Re: [RFC PATCH v2 10/11] hw/arm/smmuv3: Populate OAS based on CPU PARANGE

[Mostafa Saleh <smostafa@google.com>]

Hi Eric,

> > +     * According to 6.3.6 SMMU_IDR5, OAS must match the system physical address
> > +     * size.
> > +     */
> > +    ARMCPU *armcpu = ARM_CPU(qemu_get_cpu(0));
> > +    uint8_t oas = FIELD_EX64(armcpu->isar.id_aa64mmfr0, ID_AA64MMFR0, PARANGE);
> is this working in accelerated mode?
I didn't try with accel, I will give it a try, but from what I see, that
ARM_CPU() is used to get the CPU in traget/arm/kvm.c which is used from
accel/kvm-all.c, so it seems this would work for accelerated mode.

> > +
> >      /**
> >       * IDR0: stage1 only, AArch64 only, coherent access, 16b ASID,
> >       *       multi-level stream table
> > @@ -265,7 +272,7 @@ static void smmuv3_init_regs(SMMUv3State *s)
> >      s->idr[5] = FIELD_DP32(s->idr[5], IDR5, GRAN4K, 1);
> >      s->idr[5] = FIELD_DP32(s->idr[5], IDR5, GRAN16K, 1);
> >      s->idr[5] = FIELD_DP32(s->idr[5], IDR5, GRAN64K, 1);
> > -    s->idr[5] = FIELD_DP32(s->idr[5], IDR5, OAS, SMMU_IDR5_OAS); /* 44 bits */
> > +    s->idr[5] = FIELD_DP32(s->idr[5], IDR5, OAS, oas);
> I am not sure you can change that easily. In case of migration this is
> going to change the behavior of the device, no?

I see IDR registers are not migrated. I guess we can add them in a
subsection and if they were not passed (old instances) we set OAS to
44.
Maybe this should be another change outside of this series.

Thanks,
Mostafa