1 files changed, 20 insertions, 0 deletions

diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index f8492da65bfc..086eb58c6e80 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -22,6 +22,7 @@
 #include <asm/msr.h>
 #include <asm/apic.h>
 #include <linux/percpu.h>
+#include <linux/hardirq.h>
 
 #include <asm/x86_init.h>
 #include <asm/reboot.h>
@@ -114,6 +115,25 @@ static void kvm_get_preset_lpj(void)
         preset_lpj = lpj;
 }
 
+bool kvm_check_and_clear_guest_paused(void)
+{
+        bool ret = false;
+        struct pvclock_vcpu_time_info *src;
+
+        /*
+         * per_cpu() is safe here because this function is only called from
+         * timer functions where preemption is already disabled.
+         */
+        WARN_ON(!in_atomic());
+        src = &__get_cpu_var(hv_clock);
+        if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) {
+                __this_cpu_and(hv_clock.flags, ~PVCLOCK_GUEST_STOPPED);
+                ret = true;
+        }
+
+        return ret;
+}
+
 static struct clocksource kvm_clock = {
         .name = "kvm-clock",
         .read = kvm_clock_get_cycles,