IP Library Granted Patent US 11,630,782
Granted Patent B2
US 11,630,782 · App. 17/475,229 · Granted Apr 18, 2023

Hardware offloading for an emulated IOMMU device

Inventors: Gal Hammer (Ra'anana, IL); Marcel Apfelbaum (Ra'anana, IL)
Assignee: Red Hat, Inc.
G06F12/1036G06F9/45558G06F12/0646G06F12/1009G06F12/1072G06F2009/45583
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Quick Facts
Patent No.
US 11,630,782
App. No.
17/475,229
Granted
Apr 18, 2023
Kind
B2
Abstract

Disclosed is a method of managing memory of a virtual machine (VM), including receiving, at a physical input-output memory management unit (IOMMU) of a processing device operating the VM, a request from a VM IOMMU for VM memory address translation for a VM peripheral component interconnect (PCI) device created on the VM; determining, by the physical IOMMU, a corresponding VM memory address translation result based on the request as received and a memory translation table; and transmitting, by the physical IOMMU to the VM IOMMU, the corresponding VM memory address translation result for servicing the request for VM memory address translation of the VM PCI device.

Claims (35)

1. A method of managing memory of a virtual machine (VM), the method comprising:

receiving, at a physical input-output memory management unit (IOMMU) of a processing device executing the VM, a request from a VM IOMMU for VM memory address translation for a VM peripheral component interconnect (PCI) device;

determining, by the physical IOMMU, a corresponding VM memory address translation result based on the request as received and a memory translation table; and

transmitting, by the physical IOMMU to the VM IOMMU, the corresponding VM memory address translation result for servicing the request for VM memory address translation of the VM PCI device.

2. The method of claim 1 , wherein the method further comprises generating, by the physical IOMMU, the memory translation table based on instructions from the VM IOMMU.

3. The method of claim 2 , wherein the memory translation table comprises translations from VM virtual memory addresses to corresponding VM physical memory addresses.

4. The method of claim 2 , wherein generating the memory translation table comprises configuring, by the VM IOMMU, the physical IOMMU to generate a discrete memory translation table for each VM PCI device created on the VM.

5. The method of claim 1 , wherein the request is generated by the VM PCI device and intercepted by the VM IOMMU for transmission to the physical IOMMU, and

wherein the request is a VM memory access request comprising a VM virtual memory address associated with the VM PCI device to be translated into a corresponding VM physical memory address.

6. The method of claim 5 , wherein the corresponding VM memory address translation result comprises the corresponding VM physical memory address.

7. The method of claim 1 , wherein at least one of the VM PCI devices comprises a network interface controller (NIC), a graphics card (GPU), or a storage controller generated by the VM.

8. A memory management system comprising:

a memory;

a processing device operatively coupled to the memory, the processing device to execute a virtual machine (VM), the VM including VM memory; and

a physical input-output memory management unit (IOMMU) operatively coupled to the processing device, the physical IOMMU to:

receive a request from a VM IOMMU for VM memory address translation for a VM peripheral component interconnect (PCI) device created on the VM;

determine a corresponding VM memory address translation result based on the request as received and a memory translation table; and

transmit the corresponding VM memory address translation result for servicing the request for VM memory address translation of the VM PCI device to the VM IOMMU.

9. The memory management system of claim 8 , the physical IOMMU further to generate the memory translation table based on instructions from the VM IOMMU.

10. The memory management system of claim 9 , wherein the memory translation table comprises translations from VM virtual memory addresses to corresponding VM physical memory addresses.

11. The memory management system of claim 9 , the VM IOMMU to configure the physical IOMMU to generate a discrete memory translation table for each VM PCI device created on the VM.

12. The memory management system of claim 8 , wherein the request is generated by the VM PCI device and intercepted by the VM IOMMU for transmission to the physical IOMMU, and

wherein the request is a VM memory access request comprising a VM virtual memory address associated with the VM PCI device to be translated into a corresponding VM physical memory address.

13. The memory management system of claim 12 , wherein the corresponding VM memory address translation result comprises the corresponding VM physical memory address.

14. The memory management system of claim 8 , wherein at least one of the VM PCI devices comprises a network interface controller (NIC), a graphics card (GPU), or a storage controller generated by the VM.

15. A non-transitory computer-readable storage medium including instructions that, when executed by a processing device operating a virtual machine (VM), cause the processing device to:

receive, at a physical input-output memory management unit (IOMMU) of the processing device, a request from a VM IOMMU for VM memory address translation for a VM peripheral component interconnect (PCI) device created on the VM;

determine, by the physical IOMMU, a corresponding VM memory address translation result based on the request as received and a memory translation table; and

transmit, by the physical IOMMU to the VM IOMMU, the corresponding VM memory address translation result for servicing the request for VM memory address translation of the VM PCI device.

16. The non-transitory computer-readable storage medium of claim 15 , wherein the processing device is further caused to generate, using the physical IOMMU, the memory translation table based on instructions from the VM IOMMU.

17. The non-transitory computer-readable storage medium of claim 16 , wherein the memory translation table comprises translations from VM virtual memory addresses to corresponding VM physical memory addresses.

18. The non-transitory computer-readable storage medium of claim 16 , the VM IOMMU to configure the physical IOMMU to generate a discrete memory translation table for each VM PCI device created on the VM.

19. The non-transitory computer-readable storage medium of claim 15 , wherein the request is generated by the PCI device and intercepted by the VM IOMMU for transmission to the physical IOMMU, and

wherein the request is a VM memory access request comprising a VM virtual memory address associated with the VM PCI device to be translated into a corresponding VM physical memory address.

20. The non-transitory computer-readable storage medium of claim 19 , wherein the corresponding VM memory address translation result comprises the corresponding VM physical memory address.

Assignments (2)
CHANGE OF NAME Recorded Mar 3, 2026
From: RED HAT, INC.
To: RED HAT, LLC
Reel/Frame 074913/0759 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 1, 2021
From: HAMMER, GAL; APFELBAUM, MARCEL
To: RED HAT, INC.
Reel/Frame 057675/0357 →