Re: [Xen-devel] Modules support in Xen (WAS: Re: [ARM] Native application design and discussion (I hope))

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 12 May 2017, George Dunlap wrote:
> So given your examples, I see no reason not to have several
> implementations of different mediators or emulated devices in tree, or
> in a XenProject-managed git repo (like mini-os.git).  I don't know the
> particulars about mediators or the devices you have in mind, but if
> you can show technical reasons why they need to be run in the
> hypervisor rather than somewhere else (for performance or security
> sake, for instance), there's no reason in principle not to add them to
> the hypervisor code; and if they're in the hypervisor, then they
> should be in xen.git.

On the topic of the technical reasons for being out of the hypervisor
(EL0 app or stubdom), I'll spend a couple of words on security.

How large are these components? If they increase the hypervisor code
size too much, it's best if they are run elsewhere.

What is their guest-exposed attack surface? If it's large it's best to
run them out of the hypervisor.

My gut feeling is that both these points might be a problem.

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