1 files changed, 32 insertions, 68 deletions

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 90c8de22a2a0..1be3d8da49e9 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -544,13 +544,13 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)
         int rc = 0;
 
         if (atomic_read(&li->active)) {
-                spin_lock_bh(&li->lock);
+                spin_lock(&li->lock);
                 list_for_each_entry(inti, &li->list, list)
                         if (__interrupt_is_deliverable(vcpu, inti)) {
                                 rc = 1;
                                 break;
                         }
-                spin_unlock_bh(&li->lock);
+                spin_unlock(&li->lock);
         }
 
         if ((!rc) && atomic_read(&fi->active)) {
@@ -585,88 +585,56 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
 {
         u64 now, sltime;
-        DECLARE_WAITQUEUE(wait, current);
 
         vcpu->stat.exit_wait_state++;
-        if (kvm_cpu_has_interrupt(vcpu))
-                return 0;
 
-        __set_cpu_idle(vcpu);
-        spin_lock_bh(&vcpu->arch.local_int.lock);
-        vcpu->arch.local_int.timer_due = 0;
-        spin_unlock_bh(&vcpu->arch.local_int.lock);
+        /* fast path */
+        if (kvm_cpu_has_pending_timer(vcpu) || kvm_arch_vcpu_runnable(vcpu))
+                return 0;
 
         if (psw_interrupts_disabled(vcpu)) {
                 VCPU_EVENT(vcpu, 3, "%s", "disabled wait");
-                __unset_cpu_idle(vcpu);
                 return -EOPNOTSUPP; /* disabled wait */
         }
 
+        __set_cpu_idle(vcpu);
         if (!ckc_interrupts_enabled(vcpu)) {
                 VCPU_EVENT(vcpu, 3, "%s", "enabled wait w/o timer");
                 goto no_timer;
         }
 
         now = get_tod_clock_fast() + vcpu->arch.sie_block->epoch;
-        if (vcpu->arch.sie_block->ckc < now) {
-                __unset_cpu_idle(vcpu);
-                return 0;
-        }
-
         sltime = tod_to_ns(vcpu->arch.sie_block->ckc - now);
-
         hrtimer_start(&vcpu->arch.ckc_timer, ktime_set (0, sltime) , HRTIMER_MODE_REL);
         VCPU_EVENT(vcpu, 5, "enabled wait via clock comparator: %llx ns", sltime);
 no_timer:
         srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
-        spin_lock(&vcpu->arch.local_int.float_int->lock);
-        spin_lock_bh(&vcpu->arch.local_int.lock);
-        add_wait_queue(&vcpu->wq, &wait);
-        while (list_empty(&vcpu->arch.local_int.list) &&
-                list_empty(&vcpu->arch.local_int.float_int->list) &&
-                (!vcpu->arch.local_int.timer_due) &&
-                !signal_pending(current) &&
-                !kvm_s390_si_ext_call_pending(vcpu)) {
-                set_current_state(TASK_INTERRUPTIBLE);
-                spin_unlock_bh(&vcpu->arch.local_int.lock);
-                spin_unlock(&vcpu->arch.local_int.float_int->lock);
-                schedule();
-                spin_lock(&vcpu->arch.local_int.float_int->lock);
-                spin_lock_bh(&vcpu->arch.local_int.lock);
-        }
+        kvm_vcpu_block(vcpu);
         __unset_cpu_idle(vcpu);
-        __set_current_state(TASK_RUNNING);
-        remove_wait_queue(&vcpu->wq, &wait);
-        spin_unlock_bh(&vcpu->arch.local_int.lock);
-        spin_unlock(&vcpu->arch.local_int.float_int->lock);
         vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 
         hrtimer_try_to_cancel(&vcpu->arch.ckc_timer);
         return 0;
 }
 
-void kvm_s390_tasklet(unsigned long parm)
+void kvm_s390_vcpu_wakeup(struct kvm_vcpu *vcpu)
 {
-        struct kvm_vcpu *vcpu = (struct kvm_vcpu *) parm;
-
-        spin_lock(&vcpu->arch.local_int.lock);
-        vcpu->arch.local_int.timer_due = 1;
-        if (waitqueue_active(&vcpu->wq))
+        if (waitqueue_active(&vcpu->wq)) {
+                /*
+                 * The vcpu gave up the cpu voluntarily, mark it as a good
+                 * yield-candidate.
+                 */
+                vcpu->preempted = true;
                 wake_up_interruptible(&vcpu->wq);
-        spin_unlock(&vcpu->arch.local_int.lock);
+        }
 }
 
-/*
- * low level hrtimer wake routine. Because this runs in hardirq context
- * we schedule a tasklet to do the real work.
- */
 enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer)
 {
         struct kvm_vcpu *vcpu;
 
         vcpu = container_of(timer, struct kvm_vcpu, arch.ckc_timer);
-        vcpu->preempted = true;
-        tasklet_schedule(&vcpu->arch.tasklet);
+        kvm_s390_vcpu_wakeup(vcpu);
 
         return HRTIMER_NORESTART;
 }
@@ -676,13 +644,13 @@ void kvm_s390_clear_local_irqs(struct kvm_vcpu *vcpu)
         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
         struct kvm_s390_interrupt_info  *n, *inti = NULL;
 
-        spin_lock_bh(&li->lock);
+        spin_lock(&li->lock);
         list_for_each_entry_safe(inti, n, &li->list, list) {
                 list_del(&inti->list);
                 kfree(inti);
         }
         atomic_set(&li->active, 0);
-        spin_unlock_bh(&li->lock);
+        spin_unlock(&li->lock);
 
         /* clear pending external calls set by sigp interpretation facility */
         atomic_clear_mask(CPUSTAT_ECALL_PEND, &vcpu->arch.sie_block->cpuflags);
@@ -701,7 +669,7 @@ void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
         if (atomic_read(&li->active)) {
                 do {
                         deliver = 0;
-                        spin_lock_bh(&li->lock);
+                        spin_lock(&li->lock);
                         list_for_each_entry_safe(inti, n, &li->list, list) {
                                 if (__interrupt_is_deliverable(vcpu, inti)) {
                                         list_del(&inti->list);
@@ -712,7 +680,7 @@ void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
                         }
                         if (list_empty(&li->list))
                                 atomic_set(&li->active, 0);
-                        spin_unlock_bh(&li->lock);
+                        spin_unlock(&li->lock);
                         if (deliver) {
                                 __do_deliver_interrupt(vcpu, inti);
                                 kfree(inti);
@@ -758,7 +726,7 @@ void kvm_s390_deliver_pending_machine_checks(struct kvm_vcpu *vcpu)
         if (atomic_read(&li->active)) {
                 do {
                         deliver = 0;
-                        spin_lock_bh(&li->lock);
+                        spin_lock(&li->lock);
                         list_for_each_entry_safe(inti, n, &li->list, list) {
                                 if ((inti->type == KVM_S390_MCHK) &&
                                     __interrupt_is_deliverable(vcpu, inti)) {
@@ -770,7 +738,7 @@ void kvm_s390_deliver_pending_machine_checks(struct kvm_vcpu *vcpu)
                         }
                         if (list_empty(&li->list))
                                 atomic_set(&li->active, 0);
-                        spin_unlock_bh(&li->lock);
+                        spin_unlock(&li->lock);
                         if (deliver) {
                                 __do_deliver_interrupt(vcpu, inti);
                                 kfree(inti);
@@ -817,11 +785,11 @@ int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code)
 
         VCPU_EVENT(vcpu, 3, "inject: program check %d (from kernel)", code);
         trace_kvm_s390_inject_vcpu(vcpu->vcpu_id, inti->type, code, 0, 1);
-        spin_lock_bh(&li->lock);
+        spin_lock(&li->lock);
         list_add(&inti->list, &li->list);
         atomic_set(&li->active, 1);
         BUG_ON(waitqueue_active(li->wq));
-        spin_unlock_bh(&li->lock);
+        spin_unlock(&li->lock);
         return 0;
 }
 
@@ -842,11 +810,11 @@ int kvm_s390_inject_prog_irq(struct kvm_vcpu *vcpu,
 
         inti->type = KVM_S390_PROGRAM_INT;
         memcpy(&inti->pgm, pgm_info, sizeof(inti->pgm));
-        spin_lock_bh(&li->lock);
+        spin_lock(&li->lock);
         list_add(&inti->list, &li->list);
         atomic_set(&li->active, 1);
         BUG_ON(waitqueue_active(li->wq));
-        spin_unlock_bh(&li->lock);
+        spin_unlock(&li->lock);
         return 0;
 }
 
@@ -934,12 +902,10 @@ static int __inject_vm(struct kvm *kvm, struct kvm_s390_interrupt_info *inti)
         }
         dst_vcpu = kvm_get_vcpu(kvm, sigcpu);
         li = &dst_vcpu->arch.local_int;
-        spin_lock_bh(&li->lock);
+        spin_lock(&li->lock);
         atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
-        if (waitqueue_active(li->wq))
-                wake_up_interruptible(li->wq);
-        kvm_get_vcpu(kvm, sigcpu)->preempted = true;
-        spin_unlock_bh(&li->lock);
+        spin_unlock(&li->lock);
+        kvm_s390_vcpu_wakeup(kvm_get_vcpu(kvm, sigcpu));
 unlock_fi:
         spin_unlock(&fi->lock);
         mutex_unlock(&kvm->lock);
@@ -1081,7 +1047,7 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
 
         mutex_lock(&vcpu->kvm->lock);
         li = &vcpu->arch.local_int;
-        spin_lock_bh(&li->lock);
+        spin_lock(&li->lock);
         if (inti->type == KVM_S390_PROGRAM_INT)
                 list_add(&inti->list, &li->list);
         else
@@ -1090,11 +1056,9 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
         if (inti->type == KVM_S390_SIGP_STOP)
                 li->action_bits |= ACTION_STOP_ON_STOP;
         atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
-        if (waitqueue_active(&vcpu->wq))
-                wake_up_interruptible(&vcpu->wq);
-        vcpu->preempted = true;
-        spin_unlock_bh(&li->lock);
+        spin_unlock(&li->lock);
         mutex_unlock(&vcpu->kvm->lock);
+        kvm_s390_vcpu_wakeup(vcpu);
         return 0;
 }