VMM live upgrade is an emerging approach to upgrade the VMM without the host shutdown. There are several implementations of live upgrade for KVM. However, none of them seems handling the passthrough devices flawlessly. In this talk, we will analyze the requirements for the passthrough devices handling, and present how we follow those requirements to properly handle passthrough devices in our KVM live upgrade implementation. In addition, we also optimize the startup and suspend of VM, Our experiment shows that the total downtime is 13ms for VMM live upgrade(VM has 8 virtual CPUSs, 8GB memory, 1 disk and 1 network card.)
