    - qemu: Add support for guest CPU configuration on s390(x)

  * Improvements

    - perf: Add more perf statistics
        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.

    - conf: Display <physical> for volume xml
        Add a display of the <physical> size of a disk volume in the output of
        the volume XML.

    - qemu: Use virtio-pci by default for aarch64 mach-virt guests
        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.

    - vbox: remove support for VirtualBox 3.x and older
        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.

    - virsh: pool-info: introduce option --bytes
        Add option --bytes to virsh pool-info in order ti allow display of
        units in bytes rather than default of human readable output.

    - scsi: Add parent wwnn/wwpn or fabric capability for createVport
        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.

    - qemu: aggregate pcie-root-ports onto multiple functions of a slot
        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.

  * Bug fixes

    - lxc: fix accidental killing of containers during libvirtd restart
        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.

    - qemu: Correct GetBlockInfo values
        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.

    - qemu: Make virtio console usable on ppc64 guests
        The chardev detection code has been improved and can now handle this
        configuration properly.

    - qemu: Enable mount namespace
        To avoid funny races with udev relabelling devices under our hands and
        to enhance security, libvirt now spawns each qemu process with its own
        /dev.

    - storage: Fix implementation of no-overwrite for file system backend
        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.

    - qemu: Create hugepage path on per domain basis
        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.

    - conf: Reject domains with duplicate drive addresses
        Reject duplicate drive addresses for disks and hostdevs at domain
        definition.

    - libxl: reverse defaults on HVM net device attach
        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.

    - libxl: always enable pae for x86_64 HVM
        By default pae is disabled in libxl. Without an explicit <pae/> setting
        in the domain <features> configuration, an x86_64 HVM domain would be
        get an i686 environment. pae should always be enabled for x86_64 HVM
        domains.

    - qemu: Fix XML dump of autogenerated websocket
        As a result autogenerated websocket port is regenerated on domain
        restore, migration and such as it should be.

# v2.5.0 (2016-12-04)

  * New features

    - shmem: Add support for additional models
        The shmem device can now utilize QEMU's ivshmem-plain and
        ivshmem-doorbell, more modern versions of ivshmem.

    - vbox: Add VirtualBox 5.1 support

    - libssh: New transport
        The new libssh transport allows one to connect to a running libvirtd
        via SSH, using the libssh library; for example:
        qemu+libssh://server/system.

    - vhost-scsi: Add support scsi_host hostdev passthrough
        Add the capability to pass through a scsi_host HBA and the associated
        LUNs to the guest.

    - Allow debugging of gluster volumes in qemu
        Users can now enable debug logging for native gluster volumes in qemu
        using the "gluster_debug_level" option in qemu.conf

    - Pre-allocate memory slots for 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

    - qemu: Express devices will be placed on PCIe bus by default
        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.

  * Improvements

    - docs: Better documentation for migration APIs and flags

    - vbox: Address thread safety issues

    - virsh: Add support for passing an alternative persistent XML to migrate
      command

    - vhostuser: Allow hotplug of multiqueue devices

    - NEWS: Switch to an improved format
        List user-visible changes instead of single commits for a better
        high-level overview of differences between libvirt releases.

    - website: Modernize layout and branding
        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.

  * Bug fixes

    - vz: Fix migration in P2P mode

    - Forbid newline character in names of some libvirt objects

    - Fix compilation on macOS

==============================================================================
Older libvirt releases didn't have proper release notes: if you are interested
in changes between them, you should check out ChangeLog* and docs/news-*.html.
