Re: VIRTIO - compatibility with different virtualization solutions

[Daniel Kiper <daniel.kiper@oracle.com>]

Hey,

On Thu, Feb 20, 2014 at 06:18:00PM +1030, Rusty Russell wrote:
> 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.

Could you say in short how it should be done? DMA API is an option but
if there is a simpler mechanism available in VIRTIO itself we will be
happy to use it in Xen.

Daniel