Re: [PATCH v4] hw/arm/smmuv3: Add GBPA register

[Richard Henderson]

On 2/12/23 03:23, Mostafa Saleh wrote:
> On Sat, Feb 11, 2023 at 01:48:57PM -1000, Richard Henderson wrote:
>
> > Just "return s->gbpa != SMMU_GBPA_RESET_VAL;".
>
> I will update it.
>
> > > @@ -1512,6 +1553,10 @@ static const VMStateDescription vmstate_smmuv3 = {
> > >            VMSTATE_END_OF_LIST(),
> > >        },
> > > +    .subsections = (const VMStateDescription * []) {
> > > +        &vmstate_gbpa,
> > > +        NULL
> > > +    }
> >
> > Actually, I suspect that you need a pre_load hook that resets gbpa, which
> > will then be overwritten if and only if the saved value != reset value.
>
> Please correct me if I am wrong. From what I see, the initial for value
> GBPA will be set from smmu_reset_hold which is called from context of
> qemu_system_reset from qemu_init context.
> And migration will start after that in migration_incoming_process from
> qemu_main_loop context.
>
> I validated that also by printing the value of GBPA from vmstate_smmuv3
> pre_load at migration without GPBA, and it is the same as
> SMMU_GBPA_RESET_VAL.

Is that from -loadvm on the command-line, or the loadvm command from the monitor?  It's 
the latter that I suspect requires the pre_load.


r~