NOVA, NUL, snapshotting

Julian Stecklina jsteckli at
Thu Aug 29 10:24:22 CEST 2013

Hash: SHA1

On 08/28/2013 08:50 AM, Sartakov A. Vasily wrote:
> Hi again.
> Several more questions.
> If I, for instance, want to have a functionality, similar to
> save/restore of virtual machines. For saving a virtual machine I
> can initiate a trap into VMM and use registers from UTCB.
> For VM restoring, can I fill registers in handle_cpu_init?

Probably, but that doesn't get you very far, because...

> Is that enough? What should I do with mappings (NPT in particular
> caused me questions), devices?

... you need to save and restore device state. Jacek Galowicz has
implemented this already. For a short overview of what he did check:

I understand the VMM-specific code will be published at some point.

> What is the cpu state in receive function of vbios_multiboot? Is it
> a beginning state of VM, when the Munech is uploaded?

This function is called whenever some code issues int 19h to (re)start
the BIOS boot procedure. Initially this is called by the vBIOS itself.
I am not sure what you mean with your second question.


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