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

[Mostafa Saleh <smostafa@google.com>]

On Sun, Feb 12, 2023 at 05:18:33AM -1000, Richard Henderson wrote:
> > 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.

I was testing before with migration
-From qemu monitor with migrate command
-Load it from cmdline with -incoming

I tested now with savevm/loadvm from qemu monitor
On vmload command, load_snapshot is called which in the following
order calls:
- qemu_system_reset which calls smmu_reset_hold initializing the SMMU
registers.
- qemu_loadvm_state which loads the saved state.

So From what I see, pre_load won’t be needed in this case also.

Thanks,
Mostafa