Method of Reducing VM-exit Rate Generated by Handling Access to Virtualized Hardware

Each appeal to virtualized hardware, such as hard drive or net driver leads to VM-exit event. VM-exit is an event of switching between different contexts(or different processor states), and takes up a significant amount of time. There are plenty of methods for reducing the amount of VM-exit events or reducing the time needed for handling such events. But some of these methods require guest OS kernel modifications or do not optimise all of the possible VM-exit events. Designed method allows reduction of VM-exit events without any of the disadvantages mentioned above. This method includes 3 main stages: collecting statistics, analysing potentially reduced time and preventing unnecessary VM-entries. As a result of a conducted research it was found out that this method allows to reduce time consumption by VM-exits even on the scenarios when system doesn’t try to access hardware too often.