Re: [RFC PATCH 2/5] system/memory: support unaligned access

[Peter Xu <peterx@redhat.com>]

On Fri, Jan 10, 2025 at 07:11:27PM +0900, Tomoyuki HIROSE wrote:
> > > MR implementation to be safe when unaligned accessing (current xHCI
> > > implementation does not handle unaligned accesses but the spec allows
> > > unaligned accesses).
> > > 
> > > In addition, maybe it would be better to document the constraint that
> > > the situation where 'valid.unaligned = true' and 'impl.unaligned =
> > > false' is not supported.
> > Do you perhaps mean this instead?
> > 
> >    valid.unaligned = FALSE && impl.unaligned == TRUE
> > 
> > If so, I agree.  I think we could even consider adding an assertion into
> > memory_region_init_io() to make sure it won't be set.
> > 
> > Thanks,
> > 
> 
> I'm sorry if I've misunderstood, but are the following understandings
> correct?:
> - Need to merge my patch that converts an unaligned access to aligned
>   accesses.
> - Need to add 'impl.unaligned = true' in the following two places.
>   - hw/xtensa/mx_pic.c
>   - hw/ssi/npcm7xx_fiu.c
> - Add an assertion that to check for invalid patterns, additionally.

Yes, all these sound good to me.

Thanks,

-- 
Peter Xu