[2017] Fast Write-Protect and Fast Dirtylog-Bitmap Sync Up - Guangrong Xiao

During live migration, the VMM needs to track guest memory modification and move the modified memory to the destination in the next iteration. Write-protection and dirtylog bitmap are required by memory track. The former catches memory modification and the latter tells what memory is dirty to VMM, there are the two major factors for the performance of live migration.

In the presentation, we will introduce our works to improve write protection and dirty bitmap sync up. Fast write-protect, as its name suggests, write protects guest's memory extreme efficiently which is lockless and is the O(1) algorithm that means its cost does not depend on guest's memory and the workload in guest. Fast dirty bitmap sync is the way to make the dirty bitmap be shared between VMM (Qemu) and KVM which is the fine-grained Zero-Copy approach.

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Guangrong Xiao
Tencent Cloud
Linux Kernel Developer

Xiao Guangrong is a Linux Kernel developer working on Ftrace, MM, Btrfs but his main interest is KVM. As a active contributor, he was invited to give some presentations at some conferences: Japan LinuxCon 2011, Japan LinuxCon 2012 China CLK 2012 and KVM Forum 2016. He is the maintainer of NVDIMM in Qemu’s community who designed and implemented NVDIMM in KVM and Qemu.

Видео [2017] Fast Write-Protect and Fast Dirtylog-Bitmap Sync Up - Guangrong Xiao канала KVM Forum