[PATCH 1/2] ARM: kvm: define PAGE_S2_DEVICE as read-only by default

[Peter Maydell]

On 15 September 2014 12:41, Mario Smarduch <m.smarduch at samsung.com> wrote:
> I've been working around the edges of this discussion, and
> maybe be little unclear on this.
>
> But the manuals say intersection of Stage1/Stage2 permissions are
> used. If guest sets stage1 to read-only then setting stage 2
> to read-only or read-write should have no impact. So why
> should stage 2 RW be changed?

Read versus read-write isn't relevant. The point is
that you mustn't let the guest set up a Normal memory
mapping of the same bit of hardware (phys. address
space) that some other guest or the host has set up
as Device mapping.

-- PMM