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

[Tomoyuki HIROSE]

On 2025/01/11 0:08, Peter Xu wrote:
> 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,

OK, thanks.
I will prepare patch v2 according to the above understandings.

Tomoyuki HIROSE