On Thu, 13 May 2021, at 22:30, Jonathan Cameron wrote:
> On Thu, 13 May 2021 14:36:27 +0200
> Philippe Mathieu-Daudé <[email protected]> wrote:
>
> > On 5/13/21 2:23 PM, Peter Maydell wrote:
> > > On Thu, 13 May 2021 at 12:49, Jonathan Cameron
> > > <[email protected]> wrote:
> > >> My initial suggestion was to fix this by adding the relatively
> > >> simple code needed in the driver to implement byte read / write,
> > >> but Ben pointed at the QEMU docs - docs/devel/memory.rst which
> > >> says
> > >> "
> > >> .impl.min_access_size, .impl.max_access_size define the access sizes
> > >> (in bytes) supported by the *implementation*; other access sizes will
> > >> be
> > >> emulated using the ones available. For example a 4-byte write will be
> > >> emulated using four 1-byte writes, if .impl.max_access_size = 1.
> > >> "
> > >>
> > >> This isn't true when we have the situation where
> > >> .valid.min_access_size < .imp.min_access_size
> > >>
> > >> So change the docs or try to make this work?
> >
> > See also this patch from Francisco:
> > https://www.mail-archive.com/[email protected]/msg636935.html
> >
> > And full unaligned access support from Andrew:
> > https://www.mail-archive.com/[email protected]/msg461247.html
Much better to use lore.kernel.org:
https://lore.kernel.org/qemu-devel/[email protected]/
because...
>
> Thanks - that's very similar to what I was carrying, but I think it
> only covers the read case. That's backed up by the comment:
> /* XXX: Can't do this hack for writes */
It becomes easier to find Paolo's suggestion to fix that here:
https://lore.kernel.org/qemu-devel/[email protected]/
Would love to see this resolved! Unfortunately I haven't had the
bandwidth to fix it all up for ... a long time now.
Andrew
