Direct Interrupt Routing in Virtualized Real-Time Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Real-time operating systems face challenges in virtualized environments due to high interrupt latency, which restricts the widespread adoption of virtualization for applications sensitive to timing, such as industrial control and network applications.
Innovation Solution
A novel architecture that allows guest operating systems to directly handle interrupts, eliminating the need for hypervisor intervention, thereby reducing interrupt latency and enabling real-time applications to run with low latency in virtualized environments by using a tick-less hypervisor and real-time interrupt module that routes interrupts directly to the guest OS, preventing VM exits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a hypervisor manages interrupts for guest operating systems in a virtualized environment, then multiple operating systems can run safely and reliably on a single platform, but interrupt latency increases significantly
Solution Approach 1:
The patent extracts the interrupt handling function from the hypervisor and directly assigns it to the guest operating system. When an interrupt occurs, the guest OS handles it directly without triggering a VM exit to the hypervisor, thereby eliminating the hypervisor's intervention overhead and reducing interrupt latency while maintaining virtualization benefits
Solution Approach 2:
The patent introduces a virtual interrupt controller as an intermediary between the physical interrupt controller and the guest OS. This virtual controller translates physical interrupt signals into virtual interrupt signals that the guest OS can handle directly, enabling the guest OS to manage interrupts autonomously without hypervisor involvement while preserving the virtualized environment
2Reliability
If interrupt handling involves VM exit and VM entry transitions, then the hypervisor can manage interrupts for guest OS, but the interrupt latency becomes many times longer than in non-virtualized environments
Solution Approach 1:
The patent removes the VM exit/entry transition from the interrupt handling path by enabling the guest OS to handle interrupts directly. The virtual interrupt controller allows the guest OS to receive and process interrupts without triggering hypervisor transitions, eliminating the time overhead associated with mode switching while maintaining hypervisor-managed virtualization
Solution Approach 2:
The patent enables the guest operating system to service its own interrupts autonomously through direct interrupt handling. The guest OS manages its own interrupt vectors and processing without requiring hypervisor assistance, allowing self-service interrupt management that eliminates the performance penalty of hypervisor-mediated interrupt handling
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method may comprise identifying a signal indicating real-time mode operation for a guest operating system (OS) and directly routing an interrupt for a first processor to the guest OS while the guest OS is running without causing a transition from execution by the guest OS to execution by a host system. Other embodiments are disclosed and claimed.