1 files changed, 35 insertions, 13 deletions

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 4604e9accc65..ef84a803433e 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -909,9 +909,35 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
         return ckc_irq_pending(vcpu) || cpu_timer_irq_pending(vcpu);
 }
 
+static u64 __calculate_sltime(struct kvm_vcpu *vcpu)
+{
+        u64 now, cputm, sltime = 0;
+
+        if (ckc_interrupts_enabled(vcpu)) {
+                now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
+                sltime = tod_to_ns(vcpu->arch.sie_block->ckc - now);
+                /* already expired or overflow? */
+                if (!sltime || vcpu->arch.sie_block->ckc <= now)
+                        return 0;
+                if (cpu_timer_interrupts_enabled(vcpu)) {
+                        cputm = kvm_s390_get_cpu_timer(vcpu);
+                        /* already expired? */
+                        if (cputm >> 63)
+                                return 0;
+                        return min(sltime, tod_to_ns(cputm));
+                }
+        } else if (cpu_timer_interrupts_enabled(vcpu)) {
+                sltime = kvm_s390_get_cpu_timer(vcpu);
+                /* already expired? */
+                if (sltime >> 63)
+                        return 0;
+        }
+        return sltime;
+}
+
 int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
 {
-        u64 now, sltime;
+        u64 sltime;
 
         vcpu->stat.exit_wait_state++;
 
@@ -924,22 +950,20 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
                 return -EOPNOTSUPP; /* disabled wait */
         }
 
-        if (!ckc_interrupts_enabled(vcpu)) {
+        if (!ckc_interrupts_enabled(vcpu) &&
+            !cpu_timer_interrupts_enabled(vcpu)) {
                 VCPU_EVENT(vcpu, 3, "%s", "enabled wait w/o timer");
                 __set_cpu_idle(vcpu);
                 goto no_timer;
         }
 
-        now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
-        sltime = tod_to_ns(vcpu->arch.sie_block->ckc - now);
-
-        /* underflow */
-        if (vcpu->arch.sie_block->ckc < now)
+        sltime = __calculate_sltime(vcpu);
+        if (!sltime)
                 return 0;
 
         __set_cpu_idle(vcpu);
         hrtimer_start(&vcpu->arch.ckc_timer, ktime_set (0, sltime) , HRTIMER_MODE_REL);
-        VCPU_EVENT(vcpu, 4, "enabled wait via clock comparator: %llu ns", sltime);
+        VCPU_EVENT(vcpu, 4, "enabled wait: %llu ns", sltime);
 no_timer:
         srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
         kvm_vcpu_block(vcpu);
@@ -966,18 +990,16 @@ void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu)
 enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer)
 {
         struct kvm_vcpu *vcpu;
-        u64 now, sltime;
+        u64 sltime;
 
         vcpu = container_of(timer, struct kvm_vcpu, arch.ckc_timer);
-        now = kvm_s390_get_tod_clock_fast(vcpu->kvm);
-        sltime = tod_to_ns(vcpu->arch.sie_block->ckc - now);
+        sltime = __calculate_sltime(vcpu);
 
         /*
          * If the monotonic clock runs faster than the tod clock we might be
          * woken up too early and have to go back to sleep to avoid deadlocks.
          */
-        if (vcpu->arch.sie_block->ckc > now &&
-            hrtimer_forward_now(timer, ns_to_ktime(sltime)))
+        if (sltime && hrtimer_forward_now(timer, ns_to_ktime(sltime)))
                 return HRTIMER_RESTART;
         kvm_s390_vcpu_wakeup(vcpu);
         return HRTIMER_NORESTART;