Method for speeding up page table address update on virtual machine

A computer comprising:

• a processing unit;
• a memory coupled to the processing unit;
• and
• a virtual machine control program for running a plurality of operating systems, each of which maintains at least one first address translation table stored in a first region of the memory that is allocated to a respective operating system to manage at least one virtual memory space, and causing the computer to perform functions including:
• creating, in a second region of the memory that is dedicatedly used by the virtual machine control program, a second address translation table defining address conversion information indicating correspondence between one of said at least one virtual memory space and a physical memory space of the memory on the basis of said first address translation table which manages the one of said at least one virtual memory space;
• maintaining a correspondence table having information for managing a plurality of pairs of the first and the second address translation tables;
• detecting an operation, by one of the operating systems, to switch address translation tables set in the processing unit from one of said first address translation tables to another of said first translation tables, and for searching through the correspondence table to obtain a second address translation table corresponding to the another first address translation table;
• and
• setting the second address translation table corresponding to the another first address translation table to said processing unit so that the processing unit performs address translation in accordance with the second address translation table corresponding to the another first address translation table.

A virtual machine control method for running a plurality of operating systems on a computer having a processing unit and a memory coupled to the processing unit, wherein each one of the operating systems maintains at least one first address translation table, which is stored in a first region of the memory that is allocated to respective operating systems, to manage at least one virtual memory space, the virtual machine control method comprising:

• a step of creating, in a second region of the memory that is dedicatedly used for the virtual machine control method, a second address translation table defining information indicating correspondence between one of said at least one virtual memory space and a physical memory space of the memory on the basis of a first address translation table related to the one of said at least one virtual memory space;
• a step of registering information on a pair of the first address translation tables related to the one of said at least one virtual memory space and the created second address translation table with a correspondence table which holds information indicating correspondences between the first and second address translation tables;
• a step of detecting an operation, one of the operating systems, to switch address translation tables set in the processing unit from one of said first address translation tables to another of said first translation tables, and for searching through the correspondence table to obtain a second address translation table corresponding to the another first address translation table;
• and
• a step of searching through the correspondence table in response to a detection of the operation to switch the address translation tables set in the processing unit to obtain a second address translation table corresponding to the another first address translation table;
• and
• a step of setting the second address translation table corresponding to the another first address translation table to said processing unit so that the processing unit performs address translation in accordance with the second address translation table corresponding to the another first address translation table.