Re: [PATCH v3] memory: Directly dispatch alias accesses on origin memory region

[Peter Maydell]

On Tue, 20 Apr 2021 at 21:59, Peter Xu <peterx@redhat.com> wrote:
> I think it should always be a valid request to trigger memory access via the 
> MR
> layer, say, what if the caller has no address space context at all? From the
> name of memory_region_dispatch_write|read I don't see either on why we should
> not take care of alias mrs.  That's also the reason I'd even prefer this patch
> rather than an assert.

It's a bit of an odd case to need to do direct accesses on an MR
(so if you think you need to you should probably look for whether there's
a better way to do it), but there are sometimes reasons it's necessary or
expedient -- we have about half a dozen uses which aren't part of the core
memory system using memory_region_dispatch_* as an internal function.
So I think I agree that while we have this as an API exposed to
the rest of the system it would be nice if it Just Worked for
alias MRs.

thanks
-- PMM