US Patent 10437622 Nested hypervisors with peripheral component interconnect pass-through

Operating a hypervisor includes running a hypervisor as a thread of an underlying operating system and loading a guest operating system using the hypervisor based on the thread of the underlying operating system, where the hypervisor runs independently of the guest operating system and independently of other hypervisors running as other threads of the underlying operating system. The hypervisor may be a first hypervisor and operating a hypervisor may further include running a second hypervisor nested with the first hypervisor, where the guest operating system may be loaded using both the first hypervisor and the second hypervisor. The underlying operating system may be an operating system of a storage system.