Virtual Adapter Migration on PCI Switched-Fabric Bus

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Solution Overview

Problem

Existing PCI bus systems do not allow sharing of physical I/O adapters among multiple computer systems, and they do not support the virtualization or migration of virtual I/O adapters from source to destination physical adapters.

Innovation Solution

A method and apparatus for migrating virtual adapters by stopping their processing, capturing in-flight transactions, transferring configuration information, and restoring these transactions on a destination physical adapter, allowing virtual adapters to be moved and reconfigured as needed across multiple host computer systems sharing a PCI switched-fabric bus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If physical I/O adapters are dedicated to single host computer systems, then system stability and simplicity are improved, but adapter utilization efficiency and system flexibility deteriorate

Engineering Contradiction:

Improvesystem stabilityVSAvoidadapter utilization efficiency

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent segments a physical I/O adapter into multiple virtual adapters, where each virtual adapter can be assigned to different host computer systems. This segmentation allows the physical adapter to serve multiple hosts simultaneously through virtualization, resolving the contradiction between system stability (maintained through proper virtual adapter management) and adapter utilization efficiency (improved through shared access by multiple hosts).

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements multi-functionality by enabling a single physical I/O adapter to perform multiple functions by serving multiple host computer systems through different virtual adapters. This universal approach allows the adapter to be dynamically allocated to different hosts based on workload requirements, improving utilization efficiency while maintaining system stability through controlled access mechanisms.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If virtual adapters are migrated from source to destination physical adapters, then system flexibility and adaptability are improved, but system complexity and migration overhead worsen

Engineering Contradiction:

Improvesystem flexibilityVSAvoidmigration complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses copying mechanisms to replicate virtual adapter configuration information and state from source to destination physical adapters during migration. This copying approach simplifies the migration process by maintaining configuration integrity through direct replication, reducing migration complexity while enabling flexible adapter movement across different physical platforms.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent introduces an intermediary migration management system that coordinates the transfer of virtual adapters between source and destination physical adapters. This intermediary layer handles the complexity of migration by managing configuration transfer, state preservation, and activation sequencing, thereby reducing overall system complexity while enabling flexible adapter migration.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If in-flight transactions are captured and restored during virtual adapter migration, then data integrity and reliability are improved, but migration time and processing overhead worsen

Engineering Contradiction:

Improvedata integrityVSAvoidmigration time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by capturing in-flight transactions before the virtual adapter migration is completed and restoring them afterward. This approach ensures data integrity by preserving transactions that were in progress during migration, while minimizing migration time by performing the capture and restore operations as bounded preliminary and concluding actions rather than continuous interruptions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements beforehand cushioning by creating a protective mechanism that captures in-flight transactions before migration disrupts normal processing. This cushioning approach buffers against potential data loss by preserving transaction states, ensuring reliability while allowing the migration to proceed with minimal time penalty.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS7937518B2Method, apparatus, and computer usable program code for migrating virtual adapters from source physical adapters to destination physical adapters

Publication Date: 2011.05.03 LENOVO GLOBAL TECHNOLOGIES SWITZERLAND INTERNATIONAL GMBH

AI summary

A computer-implemented method, apparatus, and computer usable program code are disclosed for migrating a virtual adapter from a source physical adapter to a destination physical adapter in a data processing system where multiple host computer systems share multiple adapters and communicate with those adapters through a PCI switched-fabric bus. The virtual adapter is first caused to stop processing transactions. All in-flight transactions that are associated with the virtual adapter are then captured. The configuration information that defines the virtual adapter is moved from the source physical adapter to the destination physical adapter. The in-flight transactions are then restored to their original locations on the destination virtual adapter. The virtual adapter is then restarted on the destination physical adapter such that the virtual adapter begins processing transactions.