Skip to Main Content
This paper presents methods for increasing the efficiency of operating systems in plural virtual machines to a near-native performance level. The proposed direct execution methods support direct I/O execution for plural virtual machines, that is, the V = R virtual machine, and the V = Resi virtual machines, including both I/O instruction issuances and I/O interrupts. All V = Resi virtual machines have an entirely resident memory and their real addresses are translated into those of the host simply by adding a constant, Â¿(Â¿ 0), which constitutes a starting address given to each V = Resi virtual machine. The V = R virtual machine has almost the same memory attribute as the V = Resi VM except for Â¿ = 0. Only one V = R virtual machine can be present in all virtual machines. The experimental results obtained confirm that a near-native performance level, that is, a level exceeding 90 percent of native performance, can be realized for the V = R virtual machine as well as for the V = Resi virtual machines.
Date of Publication: Sept. 1987