Patent ID: 11900142
Assignee: RED HAT, INC.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A method comprising:
running, by a host computer system, a Level 0 hypervisor managing a Level 1 virtual machine running a Level 1 hypervisor, wherein the Level 1 hypervisor manages a Level 2 virtual machine, wherein the Level 2 virtual machine is associated with a Peripheral Component Interconnect (PCI) device;
assigning an input/output (I/O) virtual address space to be used by the PCI device;
receiving, from the Level 1 hypervisor, a guest page table maintained by the Level 1 hypervisor;
generating, by the Level 0 hypervisor, a Level 1 page table by combining records from the guest page table with records from a host page table maintained by the Level 0 hypervisor;
causing a central processing unit (CPU) of the host computer system to use the Level 1 page table for first level address translations;
generating a Level 2 page table comprising a plurality of Level 2 page table entries, wherein each Level 2 page table entry of the plurality of Level 2 page table entries maps a I/O guest virtual address of the I/O virtual address space to a corresponding Level 2 guest physical address; and
causing a device driver of the Level 2 virtual machine to use the Level 2 page table for second level address translation.