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_storvsc 32.Nd Hyper-V Storage Virtual Service Consumer 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 implements the virtual store device for 43.Fx 44guest 45partitions running on Hyper-V. 46.Fx 47guest partitions running on Hyper-V do not have direct access to 48storage devices attached to the Hyper-V server. 49Although a 50.Fx 51guest can access storage devices using Hyper-V's 52full emulation mode, the performance in this mode tends to be unsatisfactory. 53.Pp 54To counter the above issues, the 55.Nm 56driver implements a storage 57Virtual 58Service Consumer (VSC) that relays storage requests from the guest partition 59to the storage Virtual Service Provider (VSP) hosted in the root partition 60using the high performance data exchange infrastructure provided by 61.Xr hv_vmbus 4 62driver. 63The VSP in the root partition then forwards the storage related requests to 64the physical storage device. 65.Pp 66This driver functions by presenting a SCSI HBA interface to the Comman Access 67Method (CAM) layer. 68CAM control blocks (CCBs) are 69converted into VSCSI protocol messages which are delivered to the root 70partition VSP over the Hyper-V VMBus. 71.Sh SEE ALSO 72.Xr hv_ata_pci_disengage 4 , 73.Xr hv_netvsc 4 , 74.Xr hv_utils 4 , 75.Xr hv_vmbus 4 76.Sh HISTORY 77Support for 78.Nm 79first appeared in 80.Fx 10.0 . 81The driver was developed through a joint effort between Citrix Incorporated, 82Microsoft Corporation, and Network Appliance Incorporated. 83.Sh AUTHORS 84.An -nosplit 85.Fx 86support for 87.Nm 88was first added by 89.An Microsoft BSD Integration Services Team Aq Mt bsdic@microsoft.com . 90