Patent ID: 9195492
Filing Date: 2015-11-24
Classification: G06F

Abstract:
1. A method for secure system time reporting by a hypervisor in a computing device, comprising: trapping, by the hypervisor, a current system time request from a guest operating system, the current system time request comprising a request for system time at a system clock at the computing device; reading, by the hypervisor, a current system time; comparing, by the hypervisor, the current system time to a previously requested system time, wherein the previously requested system time was previously provided by the hypervisor in response to a previous system time request from the guest operating system or another operating system other than the guest operating system, the previous system time request comprising a request for system time at the system clock at the computing device; when a difference between the current system time and the previously requested system time is at or below a predetermined minimum value and the previously requested system time was requested by the guest operating system, providing, by the hypervisor to the guest operating system, the previously requested system time in response to the current system time request; and when the difference between the current system time and the previously requested system time is above the predetermined minimum value or the previously requested system time was requested by another operating system other than the guest operating system, providing, by the hypervisor to the guest operating system, the current system time in response to the current system time request.