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

# v6.0.0 (2020-01-15)

  * Packaging changes

    - support for python2 is removed
        Libvirt is no longer able to be built using the Python 2 binary. Python
        3 must be used instead.

    - docs: the python docutils toolset is now required
        The use of rst2html has been introduced for the website build process
        since docs are now being written in the RST as an alternative to HTML.

  * New features

    - new PCI hostdev address type: unassigned
        A new PCI hostdev address type 'unassigned' is introduced. An
        unassigned PCI hostdev behaves like any regular PCI hostdev inside
        Libvirt, but it is not usable by the guest. This gives the user a new
        option to manage the binding of PCI devices via Libvirt, declaring PCI
        hostdevs in the domain XML but allowing just a subset of them to be
        assigned to the guest.

    - Provide init scripts for sub-deaemons
        So far libvirt shipped systemd unit files for sub-daemons. With this
        release, init scripts are available too. Package maintainers can choose
        which one to install via --with-init-script configure option.

    - qemu: Support cold-unplug of sound devices

    - qemu: Implement VIR_MIGRATE_PARAM_TLS_DESTINATION
        This flag, which can be enabled using virsh's --tls-destination option,
        allows migration to succeed in situations where there is a mismatch
        between the destination's hostname and the information stored in its
        TLS certificate.

    - qemu: Support reporting memory bandwidth usage stats
        Implement Intel RDT-MBM in libvirt. The stats can be obtained via virsh
        domstats --memory.

    - qemu: Allow accessing NVMe disks directly
        Before this release there were two ways to configure a NVMe disk for a
        domain. The first was using <disk/> with the <source/> pointing to the
        /dev/nvmeXXXX. The other was using PCI assignment via <hostdev/>
        element. Both have their disadvantages: the former adds latency of file
        system and block layers of the host kernel, the latter prohibits domain
        migration. In this release the third way of configuring NVMe disk is
        added which combines the advantages and drops disadvantages of the
        previous two ways. It's accessible via <disk type='nvme'/>.

  * Removed features

    - 'phyp' Power Hypervisor driver removed
        The 'phyp' Power Hypervisor driver has not seen active development
        since 2011 and does not seem to have any real world usage. It has now
        been removed.

  * Improvements

    - qemu: xz save image compression is faster
        When using the xz format to compressed virtual machine saved state
        images, the "-3" compression level preset is now used. This results in
        slightly larger files, but with a massively reduced time to compress.
        The xz format offers the best compression level for saved state images,
        albeit still with the slowest running time. For the fastest possible
        running time, at cost of the larest compressed size, lzop should be
        used.

    - domain: Improve job stat handling
        It is now possible to retrieve stats for completed and failed jobs.

    - qemu: Don't hold monitor and agent job at the same time
        Before this change, a malicious (or buggy) qemu-guest-agent running in
        the guest could make other libvirt APIs unavailable for an unbounded
        amount of time.

  * Bug fixes

    - qemu: Report error if backing image format is not specified explicitly
        For a long time libvirt was assuming that a backing file is RAW when
        the format was not specified. This didn't pose a problem until blockdev
        support was enabled in last release. Libvirt now requires that the
        format is specified in the image metadata or domain XML and the VM will
        refuse to start otherwise. Additionally the error message now links to
        the knowledge base which summarizes how to fix the images.

    - qemu: Fix non-shared storage migration over NBD

    - qemu: Generate a single MAC address for hotplugged network devices
        Since libvirt 4.6.0, when hotplugging a network device that didn't have
        a MAC address already assigned by the user, two separate addresses
        would be generated: one for the live configuration, which would show up
        immediately, and one for the inactive configuration, which would show
        up after the first reboot. This situation was clearly undesirable, so a
        single MAC address is now generated and used both for the live
        configuration and the inactive one.

# v5.10.0 (2019-12-02)

  * New features

    - qemu: Introduce support for ARM CPU features
        The only features supported at the moment are SVE vector lengths, which
        were introduced in QEMU 4.2.0.

    - qemu: Support boot display for GPU mediated devices
        Until now, GPU mediated devices generally did not show any output until
        the guest OS had initialized the vGPU. By specifying the ramfb
        attribute, QEMU can be configured to use ramfb as a boot display for
        the device: this allows for display of firmware messages, boot loader
        menu, and other output before the guest OS has initialized the vGPU.

    - Add API to change the response timeout for guest agent commands
        By default, when a command is sent to the guest agent, libvirt waits
        forever for a response from the guest agent. If the guest is
        unresponsive for any reason, this can block the calling thread
        indefinitely. By setting a custom timeout using
        virDomainAgentSetResponseTimeout(), API users can change this behavior.

  * Improvements

    - Devices CGroup v2 support
        Libvirt supported all controllers of CGroup v2 but the devices
        controller which is implemented in this release.

    - Cold plug of sound device
        The QEMU driver now can handle cold plug of <sound/> devices.

    - Probe for default CPU types
        With QEMU 4.2.0 we can probe for the default CPU model used by QEMU for
        a particular machine type and store it in the domain XML. This way the
        chosen CPU model is more visible to users and libvirt will make sure
        the guest will see the exact same CPU after migration.

    - Adaptation to qemu's blockdev
        QEMU introduced a new way of specifying disks on the command line which
        enables fine-grained control over the block stack. Libvirt has adapted
        to this.

  * Refactors

    - More GLib integration
        More patches were merged that replace our internal functions with GLib
        ones. Also some effort was invested in replacing gnulib modules with
        GLib functions.

    - Rewrite of Perl scripts into Python
        Libvirt used Perl scripts to check for coding style, generate some code
        and things like that. To bring the number of languages used down, these
        scripts were rewritten into Python.

  * Bug fixes

    - Warn verbosely if using old loader:nvram pairs
        Some distributions still use --with-loader-nvram or nvram variable in
        qemu.conf. This is now discouraged in favour of FW descriptors.
        However, instead of silently ignoring user's config, libvirt warns if
        outdated config is detected.

    - Drop pconfig from Icelake-Server CPU model
        The pconfig feature was enabled in QEMU by accident in 3.1.0. All other
        newer versions do not support it and it was removed from the
        Icelake-Server CPU model in QEMU.

    - Wait longer for device removal confirmation on PPC64
        After sending device hot unplug request to QEMU, libvirt waits up to 5
        seconds for qemu to confirm the device removal. On some architectures
        (like PPC64) this can take longer time and libvirt now reflects that.

    - Forcibly create nodes in domain's namespace
        The QEMU driver starts a domain in a namepsace with private /dev and
        creates only those nodes there which the domain is configured to have.
        However, it may have happened that if a node changed its minor number
        this change wasn't propagated to the namespace.

    - Various AppArmor bugfixes
        The AppArmor driver now knows how to handle <shmem/> devices and also
        snapshotting more disks at once.

    - Improved video model autoselection
        If a graphics device was added to XML that had no video device, libvirt
        automatically added a video device which was always of type 'cirrus' on
        x86_64, even if the underlying qemu didn't support cirrus. Libvirt now
        bases the decision on qemu's capabilities.

# v5.9.0 (2019-11-05)

  * Packaging changes

    - Start linking against GLib and using its features
        Up until now, libvirt has been dealing with platform portability and
        the lack of certain features in libc by using gnulib and implementing
        its own functions and data structures respectively; going forward, it
        will prefer the facilities offered by GLib instead.

    - Stop distributing generated documentation
        Most downstreams already patch the libvirt source to some extent, so
        this change will probably not affect them.

    - Rewrite several Perl scripts in Python
        Phasing out Perl usage is part of the project strategy.

  * New features

    - qemu: Introduce a new video model of type 'ramfb'
        Introduce a new video model type to the domain XML that supports the
        ramfb standalone device in qemu.

    - qemu: Implement the ccf-assist pSeries feature
        Users can now decide whether ccf-assist (Count Cache Flush Assist)
        support should be available to pSeries guests.

    - Xen: Support specifying ACPI firmware path
        The libxl driver now supports specifying an ACPI firmware path using
        the acpi element.

    - qemu: Support specifying resolution for video devices

  * Removed features

    - logging: Drop support for including stack traces
        This feature was intended to aid debugging, but in practice it resulted
        in logs that were too verbose to be useful and also resulted in a
        significant performance penalty.

  * Improvements

    - qemu: Implement CPU comparison/baseline on s390x
        This functionality has been historically limited to x86_64, but it's
        now available on s390x too.

  * Bug fixes

    - lib: autostart objects exactly once
        If libvirtd or any of the sub-daemons is started with socket activation
        then objects might be autostarted more than once. For instance, if a
        domain under qemu:///session URI is mark as autostarted and the session
        daemon is started then the domain is started with it. If user shuts the
        domain down and the session daemon is started again, the user's wish to
        keep the domain shut off is ignored and the domain is autostarted
        again. This is now fixed.

    - qemu: Properly advertise bochs-display availability
        Support for bochs-display was introduced in libvirt 5.6.0, but until
        now the model was not listed in the domain capabilities.

    - security: Don't remember labels for TPM devices
        Due to the way they're implemented in the kernel, trying to remember
        labels for TPM devices makes it impossible to use them.

    - security: Properly rollback after failure in a stacked driver
        When multiple security drivers are involved, failure in one of them
        would result in only the corresponding changes being rolled back,
        leaving the ones performed by drivers that had been activated earlier
        in place. All changes are rolled back now.

    - Fix build with musl libc

    - Improve compatibility with non-bash shells

# v5.8.0 (2019-10-05)

  * New features

    - qemu: Support use of precreated tap/macvtap devices by unprivileged
      libvirtd
        It is now possible for an unprivileged libvirtd to make use of tap and
        macvtap devices that were previously created by some other entity. This
        is done by setting managed='no' along with the device name in the
        target subelement of <interface type='ethernet'>.

    - qemu: Support vhost-user-gpu
        Support for running virtio GPUs in separate processes with vhost-user
        backend. It requires QEMU newer than 4.1.

    - Introduce virConnectSetIdentity API
        When split daemons are in use, this API is used to forward uid, gid and
        SELinux info from virproxyd to other driver daemons such as virtqemud.

  * Improvements

    - qemu: Support running SLIRP networking in a separate process
        User can configure the slirp-helper path in qemu.conf. It will start a
        slirp-helper process to provide SLIRP networking when the VM is started
        with network interface "user". That will allow stricter security
        policies for QEMU SLIRP network.

  * Removed features

    - Remove xenapi driver
        The xenapi driver is removed since it has not received any significant
        development since its initial contribution nine years ago and has no
        known user base.

# v5.7.0 (2019-09-03)

  * New features

    - qemu: Support Direct Mode for Hyper-V Synthetic timers
        The QEMU driver now supports Direct Mode for Hyper-V Synthetic timers
        for Hyper-V guests.

    - lib: Add virDomainGetGuestInfo()
        This API is intended to aggregate several guest agent information
        queries and is inspired by stats API virDomainListGetStats(). It is
        anticipated that this information will be provided by a guest agent
        running within the domain. It's exposed as virsh guestinfo.

    - Experimental split of libvirtd into separate daemons
        The big monolithic libvirtd daemon can now be replaced by smaller
        per-driver daemons. The new split daemons are considered experimental
        at this time and distributions are encouraged to continue using the
        traditional libvirtd by default.

    - qemu: Support kvm-hint-dedicated performance hint
        With <hint-dedicated state='on'/> and <cpu mode='host-passthrough'/>,
        it allows a guest to enable optimizations when running on dedicated
        vCPUs. QEMU newer than 2.12.0 and kernel newer than 4.17 are required.

  * Removed features

    - Remove KVM assignment support
        The KVM style of PCI device assignment was removed from the kernel in
        version 4.12.0 after being deprecated since 4.2.0. Libvirt defaults to
        VFIO for a long time. Remove support for KVM device assignment from
        libvirt too.

    - libxml: min required libxml is now 2.9.1
        Support for building with libxml versions older than 2.9.1 has been
        dropped.

  * Improvements

    - virsh: Support setting bandwidth in migrate subcommand
        In addition to postcopy bandwidth, the virsh migrate subcommand now
        supports specifying precopy bandwidth with the --bandwidth parameter.

    - libxl: Implement domain metadata getter/setter
        The libxl driver now supports virDomainGetMetadata() and
        virDomainSetMetadata() APIs.

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

    - Report RNG device in domain capabilities XML
        Libvirt now reports if RNG devices are supported by the underlying
        hypervisor in the domain capabilities XML.

    - Stop linking NSS plugins with libvirt.so
        This reduces the amount of code and 3rd party libraries are that loaded
        into all processes.

    - Split the setuid virt-login-shell binary into two pieces
        The setuid virt-login-shell binary is now a tiny shim that sanitizes
        the process execution environment variables and arguments, before
        launching the trusted virt-login-shell-helper binary.

    - qemu: Allow migration with disk cache on
        When QEMU supports flushing caches at the end of migration, we can
        safely allow migration even if disk/driver/@cache is neither none nor
        directsync.

  * Bug fixes

    - Various security label remembering fixes
        In the previous release libvirt introduced remembering of original
        owners and SELinux labels on files. However, the feature did not work
        properly with snapshots, on migrations or on network filesystems. This
        is now fixed.

    - Allow greater PCI domain numbers
        Libvirt used to require PCI domain number to be not greater than
        0xFFFF. The code was changed to allow 32 bits long numbers.

    - Various D-Bus fixes
        When D-Bus is not available, libvirt was reporting random errors. These
        are now gone.

    - Prefer read-only opening of PCI config files
        When enumerating PCI bus, libvirt opens config files under sysfs mount
        and parses them to learn various aspects of the device (e.g. its
        capabilities). Only in a very limited number of cases it is actually
        writing into the file. However, it used to open the file also for
        writing even if it was only reading from it.

    - Fix AppArmor profile
        Since the 5.6.0 release, libvirt uses procfs to learn the list of
        opened file descriptors when spawning a command. However, our AppArmor
        profile was not allowing such access.

    - Don't block storage driver when starting or building a pool
        Starting or building a storage pool can take a long time to finish.
        During this time the storage driver was blocked and thus no other API
        involving the storage driver could run. This is now fixed.

# v5.6.0 (2019-08-05)

  * New features

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

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

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

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

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

  * Removed features

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

  * Improvements

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

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

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

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

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

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

  * Bug fixes

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

# v5.5.0 (2019-07-02)

  * Security

    - api: Prevent access to several APIs over read-only connections
        Certain APIs give root-equivalent access to the host, and as such
        should be limited to privileged users. CVE-2019-10161, CVE-2019-10166,
        CVE-2019-10167, CVE-2019-10168.

  * New features

    - qemu: Support SMMUv3 IOMMU
        SMMUv3 is an IOMMU implementation for ARM virt guests.

    - network: Introduce the network port API
        This new public API can be used by virtualization drivers to manage
        network resources associated with guests, and is a further step towards
        splitting libvirtd into multiple daemons.

  * Removed features

    - qemu: Remove support for virDomainQemuAttach and
      virConnectDomainXMLFromNative APIs
        The qemu implementations for the APIs mentioned above were removed and
        the APIs now return an error. The implementation was stale for a long
        time and did not work with modern QEMU command lines, generated from
        libvirt or otherwise.

    - Stop supporting migration of config files from pre-XDG layout
        The new layout was introduced with libvirt 0.9.13 (Jul 2012).

    - Remove Avahi mDNS support
        This feature was never used outside of virt-manager, which has itself
        stopped using it a while ago.

  * Improvements

    - sysinfo: Report SMBIOS information on aarch64
        While SMBIOS support has historically been limited to x86_64, modern
        aarch64 machines often offer access to the same information as well,
        and libvirt now exposes it to the user when that's the case.

    - test driver: Expand API coverage
        Even more APIs that were missing from the test driver have now been
        implemented.

    - virt-xml-validate: Allow input to be read from stdin

    - qemu: Validate spapr-vio addresses as 32-bit
        libvirt has always considered these addresses (used for pSeries guests)
        as 64-bit, but the sPAPR specification says that they're 32-bit
        instead.

  * Bug fixes

    - qemu: Set process affinity correctly when using <numatune>
        libvirt would mistakenly interpret the nodeset attribute as a list of
        CPUs instead of as a list of NUMA node, and the process affinity would
        be set incorrectly as a result; this has now been fixed.

# v5.4.0 (2019-06-03)

  * Security

    - cpu: Introduce support for the md-clear CPUID bit
        This bit is set when microcode provides the mechanism to invoke a flush
        of various exploitable CPU buffers by invoking the x86 VERW
        instruction. CVE-2018-12126, CVE-2018-12127, CVE-2018-12130,
        CVE-2019-11091.

    - Restrict user access to virt-admin, virtlogd and virtlockd
        The intended users for these facilities are the root user and the
        libvirtd service respectively, but these restrictions were not enforced
        correctly. CVE-2019-10132.

  * Improvements

    - test driver: Expand API coverage
        Several APIs that were missing from the test driver have now been
        implemented.

    - Avoid unnecessary static linking
        Most binaries shipped as part of libvirt, for example virtlogd and
        libvirt_iohelper, were embedding parts of the library even though they
        also linked against the libvirt.so dynamic library. This is no longer
        the case, which results in both the disk and memory footprint being
        reduced.

    - qemu: Report stat-htlb-pgalloc and stat-htlb-pgfail balloon stats
        These stats have been introduced in QEMU 3.0.

  * Bug fixes

    - qemu: Fix emulator scheduler support
        Setting the scheduler for QEMU's main thread before QEMU had a chance
        to start up other threads was misleading as it would affect other
        threads (vCPU and I/O) as well. In some particular situations this
        could also lead to an error when the thread for vCPU #0 was being moved
        to its cpu,cpuacct cgroup. This was fixed so that the scheduler for the
        main thread is set after QEMU starts.

    - apparmor: Allow hotplug of vhost-scsi devices

# v5.3.0 (2019-05-04)

  * New features

    - qemu: Add support for setting the emulator scheduler parameters
        I/O threads and vCPU threads already support setting schedulers, but
        until now it was impossible to do so for the main QEMU thread (emulator
        thread in the libvirt naming). This is, however, requested for some
        very specific scenarios, for example when vCPU threads are running at
        such priority that could starve the main thread.

  * Removed features

    - vbox: Drop support for VirtualBox 4.x releases
        Support for all the 4.x releases was ended by VirtualBox maintainers in
        December 2015. Therefore, libvirt support for these releases is
        dropped.

  * Improvements

    - qemu: Use PCI by default for RISC-V guests
        PCI support for RISC-V guests was already available in libvirt 5.1.0,
        but it required the user to opt-in by manually assigning PCI addresses:
        with this release, RISC-V guests will use PCI automatically when
        running against a recent enough (4.0.0+) QEMU release.

    - qemu: Advertise firmware autoselection in domain capabilities
        The firmware autoselection feature is now exposed in domain
        capabilities and management applications can query for accepted values,
        i.e. values that are accepted and for which libvirt found firmware
        descriptor files. Firmware Secure Boot support is also advertised.

    - Drop YAJL 1 support
        YAJL 2 is widely adopted and maintaining side by side support for two
        versions is unnecessary.

  * Bug fixes

    - rpc: cleanup in virNetTLSContextNew
        Failed new gnutls context allocations in virNetTLSContextNew function
        results in double free and segfault. Occasional memory leaks may also
        occur.

    - virsh: various completers fixes
        There were some possible crashers, memory leaks, etc. which are now
        fixed.

    - qemu: Make hugepages work with memfd backend
        Due to a bug in command line generation libvirt did not honor hugepages
        setting with memfd backend.

    - Enforce ACL write permission for getting guest time & hostname
        Getting the guest time and hostname both require use of guest agent
        commands. These must not be allowed for read-only users, so the
        permissions check must validate "write" permission not "read".

# v5.2.0 (2019-04-03)

  * New features

    - Add Storage Pool Capabilities output
        Add support to list an enumerated list of supported Storage Pools via
        the virConnectGetCapabilities API when connected via a Storage Driver.
        Add support to get a more detailed list XML output Storage Pool
        Capabilities vis the virConnectGetStoragePoolCapabilites API.

    - qemu: Support virtio-{non-}transitional device models
        virtio-transitional and virtio-non-transitional model values were added
        to the QEMU driver for the following devices: disk, interface,
        filesystem, rng, vsock, memballoon, controller type scsi, controller
        type virtio-serial, input bus virtio type passthrough, hostdev type
        scsi_host. These new models can be used to give fine grained control
        over what virtio device version is presented to the guest.

    - qemu: Enable firmware autoselection
        Libvirt allows users to provide loader path for some time now. However,
        this puts some burden on users because they need to know what firmware
        meets their requirements. Now that QEMU ships firmware description
        files this burden can be moved onto libvirt. It is as easy as setting
        the firmware attribute in the os element (accepted values are bios and
        efi). Moreover, libvirt automatically enables domain features needed
        for firmware it chooses.

    - snapshots: Add support for topological listings
        A new flag VIR_DOMAIN_SNAPSHOT_LIST_TOPOLOGICAL is available for the
        various snapshot listing APIs such as virDomainListAllSnapshots(). For
        drivers that support the flag, the listed snapshots are guaranteed to
        be sorted such that parents occur before children.

    - Xen: Add support for max grant frames setting
        Add support for Xen's max_grant_frames setting by adding a new xenbus
        controller type with a maxGrantFrames attribute. E.g. <controller
        type='xenbus' maxGrantFrames='64'/>

    - qemu: Add support for parallel migration
        With QEMU 4.0.0 libvirt can enable parallel migration which causes the
        memory pages to be processed in parallel by several threads and sent to
        the destination host using several connections at the same time. This
        may increase migration speed in case a single thread is unable to
        saturate the network link.

  * Removed features

    - Drop support for Upstart and "Red Hat" init scripts
        Not a single one of the platforms we target still uses Upstart, and the
        Upstart project itself has been abandoned for several years now; the
        same is true for the "Red Hat" (really System V) init scripts, since
        RHEL 7 and later releases use systemd.

  * Improvements

    - Report class information for PCI node device capability.

    - Split setup of IPv4 and IPv6 top level chain
        The requirement resulting from private chains improvement done in
        v5.1.0 was refined so that only tables from corresponding IP version
        are required. This means that if a network doesn't have IPv6 enabled
        then those tables are not required.

    - Don't default to building the QEMU driver
        Historically, the QEMU driver has been special in that it was enabled
        by default, with the option to explicitly opt-out of it; starting now,
        we're enabling it opportunistically if we detect that all requirements
        are available, just like we do with other drivers.

  * Bug fixes

    - virt-host-validate: Fix IOMMU check on s390x

    - qemu: Allow creating pSeries guests with graphics and no USB mouse
        It's now possible to prevent libvirt from automatically adding a USB
        mouse to pSeries guests by including a USB tablet in the input XML:
        doing so is desiderable as using a tablet results in a much better user
        experience when working with GUIs.

    - qemu: Set $HOME and XGD variables for qemu:///system guests
        This avoids files being accidentally created under / or the guests not
        being able to start because they lack the necessary permissions to
        write to that location.

# v5.1.0 (2019-03-04)

  * New features

    - bhyve: Add support for additional command-line arguments
        The bhyve driver now supports passing additional command-line arguments
        to the bhyve process using the new <bhyve:commandline> element in
        domain configuration.

    - network: Support setting a firewalld "zone" for virtual network bridges
        All libvirt virtual networks with bridges managed by libvirt (i.e.
        those with forward mode of "nat", "route", "open", or no forward mode)
        will now be placed in a special firewalld zone called "libvirt" by
        default. The zone of any network bridge can be changed using the zone
        attribute of the network's bridge element.

    - bhyve: Support for ignoring unknown MSRs reads and writes
        A new <features> element <msrs unknown='ignore'/> was introduced and
        the bhyve driver supports it to control unknown Model Specific
        Registers (MSRs) reads and writes.

    - qemu: Add support for encrypted VNC TLS keys
        Use the password stored in the secret driver under the uuid specified
        by the vnc_tls_x509_secret_uuid option in qemu.conf.

    - Add storage pool namespace options
        Allow for adjustment of RBD configuration options via Storage Pool XML
        Namespace adjustments.

    - qemu: Add support for setting post-copy migration bandwidth
        Users can now limit the bandwidth of post-copy migration, e.g. via
        virsh migrate --postcopy-bandwidth.

  * Improvements

    - Create private chains for virtual network firewall rules
        Historically firewall rules for virtual networks were added straight
        into the base chains. This works but has a number of bugs and design
        limitations. To address them, libvirt now puts firewall rules into its
        own chains. Note that with this change the filter, nat and mangle
        tables are required for both IPv4 and IPv6.

    - Detect CEPH and GPFS as shared FS
        When starting a migration libvirt performs some sanity checks to make
        sure domain will be able to run on the destination. One of the
        requirements is that the disk has to either be migrated too or be
        accessible from a network filesystem. CEPH and GPFS weren't detected as
        a network filesystem.

    - Advertise network MTU via DHCP when specified
        If network MTU is set and the network has DHCP enabled, advertise the
        MTU in DHCP transaction too so that clients can adjust their link
        accordingly.

    - qemu: Allocate memory at the configured NUMA nodes from start
        Libvirt used to just start QEMU, let it allocate memory for the guest,
        and then use CGroups to move the memory to configured NUMA nodes. This
        is suboptimal as huge chunks of memory have to be moved. Moreover, this
        relies on ability to move memory later which is not always true. A
        change was made to set process affinity correctly from the start so
        that memory is allocated on the configured nodes from the beginning.

    - Support for newer Wireshark
        Adapt libvirt to use the more recent release requiring a source build
        configuration of libvirt --with-wireshark to upgrade to the more recent
        version.

    - Batch mode virsh and virt-admin parsing improvements
        When parsing a single-argument command_string in batch mode, virsh and
        virt-admin now permit newlines in addition to semicolons for splitting
        commands, and backslash-newline for splitting long lines, to be more
        like shell parsing.

  * Bug fixes

    - qemu: Use CAP_DAC_OVERRIDE during QEMU capabilities probing
        By default, libvirt runs the QEMU process as qemu:qemu which could
        cause issues during probing as some features like AMD SEV might be
        inaccessible to QEMU because of file system permissions. Therefore,
        CAP_DAC_OVERRIDE is granted to overcome these for the purposes of
        probing.

    - storage: Add default mount options for fs/netfs storage pools
        Altered the command line generation for fs/netfs storage pools to add
        some default options. For Linux based systems, the options added are
        "nodev, nosuid, noexec". For FreeBSD based systems, the options added
        are "nosuid, noexec".

    - qemu: Allow use of PCI for RISC-V guests
        This works with QEMU 4.0.0+ only and is opt-in at the moment, since it
        requires users to manually assign PCI addresses, but is otherwise fully
        functional.

    - network: Fix virtual networks on systems using firewalld+nftables
        Because of the transitional state of firewalld's new support for
        nftables, not all iptables features required by libvirt are yet
        available, so libvirt must continue to use iptables for its own packet
        filtering rules even when the firewalld backend is set to use nftables.
        However, due to the way iptables support is implemented in kernels
        using nftables (iptables rules are converted to nftables rules and
        processed in a separate hook from the native nftables rules), guest
        networking was broken on hosts with firewalld configured to use
        nftables as the backend. This has been fixed by putting libvirt-managed
        bridges in their own firewalld zone, so that guest traffic can be
        forwarded beyond the host and host services can be exposed to guests on
        the virtual network without opening up those same services to the rest
        of the physical network. This means that host access from virtual
        machines is no longer controlled by the firewalld default zone (usually
        "public"), but rather by the new firewalld zone called "libvirt"
        (unless configured otherwise using the new zone attribute of the
        network bridge element).

    - qemu: Fix i6300esb watchdog hotplug on Q35
        Ensure that libvirt allocates a PCI address for the device so that QEMU
        did not default to an address that would not allow for device hotplug.

    - lxc: Don't reboot host on virDomainReboot
        If the container is really a simple one (init is just bash and the
        whole root is passed through) then virDomainReboot and
        virDomainShutdown would reboot or shutdown the host. The solution is to
        use different method to reboot or shutdown the container in that case
        (e.g. signal).

    - rpc: Various stream fixes
        One particular race was fixed, one locking problem and error reporting
        from streams was made better.

    - qemu: Fix guestfwd hotplug/hotunplug
        Fixed the generation of the guestfwd hotplug/unplug command sent to
        QEMU to match the syntax used when creating the initial command line.

    - qemu: Forbid CDROMs on virtio bus
        Attempting to create an empty virtio-blk drive or attempting to eject
        it results into an error. Forbid configurations where users would
        attempt to use CDROMs in virtio bus.

    - qemu: Use 'raw' for 'volume' disks without format
        Storage pools might want to specify format of the image when
        translating the volume thus libvirt can't add any default format when
        parsing the XML. Add an explicit format when starting the VM and format
        is not present neither by user specifying it nor by the storage pool
        translation function.

    - qemu: Assume 'raw' default storage format also for network storage
        Post parse callback adds the 'raw' type only for local files. Remote
        files can also have backing store (even local) so we should do this
        also for network backed storage.

    - qemu: Fix block job progress reporting and advocate for READY event
        In some cases QEMU can get to 100% and still not reach the synchronised
        phase. Initiating a pivot in that case will fail. Therefore it is
        strongly advised to wait for VIR_DOMAIN_BLOCK_JOB_READY event which
        does not suffer from this problem.

    - qemu: Don't format image properties for empty drive
        If a -drive has no image, then formatting attributes such as cache,
        readonly, etc. would cause errors to be reported from QEMU. This was
        fixed by not supplying the attributes for devices without an image.

    - External snapshot metadata redefinition is fixed
        Attempting to use VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE to reinstate the
        metadata describing an external snapshot created earlier for an offline
        domain no longer fails.

# v5.0.0 (2019-01-15)

  * New features

    - Xen: Add support for openvswitch
        The libxl driver now supports virtual interfaces that connect to an
        openvswitch bridge, including interfaces with VLAN tagging and trunking
        configuration.

    - qemu: Report whether KVM nesting is available
        Running nested KVM guests requires specific configuration steps to be
        performed on the host; libvirt will now report in the host capabilities
        whether KVM nesting support is available.

  * Removed features

    - Drop UML driver
        The UML driver was unmaintained and not tested for quite some time now.
        Worse, there is a bug that causes it to deadlock on some very basic
        operations (e.g. dumping domain XML). These facts make us believe no
        one uses it.

  * Improvements

    - qemu: Add support for ARMv6l guests

    - Support more NVDIMM configuration options
        Introduce more configuration options. For the source element, add the
        'alignsize' and 'pmem' subelements. For the target element, add the
        'readonly' subelement.

    - cpu: Add support for "stibp" x86_64 feature
        Add cpu flag stibp (Single Thread Indirect Branch Predictors) to
        prevent indirect branch predictions from being controlled by the
        sibling Hyperthread.

    - libxl: Handle external domain destroy
        Historically, if a domain was destroyed using xl rather than through
        libvirt APIs, libvirt would not be aware of the fact and keep
        considering it as running. This is no longer the case.

    - Start selecting the first available DRI device for OpenGL operations
        If OpenGL support is needed (either with SPICE gl enabled or with
        egl-headless), libvirt is now able to pick the first available DRI
        device for the job. At the same time, this improvement is also a bugfix
        as it prevents permission-related issues with regards to our mount
        namespaces and the default DRI render node's permissions which would
        normally prevent QEMU from accessing such a device.

    - qemu: Add support for postcopy-requests migration statistics
        The virDomainJobInfo can get number page requests received from the
        destination host during post-copy migration.

  * Bug fixes

    - lxc: Don't forbid interfaces with type=direct
        Such interfaces are supported by lxc and should be allowed.

    - qemu: Fully clean up RNG devices on detach
        Some RNG device types, such as those using EGD, might need extra clean
        up on the host in addition to removing the guest-side device.

# v4.10.0 (2018-12-03)

  * New features

    - qemu: Add Hyper-V PV IPI and Enlightened VMCS support
        The QEMU driver now has support for Hyper-V PV IPI and Enlightened VMCS
        for Windows and Hyper-V guests.

    - qemu: Added support for PCI devices on S390
        PCI addresses can now include the new zpci element which contains uid
        (user-defined identifier) and fid (PCI function identifier) attributes
        and makes the corresponding devices usable by S390 guests.

    - Support changing IOThread polling parameters for a live guest
        Introduced virDomainSetIOThreadParams which allows dynamically setting
        the IOThread polling parameters used by QEMU to manage the thread
        polling interval and the algorithm for growth or shrink of the polling
        time. The values only affect a running guest with IOThreads. The
        guest's IOThread polling values can be viewed via the domain
        statistics.

    - Xen: Add support for PVH
        The libxl driver now supports Xen's PVH virtual machine type. PVH
        machines are enabled with the new "xenpvh" OS type, e.g.
        <os><type>xenpvh</type></os>

    - qemu: Added support for CMT (Cache Monitoring Technology)
        Introduced cache monitoring using the monitor element in cachetune for
        vCPU threads. Added interfaces to get and display the cache utilization
        statistics through the command 'virsh domstats' via the
        virConnectGetAllDomainStats API.

    - qemu: Add support for nested HV for pSeries guests
        Nested HV support makes it possible to run nested (L2) guests with
        minimal performance penalty when compared to regular (L1) guests on
        ppc64 hardware.

  * Bug fixes

    - Xen: Handle soft reset shutdown event
        The pvops Linux kernel uses soft reset to handle the crash machine
        operation. The libxl driver now supports the soft reset shutdown event,
        allowing proper crash handling of pvops-based HVM domains.

# v4.9.0 (2018-11-04)

  * New features

    - util: Add cgroup v2 support
        cgroup v2 support has been implemented in libvirt, with both "unified"
        (v2 only) and "hybrid" (v2 + v1) setups being usable; existing "legacy"
        (v1 only) setups will keep working.

    - qemu: Add vfio AP support
        The QEMU driver now has support to passthrough adjunct processors into
        QEMU guests on S390.

  * Improvements

    - rpc: Make 'genprotocol' output reproducible
        This is another step towards making libvirt builds fully reproducible.

  * Bug fixes

    - security: Fix permissions for UNIX sockets
        Since 4.5.0, libvirt is using FD passing to hand sockets over to QEMU,
        which in theory removes the need for them to be accessible by the user
        under which the QEMU process is running; however, other processes such
        as vdsm need to access the sockets as well, which means adjusting
        permissions is still necessary.

    - cpu_map: Add Icelake model definitions
        These CPU models will be available in the upcoming 3.1.0 QEMU release.

    - util: Properly parse URIs with missing trailing slash
        Some storage URIs were not parsed correctly, in which case libvirt
        ended up emitting XML that it would then refuse to parse back.

# v4.8.0 (2018-10-01)

  * New features

    - Xen: Support PM Suspend and Wakeup
        The libxl driver now supports the virDomainPMSuspendForDuration and
        virDomainPMWakeup APIs.

  * Removed features

    - Xen: Drop support for Xen 4.4 and 4.5
        Xen 4.4 and 4.5 are no longer supported by the Xen community. Drop
        support for these older versions and require Xen >= 4.6.

    - nwfilter: Disallow binding creation in session mode
        Ensure that a filter binding creation is not attempted in session mode
        and generates a proper error message.

  * Improvements

    - qemu: Retrieve guest hostname through QEMU Guest Agent command
        QEMU is now able to retrieve the guest hostname using a new QEMU-GA
        command called 'guest-get-host-name'. Virsh users can execute
        'domhostname' for QEMU driver for domains configured to use the Guest
        Agent.

    - virsh: Implement vsh-table in virsh and virsh-admin
        The new API fixes problems with table-alignment, making the tables more
        readable and deals with unicode.

  * Bug fixes

    - storage: Allow inputvol to be encrypted
        When creating a storage volume based on another volume, the base input
        volume is allowed to be encrypted.

    - virsh: Require explicit --domain for domxml-to-native
        The --domain option for domxml-to-native virsh command has always been
        documented as required, but commit v4.3.0-127-gd86531daf2 accidentally
        made it optional.

    - lxc_monitor: Avoid AB / BA lock race
        A deadlock situation could occur when autostarting a LXC domain 'guest'
        due to two threads attempting to take opposing locks while holding
        opposing locks (AB BA problem).

# v4.7.0 (2018-09-03)

  * New features

    - storage: add storage pool iscsi-direct
        Introduce a new storage pool backend that uses libiscsi instead of
        iscsiadm. It support basic pool operations: checkPool and refreshPool.

    - Add support for MBA (Memory Bandwidth Allocation technology)
        Domain vCPU threads can now have allocated some parts of host memory
        bandwidth by using the memorytune element in cputune.

    - qemu: Add support for RISC-V guests
        riscv32 and riscv64 guest architectures are now supported.

  * Improvements

    - qemu: Add ccw support for vhost-vsock
        Support the vhost-vsock-ccw device on S390.

    - qemu: Make default machine type independent of QEMU
        We can't control whether or not QEMU will change its default machine
        type in the future, or whether downstream distributions will decide to
        compile out some machine types, so our only option to provide a
        predictable behavior is taking care of the default ourselves;
        management applications and users are encouraged to explicitly pick a
        machine type when creating new guests.

    - apparmor: Various improvements
        Rules have been added to deal with a number of scenarios that didn't
        work correctly.

  * Bug fixes

    - esx: Truncate CPU model name
        Some CPU model names are too long to be stored into the corresponding
        property, and should be explicitly truncated to avoid unexpected
        behavior in users of the virNodeGetInfo() API such as virsh nodeinfo.

    - utils: Remove arbitrary limit on socket_id/core_id
        Both values were assumed to be smaller than 4096, but in fact they are
        entirely hardware-dependent and there have been reports of machines
        presenting much bigger values, preventing libvirt from working
        correctly; all such limits have now been removed.

# v4.6.0 (2018-08-06)

  * New features

    - qemu: Implement the HTM pSeries feature
        Users can now decide whether HTM (Hardware Transactional Memory)
        support should be available to the guest.

    - qemu: Enable VNC console for mediated devices
        Host devices now support a new atribute 'display' which can be used to
        turn on frame buffer rendering on a vgpu mediated device instead of on
        an emulated GPU, like QXL.

  * Improvements

    - qemu: Introduce a new video model of type 'none'
        Introduce a new video model type that disables the automatic addition
        of a video device to domains with 'graphics' specified in their XML.
        This can be useful with GPU mediated devices which can serve as the
        only rendering devices within the guest.

    - virsh: Add --alias to attach-disk and attach-interface commands
        Add option --alias to set customized device alias name when using
        attach-disk or attach-interface commands.

    - virsh: Support usb and sata address to attach-disk
        Usb or sata address could be used when attach-disk with --address. For
        example, use usb address as usb:<bus>.<port>, use sata address as
        <controller>.<bus>.<unit>.

# v4.5.0 (2018-07-02)

  * New features

    - qemu: Provide TPM emulator support
        Support QEMU's TPM emulator based on swtpm. Each QEMU guest gets its
        own virtual TPM.

    - bhyve: Support specifying guest CPU topology
        Bhyve's guest CPU topology could be specified using the <cpu><topology
        ../></cpu> element.

    - qemu: Add support for extended TSEG size
        Support specifying extended TSEG size for SMM in QEMU.

    - qemu: Add support for SEV guests
        SEV (Secure Encrypted Virtualization) is a feature available on AMD
        CPUs that encrypts the guest memory and makes it inaccessible even to
        the host OS.

  * Removed features

    - Remove support for qcow/default encrypted volumes
        Disallow using a qcow encrypted volume for the guest and disallow
        creation of the qcow or default encrypted volume from the storage
        driver. Support for qcow encrypted volumes has been phasing out since
        QEMU 2.3 and by QEMU 2.9 creation of a qcow encrypted volume via
        qemu-img required usage of secret objects, but that support was never
        added to libvirt.

    - Make GnuTLS mandatory
        Building without GnuTLS is no longer possible.

    - qemu: Remove allow_disk_format_probing configuration option
        The option represented a security risk when used with malicious disk
        images, so users were recommended against enabling it; with this
        release, it's been removed altogether.

  * Improvements

    - capabilities: Provide info about host IOMMU support
        Capabilities XML now provide information about host IOMMU support.

    - virsh: Add --all to domblkinfo command
        Alter the domblkinfo command to add the option --all in order to
        display the size details of each domain block device from one command
        in a output table.

    - qemu: Allow concurrent access to monitor and guest agent
        Historically libvirt prevented concurrent accesses to the qemu monitor
        and the guest agent. Therefore two independent calls (one querying the
        monitor and the other querying guest agent) would serialize which hurts
        performance. The code was reworked to allow two independent calls run
        at the same time.

    - qemu: Allow configuring the page size for HPT pSeries guests
        For HPT pSeries guests, the size of the host pages used to back guest
        memory and the usable guest page sizes are connected; the new setting
        can be used to request that a certain page size is available in the
        guest.

    - Add support to use an raw input volume for encryption
        It is now possible to provide a raw input volume as input for to
        generate a luks encrypted volume via either virsh vol-create-from or
        virStorageVolCreateXMLFrom.

    - qemu: Add support for vsock hot (un)plug and cold (un)plug

    - qemu: Add support for NBD over TLS
        NBD volumes can now be accessed securely.

    - qemu: Implement FD passing for Unix sockets
        Instead of having QEMU open the socket and then connecting to it, which
        is inherently racy, starting with QEMU 2.12 we can open the socket
        ourselves and pass it to QEMU, avoiding race conditions.

    - virsh: Introduce --nowait option for domstat command
        When this option is specified, virsh will try to fetch the guest stats
        but abort instead of stalling if they can't be retrieved right away.

  * Bug fixes

    - qemu: Fix a potential libvirtd crash on VM reconnect
        Initialization of the driver worker pool needs to come before libvirtd
        trying to reconnect to all machines, since one of the QEMU processes
        migh have already emitted events which need to be handled prior to us
        getting to the worker pool initialization.

    - qemu: Fix domain resume after failed migration
        Recent versions of QEMU activate block devices before the guest CPU has
        been started, which makes it impossible to roll back a failed
        migration. Use the late-block-activate migration capability if
        supported to avoid the issue.

    - vmx: Permit guests to have an odd number of vCPUs
        An odd number of vCPUs greater than 1 was forbidden in the past, but
        current versions of ESXi have lifted that restriction.

# v4.4.0 (2018-06-04)

  * New features

    - bhyve: Support locking guest memory
        Bhyve's guest memory may be wired using the
        <memoryBacking><locked/></memoryBacking> element.

    - qemu: Provide VFIO channel I/O passthrough support
        Support passthrough devices that use channel I/O based mechanism in a
        QEMU virtual machine.

    - qemu: Add support for migration of VMs with non-shared storage over TLS
        It's now possible to use the VIR_MIGRATE_TLS flag together with
        VIR_MIGRATE_NON_SHARED_DISK. The connection is then secured using the
        TLS environment which is setup for the migration connection.

    - Add support for VM Generation ID
        The VM Generatation ID exposes a 128-bit, cryptographically random,
        integer value identifier, referred to as a Globally Unique Identifier
        (GUID) to the guest in order to notify the guest operating system when
        the virtual machine is executed with a different configuration. Add a
        new domain XML processing and a domain capabilities feature.

    - Introduce virDomainDetachDeviceAlias
        This new API enables users to detach device using only its alias.

    - Introduce new virConnectCompareHypervisorCPU and
      virConnectBaselineHypervisorCPU APIs
        Unlike the old virConnectCompareCPU and virConnectBaselineCPU APIs,
        both new APIs consider capabilities of a specific hypervisor.

    - Introduce SCSI persistent reservations support
        The QEMU driver gained support for qemu-pr-helper which enables guests
        to issue SCSI commands for persistent reservation.

    - qemu: Implement multiple screen support for virDomainScreenshot
        While the virDomainScreenshot API supported multihead video cards, the
        implementation was missing. But now that QEMU implemented it libvirt
        has done as well.

    - qemu: add support for vhost-vsock-device
        A new vsock device was introduced, allowing communication between the
        guest and the host via the AF_VSOCK family.

  * Improvements

    - qemu: Add suport for OpenGL rendering with SDL
        Domains using SDL as a graphics backend will now be able to use OpenGL
        accelerated rendering.

    - qemu: Add support for 'output' audio codec
        Support QEMU's 'hda-output' codec advertising only a line-out for ich6
        and ich9 sound devices.

    - virsh: Enhance event name completion
        Implement event name completion for some commands (e.g. event,
        secret-event, pool-event and nodedev-event)

# v4.3.0 (2018-05-02)

  * New features

    - qemu: Add support for the pcie-to-pci-bridge controller
        Pure PCIe guests such as x86_64/q35 and aarch64/virt will now add this
        controller when traditional PCI devices are in use.

    - Xen: Support setting CPU features for host-passthrough model
        The CPU model presented to Xen HVM domains is equivalent to libvirt's
        host-passthrough model, although individual features can be enabled and
        disabled via the cpuid setting. The libvirt libxl driver now supports
        enabling and disabling individual features of the host-passthrough CPU
        model.

  * Removed features

    - Xen: Drop the legacy xend-based driver
        The xm/xend toolstack was deprecated in Xen 4.2 and removed from the
        Xen sources in the 4.5 development cycle. The libvirt driver based on
        xend is now removed from the libvirt sources.

  * Improvements

    - qemu: Support hot plug and hot unplug of mediated devices
        Libvirt now allows mediated devices to be hot plugged and hot unplugged
        from a guest rather than reporting an error that this isn't supported.
        In fact, kernel has been supporting this since 4.10.

  * Bug fixes

    - Improve handling of device mapper targets
        When starting a domain with a disk backed by a device mapper volume
        libvirt also needs to allow the storage backing the device mapper in
        CGroups. In the past kernel did not care, but starting from 4.16
        CGroups are consulted on each access to the device mapper target.

# v4.2.0 (2018-04-01)

  * New features

    - Support building with Python 3
        Python is required to build libvirt, and up until now only Python 2
        could be used as an interpreter. All scripts used during build have now
        been made compatible with Python 3, which means both major releases of
        the language are fully supported.

    - qemu: Provide ccw address support for graphics and input devices
        Support the virtio-gpu-ccw device as a video device and
        virtio-{keyboard, mouse, tablet}-ccw devices as input devices on S390.

  * Improvements

    - qemu: Add logging of guest crash information on S390
        On S390, when the guest crashes and QEMU exposes the guest crash
        information, log the relevant data to the domain log file.

    - qemu: use arp table of host to get the IP address of guests
        Find IP address of a VM by arp table on hosts. If someone customizing
        IP address inside VM, it will be helpful.

    - Xen: Remove hard-coded scheduler weight
        The libxl driver was accidentally hard-coding the per-domain scheduler
        weight to 1000, silently ignoring any user-provided <shares> in
        <cputune>. The driver now honors <shares>, and defers setting a default
        value to Xen. Note that the Xen default is 256, so any domains started
        after this improvement will have one fourth the shares of previously
        started domains. If all domains must have equal CPU shares,
        administrators must manually set the weight of previously started
        domains to 256, or restart them.

  * Bug fixes

    - qemu: TLS migration now enforces use of TLS for the NBD connection
        When the VIR_MIGRATE_TLS flag was used with the migration API libvirt
        did not ensure that the NBD connection was using TLS as well. The code
        now rejects such migration as the TLS transport for NBD is not ready
        yet, but prevents a false sense of security that TLS would be used. The
        support TLS for NBD will be added soon.

# v4.1.0 (2018-03-05)

  * New features

    - Added support for CAT (Cache allocation Technology)
        Domain vCPU threads can now have allocated some parts of host cache
        using the cachetune element in cputune.

    - Allow opening secondary drivers
        Up until now it was possible to connect to only hypervisor drivers
        (e.g. qemu:///system, lxc:///, vbox:///system, and so on). The internal
        drivers (like network driver, node device driver, etc.) were hidden
        from users and users could use them only indirectly. Starting with this
        release new connection URIs are accepted. For instance
        network:///system, storage:///system and so on.

    - virtlogd, virtlockd: Add support for admin protocol
        These two daemons now support admin protocol through which some admin
        info can be gathered or some configuration tweaked on the fly.

  * Improvements

    - virsh: Enhance bash completion
        Implement more bash completions so that basic libvirt objects can be
        auto-completed (e.g. networks, interfaces, NWFilters, and so on).

    - qemu: Use VIR_ERR_DEVICE_MISSING for various hotplug/detach messages

    - qemu: Allow showing the dump progress for memory only dump
        Alter the QEMU dump-guest-memory command processing to check for and
        allow asynchronous completion which then allows for the virsh dump
        --memory-only --verbose command to display percent completion data.

    - conf: add support for setting Chassis SMBIOS data fields

    - libxl: add support for setting clock offset and adjustment

    - Make port allocator global
        Up until now each driver had their own port allocator module. This
        meant that info on port usage was not shared. Starting with this
        release, the port allocator module is made global and therefore drivers
        allocate ports from global pool.

    - Fixed some compiler warnings that appear with GCC 8

  * Bug fixes

    - qemu: Check for unsafe migration more thoroughly
        If a domain disk is stored on local filesystem (e.g. ext4) but is not
        being migrated it is very likely that domain is not able to run on
        destination. Regardless of share/cache mode.

    - qemu: Fix updating device with boot order
        Starting with 3.7.0 release updating any device with boot order would
        fail with 'boot order X is already used by another device' while in
        fact it was the very same device.

    - virlog: determine the hostname on startup CVE-2018-6764
        At later point it might not be possible or even safe to use
        getaddrinfo(). It can in turn result in a load of NSS module which can
        even be loaded from unsage guest filesystem and thus escape the
        confinment of its container.

    - qemu: Rework vCPU statistics fetching
        Fetching vCPU statistics was very expensive because it lead to waking
        up vCPU threads in QEMU and thus it degraded performance. The code was
        reworked so that fetching statistics does not wake up halted vCPUs.

    - qemu: unlink memory backing file on domain shutdown
        Depending on the filesystem where domain memory is stored, some files
        might have been left behind. This is not a problem on hugetlbfs, but it
        is a problem on regular filesystems like ext4.

    - qemu: Fix shutting down domains in parallel
        If multiple domains were being shut down in parallel, libvirtd might
        have deadlocked.

    - nodedev: Update PCI mdev capabilities dynamically
        PCI devices may have other nested capabilities, like SRIOV and mdev
        which depend on the device being plugged into the native vendor driver.
        However, in case such a device is directly assigned to a guest using
        VFIO driver, the device will naturally lose these capabilities and
        libvirt needs to reflect that.

# v4.0.0 (2018-01-19)

  * New features

    - tools: Provide bash completion support
        Both virsh and virt-admin now implement basic bash completion support.

    - qemu: Refresh capabilities on host microcode update
        A microcode update can cause the CPUID bits to change; therefore, the
        capabilities cache should be rebuilt when such an update is detected on
        the host.

    - lxc: Set hostname based on container name

  * Improvements

    - CPU frequency reporting improvements
        The CPU frequency will now be reported by virsh nodeinfo and other
        tools for s390 hosts; at the same time; CPU frequency has been disabled
        on aarch64 hosts because there's no way to detect it reliably.

    - libxl: Mark domain0 as persistent

    - Xen: Add support for multiple IP addresses on interface devices

    - qemu: Add support for hot unplugging redirdev device

  * Bug fixes

    - qemu: Enforce vCPU hotplug granularity constraints
        QEMU 2.7 and newer don't allow guests to start unless the initial vCPUs
        count is a multiple of the vCPU hotplug granularity, so validate it and
        report an error if needed.

# v3.10.0 (2017-12-04)

  * New features

    - conf: Support defining distances between virtual NUMA cells
        A NUMA hardware architecture supports the notion of distances between
        NUMA cells. This can now be specified using the <distances> element
        within the NUMA cell configuration. Drivers which support this include
        Xen and QEMU.

    - Xen: Support defining vNUMA topology
        Xen now supports defining a virtual NUMA topology for VMs, including
        specifying distances between NUMA cells.

    - qemu: Add the ability to configure HPT resizing for pSeries guests
        The user can now decide whether HPT (Hash Page Table) resizing should
        be enabled, disabled or required instead of leaving it up to hypervisor
        defaults and negotiation between the guest and the host.

    - qemu: Add vmcoreinfo feature
        Starting with QEMU 2.11, the guest can save kernel debug details when
        this feature is enabled and the kernel supports it. It is useful to
        process kernel dump with KASLR enabled, and also provides various
        kernel details to crash tools.

    - conf: Move the auth and encryption definitions to disk source
        Allow parsing and formatting of the auth and encryption sub-elements to
        be a child of the source element. This will allow adding an auth
        sub-element to a backingStore or mirror elements as a means to track
        specific authentication and/or encryption needs.

  * Improvements

    - vbox: Add VirtualBox 5.2 support

    - vbox: Add support for configuring storage controllers
        The VirtualBox driver now supports the <controller> element in the
        domain XML for configuring storage controllers in VBOX VMs.
        Additionally, libvirt's domain XML schema was updated to allow optional
        model attribute for <controller type='ide'> which is used by the VBOX
        driver to set the IDE controller model to be one of 'piix4', 'piix4'
        (default), or 'ich6'. Finally, with this change dumpxml generates
        <controller> elements that correspond to current VBOX VM storage
        controller configuration.

    - vbox: Add support for attaching empty removable disks
        The VirutalBox driver now supports adding CD-ROM and floppy disk
        devices that do not have the disk source specified. Previously such
        devices were silently ignored.

    - vbox: Add support for attaching SAS storage controllers
        In VirtualBox, SCSI and SAS are distinct controller types whereas
        libvirt does not make such distinction. Therefore, the VBOX driver was
        updated to allow attaching SAS controllers via <controller type='scsi'
        model='lsisas1068'> element. If there are both SCSI and SAS controllers
        present in the VBOX VM, the domain XML can associate the disk device
        using the <address> element with the controller attribute, and
        optionally, set the port via unit attribute.

    - qemu: Generate predictable paths for qemu memory backends
        In some cases management applications need to know paths passed to
        memory-backend-file objects upfront. Libvirt now generates predictable
        paths so applications can prepare the files if they need to do so.

    - Shareable disks work properly with recent qemu
        Recent qemu versions added image locking to avoid potential corruption
        of disk images. This broke shareable disks with libvirt since the
        feature was turned on by default in qemu. Libvirt now enables sharing
        of those disks in qemu so that the image locking is not applied in that
        case. Additionally libvirt now checks that shareable disks have
        supported format (raw) to avoid metadata corruption.

    - Improve serial console behavior on non-x86 architectures
        ppc64, aarch64 and s390x guests were treating the <serial> and
        <console> elements differently from x86, in some cases presenting
        misleading information to the user. The behavior is now consistent
        across all architectures and the information reported is always
        accurate.

  * Bug fixes

    - vbox: Do not ignore failures to attach disk devices when defining
        The define now fails and reports an error if any of the controller or
        disk devices specified in the domain XML fail to attach to the
        VirtualBox VM.

    - vbox: Fix dumpxml to always output disk devices
        The VirtualBox driver was ignoring any disk devices in dumpxml output
        if there was a SAS storage controller attached to the VM.

    - vbox: Fix dumpxml to always generate valid domain XML
        When a VirtualBox VM has multiple disks attached, each to a different
        storage controller that uses 'sd' prefix for block device names e.g.
        one disk attached to SATA and one to SCSI controller, it no longer
        generates XML where both would have 'sda' device name assigned. Instead
        it properly assigns 'sda' and 'sdb' to those disks in the order of
        appearance.

    - Securely pass iSCSI authentication data
        Rather than supplying the authentication data as part of the iSCSI URL
        for a disk or host device, utilize the encrypted secret object to
        securely pass the authentication data.

# v3.9.0 (2017-11-02)

  * New features

    - Add capability to allow hot (un)plug of a domain watchdog device

    - Allow users to set device aliases
        Users can set aliases to domain devices and thus identify them easily.

    - qemu: Support multiqueue for virtio-blk
        Multiqueue support for virtio-blk has been available in QEMU ever since
        2.7.0, and now libvirt guests can enable it.

    - Add virDomainSetLifecycleAction API
        Provided a new API to allow dynamic guest lifecycle control for guest
        reactions to poweroff, restart, or crash type events related to the
        domain XML on_poweroff, on_reboot, and on_crash elements. The virsh
        set-lifecycle-action command was created to control the actions.

    - qemu: Allow cold(un)plugging and hot(un)plugging input devices

    - net: Implement QoS for vhostuser

  * Improvements

    - Allow a logical volume to be create using LUKS
        A logical volume may be created using an encryption element using
        "luks" format. This does require a previously created secret to store
        the passphrase used to encrypt the volume Adding the volume to a domain
        can then either provide the secret or allow the consumer in the guest
        to provide the passphrase in order to decrypt the volume.

    - net: Ignore auto-generated MAC address when detaching an interface
        If the MAC address has not been specified by the user, libvirt will try
        and fill in the gaps by generating one; however, for some error paths
        that led to some confusing error messages, so when an auto-generated
        MAC address is specified the error message will not include the
        auto-generated MAC.

    - net: Enable MAC address lookup for virDomainInterfaceStats

    - apparmor: Several improvements
        Changes include permitting access to data about USB devices and dnsmasq
        instances, allowing spaces in guest names and many more.

    - cpu: Use CPU information obtained from QEMU when possible
        Recent QEMU versions can expose information about which CPU models are
        available and usable on the host; libvirt will now make use of such
        information whenever possible.

    - hyperv: Various improvements
        The error reported when clients can't connect to Hyper-V has been made
        more descriptive, and memory limits for guests are now mapped to more
        appropriate libvirt equivalents.

    - qemu: Report QEMU error on failed migration
        Instead of reporting a generic error, ask QEMU for a more detailed and
        thus hopefully more helpful one.

    - vbox: Implement autoport for RDP
        libvirt will now obtain the (dynamically allocated) RDP port number
        from VirtualBox itself, avoiding conflicts between multiple guests
        wanting to use RDP at the same time.

    - qemu: Allow rotation of small logs
        On a host where numerous unique instances are executed per day, it's
        quite possible that, even though each of the single log files are
        fairly small, collectively the quantity and volume may add tens of
        thousands of log files to the /var/log/libvirt/qemu/ directory.
        Removing the constraints that log have to be bigger than 100 KiB before
        they can be rotated solves the issue.

  * Bug fixes

    - Fix swapped interface statistics and QoS
        Due to internal implementation, reported statistics for some types of
        interfaces were swapped (RX appeared in TX and vice versa). Similarly,
        QoS was set in reversed way.

    - Properly resize local LUKS encrypted volume
        Resizing of a local LUKS encrypted volume will now use qemu-img to
        resize the volume. This will require configuring a secret for the LUKS
        encrypted volume.

    - qemu: Reserve PCI addresses for implicit i440fx devices
        Failing to do so causes the addresses to be considered usable by
        libvirt, which means they could be assigned to more than one device
        resulting in the guest failing to start.

    - spec: Restart libvirtd only at the end of the upgrade process
        Use %posttrans to make sure libvirtd is not restarted before all other
        components, such as the library itself and storage / hypervisor
        drivers, have already been upgraded.

  * Security

    - qemu: Ensure TLS clients always verify the server certificate
        While it's reasonable to turn off client certificate validation, as
        setting it up can be non-trivial, clients should always verify the
        server certificate to avoid MITM attacks. However, libvirt was using
        the same knob to control both checks, leading to CVE-2017-1000256 /
        LSN-2017-0002.

# v3.8.0 (2017-10-04)

  * New features

    - qemu: Added support for cold-(un)plug of watchdog devices

    - qemu: Added support for setting IP address os usernet interfaces

    - qemu: Added support for Veritas Hyperscale (VxHS) block devices

    - storage: Added new events for pool-build and pool-delete

  * Improvements

    - qemu: Set DAC permissions properly for spice rendernode
        When a rendernode path is set for SPICE GL on qemu:///system, we now
        correctly set DAC permissions on the device at VM startup. This is the
        last remaining hurdle to let SPICE GL work for qemu:///system without
        any external host changes.

    - nodedev: Add switchdev offload query to NIC capabilities
        Allow querying the NIC interface capabilities for the availability of
        switchdev offloading (also known as kernel-forward-plane-offload).

    - New CPU models for AMD and Intel
        AMD EPYC and Intel Skylake-Server CPU models were added together with
        their features

    - Improve long waiting when saving a domain
        While waiting for a write to disk to be finished, e.g. during save,
        even simple operations like virsh list would be blocking due to domain
        lock. This is now resolved by unlocking the domain in places where it
        is not needed.

  * Bug fixes

    - Proper units are now used in virsh manpage for dom(mem)stats
        Previously the documentation used multiples of 1000, but now it is
        fixed to use multiples of 1024.

    - qemu: Fix error reporting when disk attachment fails
        There was a possibility for the actual error to be overridden or
        cleared during the rollback.

    - qemu: Fix assignment of graphics ports after daemon restart
        This could be seen with newer kernels that have bug regarding
        SO_REUSEADDR. After libvirtd was restarted it could assign already used
        address to new guests which would make them fail to start. This is
        fixed by marking used ports unavailable when reconnecting to running
        QEMU domains.

    - Fix message decoding which was causing a very strange bug
        When parsing an RPC message with file descriptors was interrupted and
        had to restart, the offset of the payload was calculated badly causing
        strange issues like not being able to find a domain that was not
        requested.

# v3.7.0 (2017-09-04)

  * New features

    - qemu: Add managedsave-edit commands
        Using managedsave-dumpxml, managedsave-define and managedsave-edit
        commands, now we can dump and edit the XML configuration of domain
        which has managedsave image.

    - qemu: Add migrate-getmaxdowntime command
        Currently, the maximum tolerable downtime for a domain being migrated
        is write-only from libvirt, via migrate-setmaxdowntime. This implements
        a complementary migrate-getmaxdowntime command

    - bhyve: Support autoport for VNC ports
        It's no longer necessary to explicitly specify VNC port for the bhyve
        guests. With the autoport feature it will be allocated automatically.
        Please refer to the bhyve driver documentation for examples.

    - qemu: Added support for setting heads of virtio GPU

    - qemu: Added support to configure reconnect timeout for chardev devices
        When you have a TCP or UNIX chardev device and it's connected somewhere
        you can configure reconnect timeout if the connection is closed.

  * Improvements

    - qemu: Report a clear error when dropping a VM during startup
        "Failed to load config for domain 'DOMNAME'" is now reported if a VM
        config can't be parsed for some reason, and thus provides a clear
        indication for users (and devs).

    - apparmor: Update for QEMU 2.10 compatibility
        Starting with QEMU 2.10, disk images and NVRAM files get automatically
        locked to prevent them from being corrupted; however, file locking
        needs to be explicitly allowed through virt-aa-helper or AppArmor will
        reject the requests and the guest will not be able to run.

    - virsh: List Unix sockets in 'domdisplay' output
        VNC and SPICE graphics can use Unix sockets instead of TCP/IP sockets
        as connection endpoints, but such a configuration was not handled
        correctly by virsh domdisplay, causing the respective endpoints to be
        missing from the output.

    - qemu: Don't check whether offline migration is safe
        Since offline migration only copies the guest definition to the
        destination host, data corruption is not a concern and the operation
        can always be performed safely.

    - virt-host-validate: Fix IOMMU detection on ppc64

  * Bug fixes

    - qemu: Better support for international domain names (with wide
      characters)
        There were some issues with multi-byte domains getting lost on daemon
        restart due to truncation, so the code now handles multi-byte names a
        bit better.

    - qemu: Support long domain names with namespaces
        Domains with extremely long names would fail to start due to temporary
        namespace paths being created with the whole name. The path is now
        generated with shortened name instead.

    - qemu: Tolerate missing emulator binary during libvirtd restart
        For some time libvirt required qemu capabilities being present when
        parsing VM configs during startup. As a side effect VM configs would
        fail to parse and thus vanish, if the emulator binary would be
        uninstalled or broken. Libvirt now tolerates when capabilities are
        missing during startup.

    - qemu: Prevent pSeries guests from disappearing in some situations
        pSeries guest would disappear if any of the host devices they were
        configured to use was not available during libvirtd startup, which
        could easily happen for SR-IOV Virtual Functions. This scenario is now
        handled correctly.

    - qemu: Honor <on_reboot/> setting
        The setting was accepted by the parser, but not actually implemented.

    - Fix --verbose option for all daemons
        Since v3.0.0, the option had been ignored by all libvirt daemons
        (libvirtd, virtlogd and virtlockd); it's now working as intended once
        again.

# v3.6.0 (2017-08-02)

  * New features

    - hyperv: Implement virDomainSetMemory and virDomainSendKey APIs

    - qemu: Support multiple PHBs for pSeries guests
        pSeries guests can now have multiple PHBs (PCI Host Bridges), which
        show up as separate PCI domains in the guest. To create additional
        PHBs, simply add PCI controllers with model pci-root to the guest
        configuration.

    - qemu: Isolate hostdevs on pSeries guests
        To enable better error reporting and recovery, unrelated hostdevs will
        now be automatically isolated on pSeries guests by placing them on
        separate PHBs (PCI Host Bridges).

  * Improvements

    - qemu: platform serial devices can now use chardev features
        QEMU VMs that depend on platform serial devices can now use QEMU's
        -chardev option, which enables access to advanced features like log
        file configuration. This applies to the default serial devices for arm,
        aarch64, and some ppc configurations.

    - Require use of GCC 4.4 or Clang compilers
        We only ever test libvirt with GCC or Clang (which provides a GCC
        compatible compilation environment). Between them, these compilers
        cover every supported operating system platform, including Windows.

    - qemu: shared disks with directsync cache should be safe for migration
        At present shared disks can be migrated with either readonly or
        cache=none. But cache=directsync should be safe for migration, because
        both cache=directsync and cache=none don't use the host page cache, and
        cache=direct write through qemu block layer cache.

    - Handle hotplug change on VLAN configuration using OVS
        Libvirt was taught to handle VLAN change for running OVS interface.

  * Bug fixes

    - qemu: Use vCPU 'node-id' property and pass it back to qemu
        vCPU properties gathered from query-hotpluggable-cpus need to be passed
        back to QEMU. As QEMU did not use the node-id property until now and
        libvirt forgot to pass it back properly (it was parsed but not passed
        around) we did not honor this.

    - Miscellaneous stream fixes
        After introducing sparse stream features there were still some known
        bugs left. Those are fixed in this release.

    - qemu: Miscellaneous domain NS fixes
        Libvirt starts qemu domains in separate Linux namespaces for a while
        now. However, there were still some bugs lingering. For instance
        libvirt did not know how to handle file based bind mounts.

    - Various CPU driver improvements
        There were some minor bugs when using 'host-model' CPU.

# v3.5.0 (2017-07-04)

  * New features

    - qemu: Add support for loadparm for a boot device
        Add an optional boot parameter 'loadparm' for a boot device. Loadparm
        is an 8 byte parameter that, when present, is queried by S390 guests
        via sclp or diag 308. Linux guests on S390 use it to select a boot
        entry.

    - Support controlling how video devices are exposed to the bhyve guests
        The vgaconf attribute was added to video's driver element. Possible
        values are: on, off, and io. It controls the way how bhyve exposes
        video devices to its guests; various guest OSes might require different
        settings to boot properly.

    - qemu: Add support for live updates of coalesce settings
        Users can now use virsh update-device to change the coalesce settings
        of an interfaces while the domain is running.

    - qemu: Allow VirtIO devices to use vIOMMU
        It is now possible to turn on IOTBL for the vIOMMU and have VirtIO
        devices use it, provided they have been configured appropriately.

  * Improvements

    - qemu: block copy job can be used with persistent domains
        Until now it was not possible to use block copy with persistent VMs. In
        use cases where it's not required to recover the job after VM shutdown,
        it's possible to specify VIR_DOMAIN_BLOCK_COPY_TRANSIENT_JOB flag to
        start the copy job.

    - JSON pseudo-protocol backing store parser supports new format of qemu 2.9
        QEMU 2.9 modified a few structures corresponding to the JSON format of
        specifying a backing store for a disk image. Libvirt now implements the
        new format.

    - Capabilities now include info about host's CAT settings
        Various information about resource control from the host is gathered
        and presented in capabilities if available.

    - apparmor: Several improvements
        Allow access to Ceph config, EFI firmware on both x86_64 and aarch64,
        device tree on ppc64 and more.

    - qemu: Support host-model on POWER9 machines

  * Bug fixes

    - qemu: snapshot: retrieve image metadata from user provided files
        Disk images of an external snapshot created with
        VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT flag specified would not be
        scanned for metadata after recent changes. The metadata is necessary to
        allow keeping relative paths between images when doing a block-commit.

    - Parse decimal numbers in a locale-independent way
        Some locales, such as de_DE and pt_BR, use comma rather than dot to
        separate the integer part from the fractional part of a decimal number;
        however, several data sources such as the kernel use a
        locale-independent representation and need to be treated accordingly.

    - Support compilation with newer compiler and libc versions
        Several fixes have been included to make compilation with Clang 4.0.0,
        GCC 7.1 and glibc >= 2.25.90 possible.

    - qemu: Query name for vhost-user interfaces at runtime
        This makes it possible to use virsh subcommands such as domiflist and
        domifstat on vhost-user interfaces.

    - qemu: Set MTU for hotplugged interfaces correctly
        When hotplugging a network interface, the MTU was only set on the guest
        side. Set it on the host side as well.

    - qemu: Forbid updating MTU for interfaces of running guests
        The MTU setting can't be modified while the guest is running, so any
        attempt to alter it at runtime will now result in an error rather than
        being silently ignored.

    - qemu: Fix specifying QXL heads with older QEMU releases
        Specifying the number of QXL heads was not working correctly for QEMU
        releases older than 1.6.

    - qemu: Fix migration to older libvirt/QEMU versions
        When the guest is started, libvirt updates the CPU definition to
        reflect the actual CPU features to enforce ABI. We need to send
        original and updated CPU definition in order to support migration to
        older libvirt/QEMU versions. Only the updated CPU definition was sent
        to destination.

# 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 docs/news-*.html or the full git
log (see instructions in ChangeLog).
