1.\" $FreeBSD$ 2.\" 3.\" Copyright (c) 2012 Microsoft Corp. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.Dd September 10, 2013 28.Dt HYPER-V 4 29.Os 30.Sh NAME 31.Nm hv_kvp 32.Nd Hyper-V Key Value Pair Driver 33.Sh SYNOPSIS 34To compile this driver into the kernel, place the following lines in 35the system kernel configuration file: 36.Bd -ragged -offset indent 37.Cd "device hyperv" 38.Ed 39.Sh DESCRIPTION 40The 41.Nm 42driver provides the ability to store, retrieve, modify and delete 43key value pairs for 44.Fx 45guest partitions running on Hyper-V. 46Hyper-V allows administrators to store custom metadata in the form 47of key value pairs inside the 48.Fx 49guest partition. 50Administrators can use Windows Powershell scripts to add, read, 51modify and delete such key value pairs. 52.Pp 53The driver is bare bones and merely forwards requests to its counterpart 54user mode daemon, 55.Xr hv_kvp_daemon 8 . 56The daemon maintains pools of key value 57pairs and does the actual metadata management. 58.Pp 59The same driver and daemon combination are also used to set and get 60IP addresses from a 61.Fx 62guest. 63.Pp 64The set functionality is particularly 65useful when the 66.Fx 67guest is assigned a static IP address and is failed over from one 68Hyper-V host to another. 69After failover, Hyper-V uses the set IP functionality to automatically 70update the 71.Fx 72guest's IP address to its original static value. 73.Pp 74On the other hand, the get IP functionality is used to update the guest IP 75address in the Hyper-V management console window. 76.Sh SEE ALSO 77.Xr hv_ata_pci_disengage 4 , 78.Xr hv_netvsc 4 , 79.Xr hv_storvsc 4 , 80.Xr hv_utils 4 , 81.Xr hv_vmbus 4 , 82.Xr hv_kvp_daemon 8 83.Sh HISTORY 84Support for 85.Nm 86first appeared in 87.Fx 10.0 . 88The driver was developed through a joint effort between Citrix 89Incorporated, Microsoft Corporation and Network Appliance Incorporated. 90.Sh AUTHORS 91.An -nosplit 92.Fx 93support for 94.Nm 95was first added by 96.An Microsoft BSD Integration Services Team Aq Mt bsdic@microsoft.com . 97