RE: [Xen-devel] Live migration leaves page tables read-only?

["Ian Pratt" <m+Ian.Pratt@xxxxxxxxxxxx>]

> Solaris implements PROT_NONE by entirely invalidating the PTE (ie. it
> becomes zero). Hence our PTEs always had either zero or have the
PRESENT
> bit set.  The only exception to this was adding some fixage to allow
> for the old Xen writable page table approach which temporarily made
> the upper table non-PRESENT.
> 
> So you can make not-present, but non-zero entries mean anything you
want.
> As long as it's the guest OS that creates the entries, we'll just not
do
> it.

Just to be confirm: in Solaris there are no not-present PTE's that
contain machine addresses.

This means we need to implement the scheme that Keir suggested to enable
the guest OS to tell xen/xc_save/restore about flags in not-present PTEs
that should trigger a m2p conversion.

Ian 

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