Re: [virtio-comment] [PATCH v1 1/2] virtio-mem: introduce VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE

[David Hildenbrand <david@redhat.com>]

On 17.08.21 11:23, Cornelia Huck wrote:
> On Tue, Aug 17 2021, David Hildenbrand <david@redhat.com> wrote:
>
> > On 17.08.21 10:50, Cornelia Huck wrote:
> > > On Thu, Aug 12 2021, David Hildenbrand <david@redhat.com> wrote:
> > > > +With VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE, the device MAY allow the CPU to
> > >
> > > "If VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE has been negotiated, ..."
> >
> > ack
> >
> > > > +read memory of unplugged memory blocks inside \field{usable_region_size}.
> > >
> > > A compliant driver would not read that memory, would it?
> >
> > Indeed. The device could decide to allow for reading, but it's pretty
> > much undefined behavior.
>
> Maybe make it "SHOULD NOT"? Less strong than "MUST NOT", but still makes
> clear that a driver reading it is pretty much doing the wrong thing.

I was also wondering to just drop it completely, because it's actually 
undefined behavior. What do you think?

--
Thanks,

David / dhildenb