xen/arm: account for stolen ticks

Register the runstate_memory_area with the hypervisor.
Use pv_time_ops.steal_clock to account for stolen ticks.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index fc7ea529f462..ebbfa64e4add 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -12,6 +12,7 @@
 #include <xen/page.h>
 #include <xen/interface/sched.h>
 #include <xen/xen-ops.h>
+#include <asm/paravirt.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 #include <asm/system_misc.h>
@@ -79,6 +80,19 @@ int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
 }
 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);
 
+static unsigned long long xen_stolen_accounting(int cpu)
+{
+        struct vcpu_runstate_info state;
+
+        BUG_ON(cpu != smp_processor_id());
+
+        xen_get_runstate_snapshot(&state);
+
+        WARN_ON(state.state != RUNSTATE_running);
+
+        return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline];
+}
+
 static void xen_percpu_init(void)
 {
         struct vcpu_register_vcpu_info info;
@@ -104,6 +118,8 @@ static void xen_percpu_init(void)
         BUG_ON(err);
         per_cpu(xen_vcpu, cpu) = vcpup;
 
+        xen_setup_runstate_info(cpu);
+
 after_register_vcpu_info:
         enable_percpu_irq(xen_events_irq, 0);
         put_cpu();
@@ -271,6 +287,9 @@ static int __init xen_guest_init(void)
 
         register_cpu_notifier(&xen_cpu_notifier);
 
+        pv_time_ops.steal_clock = xen_stolen_accounting;
+        static_key_slow_inc(&paravirt_steal_enabled);
+
         return 0;
 }
 early_initcall(xen_guest_init);