US Patent 10884790 Eliding redundant copying for virtual machine migration

Systems and methods are provided to reduce the number of redundant copy operations performed as part of a live migration of a virtual machine executing a guest. While pre-copying for the live migration of the VM, the guest may continue to write to the pages. A hypervisor may clear the dirty pages and schedule the copy operations of the modified pages in a processing engine for copying to a target device. In one embodiment, before initiating the copy operation, the processing engine may check if the page has been modified again and omit the copy operation if the page has been modified again.