Methods and systems for using a peripheral device to assist virtual machine IO memory access tracking

US12277432B2 · kind B2 · utility

Assignee

• Pensando Systems Inc. · US

Inventors

• Chaitanya Huilgol · Kanchinakote, IN
• J. Bradley Smith · San Jose, US
• Allen Hubbe · Durham, US
• Balakrishnan Raman · Fremont, US
• Harinadh Nagulapalli · San Jose, US
• Krishna Doddapaneni · Sunnyvale, US
• Murty Subba Rama Chandra Kotha · San Jose, US
• Varada Raja Kumar Kari · Bengaluru, IN

Key dates

• Filing date: Feb 15, 2021
• Grant date: Apr 15, 2025
• Expiry date: May 11, 2042

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F2213/0026
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

SR-IOV (single root IO virtualization) capable PCIe devices can implement virtual functions (VFs) that are assigned to VMs running on a host machine, thereby speeding IO operation by writing directly to the VMs' memory while bypassing the hypervisor managing the VMs. As such, VFs thwart the dirty page tracking that hypervisors use to minimize VM downtime when the VM is migrated between hosts. The SR-IOV PCIe devices can help resolve this problem by maintaining dirty page tracking data for VMs running on the host machine. The SR-IOV PCIe devices bypassing the hypervisor while writing into a memory page of the VM can set the dirty page tracking data to indicate the memory pages that are dirty (i.e., written to by the VF), and can provide access to the dirty page tracking data. The hypervisor can thereby obtain and use the dirty page tracking data.