Baby-step towards safe regcache support: * unpin all pages from memory regions when the mmu notifier   detects that some of them are being invalidated * restore the region to its unpinned state so that the next   demand-pinning will repin it again So we don't need to notify user-space at all. It just gives region segments and we take care of pinning when needed/valid.
Baby-step towards safe regcache support:
* unpin all pages from memory regions when the mmu notifier
  detects that some of them are being invalidated
* restore the region to its unpinned state so that the next
  demand-pinning will repin it again
So we don't need to notify user-space at all. It just gives
region segments and we take care of pinning when needed/valid.

Requires demandpin=1 and pininvalidate=1 for now.

Needs to get some proper locking.

git-svn-id: 29c1264a5cf5e3532df57b06678e7347571c1a3c@2104 f1ba3bf5-cb5c-402b-92a9-7c6bdc83a356

ananos/open-mx,ananos/xen2mx,ananos/xen2mx,ananos/xen2mx,ananos/xen2mx,ananos/open-mx,ananos/open-mx