Creating a communication channel between different privilege levels using wait-for-event instruction in systems operable at multiple levels hierarchical privilege levels
US9535772B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2014 |
| Grant date | Jan 3, 2017 |
| Priority date | — |
| Expiry date | Jan 20, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2009/45591
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a computer system operable at multiple hierarchical privilege levels, a “wait-for-event” (WFE) communication channel between components operating at different privilege levels is established. Initially, a central processing unit (CPU) is configured to to “trap” WFE instructions issued by a client, such as an operating system, operating at one privilege level to an agent, such as a hypervisor, operating at a more privileged level. After storing a predefined special sequence in a storage component (e.g., a register), the client executes a WFE instruction. As part of trapping the WFE instruction, the agent reads and interprets the special sequence from the storage component and may respond to the special sequence by storing another special sequence in a storage component that is accessible to the client. Advantageously, the client may leverage this WFE communication channel to establish low-overhead watchdog functionality for the client.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.