Specifications

Chapter 7. Virtualization 279
POWER Hypervisor technology is integrated with all IBM POWER servers,
including the Power Systems compute nodes. The hypervisor orchestrates and
manages system virtualization, including creating logical partitions and
dynamically moving resources across multiple operating environments. POWER
Hypervisor is a basic component of the system firmware that is layered between
the hardware and the operating system.
The POWER Hypervisor has the following features:
򐂰 Provides an abstraction layer between the physical hardware resources and
the logical partitions that use them
򐂰 Enforces partition integrity by providing a security layer between
logical partitions
򐂰 Controls the dispatch of virtual processors to physical processors and saves
and restores all processor state information during a logical processor
context switch
򐂰 Controls hardware I/O interrupt management facilities for logical partitions
򐂰 Provides virtual Ethernet switches between logical partitions that help to
reduce the need for physical Ethernet adapters for
interpartition communication
򐂰 Monitors the service processor and performs a reset or reload if it detects the
loss of the service processor, notifying the operating system if the problem is
not corrected
򐂰 Uses Micro-Partitioning to allow multiple instances of the operating system
The POWER Hypervisor is always installed and activated, regardless of system
configuration. It does not own any physical I/O devices; all physical I/O devices in
the system are owned by logical partitions or by the Virtual I/O Server.
Memory is required to support the resource assignment to the logical partitions
on the server. The amount of memory required by the POWER Hypervisor
firmware varies according to several factors. The following factors influence
POWER Hypervisor memory requirements:
򐂰 Number of logical partitions
򐂰 Number of physical and virtual I/O devices used by the logical partitions
򐂰 Maximum memory values specified in the logical partition profiles