Re: [PATCH] Xen/i386 cleanups - AGP bus/phys cleanups

[Tupshin Harper]

Paul Mackerras wrote:

> Rik van Riel writes:
>
>  
>
> > Thing is, the rest of the kernel uses virt_to_phys for
> > two different things.  Only one of them has to do with
> > the real physical address, the other is about getting
> > the page frame number.
> >    
>
> So fix the places that are using virt_to_phys to get the page frame
> number to use virt_to_pfn instead. :)
>
>  
>
> > On native x86, x86-64 and others, the page frame number
> > and physical address are directly related to each other.
> > Under Xen, however, the two are different - and the
> > AGPGART really needs to have the physical address ;)
> >    
>
> If Xen is letting the kernel program the GART, you just lost any
> memory isolation between partitions you might have been trying to
> enforce. :)
>  
Since xen only lets the  dom0 (privileged domain) program the GART, all 
of the domU's  (non-privileged domains) are still isolated from each other.

-Tupshin
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/