Re: [Xen-devel] xen dire-map area

[Tim Deegan <tim@xxxxxxx>]

At 15:15 +0800 on 15 Jun (1339773354), Baozeng wrote:
> I see. I want to monitor Xen's data structures in a trusted VM(dom0).

I don't understand.  Given that Xen controls dom0 entirely, how can it
monitor Xen's datastructures?

> One challenge is how to make dom0 can read Xen's data structure (just
> read, do not need to write). Since Xen has more privilege, dom0 cannot
> read its data directly.  Can we set up appropriate hypervisor-page
> tables for dom0 that map Xen's relevant physical (or virtual) memory
> areas? How to do that? Do we need modify Xen's code? or just the
> dom0's code?

You would need to modify Xen (to allow dom0 to have read-only mappings
of all memory) and dom0 (to understand Xen well enough to follow its
datastructures).  But since a compromised Xen could lie to dom0
about its pagetables, this seems like a very weak kind of security --
especially compared with something like HyperSafe or CloudVisor that
uses a _more_ privileged element to protect the hypervisor.

Tim.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel