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Structural design of Microsoft's hypervisor implementation

Core Idea: Hyper-V implements virtualization through a partition-based architecture with a parent partition that hosts the management OS and child partitions that host guest operating systems.

Key Elements

Partition Structure

• Partition: A logical unit of isolation supported by the hypervisor
• Parent Partition: Must have at least one parent running a supported Windows version
  • Contains the Virtualization Service Provider (VSP)
  • Runs the Virtual Machine Management Service
  • Creates and manages child partitions via the hypercall API
  • Has direct access to physical hardware resources
• Child Partitions: Host guest operating systems
  • Do not have direct access to physical processor
  • Run in Guest Virtual Address space
  • Use virtual view of resources through virtual devices
  • Cannot handle real hardware interrupts directly

Communication Layer

• VMBus: Logical channel that enables inter-partition communication
  • Redirects requests from child partitions to devices in parent partition
  • Provides high-speed communication pathway
• Synthetic Interrupt Controller (SynIC): Handles interrupts to the processor
  • Redirects them to respective partitions

Memory Management

• Guest Virtual Address spaces can be hardware-accelerated using:
  • Extended Page Table (EPT) on Intel processors
  • Rapid Virtualization Indexing (RVI, formerly NPT) on AMD processors

I/O Operations

• Virtualization Service Provider (VSP): Runs in parent partition
  • Connects to VMBus
  • Handles device access requests from child partitions
• Virtualization Service Client (VSC): Runs in child partition
  • Redirects requests to VSPs via VMBus
• Enlightened I/O: Specialized virtualization-aware implementation of communication protocols
  • Bypasses device emulation layers
  • Takes advantage of VMBus directly
  • Improves performance for supported guest operating systems

Additional Connections

• Broader Context: Hypervisor Types (Hyper-V is a Type 1 or native hypervisor)
• Applications: Server Virtualization (implementation considerations)
• See Also: Paravirtualization (relates to Enlightened I/O concept)

References

1. Microsoft Hyper-V Architecture Documentation
2. "Hypervisor Top Level Functional Specification" - Microsoft

#hypervisor #virtualization #microsoft #system-architecture

Connections:

Sources:

• From: Hyper-V - Wikipedia