QEMU live migration device state transfer parallelization via multifd channels
Current QEMU live migration device state transfer is done via the (single) main migration channel.
Such way of transferring device state migration data reduces performance and severally impacts the migration downtime for VMs having large device state that needs to be transferred during the switchover phase.
Some examples of devices that have such large switchover phase device state are some types of VFIO SmartNICs and GPUs.
This talk describes the efforts to parallelize the transfer and loading of device state for these VFIO devices by utilizing QEMU existing support for having multiple migration connections – that is, by utilizing multifd channels for their transfer, together with other parallelization improvements.
Slides:
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Maciej S. Szmigiero
Maciej S. Szmigiero is a Principal MTS in the Linux Virtualization and Security engineering team at Oracle, where he is responsible both for giving Windows guests a comfortable ride on top of KVM/QEMU virtualization stack and also for researching future guests live migration performance improvements.
Outside of work, in his (sadly limited) spare time he loves working on improving other FOSS projects, doing DIY electronics stuff, and generally reading and learning about new developments in technology and the people behind it.
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