Precise branch counting in virtualization systems
US9027003B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2008 |
| Grant date | May 5, 2015 |
| Priority date | — |
| Expiry date | Nov 14, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2201/88
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for precisely counting guest branch instructions in a virtualized computer system is described. In one embodiment, guest instructions execute in a direct execution mode of the virtualized computer system. The direct execution mode operates at a first privilege level having a lower privilege than a second privilege level. A branch count of previously executed first privilege level branch instructions is maintained as instructions execute. Execution of a first privilege level branch instruction caused by a control transfer to the direct execution mode is detected. Responsive to the detection, a guest branch instruction count is determined based on the first privilege level branch count.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.