|
|
|
|
|
|
|
|
|
|
xen-devel
RE: [Xen-devel] question on get_page_and_type()
Yes, of course. Thanks, Ian.
I am not thinking straight (Tired, working late to finish the slides for
the summit).
Regards
Renato
> -----Original Message-----
> From: Ian Pratt [mailto:Ian.Pratt@xxxxxxxxxxxx]
> Sent: Saturday, April 14, 2007 9:20 PM
> To: Santos, Jose Renato G; Ian Pratt; xen-devel@xxxxxxxxxxxxxxxxxxx
> Subject: RE: [Xen-devel] question on get_page_and_type()
>
> > Ah, OK. Thanks for clarifying!
> > I assume this could only happen if the guest is buggy,
> right? Normally
> > the guest should not do a grant_copy into its pagetables or issue a
> > grant for its page tables. But in case it does it is only
> corrupting
> > itself right? I assume only the page owner could use the
> page for page
> > tables. Is it fair to say that the get_page_and_type() is only
> > protecting a guest to harm itself? In that case would it be
> acceptable
> > to transfer this enforcement to the guest itself if this
> gives a boost
> > in performance?
>
> No, for direct pagetable mode guests it's necessary for
> correctness, otherwise a guest can corrupt it's pagetables
> and access memory belonging to other guests or the
> hypervisor, or even tripple fault the machine.
>
> Ian
>
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
|
|
|
|
|