Re: [PATCH] target/arm: Restrict translation disabled alignment check to VMSA

[Philippe Mathieu-Daudé]

On 22/4/24 19:09, Richard Henderson wrote:
> On 4/22/24 10:07, Richard Henderson wrote:
> > For cpus using PMSA, when the MPU is disabled, the default memory
> > type is Normal, Non-cachable.
> >
> > Fixes: 59754f85ed3 ("target/arm: Do memory type alignment check when 
> > translation disabled")
> > Reported-by: Clément Chigot <chigot@adacore.com>
> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> > ---
> >
> > Since v9 will likely be tagged tomorrow without this fixed,
> > Cc: qemu-stable@nongnu.org
> >
> > ---
> >   target/arm/tcg/hflags.c | 12 ++++++++++--
> >   1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/target/arm/tcg/hflags.c b/target/arm/tcg/hflags.c
> > index 5da1b0fc1d..66de30b828 100644
> > --- a/target/arm/tcg/hflags.c
> > +++ b/target/arm/tcg/hflags.c
> > @@ -38,8 +38,16 @@ static bool aprofile_require_alignment(CPUARMState 
> > *env, int el, uint64_t sctlr)
> >       }
> >       /*
> > -     * If translation is disabled, then the default memory type is
> > -     * Device(-nGnRnE) instead of Normal, which requires that alignment
> > +     * With PMSA, when the MPU is disabled, all memory types in the
> > +     * default map is Normal.
> > +     */
> > +    if (arm_feature(env, ARM_FEATURE_PMSA)) {
> > +        return false;
> > +    }
> > +
> > +    /*
> > +     * With VMSA, if translation is disabled, then the default memory 
> > type
> > +     * is Device(-nGnRnE) instead of Normal, which requires that 
> > alignment
> >        * be enforced.  Since this affects all ram, it is most efficient
> >        * to handle this during translation.
> >        */
>
> Oh, I meant to add: since the armv7 manual has both VMSA and PMSA 
> sections, and the language about default Device type and alignment 
> traps, is in the VMSA section.

To the best of my knowledge,
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>