Re: Re: how to enable shadow page table? Do I have to run HVM guest systems for shadow paging mode?

[Jeremy Fitzhardinge <jeremy@goop.org>]

Long Wang wrote:
> I looked into the live migration code in Xen. I need more than the mechanism
> provided in live migration, as described below:
>
> 1. scan the states of all the memory pages of a domain, set dirty pages as
> read-only, and clear all dirty bits for all the memory pages (so read-only
> and dirty are two different bits). This procedure is done periodically.
>
> 2. When a readonly page is to be updated by the domain, the update is
> trapped into the hypervisor, when I copy the page content to another place,
> and set the page as writable (this page is not a page table page), makes the
> update.
>
> I find that the mechanism used in live migration cannot handle these. How
> can I enable shadow paging in PV? If not, do I have to find a machine with
> vmx-featured processor and run HVM for this machine?
>   

Well, that's an option.  But if you're going to be hacking Xen anyway, 
then it sounds like log-dirty is close to what you want.  But Tim is 
probably the person to ask about that.

    J