US 12,461,771 B2
Hypercall acceleration for nested virtual machines
Michael Tsirkin, Yokneam Illit (IL); and Karen Noel, Pembroke, NH (US)
Assigned to Red Hat, Inc., Raleigh, NC (US)
Filed by RED HAT, INC., Raleigh, NC (US)
Filed on Jun. 8, 2023, as Appl. No. 18/331,514.
Application 18/331,514 is a continuation of application No. 16/866,510, filed on May 4, 2020, granted, now 11,698,806.
Prior Publication US 2023/0315508 A1, Oct. 5, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 9/455 (2018.01)
CPC G06F 9/45558 (2013.01) [G06F 2009/45583 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method comprising:
executing, by a host computer system, a Level 0 hypervisor managing a Level 1 virtual machine (VM);
receiving, by a Level 1 hypervisor managing a Level 2 VM, a first function component from a Level 2 hypervisor managing a Level 3 VM, wherein the first function component performs a first functionality associated with a hypercall issued by the Level 3 VM, wherein the first function component performs a first modification of a context of the Level 2 VM;
generating, by the Level 1 hypervisor, a second function component that performs a second functionality associated with the hypercall issued by the Level 3 VM; and
responsive to detecting the hypercall issued by the Level 3 VM, causing the Level 0 hypervisor to
directly perform, without transferring control away from the Level 0 hypervisor and using the first function component and the second function component, the first modification of the context of the Level 2 VM.