xen: re-register runstate area earlier on resume.

This is necessary to ensure the runstate area is available to
xen_sched_clock before any calls to printk which will require it in
order to provide a timestamp.

I chose to pull the xen_setup_runstate_info out of xen_time_init into
the caller in order to maintain parity with calling
xen_setup_runstate_info separately from calling xen_time_resume.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stable Kernel <stable@kernel.org>

3 files changed, 5 insertions, 3 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index dfbf70e65860..cb61f77e4496 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -148,6 +148,8 @@ void xen_vcpu_restore(void)
                             HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
                                 BUG();
 
+                        xen_setup_runstate_info(cpu);
+
                         xen_vcpu_setup(cpu);
 
                         if (other_cpu &&
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 0a5aa44299a5..6bbff94328d2 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -100,7 +100,7 @@ bool xen_vcpu_stolen(int vcpu)
         return per_cpu(runstate, vcpu).state == RUNSTATE_runnable;
 }
 
-static void setup_runstate_info(int cpu)
+void xen_setup_runstate_info(int cpu)
 {
         struct vcpu_register_runstate_memory_area area;
 
@@ -442,8 +442,6 @@ void xen_setup_timer(int cpu)
 
         evt->cpumask = cpumask_of(cpu);
         evt->irq = irq;
-
-        setup_runstate_info(cpu);
 }
 
 void xen_teardown_timer(int cpu)
@@ -494,6 +492,7 @@ __init void xen_time_init(void)
 
         setup_force_cpu_cap(X86_FEATURE_TSC);
 
+        xen_setup_runstate_info(cpu);
         xen_setup_timer(cpu);
         xen_setup_cpu_clockevents();
 }
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 355fa6b99c9c..32529326683d 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -41,6 +41,7 @@ void __init xen_build_dynamic_phys_to_machine(void);
 
 void xen_init_irq_ops(void);
 void xen_setup_timer(int cpu);
+void xen_setup_runstate_info(int cpu);
 void xen_teardown_timer(int cpu);
 cycle_t xen_clocksource_read(void);
 void xen_setup_cpu_clockevents(void);