Re: VIRTIO - compatibility with different virtualization solutions

[Rusty Russell <rusty@au1.ibm.com>]

Ian Campbell <Ian.Campbell@citrix.com> writes:
> On Wed, 2014-02-19 at 10:56 +1030, Rusty Russell wrote:
>> For platforms using EPT, I don't think you want anything but guest
>> addresses, do you?
>
> No, the arguments for preventing unfettered access by backends to
> frontend RAM applies to EPT as well.

I can see how you'd parse my sentence that way, I think, but the two
are orthogonal.

AFAICT your grant-table access restrictions are page granularity, though
you don't use page-aligned data (eg. in xen-netfront).  This level of
access control is possible using the virtio ring too, but noone has
implemented such a thing AFAIK.

Hope that clarifies,
Rusty.
PS.  Random aside: I greatly enjoyed your blog post on 'Xen on ARM and
     the Device Tree vs. ACPI debate'.