Re: Is machine_to_phys_mapping a 4MB 'superpage'?

[Jacob Gorm Hansen <jacobg@diku.dk>]

Keir Fraser wrote:
> 
> On 31 Mar 2005, at 04:25, Jacob Gorm Hansen wrote:
> 
>> The machine_to_phys_mapping table is mapped permanently at 0xFC000000 
>> (on x86-32). I would like to experiment with letting the domU map it 
>> at other locations in its virtual address space, but I suppose that 
>> for performance it is mapped as a 4MB 'super' page, and as such needs 
>> special treatment, is this correct?
> 
> 
> It doesn't *have* to be mapped as a superpage -- control tools don't 
> when doing suspend/resume, for example. Fixing the permission checking 
> so that other than domain0 can remap the m2p table shouldn't be very 
> hard, but I'm not sure what the cleanest method would be.

actually I would just like for domUs to be able to map it in different 
locations, in order to get a little more flexible memory layout.

I will probably just try and hack something up for my immediate needs.

Jacob