Re: [PATCH v3 1/2] system/memory: Use qemu_ram_{copy, move}() in ram device region accessors

[Peter Xu <peterx@redhat.com>]

On Tue, Jul 21, 2026 at 03:37:53PM +1000, Gavin Shan wrote:
> If Peter is fine with two variants for x86 and non-x86 architectures.
> I can post (v4) for further review. That will be something like below
> and let me know if there are any other improvements are needed.

I have a generic question on the "unaligned access for x86": I think the
question is about the one Michael raised here on unaligned access may break
x86 here:

  https://lore.kernel.org/qemu-devel/20260617022330-mutt-send-email-mst@kernel.org/

  3. (theoretical concern) also on x86, unaligned accesses are
  possible on guest and host, so converting an unaligned access to a
  series of aligned ones can in theory break devices.

Is that a real problem we need to consider, or can we start with unified
approach and leave it for later?

PS: I apologize if I missed important piece of info along the way; I didn't
follow closely on the discussion on this topic in the past few weeks.

One thing to mention is, what we change should only need to affect
ram_device, AFAIU.. so most memcpy()/memmove() shouldn't be changed for any
arch when it's pure RAM.

Thanks,

-- 
Peter Xu