On Thu, Nov 19, 2015 at 1:55 PM, Boris Ostrovsky
[off-list ref] wrote:

The first patch fixes Xen PV regression introduced by 32-bit rewrite. Unlike the
earlier version it uses ALTERNATIVE instruction and avoids using xen_sysexit
(and sysret32 in compat mode) pv ops, as suggested by Andy.

As result of this patch irq_enable_sysexit and usergs_sysret32 pv ops are not
used anymore by anyone and so can be removed.

This whole series is:

Acked-by: Andy Lutomirski <luto@kernel.org>

Now I just have to sucker someone into getting rid of
PARAVIRT_ADJUST_EXCEPTION_FRAME (by using stub entries) and the
overcomplicated syscall entry stuff.  :)  And whoever gets rid of
PARAVIRT_ADJUST_EXCEPTION_FRAME gets to wonder why it doesn't crash
and burn for NMIs on Xen, since I'm reasonably confident that it can't
possibly be correct.

--Andy