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Vagrant Libvirt Documentation

Although it should work without any configuration for most people, this provider exposes quite a few provider-specific configuration options.

Provider Options

Connection Options

The following options allow you to configure how vagrant-libvirt connects to Libvirt, and are used to generate the Libvirt connection URI:

  • driver - A hypervisor name to access. For now only KVM and QEMU are supported
  • host - The name of the server, where Libvirtd is running
  • connect_via_ssh - If use ssh tunnel to connect to Libvirt. Absolutely needed to access Libvirt on remote host. It will not be able to get the IP address of a started VM otherwise.
  • username - Username and password to access Libvirt
  • password - Password to access Libvirt
  • id_ssh_key_file - If not nil, uses this ssh private key to access Libvirt. Default is $HOME/.ssh/id_rsa. Prepends $HOME/.ssh/ if no directory
  • socket - Path to the Libvirt unix socket (e.g. /var/run/libvirt/libvirt-sock)
  • uri - For advanced usage. Directly specifies what Libvirt connection URI vagrant-libvirt should use. Overrides all above connection configuration options
  • proxy_command - For advanced usage. When connecting to remote libvirt instances, if the default constructed proxy_command which uses -W %h:%p does not work, set this as needed. It performs interpolation using {key} and supports only {host}, {username}, and {id_ssh_key_file}. This is to try and avoid issues with escaping % and $ which might be necessary to the ssh command itself. e.g.: libvirt.proxy_command = "ssh {host} -l {username} -i {id_ssh_key_file} nc %h %p"

In the event that none of these are set (excluding the driver option) the provider will attempt to retrieve the uri from the environment variable LIBVIRT_DEFAULT_URI similar to how virsh works. If any of them are set, it will ignore the environment variable. The reason the driver option is ignored is that it is not uncommon for this to be explicitly set on the box itself and there is no easily to determine whether it is being set by the user or the box packager.

Connection-independent options:

  • storage_pool_name - Libvirt storage pool name, where box image and instance snapshots (if snapshot_pool_name is not set) will be stored.
  • snapshot_pool_name - Libvirt storage pool name. If set, the created snapshot of the instance will be stored at this location instead of storage_pool_name.

Connection example:

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.host = "example.com"
  end
end

Domain Specific Options

  • title - A short description of the domain.
  • description - A human readable description of the virtual machine.
  • random_hostname - To create a domain name with extra information on the end to prevent hostname conflicts.
  • default_prefix - The default Libvirt guest name becomes a concatenation of the <current_directory>_<guest_name>. The current working directory is the default prefix to the guest name. The default_prefix options allow you to set the guest name prefix.
  • disk_bus - The type of disk device to emulate. Defaults to virtio if not set. Possible values are documented in Libvirt’s description for target. NOTE: this option applies only to disks associated with a box image. To set the bus type on additional disks, see the Additional Disks section.
  • disk_controller_model - the controller model to use. Ignored unless either disk_bus is set to scsi or disk_device starts with sd, which is a hint to use scsi. Defaults to virtio-scsi when it encounters either of the config values for disk_bus or disk_device. See libvirt controller models for other possible values. NOTE: this option applies only to the disks associated with a box image.
  • disk_device - The disk device to emulate. Defaults to vda if not set, which should be fine for paravirtualized guests, but some fully virtualized guests may require hda. NOTE: this option also applies only to disks associated with a box image.
  • disk_address_type - The address type of disk device to emulate. Libvirt uses a sensible default if not set, but some fully virtualized guests may need to override this (e.g. Debian on virt machine may need virtio-mmio). Possible values are documented in libvirt’s description for address.
  • disk_driver - Extra options for the main disk driver (see Libvirt documentation). NOTE: this option also applies only to disks associated with a box image. In all cases, the value nil can be used to force the hypervisor default behaviour (e.g. to override settings defined in top-level Vagrantfiles). Supported options include:
    • :cache - Controls the cache mechanism. Possible values are “default”, “none”, “writethrough”, “writeback”, “directsync” and “unsafe”.
    • :io - Controls specific policies on I/O. Possible values are “threads” and “native”.
    • :copy_on_read - Controls whether to copy read backing file into the image file. The value can be either “on” or “off”.
    • :discard - Controls whether discard requests (also known as “trim” or “unmap”) are ignored or passed to the filesystem. Possible values are “unmap” or “ignore”. Note: for discard to work, you will likely also need to set disk_bus = 'scsi'
    • :detect_zeroes - Controls whether to detect zero write requests. The value can be “off”, “on” or “unmap”.
    • address_type - Address type of disk device to emulate. If unspecified, Libvirt uses a sensible default.
  • nic_model_type - parameter specifies the model of the network adapter when you create a domain, default is ‘virtio’. For possible values, see the documentation for Libvirt.
  • shares - Proportional weighted share for the domain relative to others. For more details see documentation.
  • memory - Amount of memory in MBytes. Defaults to 512 if not set.
  • cpus - Number of virtual cpus. Defaults to 1 if not set.
  • cpuset - Physical cpus to which the vcpus can be pinned. For more details see documentation.

  • cputopology - Number of CPU sockets, cores and threads running per core. All fields of :sockets, :cores and :threads are mandatory, cpus domain option must be present and must be equal to total count of sockets * cores * threads. For more details see documentation.

    Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.cpus = 4
    libvirt.cpuset = '1-4,^3,6'
    libvirt.cputopology :sockets => '2', :cores => '2', :threads => '1'
  end
end

  • cpuaffinitiy - Mapping of vCPUs to host CPUs. See vcpupin.

    Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.cpus = 4
    libvirt.cpuaffinitiy 0 => '0-4,^3', 1 => '5', 2 => '6,7'
  end
end
  • nodeset - Physical NUMA nodes where virtual memory can be pinned. For more details see documentation.
  • nested - Enable nested virtualization. Default is false.
  • cpu_mode - CPU emulation mode. Defaults to ‘host-model’ if not set. Allowed values: host-model, host-passthrough, custom.
  • cpu_model - CPU Model. Defaults to ‘qemu64’ if not set and cpu_mode is custom and to ‘’ otherwise. This can really only be used when setting cpu_mode to custom.
  • cpu_fallback - Whether to allow Libvirt to fall back to a CPU model close to the specified model if features in the guest CPU are not supported on the host. Defaults to ‘allow’ if not set. Allowed values: allow, forbid.

  • numa_nodes - Specify an array of NUMA nodes for the guest. The syntax is similar to what would be set in the domain XML. memory must be in MB. Symmetrical and asymmetrical topologies are supported but make sure your total count of defined CPUs adds up to v.cpus.

    The sum of all the memory defined here will act as your total memory for your guest VM. This sum will override what is set in v.memory

    v.cpus = 4
v.numa_nodes = [
  {:cpus => "0-1", :memory => "1024"},
  {:cpus => "2-3", :memory => "4096"}
]
  • launchsecurity - Configure Secure Encryption Virtualization for the guest, requires additional components to be configured to work, see examples. For more information look at libvirt documentation. 
    libvirt.launchsecurity :type => 'sev', :cbitpos => 47, :reducedPhysBits => 1, :policy => "0x0003"
  • memtune - Configure the memtune settings for the guest, primarily exposed to facilitate enabling Secure Encryption Virtualization. Note that when configuring hard_limit that the value is in kB as opposed to libvirt.memory which is in Mb. Additionally it must be set to be higher than libvirt.memory, see libvirt documentation for details on why. 
    libvirt.memtune :type => "hard_limit", :value => 2500000 # Note here the value in kB (not in Mb)
  • loader - Sets path to custom UEFI loader.
  • kernel - To launch the guest with a kernel residing on host filesystems. Equivalent to qemu -kernel.
  • initrd - To specify the initramfs/initrd to use for the guest. Equivalent to qemu -initrd.
  • cmd_line - Arguments passed on to the guest kernel initramfs or initrd to use. Equivalent to qemu -append, only possible to use in combination with initrd and kernel.
  • graphics_type - Sets the protocol used to expose the guest display. Defaults to vnc. Possible values are “sdl”, “curses”, “none”, “gtk”, “vnc” or “spice”.
  • graphics_port - Sets the port for the display protocol to bind to. Defaults to -1, which will be set automatically by libvirt.
  • graphics_websocket - Sets the websocket port for the display protocol to bind to. Defaults to -1, which will be set automatically by libvirt. The autoport configuration has no effect on the websocket port due to security reasons.
  • graphics_ip - Sets the IP for the display protocol to bind to. Defaults to “127.0.0.1”.
  • graphics_passwd - Sets the password for the display protocol. Working for vnc and Spice. by default working without passsword.
  • graphics_autoport - Sets autoport for graphics, Libvirt in this case ignores graphics_port value, Defaults to ‘yes’. Possible value are “yes” and “no”
  • graphics_gl - Set to true to enable OpenGL. Defaults to true if video_accel3d is true.
  • keymap - Set keymap for vm. default: en-us
  • kvm_hidden - Hide the hypervisor from the guest. Useful for GPU passthrough on stubborn drivers. Default is false.
  • video_type - Sets the graphics card type exposed to the guest. Defaults to “cirrus”. Possible values are “vga”, “cirrus”, “vmvga”, “xen”, “vbox”, or “qxl”.
  • video_vram - Used by some graphics card types to vary the amount of RAM dedicated to video. Defaults to 16384.
  • video_accel3d - Set to true to enable 3D acceleration. Defaults to false.
  • sound_type - Set the virtual sound card Defaults to “ich6”.
  • machine_type - Sets machine type. Equivalent to qemu -machine. Use qemu-system-x86_64 -machine help to get a list of supported machines.
  • machine_arch - Sets machine architecture. This helps Libvirt to determine the correct emulator type. Possible values depend on your version of QEMU. For possible values, see which emulator executable qemu-system-* your system provides. Common examples are aarch64, alpha, arm, cris, i386, lm32, m68k, microblaze, microblazeel, mips, mips64, mips64el, mipsel, moxie, or32, ppc, ppc64, ppcemb, s390x, sh4, sh4eb, sparc, sparc64, tricore, unicore32, x86_64, xtensa, xtensaeb.
  • machine_virtual_size - Sets the disk size in GB for the machine overriding the default specified in the box. Allows boxes to defined with a minimal size disk by default and to be grown to a larger size at creation time. Will ignore sizes smaller than the size specified by the box metadata. Note that currently there is no support for automatically resizing the filesystem to take advantage of the larger disk.
  • emulator_path - Explicitly select which device model emulator to use by providing the path, e.g. /usr/bin/qemu-system-x86_64. This is especially useful on systems that fail to select it automatically based on machine_arch which then results in a capability error.
  • boot - Change the boot order and enables the boot menu. Possible options are “hd”, “network”, “cdrom”. Defaults to “hd” with boot menu disabled. When “network” is set without “hd”, only all NICs will be tried; see below for more detail. Defining this in subsequent provider blocks or latter Vagrantfile’s (see Load Order and Merging) will result in the definition in the last block being used.
  • nic_adapter_count - Defaults to ‘8’. Only use case for increasing this count is for VMs that virtualize switches such as Cumulus Linux. Max value for Cumulus Linux VMs is 33.
  • uuid - Force a domain UUID. Defaults to autogenerated value by Libvirt if not set.
  • suspend_mode - What is done on vagrant suspend. Possible values: ‘pause’, ‘managedsave’. Pause mode executes a la virsh suspend, which just pauses execution of a VM, not freeing resources. Managed save mode does a la virsh managedsave which frees resources suspending a domain.
  • tpm_model - The model of the TPM to which you wish to connect.
  • tpm_type - The type of TPM device to which you are connecting.
  • tpm_path - The path to the TPM device on the host system.
  • tpm_version - The TPM version to use.
  • sysinfo - The SMBIOS System Information to use. This is a hash with key names aligning with the different section XML tags of bios, system, base board, chassis, and oem strings. Nested hashes then use entry attribute names as the keys for the values to assign, except for oem strings which is a simple array of strings.
  • dtb - The device tree blob file, mostly used for non-x86 platforms. In case the device tree isn’t added in-line to the kernel, it can be manually specified here.
  • autostart - Automatically start the domain when the host boots. Defaults to ‘false’.
  • channel - Libvirt channels. Configure a private communication channel between the host and guest, e.g. for use by the QEMU guest agent and the Spice/QXL graphics type.
  • mgmt_attach - Decide if VM has interface in mgmt network. If set to ‘false’ it is not possible to communicate with VM through vagrant ssh or run provisioning. Setting to ‘false’ is only possible when VM doesn’t use box or vagrant is told not to connect via ssh. Defaults set to ‘true’.
  • serial - libvirt serial devices. Configure a serial/console port to communicate with the guest. Can be used to log to file boot time messages sent to ttyS0 console by the guest.

Specific domain settings can be set for each domain separately in multi-VM environment. Example below shows a part of Vagrantfile, where specific options are set for dbserver domain.

Vagrant.configure("2") do |config|
  config.vm.define :dbserver do |dbserver|
    dbserver.vm.box = "centos64"
    dbserver.vm.provider :libvirt do |domain|
      domain.memory = 2048
      domain.cpus = 2
      domain.nested = true
      domain.disk_driver :cache => 'none'
    end
  end

  # ...

The following example shows part of a Vagrantfile that enables the VM to boot from a network interface first and a hard disk second. This could be used to run VMs that are meant to be a PXE booted machines. Be aware that if hd is not specified as a boot option, it will never be tried.

Vagrant.configure("2") do |config|
  config.vm.define :pxeclient do |pxeclient|
    pxeclient.vm.box = "centos64"
    pxeclient.vm.provider :libvirt do |domain|
      domain.boot 'network'
      domain.boot 'hd'
    end
  end

  # ...

Reload behavior

On vagrant reload the following domain specific attributes are updated in defined domain:

  • disk_bus - Is updated only on disks. It skips CDROMs
  • nic_model_type - Updated
  • memory - Updated
  • cpus - Updated
  • nested - Updated
  • cpu_mode - Updated. Pay attention that custom mode is not supported
  • graphics_type - Updated
  • graphics_port - Updated
  • graphics_websocket - Updated
  • graphics_ip - Updated
  • graphics_passwd - Updated
  • graphics_autoport - Updated
  • keymap - Updated
  • video_type - Updated
  • video_vram - Updated
  • tpm_model - Updated
  • tpm_type - Updated
  • tpm_path - Updated
  • tpm_version - Updated

Networks

Networking features in the form of config.vm.network support private networks concept. It supports both the virtual network switch routing types and the point to point Guest OS to Guest OS setting using UDP/Mcast/TCP tunnel interfaces.

http://wiki.libvirt.org/page/VirtualNetworking

https://libvirt.org/formatdomain.html#tcp-tunnel

http://libvirt.org/formatdomain.html#multicast-tunnel

http://libvirt.org/formatdomain.html#udp-unicast-tunnel (in Libvirt v1.2.20 and higher)

Public Network interfaces are currently implemented using the macvtap driver. The macvtap driver is only available with the Linux Kernel version >= 2.6.24. See the following Libvirt documentation for the details of the macvtap usage.

http://www.libvirt.org/formatdomain.html#direct-attachment-to-physical-interface

An examples of network interface definitions:

  # Private network using virtual network switching
  config.vm.define :test_vm1 do |test_vm1|
    test_vm1.vm.network :private_network, :ip => "10.20.30.40"
  end

  # Private network using DHCP and a custom network
  config.vm.define :test_vm1 do |test_vm1|
    test_vm1.vm.network :private_network,
      :type => "dhcp",
      :libvirt__network_address => '10.20.30.0'
  end

  # Private network (as above) using a domain name
  config.vm.define :test_vm1 do |test_vm1|
    test_vm1.vm.network :private_network,
      :ip => "10.20.30.40",
      :libvirt__domain_name => "test.local"
  end

  # Private network. Point to Point between 2 Guest OS using a TCP tunnel
  # Guest 1
  config.vm.define :test_vm1 do |test_vm1|
    test_vm1.vm.network :private_network,
      :libvirt__tunnel_type => 'server',
      # default is 127.0.0.1 if omitted
      # :libvirt__tunnel_ip => '127.0.0.1',
      :libvirt__tunnel_port => '11111'
    # network with ipv6 support
    test_vm1.vm.network :private_network,
      :ip => "10.20.5.42",
      :libvirt__guest_ipv6 => "yes",
      :libvirt__ipv6_address => "2001:db8:ca2:6::1",
      :libvirt__ipv6_prefix => "64"

  # Guest 2
  config.vm.define :test_vm2 do |test_vm2|
    test_vm2.vm.network :private_network,
      :libvirt__tunnel_type => 'client',
      # default is 127.0.0.1 if omitted
      # :libvirt__tunnel_ip => '127.0.0.1',
      :libvirt__tunnel_port => '11111'
    # network with ipv6 support
    test_vm2.vm.network :private_network,
      :ip => "10.20.5.45",
      :libvirt__guest_ipv6 => "yes",
      :libvirt__ipv6_address => "2001:db8:ca2:6::1",
      :libvirt__ipv6_prefix => "64"


  # Public Network
  config.vm.define :test_vm1 do |test_vm1|
    test_vm1.vm.network :public_network,
      :dev => "virbr0",
      :mode => "bridge",
      :type => "bridge"
  end

In example below, one network interface is configured for VM test_vm1. After you run vagrant up, VM will be accessible on IP address 10.20.30.40. So if you install a web server via provisioner, you will be able to access your testing server on http://10.20.30.40 URL. But beware that this address is private to Libvirt host only. It’s not visible outside of the hypervisor box.

If network 10.20.30.0/24 doesn’t exist, provider will create it. By default created networks are NATed to outside world, so your VM will be able to connect to the internet (if hypervisor can). And by default, DHCP is offering addresses on newly created networks.

The second interface is created and bridged into the physical device eth0. This mechanism uses the macvtap Kernel driver and therefore does not require an existing bridge device. This configuration assumes that DHCP and DNS services are being provided by the public network. This public interface should be reachable by anyone with access to the public network.

Private Network Options

Note: These options are not applicable to public network interfaces.

There is a way to pass specific options for Libvirt provider when using config.vm.network to configure new network interface. Each parameter name starts with libvirt__ string. Here is a list of those options:

  • :libvirt__network_name - Name of Libvirt network to connect to. By default, network ‘default’ is used.
  • :libvirt__netmask - Used only together with :ip option. Default is ‘255.255.255.0’.
  • :libvirt__network_address - Used only when :type is set to dhcp. Only /24 subnet is supported. Default is 172.28.128.0.
  • :libvirt__host_ip - Address to use for the host (not guest). Default is first possible address (after network address).
  • :libvirt__domain_name - DNS domain of the DHCP server. Used only when creating new network.
  • :libvirt__dhcp_enabled - If DHCP will offer addresses, or not. Used only when creating new network. Default is true.
  • :libvirt__dhcp_start - First address given out via DHCP. Default is third address in range (after network name and gateway).
  • :libvirt__dhcp_stop - Last address given out via DHCP. Default is last possible address in range (before broadcast address).
  • :libvirt__dhcp_bootp_file - The file to be used for the boot image. Used only when dhcp is enabled.
  • :libvirt__dhcp_bootp_server - The server that runs the DHCP server. Used only when dhcp is enabled.By default is the same host that runs the DHCP server.
  • :libvirt__tftp_root - Path to the root directory served via TFTP.
  • :libvirt__adapter - Number specifying sequence number of interface.
  • :libvirt__forward_mode - Specify one of veryisolated, none, open, nat or route options. This option is used only when creating new network. Mode none will create isolated network without NATing or routing outside. You will want to use NATed forwarding typically to reach networks outside of hypervisor. Routed forwarding is typically useful to reach other networks within hypervisor. veryisolated described here. By default, option nat is used.
  • :libvirt__forward_device - Name of interface/device, where network should be forwarded (NATed or routed). Used only when creating new network. By default, all physical interfaces are used.
  • :libvirt__tunnel_type - Set to ‘udp’ if using UDP unicast tunnel mode (libvirt v1.2.20 or higher). Set this to either “server” or “client” for tcp tunneling. Set this to ‘mcast’ if using multicast tunneling. This configuration type uses tunnels to generate point to point connections between Guests. Useful for Switch VMs like Cumulus Linux. No virtual switch setting like libvirt__network_name applies with tunnel interfaces and will be ignored if configured.
  • :libvirt__tunnel_ip - Sets the source IP of the Libvirt tunnel interface. By default this is 127.0.0.1 for TCP and UDP tunnels and 239.255.1.1 for Multicast tunnels. It populates the address field in the <source address="XXX"> of the interface xml configuration.
  • :libvirt__tunnel_port - Sets the source port the tcp/udp/mcast tunnel with use. This port information is placed in the <source port=XXX/> section of interface xml configuration.
  • :libvirt__tunnel_local_port - Sets the local port used by the udp tunnel interface type. It populates the port field in the <local port=XXX"> section of the interface xml configuration. (This feature only works in Libvirt 1.2.20 and higher)
  • :libvirt__tunnel_local_ip - Sets the local IP used by the udp tunnel interface type. It populates the ip entry of the <local address=XXX"> section of the interface xml configuration. (This feature only works in Libvirt 1.2.20 and higher)
  • :libvirt__guest_ipv6 - Enable or disable guest-to-guest IPv6 communication. See here, and here for for more information. Note: takes either ‘yes’ or ‘no’ for value
  • :libvirt__ipv6_address - Define ipv6 address, require also prefix.
  • :libvirt__ipv6_prefix - Define ipv6 prefix. generate string <ip family="ipv6" address="address" prefix="prefix" >
  • :libvirt__iface_name - Define a name for the corresponding network interface created on the host. With this feature one can simulate physical link failures. Note that you cannot use names reserved for libvirt’s usage based on documentation.
  • :libvirt__mac - MAC address for the interface. Note: specify this in lowercase since Vagrant network scripts assume it will be!
  • :libvirt__mtu - MTU size for the Libvirt network, if not defined, the created network will use the Libvirt default (1500). VMs still need to set the MTU accordingly.
  • :libvirt__model_type - parameter specifies the model of the network adapter when you create a domain value by default virtio KVM believe possible values, see the documentation for Libvirt
  • :libvirt__driver_name - Define which network driver to use. More info
  • :libvirt__driver_queues - Define a number of queues to be used for network interface. Set equal to number of vCPUs for best performance. More info
  • :autostart - Automatic startup of network by the Libvirt daemon. If not specified the default is ‘false’.
  • :libvirt__bus - The bus of the PCI device. Both :bus and :slot have to be defined.
  • :libvirt__slot - The slot of the PCI device. Both :bus and :slot have to be defined.
  • :libvirt__always_destroy - Allow domains that use but did not create a network to destroy it when the domain is destroyed (default: true). Set to false to only allow the domain that created the network to destroy it.

When the option :libvirt__dhcp_enabled is to to ‘false’ it shouldn’t matter whether the virtual network contains a DHCP server or not and vagrant-libvirt should not fail on it. The only situation where vagrant-libvirt should fail is when DHCP is requested but isn’t configured on a matching already existing virtual network.

Public Network Options

  • :dev - Physical device that the public interface should use. Default is ‘eth0’.
  • :mode - The mode in which the public interface should operate in. Supported modes are available from the libvirt documentation. Default mode is ‘bridge’.
  • :type - is type of interface.(<interface type="#{@type}">)
  • :mac - MAC address for the interface.
  • :network_name - Name of Libvirt network to connect to.
  • :portgroup - Name of Libvirt portgroup to connect to.
  • :ovs - Support to connect to an Open vSwitch bridge device. Default is ‘false’.
  • :ovs_interfaceid - Add Open vSwitch ‘interfaceid’ parameter.
  • :trust_guest_rx_filters - Support trustGuestRxFilters attribute. Details are listed here. Default is ‘false’.
  • :libvirt__iface_name - Define a name for the corresponding network interface that is created on the host connected to the bridge dev. This can be used to help attach VLAN tags to specific VMs by adjusting the pattern to match. Note that you cannot use names reserved for libvirt’s usage based on documentation.
  • :libvirt__mtu - MTU size for the Libvirt interface, if not defined, the created network will use the Libvirt default (1500). VMs still need to configure their internal interface MTUs.

Additionally for public networks, to facilitate validating if the device provided can be used, vagrant-libvirt will check both the host interfaces visible to libvirt and the existing networks for any existing bridge names. While some name patterns are automatically excluded as presumed incorrect, if this pattern list is incorrect it may be overridden by setting the option:

  • host_device_exclude_prefixes - ignore any device starting with any of these string patterns as a valid bridge device for a public network definition.

Management Network

vagrant-libvirt uses a private network to perform some management operations on VMs. All VMs will have an interface connected to this network and an IP address dynamically assigned by Libvirt unless you set :mgmt_attach to ‘false’. This is in addition to any networks you configure. The name and address used by this network are configurable at the provider level.

  • management_network_name - Name of Libvirt network to which all VMs will be connected. If not specified the default is ‘vagrant-libvirt’.
  • management_network_address - Address of network to which all VMs will be connected. Must include the address and subnet mask. If not specified the default is ‘192.168.121.0/24’.
  • management_network_mode - Network mode for the Libvirt management network. Specify one of veryisolated, none, open, nat or route options. Further documented under Private Networks
  • management_network_guest_ipv6 - Enable or disable guest-to-guest IPv6 communication. See here, and here for for more information.
  • management_network_autostart - Automatic startup of mgmt network, if not specified the default is ‘false’.
  • management_network_pci_bus - The bus of the PCI device.
  • management_network_pci_slot - The slot of the PCI device.
  • management_network_mac - MAC address of management network interface.
  • management_network_domain - Domain name assigned to the management network.
  • management_network_mtu - MTU size of management network. If not specified, the Libvirt default (1500) will be used.
  • management_network_keep - Starting from version 0.7.0, always_destroy is set to true by default for any network. This option allows to change this behaviour for the management network.
  • management_network_iface_name - Allow controlling of the network device name that appears on the host for the management network, same as :libvirt__iface_name for public and private network definitions. (unreleased).
  • management_network_model_type - Model of the network adapter to use for the management interface. Default is nic_model_type, which in turn defaults to ‘virtio’.

You may wonder how vagrant-libvirt knows the IP address a VM received. Libvirt doesn’t provide a standard way to find out the IP address of a running domain. But we do know the MAC address of the virtual machine’s interface on the management network. Libvirt is closely connected with dnsmasq, which acts as a DHCP server. dnsmasq writes lease information in the /var/lib/libvirt/dnsmasq directory. Vagrant-libvirt looks for the MAC address in this file and extracts the corresponding IP address.

It is also possible to use the Qemu Agent to extract the management interface configuration from the booted virtual machine. This is helpful in libvirt environments where no local dnsmasq is used for automatic address assignment, but external dhcp services via bridged libvirt networks.

Prerequisite is to enable the qemu agent channel via (Libvirt communication channels) and the virtual machine image must have the agent pre-installed before deploy. The agent will start automatically if it detects an attached channel during boot.

  • qemu_use_agent - false by default, if set to true, attempt to extract configured ip address via qemu agent.

By default if qemu_use_agent is set to true the code will automatically inject a suitable channel unless there already exists an entry with a :target_name matching 'org.qemu.guest_agent.'. Alternatively if setting qemu_use_agent but, needing to disable the addition of the channel, simply use a disabled flag as follows:

Vagrant.configure(2) do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.channel :type => 'unix', :target_name => 'org.qemu.guest_agent.0', :disabled => true
  end
end

To use the management network interface with an external dhcp service you need to setup a bridged host network manually and define it via management_network_name in your Vagrantfile.

Additional Disks

You can create and attach additional disks to a VM via libvirt.storage :file. It has a number of options:

  • path - Location of the disk image. If unspecified, a path is automatically chosen in the same storage pool as the VMs primary disk.
  • device - Name of the device node the disk image will have in the VM, e.g. vdb. If unspecified, the next available device is chosen.
  • size - Size of the disk image. If unspecified, defaults to 10G.
  • type - Type of disk image to create. Defaults to qcow2.
  • bus - Type of bus to connect device to. Defaults to virtio.
  • allow_existing - Set to true if you want to allow the VM to use a pre-existing disk. If the disk doesn’t exist it will be created. Disks with this option set to true need to be removed manually.
  • shareable - Set to true if you want to simulate shared SAN storage.
  • serial - Serial number of the disk device.
  • wwn - WWN number of the disk device.

The following disk performance options can also be configured (see the libvirt documentation for possible values or here for a fuller explanation). In all cases, the options use the hypervisor default if not specified, or if set to nil.

  • cache - Cache mode to use. Value may be default, none, writeback, writethrough, directsync or unsafe.
  • io - Controls specific policies on I/O. Value may be threads or native.
  • copy_on_read - Controls whether to copy read backing file into the image file. Value may be on or off.
  • discard - Controls whether discard requests (also known as “trim” or “unmap”) are ignored or passed to the filesystem. Value may be unmap or ignore. Note: for discard to work, you will likely also need to set :bus => 'scsi'
  • detect_zeroes - Controls whether to detect zero write requests. Value may be off, on or unmap.

The following example creates two additional disks.

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.storage :file, :size => '20G'
    libvirt.storage :file, :size => '40G', :bus => 'scsi', :type => 'raw', :discard => 'unmap', :detect_zeroes => 'on'
  end
end

For shared SAN storage to work the following example can be used:

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.storage :file, :size => '20G', :path => 'my_shared_disk.img', :allow_existing => true, :shareable => true, :type => 'raw'
  end
end

Reload behavior

On vagrant reload the following additional disk attributes are updated in defined domain:

  • bus - Updated. Uses device as a search marker. It is not required to define device, but it’s recommended. If device is defined then the order of additional disk definition becomes irrelevant.

CDROMs

You can attach up to four CDROMs to a VM via libvirt.storage :file, :device => :cdrom. Available options are:

  • path - The path to the iso to be used for the CDROM drive.
  • dev - The device to use (hda, hdb, hdc, or hdd). This will be automatically determined if unspecified.
  • bus - The bus to use for the CDROM drive. Defaults to ide

The following example creates three CDROM drives in the VM:

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.storage :file, :device => :cdrom, :path => '/path/to/iso1.iso'
    libvirt.storage :file, :device => :cdrom, :path => '/path/to/iso2.iso'
    libvirt.storage :file, :device => :cdrom, :path => '/path/to/iso3.iso'
  end
end

Floppies

You can attach up to two floppies to a VM via libvirt.storage :file, :device => :floppy. Available options are:

  • path - The path to the vfd image to be used for the floppy drive.
  • dev - The device to use (fda or fdb). This will be automatically determined if unspecified.

The following example creates a floppy drive in the VM:

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.storage :file, :device => :floppy, :path => '/path/to/floppy.vfs'
  end
end

Input

You can specify multiple inputs to the VM via libvirt.input. Available options are listed below. Note that both options are required:

  • type - The type of the input
  • bus - The bus of the input
Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # this is the default
    # libvirt.input :type => "mouse", :bus => "ps2"

    # very useful when having mouse issues when viewing VM via VNC
    libvirt.input :type => "tablet", :bus => "usb"
  end
end

PCI device passthrough

You can specify multiple PCI devices to passthrough to the VM via libvirt.pci. Available options are listed below. Note that all options are required, except domain, which defaults to 0x0000:

  • domain - The domain of the PCI device
  • bus - The bus of the PCI device
  • slot - The slot of the PCI device
  • function - The function of the PCI device

You can extract that information from output of lspci command. First characters of each line are in format [<domain>]:[<bus>]:[<slot>].[<func>]. For example:

$ lspci| grep NVIDIA
0000:03:00.0 VGA compatible controller: NVIDIA Corporation GK110B [GeForce GTX TITAN Black] (rev a1)

In that case domain is 0x0000, bus is 0x03, slot is 0x00 and function is 0x0.

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.pci :domain => '0x0000', :bus => '0x06', :slot => '0x12', :function => '0x5'

    # Add another one if it is necessary
    libvirt.pci :domain => '0x0000', :bus => '0x03', :slot => '0x00', :function => '0x0'
  end
end

Note! Above options affect configuration only at domain creation. It won’t change VM behaviour on vagrant reload after domain was created.

Don’t forget to set kvm_hidden option to true especially if you are passthroughing NVIDIA GPUs. Otherwise GPU is visible from VM but cannot be operated.

Using USB Devices

There are several ways to pass a USB device through to a running instance:

  • Use libvirt.usb to attach a USB device at boot, with the device ID specified in the Vagrantfile
  • Use a client (such as virt-viewer or virt-manager) to attach the device at runtime via USB redirectors
  • Use virsh attach-device once the VM is running (however, this is outside the scope of this readme)

In all cases, if you wish to use a high-speed USB device, you will need to use libvirt.usb_controller to specify a USB2 or USB3 controller, as the default configuration only exposes a USB1.1 controller.

USB Controller Configuration

The USB controller can be configured using libvirt.usb_controller, with the following options:

  • model - The USB controller device model to emulate. (mandatory)
  • ports - The number of devices that can be connected to the controller.
Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Set up a USB3 controller
    libvirt.usb_controller :model => "qemu-xhci"
  end
end

See the libvirt documentation for a list of valid models.

If any USB devices are passed through by setting libvirt.usb or libvirt.redirdev, a default controller will be added using the model qemu-xhci in the absence of a user specified one. This should help ensure more devices work out of the box as the default configured by libvirt is pii3-uhci, which appears to only work for USB 1 devices and does not work as expected when connected via a USB 2 controller, while the xhci stack should work for all versions of USB.

USB Device Passthrough

You can specify multiple USB devices to passthrough to the VM via libvirt.usb. The device can be specified by the following options:

  • bus - The USB bus ID, e.g. “1”
  • device - The USB device ID, e.g. “2”
  • vendor - The USB devices vendor ID (VID), e.g. “0x1234”
  • product - The USB devices product ID (PID), e.g. “0xabcd”

At least one of these has to be specified, and bus and device may only be used together.

The example values above match the device from the following output of lsusb:

Bus 001 Device 002: ID 1234:abcd Example device

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # pass through specific device based on identifying it
    libvirt.usb :vendor => '0x1234', :product => '0xabcd'
    # pass through a host device where multiple of the same vendor/product exist
    libvirt.usb :bus => '1', :device => '1'
  end
end

Additionally, the following options can be used:

  • startupPolicy - Is passed through to Libvirt and controls if the device has to exist. Libvirt currently allows the following values: “mandatory”, “requisite”, “optional”.

USB Redirector Devices

You can specify multiple redirect devices via libvirt.redirdev. There are two types, tcp and spicevmc supported, for forwarding USB-devices to the guest. Available options are listed below.

  • type - The type of the USB redirector device. (tcp or spicevmc)
  • host - The host where the device is attached to. (mandatory for type tcp)
  • port - The port where the device is listening. (mandatory for type tcp)
Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # add two devices using spicevmc channel
    (1..2).each do
      libvirt.redirdev :type => "spicevmc"
    end
    # add device, provided by localhost:4000
    libvirt.redirdev :type => "tcp", :host => "localhost", :port => "4000"
  end
end

Note that in order to enable USB redirection with Spice clients, you may need to also set libvirt.graphics_type = "spice"

Filter for USB Redirector Devices

You can define filter for redirected devices. These filters can be positive or negative, by setting the mandatory option allow=yes or allow=no. All available options are listed below. Note the option allow is mandatory.

  • class - The device class of the USB device. A list of device classes is available on Wikipedia.
  • vendor - The vendor of the USB device.
  • product - The product id of the USB device.
  • version - The version of the USB device. Note that this is the version of bcdDevice
  • allow - allow or disallow redirecting this device. (mandatory)

You can extract that information from output of lsusb command. Every line contains the information in format Bus [<bus>] Device [<device>]: ID [<vendor>:[<product>]. The version can be extracted from the detailed output of the device using lsusb -D /dev/usb/[<bus>]/[<device>]. For example:

# get bcdDevice from
$: lsusb
Bus 001 Device 009: ID 08e6:3437 Gemalto (was Gemplus) GemPC Twin SmartCard Reader

$: lsusb -D /dev/bus/usb/001/009 | grep bcdDevice
  bcdDevice            2.00

In this case, the USB device with class 0x0b, vendor 0x08e6, product 0x3437 and bcdDevice version 2.00 is allowed to be redirected to the guest. All other devices will be refused.

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.redirdev :type => "spicevmc"
    libvirt.redirfilter :class => "0x0b", :vendor => "0x08e6", :product => "0x3437", :version => "2.00", :allow => "yes"
    libvirt.redirfilter :allow => "no"
  end
end

Serial Console Devices

You can define settings to redirect output from the serial console of any VM brought up with libvirt to a file or other devices that are listening. See libvirt documentation.

Currently only redirecting to a file is supported.

  • type - only value that has an effect is file, in the future support may be added for virtual console, pty, dev, pipe, tcp, udp, unix socket, spiceport & nmdm.
  • source - options pertaining to how the connection attaches to the host, contains sub-settings dependent on type. source options for type file
    • path - file on host to connect to the serial port to record all output. May be created by qemu system user causing some permissions issues.
Vagrant.configure("2") do |config|
  config.vm.define :test do |test|
    test.vm.provider :libvirt do |domain|
      domain.serial :type => "file", :source => {:path => "/var/log/vm_consoles/test.log"}
    end
  end
end

Random number generator passthrough

You can pass through /dev/random to your VM by configuring the domain like this:

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Pass through /dev/random from the host to the VM
    libvirt.random :model => 'random'
  end
end

At the moment only the random backend is supported.

Watchdog device

A virtual hardware watchdog device can be added to the guest via the libvirt.watchdog element. The option model is mandatory and could have on of the following values.

  • i6300esb - the recommended device, emulating a PCI Intel 6300ESB
  • ‘ib700` - emulating an ISA iBase IB700
  • diag288 - emulating an S390 DIAG288 device

The optional action attribute describes what action to take when the watchdog expires. Valid values are specific to the underlying hypervisor. The default behavior is reset.

  • reset - default, forcefully reset the guest
  • shutdown - gracefully shutdown the guest (not recommended)
  • poweroff - forcefully power off the guest
  • pause - pause the guest
  • none - do nothing
  • dump - automatically dump the guest
  • inject-nmi - inject a non-maskable interrupt into the guest
Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Add Libvirt watchdog device model i6300esb
    libvirt.watchdog :model => 'i6300esb', :action => 'reset'
  end
end

Smartcard device

A virtual smartcard device can be supplied to the guest via the libvirt.smartcard element. The option mode is mandatory and currently only value passthrough is supported. The value spicevmc for option type is default value and can be suppressed. On using type = tcp, the options source_mode, source_host and source_service are mandatory.

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Add smartcard device with type 'spicevmc'
    libvirt.smartcard :mode => 'passthrough', :type => 'spicevmc'
  end
end

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Add smartcard device with type 'tcp'
    domain.smartcard :mode => 'passthrough', :type => 'tcp', :source_mode => 'bind', :source_host => '127.0.0.1', :source_service => '2001'
  end
end

Hypervisor Features

Hypervisor features can be specified via libvirt.features as a list. The default options that are enabled are acpi, apic and pae. If you define libvirt.features you overwrite the defaults, so keep that in mind.

An example:

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Specify the default hypervisor features
    libvirt.features = ['acpi', 'apic', 'pae' ]
  end
end

A different example for ARM boards:

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Specify the default hypervisor features
    libvirt.features = ["apic", "gic version='2'" ]
  end
end

You can also specify a special set of features that help improve the behavior of guests running Microsoft Windows.

You can specify HyperV features via libvirt.hyperv_feature. Available options are listed below. Note that both options are required:

  • name - The name of the feature Hypervisor feature (see Libvirt doc)
  • state - The state for this feature which can be either on or off.
Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Relax constraints on timers
    libvirt.hyperv_feature :name => 'relaxed', :state => 'on'
    # Enable virtual APIC
    libvirt.hyperv_feature :name => 'vapic', :state => 'on'
    # Enable spinlocks (requires retries to be specified)
    libvirt.hyperv_feature :name => 'spinlocks', :state => 'on', :retries => '8191'
  end
end

Clock

The clock can be configured using one of the following methods:

  • Set nothing, and the clock will default to UTC.
  • Set libvirt.clock_offset to ‘utc’ or ‘localtime’ by assigning the respective values.
  • To set the clock to a different timezone, assign the timezone name to libvirt.clock_timezone.
  • To set the clock to the same absolute time whenever the VM starts, set libvirt.clock_absolute. The value format is that of an epoch timestamp.
  • To set the clock at an arbitrary offset to realtime, use libvirt.clock_adjustment. Specify the offset adjustment in seconds. By default, the clock offset is relative to UTC, but this can be changed by setting libvirt.clock_basis to ‘localtime’.

In addition to the above, timers can be specified via libvirt.clock_timer. Available options for timers are: name, track, tickpolicy, frequency, mode, present

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # Set clock offset to localtime
    libvirt.clock_offset = 'localtime'
    # Timers ...
    libvirt.clock_timer :name => 'rtc', :tickpolicy => 'catchup'
    libvirt.clock_timer :name => 'pit', :tickpolicy => 'delay'
    libvirt.clock_timer :name => 'hpet', :present => 'no'
    libvirt.clock_timer :name => 'hypervclock', :present => 'yes'
  end
end

CPU features

You can specify CPU feature policies via libvirt.cpu_feature. Available options are listed below. Note that both options are required:

  • name - The name of the feature for the chosen CPU (see Libvirt’s cpu_map.xml)
  • policy - The policy for this feature (one of force, require, optional, disable and forbid - see Libvirt documentation)
Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    # The feature will not be supported by virtual CPU.
    libvirt.cpu_feature :name => 'hypervisor', :policy => 'disable'
    # Guest creation will fail unless the feature is supported by host CPU.
    libvirt.cpu_feature :name => 'vmx', :policy => 'require'
    # The virtual CPU will claim the feature is supported regardless of it being supported by host CPU.
    libvirt.cpu_feature :name => 'pdpe1gb', :policy => 'force'
  end
end

Memory Backing

You can specify memoryBacking options via libvirt.memorybacking. Available options are shown below. Full documentation is available at the libvirt memoryBacking section.

NOTE: The hugepages <page> element is not yet supported

Vagrant.configure("2") do |config|
  config.vm.provider :libvirt do |libvirt|
    libvirt.memorybacking :hugepages
    libvirt.memorybacking :nosharepages
    libvirt.memorybacking :locked
    libvirt.memorybacking :source, :type => 'file'
    libvirt.memorybacking :access, :mode => 'shared'
    libvirt.memorybacking :allocation, :mode => 'immediate'
  end
end