[Lguest] two questions

[Rusty Russell]

On Mon, 2007-10-01 at 20:17 -0300, Matias Zabaljauregui wrote:
> Hello, 
> 
>     I have two questions about Lguest I'd like to ask:
> 
> 1) I'm trying to add support for 3 level paging (for PAE) to lguest.
> When the guest wants to set_pte_at() or set_pmd() , the host just
> releases the shadow versions of these guys, and demand_page will do
> the rest. But for releasing the right entries, this functions use some
> information like the top level page table. 
> 
> I don't know how to implement the PAE version of guest_set_pmd. I
> guess I should follow the release_pmd technic, but I'd need some extra
> information. Should I use the release_all_pagetables, like the
> set_pte()  case ?? 

Hi Matias!

	You can always start by doing release_all_pagetables.  It will be slow,
but it will always work!
> 
> 2) I need to invoke some hypercall and send a 64bit value but I don't
> have two 32bit argument "slots" available. Is it a good idea to use
> lguest_data for transferring the 64bit value ? 

Hmm, that's hard.  Your choice: you can also make the register refer to
the physical address of the 64 bit value.

Cheers,
Rusty.