Provided by: libsys-virt-perl_9.4.0-1_amd64 bug

NAME

       Sys::Virt - Represent and manage a libvirt hypervisor connection

SYNOPSIS

         my $conn = Sys::Virt->new(uri => $uri);

         my @domains = $conn->list_domains();

         foreach my $dom (@domains) {
           print "Domain ", $dom->get_id, " ", $dom->get_name, "\n";
         }

DESCRIPTION

       The Sys::Virt module provides a Perl XS binding to the libvirt virtual machine management
       APIs. This allows machines running within arbitrary virtualization containers to be
       managed with a consistent API.

ERROR HANDLING

       Any operations in the Sys::Virt API which have failure scenarios will result in an
       instance of the Sys::Virt::Error module being thrown. To catch these errors, simply wrap
       the method in an eval block:

         eval { my $conn = Sys::Virt->new(uri => $uri); };
         if ($@) {
           print STDERR "Unable to open connection to $addr" . $@->message . "\n";
         }

       For details of the information contained in the error objects, consult the
       Sys::Virt::Error manual page.

METHODS

       my $conn = Sys::Virt->new(uri => $uri, readonly => $ro, flags => $flags);
           Attach to the virtualization host identified by "uri". The "uri" parameter may be
           omitted, in which case the default connection made will be to the local Xen
           hypervisor. Some example URIs include:

           xen:///
               Xen on the local machine

           test:///default
               Dummy "in memory" driver for test suites

           qemu:///system
               System-wide driver for QEMU / KVM virtualization

           qemu:///session
               Per-user driver for QEMU virtualization

           qemu+tls://somehost/system
               System-wide QEMU driver on "somehost" using TLS security

           xen+tcp://somehost/
               Xen driver on "somehost" using TCP / SASL security

           For further details consult "http://libvirt.org/uri.html"

           If the optional "readonly" parameter is supplied, then an unprivileged connection to
           the hypervisor will be attempted. If it is not supplied, then it defaults to making a
           fully privileged connection to the hypervisor. If the calling application is not
           running as root, it may be necessary to provide authentication callbacks.

           If the optional "auth" parameter is set to a non-zero value, authentication will be
           enabled during connection, using the default set of credential gathering callbacks.
           The default callbacks prompt for credentials on the console, so are not suitable for
           graphical applications. For such apps a custom implementation should be supplied. The
           "credlist" parameter should be an array reference listing the set of credential types
           that will be supported. The credential constants in this module can be used as values
           in this list. The "callback" parameter should be a subroutine reference containing the
           code necessary to gather the credentials. When invoked it will be supplied with a
           single parameter, an array reference of requested credentials. The elements of the
           array are hash references, with keys "type" giving the type of credential, "prompt"
           giving a user descriptive user prompt, "challenge" giving name of the credential
           required. The answer should be collected from the user, and returned by setting the
           "result" key. This key may already be set with a default result if applicable

           As a simple example returning hardcoded credentials

               my $uri  = "qemu+tcp://192.168.122.1/system";
               my $username = "test";
               my $password = "123456";

               my $con = Sys::Virt->new(uri => $uri,
                                        auth => 1,
                                        credlist => [
                                          Sys::Virt::CRED_AUTHNAME,
                                          Sys::Virt::CRED_PASSPHRASE,
                                        ],
                                        callback =>
                    sub {
                          my $creds = shift;

                          foreach my $cred (@{$creds}) {
                             if ($cred->{type} == Sys::Virt::CRED_AUTHNAME) {
                                 $cred->{result} = $username;
                             }
                             if ($cred->{type} == Sys::Virt::CRED_PASSPHRASE) {
                                 $cred->{result} = $password;
                             }
                          }
                          return 0;
                    });

           For backwards compatibility with earlier releases, the "address" parameter is accepted
           as a synonym for the "uri" parameter. The use of "uri" is recommended for all newly
           written code.

       $conn->set_identity($identity, $flags=0)
           Change the identity that is used for access control over the connection. Normally the
           remote daemon will use the identity associated with the UNIX domain socket that the
           app opens.  Only a privileged client is usually able to override this.  The $identity
           should be a hash reference whose keys are one of the IDENTITY constants. The $flags
           parameter is currently unused, and defaults to 0 if omitted.

       my $st = $conn->new_stream($flags)
           Create a new stream, with the given flags

       my $dom = $conn->create_domain($xml, $flags=0);
           Create a new domain based on the XML description passed into the $xml parameter. The
           returned object is an instance of the Sys::Virt::Domain class. This method is not
           available with unprivileged connections to the hypervisor. The $flags parameter
           accepts one of the DOMAIN CREATION constants documented in Sys::Virt::Domain, and
           defaults to 0 if omitted.

       my $dom = $conn->create_domain_with_files($xml, $fds, $flags=0);
           Create a new domain based on the XML description passed into the $xml parameter. The
           returned object is an instance of the Sys::Virt::Domain class. This method is not
           available with unprivileged connections to the hypervisor. The $fds parameter is an
           array of UNIX file descriptors which will be passed to the init process of the
           container. This is only supported with container based virtualization. The $flags
           parameter accepts one of the DOMAIN CREATION constants documented in
           Sys::Virt::Domain, and defaults to 0 if omitted.

       my $dom = $conn->define_domain($xml, $flags=0);
           Defines, but does not start, a new domain based on the XML description passed into the
           $xml parameter. The returned object is an instance of the Sys::Virt::Domain class.
           This method is not available with unprivileged connections to the hypervisor. The
           defined domain can be later started by calling the "create" method on the returned
           "Sys::Virt::Domain" object. The $flags parameter accepts one of the DOMAIN DEFINE
           constants documented in Sys::Virt::Domain, and defaults to 0 if omitted.

       my $net = $conn->create_network($xml, $flags=0);
           Create a new network based on the XML description passed into the $xml parameter. The
           returned object is an instance of the Sys::Virt::Network class. This method is not
           available with unprivileged connections to the hypervisor. The $flags parameter
           accepts one of the NETWORK CREATION constants documented in Sys::Virt::Network, and
           defaults to 0 if omitted.

       my $net = $conn->define_network($xml, $flags=0);
           Defines, but does not start, a new network based on the XML description passed into
           the $xml parameter. The returned object is an instance of the Sys::Virt::Network
           class. This method is not available with unprivileged connections to the hypervisor.
           The defined network can be later started by calling the "create" method on the
           returned "Sys::Virt::Network" object. The $flags parameter accepts one of the NETWORK
           DEFINE constants documented in Sys::Virt::Network, and defaults to 0 if omitted.

       my $nwfilter = $conn->define_nwfilter($xml, $flags=0);
           Defines a new network filter based on the XML description passed into the $xml
           parameter. The returned object is an instance of the Sys::Virt::NWFilter class. This
           method is not available with unprivileged connections to the hypervisor. The $flags
           parameter accepts one of the NWFILTER DEFINE constants documented in
           Sys::Virt::NWFilter, and defaults to 0 if omitted.

       my $binding = $conn->create_nwfilter_binding($xml, $flags=0);
           Create a new network filter binding based on the XML description passed into the $xml
           parameter. The returned object is an instance of the Sys::Virt::NWFilterBinding class.
           The $flags parameter accepts one of the NETWORK FILTER BINDING CREATION constants
           documented in Sys::Virt::NWFilterBinding, and defaults to 0 if omitted.

       my $secret = $conn->define_secret($xml, $flags=0);
           Defines a new secret based on the XML description passed into the $xml parameter. The
           returned object is an instance of the Sys::Virt::Secret class. This method is not
           available with unprivileged connections to the hypervisor. The $flags parameter
           accepts one of the SECRET DEFINE constants documented in Sys::Virt::Secret, and
           defaults to 0 if omitted.

       my $pool = $conn->create_storage_pool($xml);
           Create a new storage pool based on the XML description passed into the $xml parameter.
           The returned object is an instance of the Sys::Virt::StoragePool class. This method is
           not available with unprivileged connections to the hypervisor.

       my $pool = $conn->define_storage_pool($xml, $flags=0);
           Defines, but does not start, a new storage pol based on the XML description passed
           into the $xml parameter. The returned object is an instance of the
           Sys::Virt::StoragePool class. This method is not available with unprivileged
           connections to the hypervisor. The defined pool can be later started by calling the
           "create" method on the returned "Sys::Virt::StoragePool" object. The $flags parameter
           accepts one of the STORAGE POOL DEFINE constants documented in Sys::Virt::StoragePool,
           and defaults to 0 if omitted.

       my $pool = $conn->create_interface($xml);
           Create a new interface based on the XML description passed into the $xml parameter.
           The returned object is an instance of the Sys::Virt::Interface class. This method is
           not available with unprivileged connections to the hypervisor.

       my $iface = $conn->define_interface($xml, $flags=0);
           Defines, but does not start, a new interface based on the XML description passed into
           the $xml parameter. The returned object is an instance of the Sys::Virt::Interface
           class. This method is not available with unprivileged connections to the hypervisor.
           The defined interface can be later started by calling the "create" method on the
           returned "Sys::Virt::Interface" object. The $flags parameter accepts one of the
           INTERFACE DEFINE constants documented in Sys::Virt::Interface, and defaults to 0 if
           omitted.

       my $dev = $conn->create_node_device($xml, $flags=0);
           Create a new virtual node device based on the XML description passed into the $xml
           parameter. The returned object is an instance of the Sys::Virt::NodeDevice class. This
           method is not available with unprivileged connections to the hypervisor. The $flags
           parameter accepts one of the NODE DEVICE CREATION constants documented in
           Sys::Virt::NodeDevice, and defaults to 0 if omitted.

       my $dev = $conn->define_node_device($xml, $flags=0);
           Defines, but does not start, a new node dev based on the XML description passed into
           the $xml parameter. The returned object is an instance of the Sys::Virt::NodeDevice
           class. This method is not available with unprivileged connections to the hypervisor.
           The defined node device can be later started by calling the "create" method on the
           returned "Sys::Virt::NodeDevice" object. The $flags parameter accepts one of the NODE
           DEVICE DEFINE constants documented in Sys::Virt::NodeDevice, and defaults to 0 if
           omitted.

       my @doms = $conn->list_domains()
           Return a list of all running domains currently known to the hypervisor. The elements
           in the returned list are instances of the Sys::Virt::Domain class. This method
           requires O(n) RPC calls, so the "list_all_domains" method is recommended as a more
           efficient alternative.

       my $nids = $conn->num_of_domains()
           Return the number of running domains known to the hypervisor. This can be used as the
           "maxids" parameter to "list_domain_ids".

       my @domIDs = $conn->list_domain_ids($maxids)
           Return a list of all domain IDs currently known to the hypervisor. The IDs can be used
           with the "get_domain_by_id" method.

       my @doms = $conn->list_defined_domains()
           Return a list of all domains defined, but not currently running, on the hypervisor.
           The elements in the returned list are instances of the Sys::Virt::Domain class. This
           method requires O(n) RPC calls, so the "list_all_domains" method is recommended as a
           more efficient alternative.

       my $ndoms = $conn->num_of_defined_domains()
           Return the number of running domains known to the hypervisor. This can be used as the
           "maxnames" parameter to "list_defined_domain_names".

       my @names = $conn->list_defined_domain_names($maxnames)
           Return a list of names of all domains defined, but not currently running, on the
           hypervisor. The names can be used with the "get_domain_by_name" method.

       my @doms = $conn->list_all_domains($flags)
           Return a list of all domains currently known to the hypervisor, whether running or
           shutoff. The elements in the returned list are instances of the Sys::Virt::Domain
           class. The $flags parameter can be used to filter the list of returned domains.

       my @nets = $conn->list_networks()
           Return a list of all networks currently known to the hypervisor. The elements in the
           returned list are instances of the Sys::Virt::Network class.  This method requires
           O(n) RPC calls, so the "list_all_networks" method is recommended as a more efficient
           alternative.

       my $nnets = $conn->num_of_networks()
           Return the number of running networks known to the hypervisor. This can be used as the
           "maxids" parameter to "list_network_ids".

       my @netNames = $conn->list_network_names($maxnames)
           Return a list of all network names currently known to the hypervisor. The names can be
           used with the "get_network_by_name" method.

       my @nets = $conn->list_defined_networks()
           Return a list of all networks defined, but not currently running, on the hypervisor.
           The elements in the returned list are instances of the Sys::Virt::Network class. This
           method requires O(n) RPC calls, so the "list_all_networks" method is recommended as a
           more efficient alternative.

       my $nnets = $conn->num_of_defined_networks()
           Return the number of running networks known to the host. This can be used as the
           "maxnames" parameter to "list_defined_network_names".

       my @names = $conn->list_defined_network_names($maxnames)
           Return a list of names of all networks defined, but not currently running, on the
           host. The names can be used with the "get_network_by_name" method.

       my @nets = $conn->list_all_networks($flags)
           Return a list of all networks currently known to the hypervisor, whether running or
           shutoff. The elements in the returned list are instances of the Sys::Virt::Network
           class. The $flags parameter can be used to filter the list of returned networks.

       my @pools = $conn->list_storage_pools()
           Return a list of all storage pools currently known to the host. The elements in the
           returned list are instances of the Sys::Virt::StoragePool class.  This method requires
           O(n) RPC calls, so the "list_all_storage_pools" method is recommended as a more
           efficient alternative.

       my $npools = $conn->num_of_storage_pools()
           Return the number of running storage pools known to the hypervisor. This can be used
           as the "maxids" parameter to "list_storage_pool_names".

       my @poolNames = $conn->list_storage_pool_names($maxnames)
           Return a list of all storage pool names currently known to the hypervisor. The IDs can
           be used with the "get_network_by_id" method.

       my @pools = $conn->list_defined_storage_pools()
           Return a list of all storage pools defined, but not currently running, on the host.
           The elements in the returned list are instances of the Sys::Virt::StoragePool class.
           This method requires O(n) RPC calls, so the "list_all_storage_pools" method is
           recommended as a more efficient alternative.

       my $npools = $conn->num_of_defined_storage_pools()
           Return the number of running networks known to the host. This can be used as the
           "maxnames" parameter to "list_defined_storage_pool_names".

       my @names = $conn->list_defined_storage_pool_names($maxnames)
           Return a list of names of all storage pools defined, but not currently running, on the
           host. The names can be used with the "get_storage_pool_by_name" method.

       my @pools = $conn->list_all_storage_pools($flags)
           Return a list of all storage pools currently known to the hypervisor, whether running
           or shutoff. The elements in the returned list are instances of the
           Sys::Virt::StoragePool class. The $flags parameter can be used to filter the list of
           returned pools.

       my @devs = $conn->list_node_devices($capability)
           Return a list of all devices currently known to the host OS. The elements in the
           returned list are instances of the Sys::Virt::NodeDevice class.  The optional
           "capability" parameter allows the list to be restricted to only devices with a
           particular capability type. This method requires O(n) RPC calls, so the
           "list_all_node_devices" method is recommended as a more efficient alternative.

       my $ndevs = $conn->num_of_node_devices($capability[, $flags])
           Return the number of host devices known to the hypervisor. This can be used as the
           "maxids" parameter to "list_node_device_names".  The "capability" parameter allows the
           list to be restricted to only devices with a particular capability type, and should be
           left as "undef" if the full list is required. The optional <flags> parameter is
           currently unused and defaults to 0 if omitted.

       my @devNames = $conn->list_node_device_names($capability, $maxnames[, $flags])
           Return a list of all host device names currently known to the hypervisor. The names
           can be used with the "get_node_device_by_name" method.  The "capability" parameter
           allows the list to be restricted to only devices with a particular capability type,
           and should be left as "undef" if the full list is required. The optional <flags>
           parameter is currently unused and defaults to 0 if omitted.

       my @devs = $conn->list_all_node_devices($flags)
           Return a list of all node devices currently known to the hypervisor. The elements in
           the returned list are instances of the Sys::Virt::NodeDevice class. The $flags
           parameter can be used to filter the list of returned devices.

       my @ifaces = $conn->list_interfaces()
           Return a list of all network interfaces currently known to the hypervisor. The
           elements in the returned list are instances of the Sys::Virt::Interface class.  This
           method requires O(n) RPC calls, so the "list_all_interfaces" method is recommended as
           a more efficient alternative.

       my $nifaces = $conn->num_of_interfaces()
           Return the number of running interfaces known to the hypervisor. This can be used as
           the "maxnames" parameter to "list_interface_names".

       my @names = $conn->list_interface_names($maxnames)
           Return a list of all interface names currently known to the hypervisor. The names can
           be used with the "get_interface_by_name" method.

       my @ifaces = $conn->list_defined_interfaces()
           Return a list of all network interfaces currently known to the hypervisor. The
           elements in the returned list are instances of the Sys::Virt::Interface class.  This
           method requires O(n) RPC calls, so the "list_all_interfaces" method is recommended as
           a more efficient alternative.

       my $nifaces = $conn->num_of_defined_interfaces()
           Return the number of inactive interfaces known to the hypervisor. This can be used as
           the "maxnames" parameter to "list_defined_interface_names".

       my @names = $conn->list_defined_interface_names($maxnames)
           Return a list of inactive interface names currently known to the hypervisor. The names
           can be used with the "get_interface_by_name" method.

       my @ifaces = $conn->list_all_interfaces($flags)
           Return a list of all interfaces currently known to the hypervisor, whether running or
           shutoff. The elements in the returned list are instances of the Sys::Virt::Interface
           class. The $flags parameter can be used to filter the list of returned interfaces.

       my @ifaces = $conn->list_secrets()
           Return a list of all secrets currently known to the hypervisor. The elements in the
           returned list are instances of the Sys::Virt::Secret class.  This method requires O(n)
           RPC calls, so the "list_all_secrets" method is recommended as a more efficient
           alternative.

       my $nuuids = $conn->num_of_secrets()
           Return the number of secrets known to the hypervisor. This can be used as the
           "maxuuids" parameter to "list_secrets".

       my @uuids = $conn->list_secret_uuids($maxuuids)
           Return a list of all secret uuids currently known to the hypervisor. The uuids can be
           used with the "get_secret_by_uuid" method.

       my @secrets = $conn->list_all_secrets($flags)
           Return a list of all secrets currently known to the hypervisor. The elements in the
           returned list are instances of the Sys::Virt::Network class.  The $flags parameter can
           be used to filter the list of returned secrets.

       my @nwfilters = $conn->list_nwfilters()
           Return a list of all nwfilters currently known to the hypervisor. The elements in the
           returned list are instances of the Sys::Virt::NWFilter class.  This method requires
           O(n) RPC calls, so the "list_all_nwfilters" method is recommended as a more efficient
           alternative.

       my $nnwfilters = $conn->num_of_nwfilters()
           Return the number of running nwfilters known to the hypervisor. This can be used as
           the "maxids" parameter to "list_nwfilter_names".

       my @filterNames = $conn->list_nwfilter_names($maxnames)
           Return a list of all nwfilter names currently known to the hypervisor. The names can
           be used with the "get_nwfilter_by_name" method.

       my @nwfilters = $conn->list_all_nwfilters($flags)
           Return a list of all nwfilters currently known to the hypervisor. The elements in the
           returned list are instances of the Sys::Virt::NWFilter class.  The $flags parameter is
           currently unused and defaults to zero.

       my @bindings = $conn->list_all_nwfilter_bindings($flags)
           Return a list of all nwfilter bindings currently known to the hypervisor. The elements
           in the returned list are instances of the Sys::Virt::NWFilterBinding class. The $flags
           parameter is currently unused and defaults to zero.

       $conn->define_save_image_xml($file, $dxml, $flags=0)
           Update the XML associated with a virtual machine's save image. The $file parameter is
           the fully qualified path to the save image XML, while $dxml is the new XML document to
           write. The $flags parameter is currently unused and defaults to zero.

       $xml = $conn->get_save_image_xml_description($file, $flags=1)
           Retrieve the current XML configuration associated with the virtual machine's save
           image identified by $file. The $flags parameter accepts the same constants as
           "Sys::Virt::Domain::managed_save_get_xml_description".

       my $dom = $conn->get_domain_by_name($name)
           Return the domain with a name of $name. The returned object is an instance of the
           Sys::Virt::Domain class.

       my $dom = $conn->get_domain_by_id($id)
           Return the domain with a local id of $id. The returned object is an instance of the
           Sys::Virt::Domain class.

       my $dom = $conn->get_domain_by_uuid($uuid)
           Return the domain with a globally unique id of $uuid. The returned object is an
           instance of the Sys::Virt::Domain class.

       my $net = $conn->get_network_by_name($name)
           Return the network with a name of $name. The returned object is an instance of the
           Sys::Virt::Network class.

       my $net = $conn->get_network_by_uuid($uuid)
           Return the network with a globally unique id of $uuid. The returned object is an
           instance of the Sys::Virt::Network class.

       my $pool = $conn->get_storage_pool_by_name($name)
           Return the storage pool with a name of $name. The returned object is an instance of
           the Sys::Virt::StoragePool class.

       my $pool = $conn->get_storage_pool_by_uuid($uuid)
           Return the storage pool with a globally unique id of $uuid. The returned object is an
           instance of the Sys::Virt::StoragePool class.

       my $pool = $conn->get_storage_pool_by_volume($vol)
           Return the storage pool with a storage volume $vol. The $vol parameter must be an
           instance of the Sys::Virt::StorageVol class. The returned object is an instance of the
           Sys::Virt::StoragePool class.

       my $pool = $conn->get_storage_pool_by_target_path($path)
           Return the storage pool with a target path of $path. The returned object is an
           instance of the Sys::Virt::StoragePool class.

       my $vol = $conn->get_storage_volume_by_path($path)
           Return the storage volume with a location of $path. The returned object is an instance
           of the Sys::Virt::StorageVol class.

       my $vol = $conn->get_storage_volume_by_key($key)
           Return the storage volume with a globally unique id of $key. The returned object is an
           instance of the Sys::Virt::StorageVol class.

       my $dev = $conn->get_node_device_by_name($name)
           Return the node device with a name of $name. The returned object is an instance of the
           Sys::Virt::NodeDevice class.

       my $dev = $conn->get_node_device_scsihost_by_wwn($wwnn, $wwpn, $flags=0)
           Return the node device which is a SCSI host identified by $wwnn and $wwpn.  The $flags
           parameter is unused and defaults to zero.  The returned object is an instance of the
           Sys::Virt::NodeDevice class.

       my $iface = $conn->get_interface_by_name($name)
           Return the interface with a name of $name. The returned object is an instance of the
           Sys::Virt::Interface class.

       my $iface = $conn->get_interface_by_mac($mac)
           Return the interface with a MAC address of $mac. The returned object is an instance of
           the Sys::Virt::Interface class.

       my $sec = $conn->get_secret_by_uuid($uuid)
           Return the secret with a globally unique id of $uuid. The returned object is an
           instance of the Sys::Virt::Secret class.

       my $sec = $conn->get_secret_by_usage($usageType, $usageID)
           Return the secret with a usage type of $usageType, identified by $usageID. The
           returned object is an instance of the Sys::Virt::Secret class.

       my $nwfilter = $conn->get_nwfilter_by_name($name)
           Return the domain with a name of $name. The returned object is an instance of the
           Sys::Virt::NWFilter class.

       my $nwfilter = $conn->get_nwfilter_by_uuid($uuid)
           Return the nwfilter with a globally unique id of $uuid. The returned object is an
           instance of the Sys::Virt::NWFilter class.

       my $binding = $conn->get_nwfilter_binding_by_port_dev($name)
           Return the network filter binding for the port device $name. The returned object is an
           instance of the Sys::Virt::NWFilterBinding class.

       my $xml = $conn->find_storage_pool_sources($type, $srcspec[, $flags])
           Probe for available storage pool sources for the pool of type $type.  The $srcspec
           parameter can be "undef", or a parameter to refine the discovery process, for example
           a server hostname for NFS discovery. The $flags parameter is optional, and if omitted
           defaults to zero. The returned scalar is an XML document describing the discovered
           storage pool sources.

       my @stats = $conn->get_all_domain_stats($stats, \@doms=undef, $flags=0);
           Get a list of all statistics for domains known to the hypervisor.  The $stats
           parameter controls which data fields to return and should be a combination of the
           DOMAIN STATS FIELD CONSTANTS.

           The optional @doms parameter is a list of Sys::Virt::Domain objects to return stats
           for. If this is undefined, then all domains will be returned. The $flags method can be
           used to filter the list of returned domains.

           The return data for the method is a list, one element for each domain.  The element
           will be a hash with two keys, "dom" pointing to an instance of "Sys::Virt::Domain" and
           "data" pointing to another hash reference containing the actual statistics.

       $conn->interface_change_begin($flags)
           Begin a transaction for changing the configuration of one or more network interfaces

       $conn->interface_change_commit($flags)
           Complete a transaction for changing the configuration of one or more network
           interfaces

       $conn->interface_change_rollback($flags)
           Abort a transaction for changing the configuration of one or more network interfaces

       $conn->restore_domain($savefile, $dxml=undef, $params=undef, $flags=0)
           Recreate a domain from the saved state file given in the $savefile parameter. The
           optional $dxml parameter can be used to alter portions of the domain XML. The $params
           parameter is a hash reference whose keys is a subset of the SAVE / RESTORE PARAMETER
           CONSTANTS. The $flags parameter accepts one of the SAVE / RESTORE FLAG CONSTANTS
           described later and defaults to zero.

       $conn->get_max_vcpus($domtype)
           Return the maximum number of vcpus that can be configured for a domain of type
           $domtype

       my $hostname = $conn->get_hostname()
           Return the name of the host with which this connection is associated.

       my $uri = $conn->get_uri()
           Return the URI associated with the open connection. This may be different from the URI
           used when initially connecting to libvirt, when 'auto-probing' or drivers occurrs.

       my $xml = $conn->get_sysinfo()
           Return an XML documenting representing the host system information, typically obtained
           from SMBIOS tables.

       my $type = $conn->get_type()
           Return the type of virtualization backend accessed by this hypervisor object.
           Currently the only supported type is "Xen".

       my $xml = $conn->domain_xml_from_native($format, $config);
           Convert the native hypervisor configuration $config which is in format <$format> into
           libvirrt domain XML. Valid values of $format vary between hypervisor drivers.

       my $config = $conn->domain_xml_to_native($format, $xml)
           Convert the libvirt domain XML configuration $xml to a native hypervisor configuration
           in format $format

       my $ver = $conn->get_version()
           Return the complete version number as a string encoded in the formula "(major *
           1000000) + (minor * 1000) + micro".

       my $ver = $conn->get_major_version
           Return the major version number of the libvirt library.

       my $ver = $conn->get_minor_version
           Return the minor version number of the libvirt library.

       my $ver = $conn->get_micro_version
           Return the micro version number of the libvirt library.

       my $ver = $conn->get_library_version
           Return the version number of the API associated with the active connection. This
           differs from "get_version" in that if the connection is to a remote libvirtd daemon,
           it will return the API version of the remote libvirt, rather than the local client.

       $conn->is_secure()
           Returns a true value if the current connection is secure against network interception.
           This implies either use of UNIX sockets, or encryption with a TCP stream.

       $conn->is_encrypted()
           Returns a true value if the current connection data stream is encrypted.

       $conn->is_alive()
           Returns a true value if the connection is alive, as determined by keep-alive packets
           or other recent RPC traffic.

       $conn->set_keep_alive($interval, $count)
           Change the operation of the keep alive protocol to send $count packets spaced
           $interval seconds apart before considering the connection dead.

       my $info = $con->get_node_info()
           Returns a hash reference summarising the capabilities of the host node. The elements
           of the hash are as follows:

           memory
               The amount of physical memory in the host

           model
               The model of the CPU, eg x86_64

           cpus
               The total number of logical CPUs.

           mhz The peak MHZ of the CPU

           nodes
               The number of NUMA cells

           sockets
               The number of CPU sockets

           cores
               The number of cores per socket

           threads
               The number of threads per core

           NB, more accurate information about the total number of CPUs and those online can be
           obtained using the "get_node_cpu_map" method.

       my ($totcpus, $onlinemap, $totonline) = $con->get_node_cpu_map();
           Returns an array containing information about the CPUs available on the host. The
           first element, "totcpus", specifies the total number of CPUs available to the host
           regardles of their online stat. The second element, "onlinemap", provides a bitmap
           detailing which CPUs are currently online. The third element, "totonline", specifies
           the total number of online CPUs. The values in the bitmap can be extracted using the
           "unpack" method as follows:

             my @onlinemap = split(//, unpack("b*", $onlinemap));

       my $info = $con->get_node_cpu_stats($cpuNum=-1, $flags=0)
           Returns a hash reference providing information about the host CPU statistics. If
           <$cpuNum> is omitted, it defaults to "Sys::Virt::NODE_CPU_STATS_ALL_CPUS" which causes
           it to return cumulative information for all CPUs in the host. If $cpuNum is zero or
           larger, it returns information just for the specified number. The $flags parameter is
           currently unused and defaults to zero. The fields in the returned hash reference are

           kernel
               The time spent in kernelspace

           user
               The time spent in userspace

           idle
               The idle time

           iowait
               The I/O wait time

           utilization
               The overall percentage utilization.

       my $info = $con->get_node_memory_stats($cellNum=-1, $flags=0)
           Returns a hash reference providing information about the host memory statistics. If
           <$cellNum> is omitted, it defaults to "Sys::Virt::NODE_MEMORY_STATS_ALL_CELLS" which
           causes it to return cumulative information for all NUMA cells in the host. If $cellNum
           is zero or larger, it returns information just for the specified number. The $flags
           parameter is currently unused and defaults to zero. The fields in the returned hash
           reference are

           total
               The total memory

           free
               The free memory

           buffers
               The memory consumed by buffers

           cached
               The memory consumed for cache

       my $params = $conn->get_node_memory_parameters($flags=0)
           Return a hash reference containing the set of memory tunable parameters for the node.
           The keys in the hash are one of the constants MEMORY PARAMETERS described later. The
           $flags parameter is currently unused, and defaults to 0 if omitted.

       $conn->set_node_memory_parameters($params, $flags=0)
           Update the memory tunable parameters for the node. The $params should be a hash
           reference whose keys are one of the MEMORY PARAMETERS constants. The $flags parameter
           is currently unused, and defaults to 0 if omitted.

       $info = $conn->get_node_sev_info($flags=0)
           Get the AMD SEV information for the host. $flags is currently unused and defaults to 0
           if omitted. The returned hash contains the following keys:

           Sys::Virt::SEV_CBITPOS
               The CBit position

           Sys::Virt::SEV_CERT_CHAIN
               The certificate chain

           Sys::Virt::SEV_PDH
               Platform diffie-hellman key

           Sys::Virt::SEV_REDUCED_PHYS_BITS
               The number of physical address bits used by SEV

           Sys::Virt::SEV_MAX_GUESTS
               Maximum number of SEV guests that can be launched

           Sys::Virt::SEV_MAX_ES_GUESTS
               Maximum number of SEV-ES guests that can be launched

           Sys::Virt::SEV_CPU0_ID
               The SEV firmware ID for CPU 0

       $conn->node_suspend_for_duration($target, $duration, $flags=0)
           Suspend the the host, using mode $target which is one of the NODE SUSPEND constants
           listed later. The $duration parameter controls how long the node is suspended for
           before waking up.

       $conn->domain_event_register($callback)
           Register a callback to received notifications of domain state change events. Only a
           single callback can be registered with each connection instance. The callback will be
           invoked with four parameters, an instance of "Sys::Virt" for the connection, an
           instance of "Sys::Virt::Domain" for the domain changing state, and a "event" and
           "detail" arguments, corresponding to the event constants defined in the
           "Sys::Virt::Domain" module. Before discarding the connection object, the callback must
           be deregistered, otherwise the connection object memory will never be released in
           garbage collection.

       $conn->domain_event_deregister()
           Unregister a callback, allowing the connection object to be garbage collected.

       $callback = $conn->domain_event_register_any($dom, $eventID, $callback)
           Register a callback to received notifications of domain events.  The $dom parameter
           can be "undef" to request events on all known domains, or a specific
           "Sys::Virt::Domain" object to filter events. The $eventID parameter is one of the
           EVENT ID constants described later in this document. The $callback is a subroutine
           reference that will receive the events.

           All callbacks receive a "Sys::Virt" connection as the first parameter and a
           "Sys::Virt::Domain" object indicating the domain on which the event occurred as the
           second parameter. Subsequent parameters vary according to the event type

           EVENT_ID_LIFECYCLE
               Extra "event" and "detail" parameters defining the lifecycle transition that
               occurred.

           EVENT_ID_REBOOT
               No extra parameters

           EVENT_ID_RTC_CHANGE
               The "utcoffset" gives the offset from UTC in seconds

           EVENT_ID_WATCHDOG
               The "action" defines the action that is taken as a result of the watchdog
               triggering. One of the WATCHDOG constants described later

           EVENT_ID_IO_ERROR
               The "srcPath" is the file on the host which had the error.  The "devAlias" is the
               unique device alias from the guest configuration associated with "srcPath". The
               "action" is the action taken as a result of the error, one of the IO ERROR
               constants described later

           EVENT_ID_GRAPHICS
               The "phase" is the stage of the connection, one of the GRAPHICS PHASE constants
               described later. The "local" and "remote" parameters follow with the details of
               the local and remote network addresses. The "authScheme" describes how the user
               was authenticated (if at all). Finally "identities" is an array ref containing
               authenticated identities for the user, if any.

           The return value is a unique callback ID that must be used when unregistering the
           event.

       $conn->domain_event_deregister_any($callbackID)
           Unregister a callback, associated with the $callbackID previously obtained from
           "domain_event_register_any".

       $callback = $conn->network_event_register_any($net, $eventID, $callback)
           Register a callback to received notifications of network events.  The $net parameter
           can be "undef" to request events on all known networks, or a specific
           "Sys::Virt::Network" object to filter events. The $eventID parameter is one of the
           EVENT ID constants described later in this document. The $callback is a subroutine
           reference that will receive the events.

           All callbacks receive a "Sys::Virt" connection as the first parameter and a
           "Sys::Virt::Network" object indicating the network on which the event occurred as the
           second parameter. Subsequent parameters vary according to the event type

           EVENT_ID_LIFECYCLE
               Extra "event" and "detail" parameters defining the lifecycle transition that
               occurred.

           The return value is a unique callback ID that must be used when unregistering the
           event.

       $conn->network_event_deregister_any($callbackID)
           Unregister a callback, associated with the $callbackID previously obtained from
           "network_event_register_any".

       $callback = $conn->storage_pool_event_register_any($pool, $eventID, $callback)
           Register a callback to received notifications of storage pool events.  The $pool
           parameter can be "undef" to request events on all known storage pools, or a specific
           "Sys::Virt::StoragePool" object to filter events. The $eventID parameter is one of the
           EVENT ID constants described later in this document. The $callback is a subroutine
           reference that will receive the events.

           All callbacks receive a "Sys::Virt" connection as the first parameter and a
           "Sys::Virt::StoragePool" object indicating the storage pool on which the event
           occurred as the second parameter. Subsequent parameters vary according to the event
           type

           EVENT_ID_LIFECYCLE
               Extra "event" and "detail" parameters defining the lifecycle transition that
               occurred.

           EVENT_ID_REFRESH
               No extra parameters.

           The return value is a unique callback ID that must be used when unregistering the
           event.

       $conn->storage_pool_event_deregister_any($callbackID)
           Unregister a callback, associated with the $callbackID previously obtained from
           "storage_pool_event_register_any".

       $callback = $conn->node_device_event_register_any($dev, $eventID, $callback)
           Register a callback to received notifications of node device events.  The $dev
           parameter can be "undef" to request events on all known node devices, or a specific
           "Sys::Virt::NodeDevice" object to filter events. The $eventID parameter is one of the
           EVENT ID constants described later in this document. The $callback is a subroutine
           reference that will receive the events.

           All callbacks receive a "Sys::Virt" connection as the first parameter and a
           "Sys::Virt::NodeDevice" object indicating the node device on which the event occurred
           as the second parameter. Subsequent parameters vary according to the event type

           EVENT_ID_LIFECYCLE
               Extra "event" and "detail" parameters defining the lifecycle transition that
               occurred.

           The return value is a unique callback ID that must be used when unregistering the
           event.

       $conn->node_device_event_deregister_any($callbackID)
           Unregister a callback, associated with the $callbackID previously obtained from
           "node_device_event_register_any".

       $callback = $conn->secret_event_register_any($secret, $eventID, $callback)
           Register a callback to received notifications of secret events.  The $secret parameter
           can be "undef" to request events on all known secrets, or a specific
           "Sys::Virt::Secret" object to filter events. The $eventID parameter is one of the
           EVENT ID constants described later in this document. The $callback is a subroutine
           reference that will receive the events.

           All callbacks receive a "Sys::Virt" connection as the first parameter and a
           "Sys::Virt::Secret" object indicating the secret on which the event occurred as the
           second parameter. Subsequent parameters vary according to the event type

           EVENT_ID_LIFECYCLE
               Extra "event" and "detail" parameters defining the lifecycle transition that
               occurred.

           EVENT_ID_VALUE_CHANGED
               No extra parameters.

           The return value is a unique callback ID that must be used when unregistering the
           event.

       $conn->secret_event_deregister_any($callbackID)
           Unregister a callback, associated with the $callbackID previously obtained from
           "secret_event_register_any".

       $conn->register_close_callback($coderef);
           Register a callback to be invoked when the connection is closed.  The callback will be
           invoked with two parameters, the $conn it was registered against, and the reason for
           the close event.  The reason value will be one of the "CLOSE REASON CONSTANTS" listed
           later in this document.

       $conn->unregister_close_callback();
           Remove the previously registered close callback.

       my $xml = $con->baseline_cpu(\@xml, $flags=0)
           Given an array ref whose elements are XML documents describing host CPUs, compute the
           baseline CPU model that is operable across all hosts. The XML for the baseline CPU
           model is returned. The optional $flags parameter can take one of

           Sys::Virt::BASELINE_CPU_EXPAND_FEATURES
               Expand the CPU definition to list all feature flags, even those implied by the
               model name.

           Sys::Virt::BASELINE_CPU_MIGRATABLE
               Only include features which can be live migrated.

       my $xml = $con->baseline_hypervisor_cpu($emulator, $arch, $machine, $virttype, \@xml,
       $flags=0)
           Given an array ref whose elements are XML documents describing host CPUs, compute the
           baseline CPU model that is operable across all hosts. The XML for the baseline CPU
           model is returned. Either $emulator or $arch must be a valid string referring to an
           emulator binary or an architecture name respectively. The $machine parameter is an
           optional name of a guest machine, and $virttype is an optional name of the
           virtualization type. The optional $flags parameter accepts the same values as
           "baseline_cpu".

       @names = $con->get_cpu_model_names($arch, $flags=0)
           Get a list of valid CPU models names for the architecture given by $arch. The $arch
           value should be one of the architectures listed in the capabilities XML document.  The
           $flags parameter is currently unused and defaults to 0.

       my $info = $con->get_node_security_model()
           Returns a hash reference summarising the security model of the host node. There are
           two keys in the hash, "model" specifying the name of the security model (eg 'selinux')
           and "doi" specifying the 'domain of interpretation' for security labels.

       my $xml = $con->get_capabilities();
           Returns an XML document describing the hypervisor capabilities

       my $xml = $con->get_domain_capabilities($emulator, $arch, $machine, $virttype, flags=0);
           Returns an XML document describing the capabilities of the requested guest
           configuration. Either $emulator or $arch must be a valid string referring to an
           emulator binary or an architecture name respectively. The $machine parameter is an
           optional name of a guest machine, and $virttype is an optional name of the
           virtualization type. $flags is unused and defaults to zero.

       my $xml = $con->get_storage_pool_capabilities($flags=0);
           Returns an XML document describing the storage pool driver capabilities (e.g. which
           storage pool types are supported and so on). $flags is currently unused and defaults
           to zero.

       my $result = $con->compare_cpu($xml, $flags=0);
           Checks whether the CPU definition in $xml is compatible with the current hypervisor
           connection. This can be used to determine whether it is safe to migrate a guest to
           this host. The returned result is one of the constants listed later The optional
           $flags parameter can take one of the following constants

           Sys::Virt::COMPARE_CPU_FAIL_INCOMPATIBLE
               Raise a fatal error if the CPUs are not compatible, instead of just returning a
               special error code.

           Sys::Virt::COMPARE_CPU_VALIDATE_XML
               Validate input XML document against the RNG schema.

       my $result = $con->compare_hypervisor_cpu($emulator, $arch, $machine, $virttype, $xml,
       $flags=0);
           Checks whether the CPU definition in $xml is compatible with the current hypervisor
           connection. This can be used to determine whether it is safe to migrate a guest to
           this host. Either $emulator or $arch must be a valid string referring to an emulator
           binary or an architecture name respectively. The $machine parameter is an optional
           name of a guest machine, and $virttype is an optional name of the virtualization type.
           The returned result is one of the constants listed later The optional $flags parameter
           can take the same values as the "compare_cpu" method.

       $mem = $con->get_node_free_memory();
           Returns the current free memory on the host

       @mem = $con->get_node_cells_free_memory($start, $end);
           Returns the free memory on each NUMA cell between $start and $end.

       @pages = $con->get_node_free_pages(\@pagesizes, $start, $end);
           Returns information about the number of pages free on each NUMA cell between $start
           and $end inclusive. The @pagesizes parameter should be an arrayref specifying which
           pages sizes information should be returned for. Information about supported page sizes
           is available in the capabilities XML. The returned array has an element for each NUMA
           cell requested. The elements are hash references with two keys, 'cell' specifies the
           NUMA cell number and 'pages' specifies the free page information for that cell. The
           'pages' value is another hash reference where the keys are the page sizes and the
           values are the free count for that size.

       $con->node_alloc_pages(\@pages, $start, $end, $flags=0)
           Allocate further huge pages for the reserved dev. The <\@pages> parameter is an array
           reference with one entry per page size to allocate for. Each entry is a further array
           reference where the first element is the page size and the second element is the page
           count. The same number of pages will be allocated on each NUMA node in the range
           $start to $end inclusive. The $flags parameter accepts two contants

           Sys::Virt::NODE_ALLOC_PAGES_ADD
               The requested number of pages will be added to the existing huge page reservation.

           Sys::Virt::NODE_ALLOC_PAGES_SET
               The huge page reservation will be set to exactly the requested number

CONSTANTS

       The following sets of constants are useful when dealing with APIs in this package

   CONNECTION
       When opening a connection the following constants can be used:

       Sys::Virt::CONNECT_RO
           Request a read-only connection

       Sys::Virt::CONNECT_NO_ALIASES
           Prevent the resolution of URI aliases

   CREDENTIAL TYPES
       When providing authentication callbacks, the following constants indicate the type of
       credential being requested

       Sys::Virt::CRED_AUTHNAME
           Identity to act as

       Sys::Virt::CRED_USERNAME
           Identity to authorize as

       Sys::Virt::CRED_CNONCE
           Client supplies a nonce

       Sys::Virt::CRED_REALM
           Authentication realm

       Sys::Virt::CRED_ECHOPROMPT
           Challenge response non-secret

       Sys::Virt::CRED_NOECHOPROMPT
           Challenge response secret

       Sys::Virt::CRED_PASSPHRASE
           Passphrase secret

       Sys::Virt::CRED_LANGUAGE
           RFC 1766 language code

       Sys::Virt::CRED_EXTERNAL
           Externally provided credential

   IDENTITY CONSTANTS
       The following constants are useful to change the connection identity

       Sys::Virt::IDENTITY_USER_NAME
           The process user name

       Sys::Virt::IDENTITY_UNIX_USER_ID
           The process UNIX user ID

       Sys::Virt::IDENTITY_GROUP_NAME
           The process group name

       Sys::Virt::IDENTITY_UNIX_GROUP_ID
           The process UNIX group ID

       Sys::Virt::IDENTITY_PROCESS_ID
           The process ID.

       Sys::Virt::IDENTITY_PROCESS_TIME
           The process start time.

       Sys::Virt::IDENTITY_SASL_USER_NAME
           The SASL authenticated user name

       Sys::Virt::IDENTITY_X509_DISTINGUISHED_NAME
           The X509 certificate distinguished name for the TLS connection

       Sys::Virt::IDENTITY_SELINUX_CONTEXT
           The SELinux process context

   CPU COMPARISON CONSTANTS
       Sys::Virt::CPU_COMPARE_INCOMPATIBLE
           This host is missing one or more CPU features in the CPU description

       Sys::Virt::CPU_COMPARE_IDENTICAL
           The host has an identical CPU description

       Sys::Virt::CPU_COMPARE_SUPERSET
           The host offers a superset of the CPU descriptoon

   NODE SUSPEND CONSTANTS
       Sys::Virt::NODE_SUSPEND_TARGET_MEM
           Suspends to memory (equivalent of S3 on x86 architectures)

       Sys::Virt::NODE_SUSPEND_TARGET_DISK
           Suspends to disk (equivalent of S5 on x86 architectures)

       Sys::Virt::NODE_SUSPEND_TARGET_HYBRID
           Suspends to memory and disk (equivalent of S3+S5 on x86 architectures)

   NODE VCPU CONSTANTS
       Sys::Virt::NODE_CPU_STATS_ALL_CPUS
           Request statistics for all CPUs

   NODE MEMORY CONSTANTS
       Sys::Virt::NODE_MEMORY_STATS_ALL_CELLS
           Request statistics for all memory cells

   MEMORY PARAMETERS
       The following constants are used to name memory parameters of the node

       Sys::Virt::NODE_MEMORY_SHARED_FULL_SCANS
           How many times all mergeable areas have been scanned.

       Sys::Virt::NODE_MEMORY_SHARED_PAGES_SHARED
           How many the shared memory pages are being used.

       Sys::Virt::NODE_MEMORY_SHARED_PAGES_SHARING
           How many sites are sharing the pages

       Sys::Virt::NODE_MEMORY_SHARED_PAGES_TO_SCAN
           How many present pages to scan before the shared memory service goes to sleep

       Sys::Virt::NODE_MEMORY_SHARED_PAGES_UNSHARED
           How many pages unique but repeatedly checked for merging.

       Sys::Virt::NODE_MEMORY_SHARED_PAGES_VOLATILE
           How many pages changing too fast to be placed in a tree.

       Sys::Virt::NODE_MEMORY_SHARED_SLEEP_MILLISECS
           How many milliseconds the shared memory service should sleep before next scan.

       Sys::Virt::NODE_MEMORY_SHARED_MERGE_ACROSS_NODES
           Whether pages can be merged across NUMA nodes

   CLOSE REASON CONSTANTS
       The following constants related to the connection close callback, describe the reason for
       the closing of the connection.

       Sys::Virt::CLOSE_REASON_CLIENT
           The client application requested the connection be closed

       Sys::Virt::CLOSE_REASON_EOF
           End-of-file was encountered reading data from the connection

       Sys::Virt::CLOSE_REASON_ERROR
           An I/O error was encountered reading/writing data from/to the connection

       Sys::Virt::CLOSE_REASON_KEEPALIVE
           The connection keepalive timer triggered due to lack of response from the server

   CPU STATS CONSTANTS
       The following constants provide the names of known CPU stats fields

       Sys::Virt::NODE_CPU_STATS_IDLE
           Time spent idle

       Sys::Virt::NODE_CPU_STATS_IOWAIT
           Time spent waiting for I/O to complete

       Sys::Virt::NODE_CPU_STATS_KERNEL
           Time spent executing kernel code

       Sys::Virt::NODE_CPU_STATS_USER
           Time spent executing user code

       Sys::Virt::NODE_CPU_STATS_INTR
           Time spent processing interrupts

       Sys::Virt::NODE_CPU_STATS_UTILIZATION
           Percentage utilization of the CPU.

   MEMORY STAS CONSTANTS
       The following constants provide the names of known memory stats fields

       Sys::Virt::NODE_MEMORY_STATS_BUFFERS
           The amount of memory consumed by I/O buffers

       Sys::Virt::NODE_MEMORY_STATS_CACHED
           The amount of memory consumed by disk cache

       Sys::Virt::NODE_MEMORY_STATS_FREE
           The amount of free memory

       Sys::Virt::NODE_MEMORY_STATS_TOTAL
           The total amount of memory

   IP address constants
       The following constants are used to interpret IP address types

       Sys::Virt::IP_ADDR_TYPE_IPV4
           An IPv4 address type

       Sys::Virt::IP_ADDR_TYPE_IPV6
           An IPv6 address type

BUGS

       Hopefully none, but the XS code needs to be audited to ensure it is not leaking memory.

AUTHORS

       Daniel P. Berrange <berrange@redhat.com>

COPYRIGHT

       Copyright (C) 2006-2009 Red Hat Copyright (C) 2006-2009 Daniel P. Berrange

LICENSE

       This program is free software; you can redistribute it and/or modify it under the terms of
       either the GNU General Public License as published by the Free Software Foundation (either
       version 2 of the License, or at your option any later version), or, the Artistic License,
       as specified in the Perl README file.

SEE ALSO

       Sys::Virt::Domain, Sys::Virt::Network, Sys::Virt::StoragePool, Sys::Virt::StorageVol,
       Sys::Virt::Error, "http://libvirt.org"