Hypercall acceleration for nested virtual machines
Systems and methods for accelerating hypercalls for nested virtual machines. An example method comprises: 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; generating, by the Level 1 hypervisor, a second function component that performs a second functionality associated with the hypercall issued by the Level 2 VM; and responsive to detecting the hypercall issued by the Level 3 VM, causing the Level 0 hypervisor to execute at least one of: the first function component or the second function component.
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.
2 . The method of claim 1 , further comprising:
determining, by the Level 0 hypervisor, a completion status of the first function component; and
returning control to the Level 2 hypervisor in view of the completion status.
3 . The method of claim 1 , wherein directly performing the first modification of the context of the Level 2 VM comprises:
determining, by the Level 0 hypervisor, a completion status of the first function component; and
executing, by the Level 0 hypervisor, the second function component in view of the completion status, the second function component to modify the context of the Level 2 VM.
4 . The method of claim 3 , further comprising:
determining, by the Level 0 hypervisor, a second completion status of the second function component; and
returning control to the Level 2 hypervisor in view of the second completion status.
5 . The method of claim 1 , wherein the second functionality is implemented by a second set of instructions that translates the first modification of the context of the Level 2 VM into a second modification of a context of the Level 1 VM.
6 . The method of claim 1 , wherein the first function component is generated by the Level 2 hypervisor based on instructions received from the Level 3 VM.
7 . The method of claim 1 , wherein the second function component is generated by the Level 1 hypervisor based on instructions received from the Level 2 VM.
8 . A system comprising:
a memory; and
a processing device, operatively coupled to the memory, the processing device configured to:
execute a Level 0 hypervisor managing a Level 1 virtual machine (VM);
receive, 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;
generate, 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, cause 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.
9 . The system of claim 8 , wherein the processing device is further to:
determine, by the Level 0 hypervisor, a completion status of the first function component; and
return control to the Level 2 hypervisor in view of the completion status.
10 . The system of claim 8 , wherein to directly perform the first modification of the context of the Level 2 VM, the processing device is to:
determine, by the Level 0 hypervisor, a completion status of the first function component; and
execute, by the Level 0 hypervisor, the second function component in view of the completion status, the second function component to modify the context of the Level 2 VM.
11 . The system of claim 10 , wherein the processing device is further to:
determine, by the Level 0 hypervisor, a second completion status of the second function component; and
return control to the Level 2 hypervisor in view of the second completion status.
12 . The system of claim 8 , wherein the second functionality is implemented by a second set of instructions that translates the first modification of the context of the Level 2 VM into a second modification of a context of the Level 1 VM.
13 . A non-transitory computer readable storage medium comprising executable instructions, which when executed by a processing device, cause the processing device to:
execute a Level 0 hypervisor managing a Level 1 virtual machine (VM);
receive, 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;
generate, 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, cause 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.
14 . The non-transitory computer readable storage medium of claim 13 , further comprising executable instructions, which when executed by the processing device, cause the processing device to:
determine, by the Level 0 hypervisor, a completion status of the first function component; and
return control to the Level 2 hypervisor in view of the completion status.
15 . The non-transitory computer readable storage medium of claim 13 , wherein, to directly perform the first modification of the context of the Level 2 VM, the processing device is to:
determine, by the Level 0 hypervisor, a completion status of the first function component; and
execute, by the Level 0 hypervisor, the second function component in view of the completion status, the second function component to modify the context of the Level 2 VM.
16 . The non-transitory computer readable storage medium of claim 13 , wherein the first function component is generated by the Level 2 hypervisor based on instructions received from the Level 3 VM.
17 . The non-transitory computer readable storage medium of claim 13 , wherein the second function component is generated by the Level 1 hypervisor based on instructions received from the Level 2 VM.