Patent ID: 7814495
Filing Date: 2010-10-12
Classification: G06F

Abstract:
1. In a virtualized computer system running one or more virtual machines on a first hypervisor virtualizing hardware resources of a physical computer, the hardware resources including a single-path input/output (I/O) device with a single I/O path, a computer implemented method of installing a second hypervisor on the physical computer and migrating control of the hardware resources from the first hypervisor to the second hypervisor, the method comprising: removing a predetermined set of the hardware resources of the physical computer from usage by the first hypervisor; launching the second hypervisor to utilize the predetermined set of the hardware resources; and migrating remaining hardware resources of the physical computer and the virtual machines from being controlled by the first hypervisor to being controlled by the second hypervisor with the first hypervisor running simultaneously with the second hypervisor during the migration, the second hypervisor sharing access to the single path I/O device with the first hypervisor in different time slots, the first hypervisor and the second hypervisor using a mutex to coordinate the shared access to the single-path I/O device.