Re: [Xen-devel] question about domU memory mapping

[Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>]

On 27 Jul 2005, at 17:15, Xin Zhao wrote:

> WHy some kernel virtual addresses cannot be virt_to_machine'd? Any
> restriction on that?
Addresses from vmalloc, kmap and fixmap are not in the 1:1 
virtual-physical kernel address space. To find the corresponding 
physical address for such a virtual address you must walk the 
pagetables.
Module structures are vmalloc'ed on i386, so you cannot use 
virt_to_machine.
If your code is Xen-specific (no need to work on native i386) then you 
can use the arbitrary_virt_to_machine() function that only xenlinux 
provides.
 -- Keir


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel