Re: paravirtualization structure

Arjan van de Ven
2007-02-20T08:18:29Z

>
> "This utilizes the cr3 filter capability of the hardware - if this works out
> then no VM exit happens"
>
> NO VM-exits happen. hmmmm... maybe I need to go over the intel manuals more
> thoroughly, however any hints will be most welcomed.

Hi,

I think you're confused a bit ;)

the cr3 filter is not a hypercall interface. It's a optimization in the
hardware that makes it not needed to go to the host (via a vmexit in
some form or another) to do a context switch inside the guest... so
guest context switches will become a lot faster.

In order for this to work, the guest needs to assist the host a bit, and
hence a hypercall interface was needed. Well it's needed anyway going
forward for other things such as the paravirtualized block and
networking drivers...

I hope this clears up some of what you're asking...

Greetings,
Arjan van de Ven
--
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org