diff --git a/share/man/man9/nv.9 b/share/man/man9/nv.9
index 4e4542c146ef..8c99f1d12200 100644
--- a/share/man/man9/nv.9
+++ b/share/man/man9/nv.9
@@ -1,1069 +1,1099 @@
 .\"
 .\" Copyright (c) 2013 The FreeBSD Foundation
 .\" Copyright (c) 2013-2015 Mariusz Zaborski <oshogbo@FreeBSD.org>
 .\" All rights reserved.
 .\"
 .\" This documentation was written by Pawel Jakub Dawidek under sponsorship
 .\" the FreeBSD Foundation.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 .\"
 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .Dd January 3, 2025
 .Dt NV 9
 .Os
 .Sh NAME
 .Nm nvlist_create ,
 .Nm nvlist_destroy ,
 .Nm nvlist_error ,
 .Nm nvlist_set_error ,
 .Nm nvlist_empty ,
 .Nm nvlist_flags ,
 .Nm nvlist_exists ,
 .Nm nvlist_free ,
 .Nm nvlist_clone ,
 .Nm nvlist_dump ,
 .Nm nvlist_fdump ,
 .Nm nvlist_size ,
 .Nm nvlist_pack ,
 .Nm nvlist_unpack ,
 .Nm nvlist_send ,
 .Nm nvlist_recv ,
 .Nm nvlist_xfer ,
 .Nm nvlist_in_array ,
 .Nm nvlist_next ,
 .Nm nvlist_add ,
 .Nm nvlist_move ,
 .Nm nvlist_get ,
 .Nm nvlist_take ,
 .Nm nvlist_append
 .Nd "library for name/value pairs"
 .Sh LIBRARY
 .Lb libnv
 .Sh SYNOPSIS
 .In sys/nv.h
 .Ft "nvlist_t *"
 .Fn nvlist_create "int flags"
 .Ft void
 .Fn nvlist_destroy "nvlist_t *nvl"
 .Ft int
 .Fn nvlist_error "const nvlist_t *nvl"
 .Ft void
 .Fn nvlist_set_error "nvlist_t *nvl" "int error"
 .Ft bool
 .Fn nvlist_empty "const nvlist_t *nvl"
 .Ft int
 .Fn nvlist_flags "const nvlist_t *nvl"
 .Ft bool
 .Fn nvlist_in_array "const nvlist_t *nvl"
 .\"
 .Ft "nvlist_t *"
 .Fn nvlist_clone "const nvlist_t *nvl"
 .\"
 .Ft void
 .Fn nvlist_dump "const nvlist_t *nvl" "int fd"
 .Ft void
 .Fn nvlist_fdump "const nvlist_t *nvl" "FILE *fp"
 .\"
 .Ft size_t
 .Fn nvlist_size "const nvlist_t *nvl"
 .Ft "void *"
 .Fn nvlist_pack "const nvlist_t *nvl" "size_t *sizep"
 .Ft "nvlist_t *"
 .Fn nvlist_unpack "const void *buf" "size_t size" "int flags"
 .\"
 .Ft int
 .Fn nvlist_send "int sock" "const nvlist_t *nvl"
 .Ft "nvlist_t *"
 .Fn nvlist_recv "int sock" "int flags"
 .Ft "nvlist_t *"
 .Fn nvlist_xfer "int sock" "nvlist_t *nvl" "int flags"
 .\"
 .Ft "const char *"
 .Fn nvlist_next "const nvlist_t *nvl" "int *typep" "void **cookiep"
 .\"
 .Ft bool
 .Fn nvlist_exists "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_type "const nvlist_t *nvl" "const char *name" "int type"
 .Ft bool
 .Fn nvlist_exists_null "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_bool "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_number "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_string "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_nvlist "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_descriptor "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_binary "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_bool_array "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_number_array "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_string_array "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_nvlist_array "const nvlist_t *nvl" "const char *name"
 .Ft bool
 .Fn nvlist_exists_descriptor_array "const nvlist_t *nvl" "const char *name"
 .\"
 .Ft void
 .Fn nvlist_add_null "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_add_bool "nvlist_t *nvl" "const char *name" "bool value"
 .Ft void
 .Fn nvlist_add_number "nvlist_t *nvl" "const char *name" "uint64_t value"
 .Ft void
 .Fn nvlist_add_string "nvlist_t *nvl" "const char *name" "const char *value"
 .Ft void
 .Fn nvlist_add_stringf "nvlist_t *nvl" "const char *name" "const char *valuefmt" "..."
 .Ft void
 .Fn nvlist_add_stringv "nvlist_t *nvl" "const char *name" "const char *valuefmt" "va_list valueap"
 .Ft void
 .Fn nvlist_add_nvlist "nvlist_t *nvl" "const char *name" "const nvlist_t *value"
 .Ft void
 .Fn nvlist_add_descriptor "nvlist_t *nvl" "const char *name" "int value"
 .Ft void
 .Fn nvlist_add_binary "nvlist_t *nvl" "const char *name" "const void *value" "size_t size"
 .Ft void
 .Fn nvlist_add_bool_array "nvlist_t *nvl" "const char *name" "const bool *value" "size_t nitems"
 .
 .Ft void
 .Fn nvlist_add_number_array "nvlist_t *nvl" "const char *name" "const uint64_t *value" "size_t nitems"
 .
 .Ft void
 .Fn nvlist_add_string_array "nvlist_t *nvl" "const char *name" "const char * const * value" "size_t nitems"
 .
 .Ft void
 .Fn nvlist_add_nvlist_array "nvlist_t *nvl" "const char *name" "const nvlist_t * const * value" "size_t nitems"
 .
 .Ft void
 .Fn nvlist_add_descriptor_array "nvlist_t *nvl" "const char *name" "const int *value" "size_t nitems"
 .\"
 .Ft void
 .Fn nvlist_move_string "nvlist_t *nvl" "const char *name" "char *value"
 .Ft void
 .Fn nvlist_move_nvlist "nvlist_t *nvl" "const char *name" "nvlist_t *value"
 .Ft void
 .Fn nvlist_move_descriptor "nvlist_t *nvl" "const char *name" "int value"
 .Ft void
 .Fn nvlist_move_binary "nvlist_t *nvl" "const char *name" "void *value" "size_t size"
 .Ft void
 .Fn nvlist_move_bool_array "nvlist_t *nvl" "const char *name" "bool *value" "size_t nitems"
 .
 .Ft void
 .Fn nvlist_move_number_array "nvlist_t *nvl" "const char *name" "uint64_t *value" "size_t nitems"
 .
 .Ft void
 .Fn nvlist_move_string_array "nvlist_t *nvl" "const char *name" "char **value" "size_t nitems"
 .
 .Ft void
 .Fn nvlist_move_nvlist_array "nvlist_t *nvl" "const char *name" "nvlist_t **value" "size_t nitems"
 .
 .Ft void
 .Fn nvlist_move_descriptor_array "nvlist_t *nvl" "const char *name" "int *value" "size_t nitems"
 .\"
 .Ft bool
 .Fn nvlist_get_bool "const nvlist_t *nvl" "const char *name"
 .Ft uint64_t
 .Fn nvlist_get_number "const nvlist_t *nvl" "const char *name"
 .Ft "const char *"
 .Fn nvlist_get_string "const nvlist_t *nvl" "const char *name"
 .Ft "const nvlist_t *"
 .Fn nvlist_get_nvlist "const nvlist_t *nvl" "const char *name"
 .Ft int
 .Fn nvlist_get_descriptor "const nvlist_t *nvl" "const char *name"
 .Ft "const void *"
 .Fn nvlist_get_binary "const nvlist_t *nvl" "const char *name" "size_t *sizep"
 .Ft "const bool *"
 .Fn nvlist_get_bool_array "const nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "const uint64_t *"
 .Fn nvlist_get_number_array "const nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "const char * const *"
 .Fn nvlist_get_string_array "const nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "const nvlist_t * const *"
 .Fn nvlist_get_nvlist_array "const nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "const int *"
 .Fn nvlist_get_descriptor_array "const nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "const nvlist_t *"
 .Fn nvlist_get_parent "const nvlist_t *nvl" "void **cookiep"
 .Ft "const nvlist_t *"
 .Fn nvlist_get_array_next "const nvlist_t *nvl"
 .Ft "const nvlist_t *"
 .Fn nvlist_get_pararr "const nvlist_t *nvl" "void **cookiep"
 .\"
 .Ft bool
 .Fn nvlist_take_bool "nvlist_t *nvl" "const char *name"
 .Ft uint64_t
 .Fn nvlist_take_number "nvlist_t *nvl" "const char *name"
 .Ft "char *"
 .Fn nvlist_take_string "nvlist_t *nvl" "const char *name"
 .Ft "nvlist_t *"
 .Fn nvlist_take_nvlist "nvlist_t *nvl" "const char *name"
 .Ft int
 .Fn nvlist_take_descriptor "nvlist_t *nvl" "const char *name"
 .Ft "void *"
 .Fn nvlist_take_binary "nvlist_t *nvl" "const char *name" "size_t *sizep"
 .Ft "bool *"
 .Fn nvlist_take_bool_array "nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "uint64_t **"
 .Fn nvlist_take_number_array "nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "char **"
 .Fn nvlist_take_string_array "nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "nvlist_t **"
 .Fn nvlist_take_nvlist_array "nvlist_t *nvl" "const char *name" "size_t *nitems"
 .Ft "int *"
 .Fn nvlist_take_descriptor_array "nvlist_t *nvl" "const char *name" "size_t *nitems"
 .\"
 .Ft void
 .Fn nvlist_append_bool_array "nvlist_t *nvl" "const char *name" "const bool value"
 .Ft void
 .Fn nvlist_append_number_array "nvlist_t *nvl" "const char *name" "const uint64_t value"
 .Ft void
 .Fn nvlist_append_string_array "nvlist_t *nvl" "const char *name" "const char * const value"
 .Ft void
 .Fn nvlist_append_nvlist_array "nvlist_t *nvl" "const char *name" "const nvlist_t * const value"
 .Ft void
 .Fn nvlist_append_descriptor_array "nvlist_t *nvl" "const char *name" "int value"
 .\"
 .Ft void
 .Fn nvlist_free "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_type "nvlist_t *nvl" "const char *name" "int type"
 .\"
 .Ft void
 .Fn nvlist_free_null "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_bool "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_number "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_string "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_nvlist "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_descriptor "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_binary "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_bool_array "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_number_array "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_string_array "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_nvlist_array "nvlist_t *nvl" "const char *name"
 .Ft void
 .Fn nvlist_free_descriptor_array "nvlist_t *nvl" "const char *name"
 .Sh DESCRIPTION
 The
 .Nm libnv
 library permits creating and managing name value pairs as well as
 sending and receiving
 them over sockets.
 A group (list) of name value pairs is called an
 .Nm nvlist .
 The API supports the following data types for values:
 .Bl -ohang -offset indent
 .It Sy null ( NV_TYPE_NULL )
 There is no data associated with the name.
 .It Sy bool ( NV_TYPE_BOOL )
 The value can be either
 .Dv true
 or
 .Dv false .
 .It Sy number ( NV_TYPE_NUMBER )
 The value is a number stored as
 .Vt uint64_t .
 .It Sy string ( NV_TYPE_STRING )
 The value is a C string.
 .It Sy nvlist ( NV_TYPE_NVLIST )
 The value is a nested nvlist.
 .It Sy descriptor ( NV_TYPE_DESCRIPTOR )
 The value is a file descriptor.
 Note that file descriptors can be sent only over
 .Xr unix 4
 domain sockets.
 .It Sy binary ( NV_TYPE_BINARY )
 The value is a binary buffer.
 .It Sy bool array ( NV_TYPE_BOOL_ARRAY )
 The value is an array of boolean values.
 .It Sy number array ( NV_TYPE_NUMBER_ARRAY )
 The value is an array of numbers, each stored as
 .Vt uint64_t .
 .It Sy string array ( NV_TYPE_STRING_ARRAY )
 The value is an array of C strings.
 .It Sy nvlist array  ( NV_TYPE_NVLIST_ARRAY )
 The value is an array of nvlists.
 When an nvlist is added to an array, it becomes part of the primary nvlist.
 Traversing these arrays can be done using the
 .Fn nvlist_get_array_next
 and
 .Fn nvlist_get_pararr
 functions.
 .It Sy descriptor array ( NV_TYPE_DESCRIPTOR_ARRAY )
 The value is an array of files descriptors.
 .El
 .Pp
 The
 .Fn nvlist_create
 function allocates memory and initializes an nvlist.
 .Pp
 The following flags can be provided:
 .Pp
 .Bl -tag -width "NV_FLAG_IGNORE_CASE" -compact -offset indent
 .It Dv NV_FLAG_IGNORE_CASE
 Perform case-insensitive lookups of provided names.
 .It Dv NV_FLAG_NO_UNIQUE
 Names in the nvlist do not have to be unique.
 .El
 .Pp
 The
 .Fn nvlist_destroy
 function destroys the given nvlist.
 This function does nothing if
 .Fa nvl
 is
 .Dv NULL .
 This function never modifies
 .Va errno .
 .Pp
 The
 .Fn nvlist_error
 function returns the first error set on
 .Fa nvl .
 If
 .Fa nvl
 is not in the error state,
 this function returns zero.
 If
 .Fa nvl
 is
 .Dv NULL ,
 .Er ENOMEM
 is returned.
 .Pp
 The
 .Fn nvlist_set_error
 function sets an the error value for
 .Fa nvl .
 Subsequent calls to
 .Fn nvlist_error
 will return
 .Fa error .
 This function cannot be used to clear the error state from an nvlist.
 This function does nothing if the nvlist is already in the error state.
 .Pp
 The
 .Fn nvlist_empty
 function returns
 .Dv true
 if
 .Fa nvl
 is empty and
 .Dv false
 otherwise.
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_flags
 function returns the flags used to create
 .Fa nvl
 with the
 .Fn nvlist_create ,
 .Fn nvlist_recv ,
 .Fn nvlist_unpack ,
 or
 .Fn nvlist_xfer
 functions.
 .Pp
 The
 .Fn nvlist_in_array
 function returns
 .Dv true
 if
 .Fa nvl
 is part of an array that is a member of another nvlist.
 .Pp
 The
 .Fn nvlist_clone
 function clones
 .Fa nvl .
 The clone shares no resources with its origin.
 This also means that all file descriptors that are part of the nvlist will be
 duplicated with the
 .Xr dup 2
 system call before placing them in the clone.
 .Pp
 The
 .Fn nvlist_dump
 function dumps nvlist content for debugging purposes to the file descriptor
 .Fa fd .
 .Pp
 The
 .Fn nvlist_fdump
 dumps nvlist content for debugging purposes to the file stream
 .Fa fp .
 .Pp
 The
 .Fn nvlist_size
 function returns the size of the binary buffer that would be generated by the
 .Fn nvlist_pack
 function.
 .Pp
 The
 .Fn nvlist_pack
 function converts the given nvlist to a binary buffer.
 The function allocates memory for the buffer which should be freed with the
 .Xr free 3
 function.
 If the
 .Fa sizep
 argument is not
 .Dv NULL ,
 the size of the buffer is stored there.
 This function returns
 .Dv NULL
 in case of an error (allocation failure).
 If the nvlist contains any file descriptors
 .Dv NULL
 will be returned.
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_unpack
 function converts a binary buffer to a new nvlist.
 The
 .Fa flags
 argument has the same meaning as the
 .Fa flags
 argument passed to
 .Fn nvlist_create .
 If
 .Fa flags
 do not match the flags used to create the initial nvlist before it was packed,
 this function will fail.
 The flags of nested nvlists are not validated by this function.
 The caller is responsible for validating the flags on any nested nvlists using
 .Fn nvlist_flags .
 This function returns the new nvlist on success or
 .Dv NULL
 in case of an error.
 .Pp
 The
 .Fn nvlist_send
 function sends
 .Fa nvl
 over the socket
 .Fa sock .
 Note that nvlists that contain file descriptors can only be sent over
 .Xr unix 4
 domain sockets.
 .Pp
 The
 .Fn nvlist_recv
 function receives an nvlist over the socket
 .Fa sock .
 As with
 .Fn nvlist_unpack ,
 the
 .Fa flags
 argument is used to construct the new nvlist and must match the flags used
 to construct the original nvlist written to
 .Fa sock
 by the peer.
 The flags of nested nvlists are not validated by this function.
 The caller is responsible for validating the flags on any nested nvlists using
 .Fn nvlist_flags .
 This function returns the new nvlist on success or
 .Dv NULL
 in case of an error.
 .Pp
 The
 .Fn nvlist_xfer
 function sends
 .Fa nvl
 over the socket
 .Fa sock
 argument and then receives a new nvlist over the same socket.
 The
 .Fa flags
 argument applies to the new nvlist similar to
 .Fn nvlist_recv .
 The nvlist
 .Fa nvl
 is always destroyed.
 This function returns the new nvlist on success or
 .Dv NULL
 in case of an error.
 .Pp
 The
 .Fn nvlist_next
 function iterates over
 .Fa nvl
 returning the names and types of subsequent
 elements.
 The
 .Fa cookiep
 argument determines which element is returned.
 If
 .Va *cookiep
 is
 .Dv NULL ,
 the values for the first element in the list are returned.
 Otherwise,
 .Va *cookiep
 should contain the result of a prior call to
 .Fn nvlist_next
 in which case values for the next element from
 .Fa nvl
 are returned.
 This function returns
 .Dv NULL
 when there are no more elements on
 .Fa nvl .
 The
 .Fa typep
 argument can be
 .Dv NULL .
 Elements may not be removed from
 .Fa nvl
 the nvlist while traversing it.
 .Fa nvl
 must not be in the error state.
 Additional actions can be performed on an element identified by a cookie
 via the
 .Xr cnv 9
 API .
 .Pp
 The
 .Fn nvlist_exists
 function returns
 .Dv true
 if an element named
 .Fa name
 exists in
 .Fa nvl
 (regardless of type) or
 .Dv false
 otherwise.
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_exists_type
 function returns
 .Dv true
 if an element named
 .Fa name
 of type
 .Fa type
 exists or
 .Dv false
 otherwise.
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_exists_null ,
 .Fn nvlist_exists_bool ,
 .Fn nvlist_exists_number ,
 .Fn nvlist_exists_string ,
 .Fn nvlist_exists_nvlist ,
 .Fn nvlist_exists_descriptor ,
 .Fn nvlist_exists_binary ,
 .Fn nvlist_exists_bool_array ,
 .Fn nvlist_exists_number_array ,
 .Fn nvlist_exists_string_array ,
 .Fn nvlist_exists_nvlist_array ,
 .Fn nvlist_exists_descriptor_array
 functions return
 .Dv true
 if element named
 .Fa name
 with the type determined by the function name
 exists or
 .Dv false
 otherwise.
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_add_null ,
 .Fn nvlist_add_bool ,
 .Fn nvlist_add_number ,
 .Fn nvlist_add_string ,
 .Fn nvlist_add_stringf ,
 .Fn nvlist_add_stringv ,
 .Fn nvlist_add_nvlist ,
 .Fn nvlist_add_descriptor ,
 .Fn nvlist_add_binary ,
 .Fn nvlist_add_bool_array ,
 .Fn nvlist_add_number_array ,
 .Fn nvlist_add_string_array ,
 .Fn nvlist_add_nvlist_array ,
 .Fn nvlist_add_descriptor_array
 functions add an element to
 .Fa nvl .
 When adding a string or binary buffer, these functions allocate memory
 and copy the data.
 When adding an nvlist, the
 .Fa value
 nvlist is cloned and the clone is added to
 .Fa nvl .
 When adding a file descriptor, the descriptor is duplicated via the
 .Xr dup 2
 system call and the new file descriptor is added.
 The array functions fail if there are any
 .Dv NULL
 elements in the array, or if the array pointer is
 .Dv NULL .
 If an error occurs while adding a new element,
 an internal error is set which can be
 examined using the
 .Fn nvlist_error
 function.
 .Pp
 The
 .Fn nvlist_move_string ,
 .Fn nvlist_move_nvlist ,
 .Fn nvlist_move_descriptor ,
 .Fn nvlist_move_binary ,
 .Fn nvlist_move_bool_array ,
 .Fn nvlist_move_number_array ,
 .Fn nvlist_move_string_array ,
 .Fn nvlist_move_nvlist_array ,
 .Fn nvlist_move_descriptor_array
 functions add an element to
 .Fa nvl ,
 but unlike the
 .Fn nvlist_add_<type>
 functions they consume the given resource.
 For string, file descriptor, binary buffer, or nvlist values,
 no value should be moved into an nvlist multiple times;
 doing so will cause that value to be freed multiple times.
 Note that strings or binary buffers must be allocated with
 .Xr malloc 3 ,
 and the pointers will be released via
 .Xr free 3
 when
 .Fa nvl
 is destroyed.
 The array functions fail if there are any
 .Dv NULL
 elements, or if the array pointer is
 .Dv NULL .
 If an error occurs while adding new element, the resource is destroyed and
 an internal error is set which can be examined using the
 .Fn nvlist_error
 function.
 .Pp
 The
 .Fn nvlist_get_bool ,
 .Fn nvlist_get_number ,
 .Fn nvlist_get_string ,
 .Fn nvlist_get_nvlist ,
 .Fn nvlist_get_descriptor ,
 .Fn nvlist_get_binary ,
 .Fn nvlist_get_bool_array ,
 .Fn nvlist_get_number_array ,
 .Fn nvlist_get_string_array ,
 .Fn nvlist_get_nvlist_array ,
 .Fn nvlist_get_descriptor_array
 functions return the value of the first element in
 .Fa nvl
 named
 .Fa name .
 For string, nvlist, file descriptor, binary buffer, or array values,
 the returned resource must not be modified - it still belongs to
 .Fa nvl .
 .Pp
 If an element named
 .Fa name
 does not exist, the program aborts.
 To avoid this, the caller should check for the existence of the element before
 trying to obtain the value or use the
 .Xr dnv 9
 extension which provides a default value in the case of a missing element.
 .Pp
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_get_parent
 function returns the parent nvlist of
 .Fa nvl .
 .Pp
 The
 .Fn nvlist_get_array_next
 function returns the next element after
 .Fa nvl
 from an array of nvlists.
 If
 .Fa nvl
 is not in an array of nvlists or it is the last element,
 this function returns
 .Dv NULL .
 An nvlist is only in an nvlist array if it was added to an nvlist array using
 .Fn nvlist_add_nvlist_array ,
 .Fn nvlist_append_nvlist_array ,
 or
 .Fn nvlist_move_nvlist_array .
 .Pp
 The
 .Fn nvlist_get_pararr
 function returns the next element after
 .Fn nvl
 from an array of nvlists.
 If
 .Fn nvl
 is the last element in an array of nvlists,
 the parent nvlist of
 .Fa nvl is
 returned.
 If
 .Fn nvl
 is not in an array of nvlists,
 .Dv NULL
 is returned.
 .Pp
 The
 .Fn nvlist_take_bool ,
 .Fn nvlist_take_number ,
 .Fn nvlist_take_string ,
 .Fn nvlist_take_nvlist ,
 .Fn nvlist_take_descriptor ,
 .Fn nvlist_take_binary ,
 .Fn nvlist_take_bool_array ,
 .Fn nvlist_take_number_array ,
 .Fn nvlist_take_string_array ,
 .Fn nvlist_take_nvlist_array ,
 .Fn nvlist_take_descriptor_array
 functions return the value of the element named
 .Fa name
 and remove the element from
 .Fa nvl .
 For string and binary buffer values, the caller is responsible for freeing
 the returned value using the
 .Xr free 3
 function.
 For nvlist values, the caller is responsible for destroying the returned nvlist
 using the
 .Fn nvlist_destroy
 function.
 For file descriptor values, the caller is responsible for closing the
 returned descriptor
 using the
 .Fn close 2
 system call.
 For array values, the caller is responsible for destroying every element of
 the array based on the element type.
 In addition, the caller must also free the pointer to the array using the
 .Xr free 3
 function.
 .Pp
 If an element named
 .Fa name
 does not exist, the program aborts.
 To avoid this, the caller should check for the existence of the element before
 trying to obtain the value or use the
 .Xr dnv 9
 extension which provides a default value in the case of a missing element.
 .Pp
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_append_bool_array ,
 .Fn nvlist_append_number_array ,
 .Fn nvlist_append_string_array ,
 .Fn nvlist_append_nvlist_array ,
 .Fn nvlist_append_descriptor_array
 functions append an element to an existing array using the same semantics
 as the add functions (that is, the element will be copied when applicable).
 If the array named
 .Fa name
 does not exist, then it will be created
 as if using the
 .Fn nvlist_add_<type>_array
 function.
 If an error occurs while appending a new element,
 an internal error is set on
 .Fa nvl .
 .Pp
 The
 .Fn nvlist_free
 function removes the first element named
 .Fa name
 from
 .Fa nvl
 (regardless of type)
 and frees all resources associated with it.
 If no element named
 .Fa name
 exists, the program aborts.
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_free_type
 function removes the first element named
 .Fa name
 of type
 .Fa type
 from
 .Fa nvl
 and frees all resources associated with it.
 If no element named
 .Fa name
 of type
 .Fa type
 exists, the program aborts.
 The nvlist must not be in the error state.
 .Pp
 The
 .Fn nvlist_free_null ,
 .Fn nvlist_free_bool ,
 .Fn nvlist_free_number ,
 .Fn nvlist_free_string ,
 .Fn nvlist_free_nvlist ,
 .Fn nvlist_free_descriptor ,
 .Fn nvlist_free_binary ,
 .Fn nvlist_free_bool_array ,
 .Fn nvlist_free_number_array ,
 .Fn nvlist_free_string_array ,
 .Fn nvlist_free_nvlist_array ,
 .Fn nvlist_free_descriptor_array
 functions remove the first element named
 .Fa name
 with the type determined by the function name from
 .Fa nvl
 free all resources associated with it.
 If no element named
 .Fa name
 with the appropriate type exists, the program aborts.
 The nvlist must not be in the error state.
-.Sh NOTES
+.Ss Notes
 The
 .Fn nvlist_pack
 and
 .Fn nvlist_unpack
 functions handle byte-order conversions, so binary buffers can be
 packed and unpacked on hosts with different endianness.
 .Pp
 The
 .Fn nvlist_recv ,
 .Fn nvlist_send ,
 and
 .Fn nvlist_xfer
 functions can transfer nvlists between hosts with different endianness.
+.Ss Kernel Considerations
+The
+.Nm nv ,
+.Nm cnv ,
+and
+.Nm dnv
+APIs can be used in the kernel with the following differences:
+.Bl -bullet
+.It
+File descriptor and file descriptor array value types are not supported.
+.It
+.Fn nvlist_recv ,
+.Fn nvlist_send ,
+and
+.Fn nvlist_xfer
+are not supported.
+.It
+All memory allocations use the
+.Dv M_NVLIST
+memory type with
+.Xr malloc 9
+and
+.Xr free 9 .
+As a result, any allocated buffers moved into an nvlist must be allocated with
+.Dv M_NVLIST ,
+and buffers returned by functions such as
+.Fn nvlist_pack
+must be freed with
+.Dv M_NVLIST .
+.El
 .Sh EXAMPLES
 The following example demonstrates how to prepare an nvlist and send it over a
 .Xr unix 4
 domain socket.
 .Bd -literal
 nvlist_t *nvl;
 int fd;
 
 fd = open("/tmp/foo", O_RDONLY);
 if (fd < 0)
         err(1, "open(\\"/tmp/foo\\") failed");
 
 nvl = nvlist_create(0);
 
 /*
  * There is no need to check if nvlist_create() succeeded
  * as the nvlist_add_<type>() functions can cope.
  * If it failed, nvlist_send() will fail.
  */
 nvlist_add_string(nvl, "filename", "/tmp/foo");
 nvlist_add_number(nvl, "flags", O_RDONLY);
 
 /*
  * We just want to send the descriptor, so we can give it
  * for the nvlist to consume (that is why we use nvlist_move
  * not nvlist_add).
  */
 nvlist_move_descriptor(nvl, "fd", fd);
 if (nvlist_send(sock, nvl) < 0) {
 	nvlist_destroy(nvl);
 	err(1, "nvlist_send() failed");
 }
 nvlist_destroy(nvl);
 .Ed
 .Pp
 Receiving an nvlist and retrieving element values:
 .Bd -literal
 nvlist_t *nvl;
 const char *command;
 char *filename;
 int fd;
 
 nvl = nvlist_recv(sock, 0);
 if (nvl == NULL)
 	err(1, "nvlist_recv() failed");
 
 /* For command we accept a pointer to the nvlist's internal buffer. */
 command = nvlist_get_string(nvl, "command");
 
 /*
  * For filename we remove it from the nvlist and take
  * ownership of the buffer.
  */
 filename = nvlist_take_string(nvl, "filename");
 
 /* The same for the file descriptor. */
 fd = nvlist_take_descriptor(nvl, "fd");
 
 printf("command=%s filename=%s fd=%d\n", command, filename, fd);
 
 /* command is freed by nvlist_destroy() */
 nvlist_destroy(nvl);
 free(filename);
 close(fd);
 .Ed
 .Pp
 Iterating over an nvlist:
 .Bd -literal
 nvlist_t *nvl;
 const char *name;
 void *cookie;
 int type;
 
 nvl = nvlist_recv(sock, 0);
 if (nvl == NULL)
 	err(1, "nvlist_recv() failed");
 
 cookie = NULL;
 while ((name = nvlist_next(nvl, &type, &cookie)) != NULL) {
 	printf("%s=", name);
 	switch (type) {
 	case NV_TYPE_NUMBER:
 		printf("%ju", (uintmax_t)nvlist_get_number(nvl, name));
 		break;
 	case NV_TYPE_STRING:
 		printf("%s", nvlist_get_string(nvl, name));
 		break;
 	default:
 		printf("N/A");
 		break;
 	}
 	printf("\\n");
 }
 .Ed
 .Pp
 Iterating over every nested nvlist:
 .Bd -literal
 nvlist_t *nvl;
 const char *name;
 void *cookie;
 int type;
 
 nvl = nvlist_recv(sock, 0);
 if (nvl == NULL)
 	err(1, "nvlist_recv() failed");
 
 cookie = NULL;
 do {
 	while ((name = nvlist_next(nvl, &type, &cookie)) != NULL) {
 		if (type == NV_TYPE_NVLIST) {
 			nvl = nvlist_get_nvlist(nvl, name);
 			cookie = NULL;
 		}
 	}
 } while ((nvl = nvlist_get_parent(nvl, &cookie)) != NULL);
 .Ed
 .Pp
 Iterating over every nested nvlist and every nvlist element:
 .Bd -literal
 nvlist_t *nvl;
 const nvlist_t * const *array;
 const char *name;
 void *cookie;
 int type;
 
 nvl = nvlist_recv(sock, 0);
 if (nvl == null)
 	err(1, "nvlist_recv() failed");
 
 cookie = NULL;
 do {
 	while ((name = nvlist_next(nvl, &type, &cookie)) != NULL) {
 		if (type == NV_TYPE_NVLIST) {
 			nvl = nvlist_get_nvlist(nvl, name);
 			cookie = NULL;
 		} else if (type == NV_TYPE_NVLIST_ARRAY) {
 			nvl = nvlist_get_nvlist_array(nvl, name, NULL)[0];
 			cookie = NULL;
 		}
 	}
 } while ((nvl = nvlist_get_pararr(nvl, &cookie)) != NULL);
 .Ed
 .Pp
 Or alternatively:
 .Bd -literal
 nvlist_t *nvl, *tmp;
 const nvlist_t * const *array;
 const char *name;
 void *cookie;
 int type;
 
 nvl = nvlist_recv(sock, 0);
 if (nvl == null)
 	err(1, "nvlist_recv() failed");
 
 cooke = NULL;
 tmp = nvl;
 do {
 	do {
 		nvl = tmp;
 		while ((name = nvlist_next(nvl, &type, &cookie)) != NULL) {
 			if (type == NV_TYPE_NVLIST) {
 				nvl = nvlist_get_nvlist(nvl, name);
 				cookie = NULL;
 			} else if (type == NV_TYPE_NVLIST_ARRAY) {
 				nvl = nvlist_get_nvlist_array(nvl, name,
 				    NULL)[0];
 				cookie = NULL;
 			}
 		}
 		cookie = NULL;
 	} while ((tmp = nvlist_get_array_next(nvl)) != NULL);
 } while ((tmp = nvlist_get_parent(nvl, &cookie)) != NULL);
 .Ed
 .Sh SEE ALSO
 .Xr close 2 ,
 .Xr dup 2 ,
 .Xr open 2 ,
 .Xr err 3 ,
 .Xr free 3 ,
 .Xr printf 3 ,
 .Xr unix 4
 .Sh HISTORY
 The
 .Nm libnv
 library appeared in
 .Fx 11.0 .
 .Sh AUTHORS
 .An -nosplit
 The
 .Nm libnv
 library was implemented by
 .An Pawel Jakub Dawidek Aq Mt pawel@dawidek.net
 under sponsorship from the FreeBSD Foundation.