Re: PAE xen + linux kernel boots ...

[Gerd Knorr <kraxel@bytesex.org>]

> The bitshifting stuff in ptwr_emulated_update() had some problems, 
> although its possible that it somehow worked for whatever cases it
> was needed for before.
> 
> Adding a physaddr_t, and fixing the bitshifting took care of the
> problem.

Looks fine, added it into my patches.

> While i was at it, i wired up support for cmpxchg8b emulation under
> PAE, and then tried to use set_pte_atomic().

Hmm, that's dead code right now, isn't it?

> That didn't quite do the trick, but killing the machine_to_physical()
> conversion in pte_val() got things working.

That looks like hiding a bug somewhere else.  All the p??_val()
functions have a separate _ma() version which doesn't do the machine
to physical translation, so I'd suspect that happening due to some
place in the code using the wrong version of the macro, not due to
the macro itself being broken ...

> I was getting to dom0 prompt under the pae 5th patch release, testing
> my patches under the 6th, the kernel fell apart in very late
> boot. Haven't looked into this just yet.

There used to be some issues independent of the PAE stuff, at least with
the 1.1385 bk version (IIRC) I've used to create patchset #5 .  I've
created patchset #6 with 1.1399, worked fine.  Updated to 1.1413 today,
also no problems so far.

  Gerd