Re: [PATCH] abstract out bits of ldt.c

[Zachary Amsden <zach@vmware.com>]

Chris Wright wrote:

> * Zachary Amsden (zach@vmware.com) wrote:
>  
>
> > Does Xen assume page aligned descriptor tables?  I assume from this 
> >    
> Yes.
>
>  
>
> > patch and snippets I have gathered from others, that is a yes, and other 
> > things here imply that DT pages are not shadowed.  If so, Xen itself 
> > must have live segments in the GDT pages, so how do you allocate space 
> > for the per-CPU GDT pages on SMP?
> >    
> early during boot.
>  
Doesn't that require 16 pages per CPU?  That seems excessive to impose 
on a native build.  Perhaps we could get away with 1 page per CPU for 
the GDT on native boots and bump that up to 16 if compiling for a 
virtualized sub-architecture - i.e. move GDT to a page aligned struct 
for native (doesn't cost too much), and give it MACH_GDT_PAGES of space 
which is defined by the sub-architecture.
Let's take this thread over to virtualization@lists.osdl.org as well.

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