Virtual Machine AP Startup via Protected Mode Execution

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Solution Overview

Problem

The complexity of virtual machine (VM) startup is increased due to the requirement for real mode execution during the startup of virtual Application Processors (APs), which complicates the role of the virtual machine monitor (VMM) and slows down the startup process, especially in systems with multiple APs.

Innovation Solution

An apparatus and method where a Bootstrap Processor (BSP) startup module writes the start state of an AP into a storage area, allowing the AP to start directly in protected mode without going through real mode execution, reducing the complexity for the VMM and speeding up the startup process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the virtual BSP sends an INIT-SIPI-SIPI IPI sequence to start virtual APs in real mode, then the APs can be sequentially booted in a specified order, but the VMM complexity increases due to the requirement to support real mode execution

Engineering Contradiction:

ImproveAP startup processVSAvoidVMM complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the real mode execution requirement from the AP startup process. Instead of requiring the VMM to support real mode execution, the system directly starts APs in protected mode by modifying the startup sequence, thereby removing the source of VMM complexity while preserving the sequential boot capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the execution mode parameter from real mode to protected mode during AP startup. By modifying the initial execution state of APs to start directly in protected mode rather than real mode, the system eliminates the need for VMM real mode support while maintaining controlled sequential startup through modified IPI sequences

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If the virtual BSP sequentially boots all virtual APs in real mode, then the startup order is controlled, but the startup process slows down due to the real mode execution requirement

Engineering Contradiction:

ImproveControlled startup sequenceVSAvoidStartup speed

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent changes the execution mode parameter from real mode to protected mode, which eliminates the mode switching overhead and accelerates the startup process. The controlled sequence is maintained through modified IPI signaling while the actual execution starts faster in protected mode directly

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent skips the real mode execution phase entirely during AP startup. By rushing through the traditional real mode boot sequence and directly initializing APs in protected mode, the system eliminates the time-consuming real mode phase while preserving the ability to control startup order through modified initialization protocols

Inventive Principle:

Principle #21Skipping (Rushing through)

Data Source

PatentUS9898307B2Starting application processors of a virtual machine

Publication Date: 2018.02.20 INTEL CORP

AI summary

Apparatuses, methods and storage medium associated with virtual machine application processor startup, are disclosed herein. In embodiments, an apparatus for computing may include a plurality of processor cores; and a plurality of OS modules of an OS. The OS modules may include a BSP module and an AP module. The BSP module may be configured to write into a storage area a start state of an AP of a VM, while the VM is being started up; and the AP module may be configured to start the AP at the start state, directly in a protected mode of execution without first going through a real mode of execution. Other embodiments may be described and/or claimed.