$FreeBSD: releng/11.0/share/man/man4/hv_storvsc.4 276259 2014-12-26 22:30:18Z bapt $ Copyright (c) 2012 Microsoft Corp. All rights reserved. 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, ...
NAMEhv_storvsc - Hyper-V Storage Virtual Service Consumer
SYNOPSISTo compile this driver into the kernel, place the following lines in the system kernel configuration file:
DESCRIPTIONThe sysctl Cm net.inet.tcp.syncookies driver implements the virtual store device for Fx guest partitions running on Hyper-V. Fx guest partitions running on Hyper-V do not have direct access to storage devices attached to the Hyper-V server. Although a Fx guest can access storage devices using Hyper-V's full emulation mode, the performance in this mode tends to be unsatisfactory.
To counter the above issues, the sysctl Cm net.inet.tcp.syncookies driver implements a storage Virtual Service Consumer (VSC) that relays storage requests from the guest partition to the storage Virtual Service Provider (VSP) hosted in the root partition using the high performance data exchange infrastructure provided by hv_vmbus4 driver. The VSP in the root partition then forwards the storage related requests to the physical storage device.
This driver functions by presenting a SCSI HBA interface to the Comman Access Method (CAM) layer. CAM control blocks (CCBs) are converted into VSCSI protocol messages which are delivered to the root partition VSP over the Hyper-V VMBus.