Re: Re: changeset 13403 ...

[Gerd Hoffmann <kraxel@suse.de>]

  Hi,

> I'm dropping in on this part way through but
> out of context the following sounds dangerous.
> 
> For example, Solaris domains assume at start
> of time, that only pages mapped in the start
> area are in use in any way. All other pages
> go immediately in our free lists. If you change
> this protocol, then we'll have backwards
> incompatibility issues to fix.

It's another protocol change: you can't switch from one self-consistent
set of page tables to another set of self-consistent page tables (where
the old set has only the old pagetables but not the new ones mapped
read-only, same for the new set and the old tables) any more.

That was added during the 3.0.3 cycle (I think) and now removed again.
domU kexec was the only user of that feature as far I know.  I've found
a way to get away without it.  I'm using a small intermediate page table
as suggested by Keir for one page table switch, the second page switch
to the final page table layout for the new kernel is easier to handle
due memory being mapped partly only in the builders initial memory layout.

cheers,
  Gerd

-- 
Gerd Hoffmann <kraxel@suse.de>