Re: [PATCH 3/3] target/arm: Determine final stage 2 output PA space based on original IPA

[Peter Maydell]

On Tue, 29 Mar 2022 at 20:09, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 3/27/22 03:34, Idan Horowitz wrote:
> > As per the AArch64.S2Walk() psuedo-code in the ARMv8 ARM, the final
> > decision as to the output address's PA space based on the SA/SW/NSA/NSA
> > bits needs to take the input IPA's PA space into account, and not the
> > PA space of the result of the stage 2 walk itself.
> >
> > Signed-off-by: Idan Horowitz <idan.horowitz@gmail.com>
>
> I believe I follow: because the walk uses walkstate.address.paddress.paspace, 
> the ipa
> input parameter is unchanged, and it is ipa that is passed to
> AArch64.S2NextWalkStateLast() to form the output address.

Textually, this is described on page D5-4802 of DDI 0487H.a;
the security of the output address of the memory access isn't
affected by the security of the output address of the translation
table walk.

-- PMM