xen: add static initialization of steal_clock op to xen_time_ops

pv_time_ops might be overwritten with xen_time_ops after the
steal_clock operation has been initialized already. To prevent calling
a now uninitialized function pointer add the steal_clock static
initialization to xen_time_ops.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

arch/x86/xen/time.c

@@ -364,6 +364,7 @@ void xen_timer_resume(void)
 
 static const struct pv_time_ops xen_time_ops __initconst = {
 	.sched_clock = xen_clocksource_read,
+	.steal_clock = xen_steal_clock,
 };
 
 static void __init xen_time_init(void)

drivers/xen/time.c

@@ -80,7 +80,7 @@ bool xen_vcpu_stolen(int vcpu)
 	return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable;
 }
 
-static u64 xen_steal_clock(int cpu)
+u64 xen_steal_clock(int cpu)
 {
 	struct vcpu_runstate_info state;
 

include/xen/xen-ops.h

@@ -29,6 +29,7 @@ bool xen_vcpu_stolen(int vcpu);
 void xen_setup_runstate_info(int cpu);
 void xen_time_setup_guest(void);
 void xen_get_runstate_snapshot(struct vcpu_runstate_info *res);
+u64 xen_steal_clock(int cpu);
 
 int xen_setup_shutdown_event(void);