Re: [Qemu-devel] [PATCH v3 3/3] target-arm: Implement the S2 MMU inputsize > pamax check

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Mon, Jan 25, 2016 at 12:57:41PM +0000, Peter Maydell wrote:
> On 22 January 2016 at 09:50, Edgar E. Iglesias <edgar.iglesias@gmail.com> wrote:
> > From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
> >
> > Implement the inputsize > pamax check for Stage 2 translations.
> > We have multiple choices for how to respond to errors and
> > choose to fault.
> >
> > Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
> > ---
> >  target-arm/helper.c | 16 ++++++++++++----
> >  1 file changed, 12 insertions(+), 4 deletions(-)
> >
> > diff --git a/target-arm/helper.c b/target-arm/helper.c
> > index 2a6fa94..8901762 100644
> > --- a/target-arm/helper.c
> > +++ b/target-arm/helper.c
> > @@ -6809,7 +6809,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, target_ulong address,
> >           */
> >          int startlevel = extract32(tcr->raw_tcr, 6, 2);
> >          unsigned int pamax = arm_pamax(cpu);
> > -        bool ok;
> > +        bool ok = true;
> >
> >          if (va_size == 32 || stride == 9) {
> >              /* AArch32 or 4KB pages */
> > @@ -6819,9 +6819,17 @@ static bool get_phys_addr_lpae(CPUARMState *env, target_ulong address,
> >              level = 3 - startlevel;
> >          }
> >
> > -        /* Check that the starting level is valid. */
> > -        ok = check_s2_startlevel(cpu, va_size == 64, level,
> > -                                 inputsize, stride, pamax);
> > +        if (va_size == 64 &&
> > +            inputsize > pamax &&
> > +            (arm_el_is_aa64(env, 1) || inputsize > 40)) {
> > +            /* We have multiple choices but choose to fault.  */
> 
> Can we say specifically "This is CONSTRAINED UNPREDICTABLE and
> we choose...", please?

I'll change this for v4.

Thanks!
Edgar