On Tue, Sep 27, 2016 at 18:16:45 +0200, Paolo Bonzini wrote:
> Anyhow, the next step is to merge either cmpxchg-based atomics
> or iothread-free single-threaded TCG. Either will do. :)
>
> I think that even iothread-free single-threaded TCG requires this
> TLB stuff, because the iothread's address_space_write (and hence
> invalidate_and_set_dirty) can race against the TCG thread's
> code generation.
What's a quick-and-dirty way to disable the fast-path TLB lookups?
Alex: you told me the monitor has an option for this, but I can't
find it. I'm looking for something that'd go in tcg/i386 to simply
bypass the fast path.
Forcing the slow TLB lookup would be an easy way to then implement
a per-TLB seqlock. I think TLB corruption might explain the crashes I
see when booting Ubuntu in a many-core guest (running on a many-core
host).
Thanks,
Emilio
