Re: [Xen-devel] [PATCH v2 2/2] xen/physmap: Do not permit a guest to populate PoD pages for itself

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 19.08.16 at 18:00, <andrew.cooper3@xxxxxxxxxx> wrote:
> PoD is supposed to be entirely transparent to guest, but this interface has
> been left exposed for a long time.
> 
> The use of PoD requires careful co-ordination by the toolstack with the
> XENMEM_{get,set}_pod_target hypercalls, and xenstore ballooning target.  The
> best a guest can do without toolstack cooperation crash.
> 
> Furthermore, there are combinations of features (e.g. c/s c63868ff "libxl:
> disallow PCI device assignment for HVM guest when PoD is enabled") which a
> toolstack might wish to explicitly prohibit (in this case, because the two
> simply don't function in combination).  In such cases, the guest mustn't be
> able to subvert the configuration chosen by the toolstack.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Acked-by: Jan Beulich <jbeulich@xxxxxxxx>


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