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by alexey-salmin 887 days ago
You don't need kernel support, just freeze it's state right after the boot and clone it afterwards.

Boot time will be the setup of shadow page tables and other hypervisor structures at new offsets. Plus a few tricks to avoid reproducible RNGs.
1 comments
inkyoto 887 days ago
> […] freeze it's state right after the boot and clone it afterwards.

You can't do that easily as devices can be attached, detached or reattached dynamically whilst the VM is running and when it is shut down.

In lieu of the hardware / VM support for device trees, with the existing design, the kernel has to probe each device upon every boot.

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alexey-salmin 887 days ago
Well it's not an ordinary boot of course, it's a clone and the state on both side of the fence should be faithfully cloned including virtual devices. The guest kernel will have no way of knowing whether it was resumed once or twice.

Applicability is limited, but works well to spin up serverless compute on-demand.

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