You can find this here on the HP site. The EVA download for VDS and VSS is here.
HP StorageWorks Arrays support Microsoft Virtual Disk Services (VDS) and Volume Shadow Copy Services (VSS) for Windows Server 2003Services (VSS) for Windows Server 2003 / 2008 / 2008 R2 Enterprise and Data Center Editions.
VDS hardware providers enable volume and logical unit management of HP StorageWorks arrays from a central Windows Server Microsoft Management Console. Administrators can discover, configure and monitor supported HP storage devices from Windows Server operating environments.
VSS hardware providers enable point-in-time copies with nearly instant recovery of a single volume or multiple volumes. VSS providers are typically used in combination with a requestor application such as backup and recovery. Microsoft VSS services enable business applications to interface seamlessly with HP StorageWorks Arrays to perform point-in-time copies with nearly instant recovery.