Microsoft Corporation
Hypervisor hot restart

Abstract:

Hot restart of a hypervisor by replacing a running first hypervisor by a second hypervisor with minimally perceptible downtime to guest partitions. A first hypervisor is executed on a computing system. The first hypervisor is configured to create one or more guest partitions. During the hot restart, a service partition is generated and initialized with a second hypervisor. At least a portion of runtime state of the first hypervisor is migrated and synchronized to the second hypervisor using inverse hypercalls. After the synchronization, the second hypervisor is devirtualized from the service partition to replace the first hypervisor. Devirtualizing includes transferring control of hardware resources from the first hypervisor to the second hypervisor, using the previously migrated and synchronized runtime state.