Re: [PATCH 2/5] target/arm/helper: Fix vae2_tlbmask()

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

On Thu, Jul 20, 2023 at 05:35:49PM +0100, Peter Maydell wrote:
> On Wed, 19 Jul 2023 at 16:56, Jean-Philippe Brucker
> <jean-philippe@linaro.org> wrote:
> >
> > When HCR_EL2.E2H is enabled, TLB entries are formed using the EL2&0
> > translation regime, instead of the EL2 translation regime. The TLB VAE2*
> > instructions invalidate the regime that corresponds to the current value
> > of HCR_EL2.E2H.
> >
> > At the moment we only invalidate the EL2 translation regime. This causes
> > problems with RMM, which issues TLBI VAE2IS instructions with
> > HCR_EL2.E2H enabled. Update vae2_tlbmask() to take HCR_EL2.E2H into
> > account.
> >
> > Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> > ---
> >  target/arm/helper.c | 26 ++++++++++++++++++--------
> >  1 file changed, 18 insertions(+), 8 deletions(-)
> >
> > diff --git a/target/arm/helper.c b/target/arm/helper.c
> > index e1b3db6f5f..07a9ac70f5 100644
> > --- a/target/arm/helper.c
> > +++ b/target/arm/helper.c
> > @@ -4663,6 +4663,21 @@ static int vae1_tlbmask(CPUARMState *env)
> >      return mask;
> >  }
> >
> > +static int vae2_tlbmask(CPUARMState *env)
> > +{
> > +    uint64_t hcr = arm_hcr_el2_eff(env);
> > +    uint16_t mask;
> > +
> > +    if (hcr & HCR_E2H) {
> > +        mask = ARMMMUIdxBit_E20_2 |
> > +               ARMMMUIdxBit_E20_2_PAN |
> > +               ARMMMUIdxBit_E20_0;
> > +    } else {
> > +        mask = ARMMMUIdxBit_E2;
> > +    }
> > +    return mask;
> > +}
> > +
> >  /* Return 56 if TBI is enabled, 64 otherwise. */
> >  static int tlbbits_for_regime(CPUARMState *env, ARMMMUIdx mmu_idx,
> >                                uint64_t addr)
> 
> > @@ -4838,11 +4853,11 @@ static void tlbi_aa64_vae2is_write(CPUARMState *env, const ARMCPRegInfo *ri,
> >                                     uint64_t value)
> >  {
> >      CPUState *cs = env_cpu(env);
> > +    int mask = vae2_tlbmask(env);
> >      uint64_t pageaddr = sextract64(value << 12, 0, 56);
> >      int bits = tlbbits_for_regime(env, ARMMMUIdx_E2, pageaddr);
> 
> Shouldn't the argument to tlbbits_for_regime() also change
> if we're dealing with the EL2&0 regime rather than EL2 ?

Yes, it affects the result since EL2&0 has two ranges

Thanks,
Jean

> 
> >
> > -    tlb_flush_page_bits_by_mmuidx_all_cpus_synced(cs, pageaddr,
> > -                                                  ARMMMUIdxBit_E2, bits);
> > +    tlb_flush_page_bits_by_mmuidx_all_cpus_synced(cs, pageaddr, mask, bits);
> >  }
> 
> thanks
> -- PMM