.\"	$OpenBSD: hyperv.4,v 1.5 2017/09/18 19:45:52 mikeb Exp $
.\"
.\" Copyright (c) 2016 Mike Belopuhov
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: September 18 2017 $
.Dt HYPERV 4
.Os
.Sh NAME
.Nm hyperv
.Nd Hyper-V guest nexus device
.Sh SYNOPSIS
.Cd "hyperv0 at pvbus?"
.Sh DESCRIPTION
.Nm
driver performs Synthetic Interrupt Controller initialization,
sets up hypercalls,
and provides access to VMBus services required by paravirtualized
devices such as disk and network interfaces.
.Pp
An access is also provided to the Key-Value Pair exchange interface
via
.Xr pvbus 4 .
All keys are associated to one of several key pools:
.Em Auto ,
.Em Guest ,
.Em External
or
.Em Guest/Parameters .
It's possible to modify values of keys in the
.Em Auto
pool as well as
set new keys in the
.Em Guest
pool with
.Xr hostctl 8 .
The Host provides its read-only keys in
.Em External
and
.Em Guest/Parameters
pools.
.Sh SEE ALSO
.Xr autoconf 4 ,
.Xr intro 4 ,
.Xr pvbus 4 ,
.Xr hostctl 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 6.1 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Mike Belopuhov Aq Mt mikeb@openbsd.org
based on the
.Fx
driver by the Microsoft BSD Integration Services Team
.Aq Mt bsdic@microsoft.com .
.Sh CAVEATS
Generation 2 Virtual Machines are currently not supported.