On Mon, 2021-11-15 at 19:49 +0100, Paolo Bonzini wrote:
> On 11/15/21 17:50, David Woodhouse wrote:
> > +			asm volatile("1:\t" LOCK_PREFIX "orq %0, %1\n"
> > +				     "\tnotq %0\n"
> > +				     "\t" LOCK_PREFIX "andq %0, %2\n"
> > +				     "2:\n"
> > +				     "\t.section .fixup,\"ax\"\n"
> > +				     "3:\tjmp\t2b\n"
> > +				     "\t.previous\n"
> > +				     _ASM_EXTABLE_UA(1b, 3b)
> > +				     : "=r" (evtchn_pending_sel)
> > +				     : "m" (vi->evtchn_pending_sel),
> > +				       "m" (v->arch.xen.evtchn_pending_sel),
> 
> These need to be "+m", I think?
> 
> And same for st->preempted actually

Ack. Although as noted, I think I'll switch to a gfn_to_pfn_cache for
the vcpu_info too, once the dust has settled on the implementation.