Re: Crash with CXL + TCG on 8.2: Was Re: qemu cxl memory expander shows numa_node -1

[Gregory Price]

On Thu, Feb 01, 2024 at 05:07:31PM +0000, Peter Maydell wrote:
> On Thu, 1 Feb 2024 at 17:04, Gregory Price <gregory.price@memverge.com> wrote:
> >
> > On Thu, Feb 01, 2024 at 04:45:30PM +0000, Alex Bennée wrote:
> 
> > > No thats different - we are actually writing to the MMIO region here.
> > > But the fact we hit cpu_abort because we can't find the TB we are
> > > executing is a little problematic.
> > >
> > > Does ra properly point to the code buffer here?
> > >
> >
> > What if the code block is ALSO in CXL (MMIO)? :D
> 
> In that case the TB is supposed to be a single insn,
> so the insn will by definition be the last one in its
> TB, and IO should be OK for it -- so can_do_io ought
> to be true and we shouldn't get into the io_recompile.
> 
> -- PMM

We saw a bug early on in CXL emulation with instructions hosted on CXL
that split a page boundary (e.g. 0xEB|0xFE)..  I'm wondering about a
code block that splits a page boundary and whether there's a similar
corner case.

~Gregory