Patent ID: 8416253

Claim:
An apparatus for detecting an update of image information, comprising: an image storage unit configured to store image information; a processor configured to transition, when a previously set transition condition is satisfied, from a first mode that causes a guest operating system to operate to a second mode that causes a virtual machine monitor managing the guest operating system to operate; a determining unit configured to determine, when the processor transitions to the second mode, a cause of the transition; a detecting unit configured to detect, when the determining unit determines that the cause of the transition is an execution of a process related to a completion of writing the image information in the image storage unit on the guest operating system, an updated portion representing an unmatched portion of the image information between before and after writing; and an emulating unit configured to emulate a multi-buffering function to switch between a first storage unit for writing the image information and a second storage unit for displaying the image information, wherein the detecting unit is configured to detect the updated portion when the determining unit determines that the cause of the transition is an access to a register by a function requesting to switch to the second storage unit upon the completion of writing the image information.