Subject: Re: Hypervisor issues with PTE
To: None <port-xen@NetBSD.org>
From: Michael Richardson <mcr@sandelman.ca>
List: port-xen
Date: 12/30/2006 11:05:33
Mathieu Ropert wrote:
> _PAGE_GNTTAB is set to use the 3th free bit of the page table entry
> (0x800).
> In NetBSD/i386 it's defined as PG_X. After looking at the code a bit, i
> think it's used by the software execute-disable feature.
> It hasn't always been in the code so i guess you can *theorically*
> remove it.
So... maybe disabling the execute-disable feature might work.
I think that there aren't any more free bits, so, unless the hypervisor provides
this one would have to live without.
I wonder what happens if I #define PG_X 0 :-)