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Commit b037a4f3 authored by Christian Borntraeger's avatar Christian Borntraeger Committed by Avi Kivity
Browse files

KVM: s390: optimize float int lock: spin_lock_bh --> spin_lock 



The floating interrupt lock is only taken in process context. We can
replace all spin_lock_bh with standard spin_lock calls.

Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarChristian Ehrhardt <ehrhardt@de.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent ca872302

arch/s390/kvm/interrupt.c

+10 −10
Original line number Diff line number Diff line
@@ -301,13 +301,13 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu) 
	}



	if ((!rc) && atomic_read(&fi->active)) {

		spin_lock_bh(&fi->lock);

		spin_lock(&fi->lock);

		list_for_each_entry(inti, &fi->list, list)

			if (__interrupt_is_deliverable(vcpu, inti)) {

				rc = 1;

				break;

			}

		spin_unlock_bh(&fi->lock);

		spin_unlock(&fi->lock);

	}



	if ((!rc) && (vcpu->arch.sie_block->ckc <
@@ -368,7 +368,7 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu) 
	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:

	spin_lock_bh(&vcpu->arch.local_int.float_int->lock);

	spin_lock(&vcpu->arch.local_int.float_int->lock);

	spin_lock_bh(&vcpu->arch.local_int.lock);

	add_wait_queue(&vcpu->arch.local_int.wq, &wait);

	while (list_empty(&vcpu->arch.local_int.list) &&
@@ -377,18 +377,18 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu) 
		!signal_pending(current)) {

		set_current_state(TASK_INTERRUPTIBLE);

		spin_unlock_bh(&vcpu->arch.local_int.lock);

		spin_unlock_bh(&vcpu->arch.local_int.float_int->lock);

		spin_unlock(&vcpu->arch.local_int.float_int->lock);

		vcpu_put(vcpu);

		schedule();

		vcpu_load(vcpu);

		spin_lock_bh(&vcpu->arch.local_int.float_int->lock);

		spin_lock(&vcpu->arch.local_int.float_int->lock);

		spin_lock_bh(&vcpu->arch.local_int.lock);

	}

	__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_bh(&vcpu->arch.local_int.float_int->lock);

	spin_unlock(&vcpu->arch.local_int.float_int->lock);

	hrtimer_try_to_cancel(&vcpu->arch.ckc_timer);

	return 0;

}
@@ -455,7 +455,7 @@ void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu) 
	if (atomic_read(&fi->active)) {

		do {

			deliver = 0;

			spin_lock_bh(&fi->lock);

			spin_lock(&fi->lock);

			list_for_each_entry_safe(inti, n, &fi->list, list) {

				if (__interrupt_is_deliverable(vcpu, inti)) {

					list_del(&inti->list);
@@ -466,7 +466,7 @@ void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu) 
			}

			if (list_empty(&fi->list))

				atomic_set(&fi->active, 0);

			spin_unlock_bh(&fi->lock);

			spin_unlock(&fi->lock);

			if (deliver) {

				__do_deliver_interrupt(vcpu, inti);

				kfree(inti);
@@ -531,7 +531,7 @@ int kvm_s390_inject_vm(struct kvm *kvm, 


	mutex_lock(&kvm->lock);

	fi = &kvm->arch.float_int;

	spin_lock_bh(&fi->lock);

	spin_lock(&fi->lock);

	list_add_tail(&inti->list, &fi->list);

	atomic_set(&fi->active, 1);

	sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS);
@@ -548,7 +548,7 @@ int kvm_s390_inject_vm(struct kvm *kvm, 
	if (waitqueue_active(&li->wq))

		wake_up_interruptible(&li->wq);

	spin_unlock_bh(&li->lock);

	spin_unlock_bh(&fi->lock);

	spin_unlock(&fi->lock);

	mutex_unlock(&kvm->lock);

	return 0;

}

arch/s390/kvm/kvm-s390.c

+2 −2
Original line number Diff line number Diff line
@@ -318,11 +318,11 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, 
	spin_lock_init(&vcpu->arch.local_int.lock);

	INIT_LIST_HEAD(&vcpu->arch.local_int.list);

	vcpu->arch.local_int.float_int = &kvm->arch.float_int;

	spin_lock_bh(&kvm->arch.float_int.lock);

	spin_lock(&kvm->arch.float_int.lock);

	kvm->arch.float_int.local_int[id] = &vcpu->arch.local_int;

	init_waitqueue_head(&vcpu->arch.local_int.wq);

	vcpu->arch.local_int.cpuflags = &vcpu->arch.sie_block->cpuflags;

	spin_unlock_bh(&kvm->arch.float_int.lock);

	spin_unlock(&kvm->arch.float_int.lock);



	rc = kvm_vcpu_init(vcpu, kvm, id);

	if (rc)

arch/s390/kvm/priv.c

+2 −2
Original line number Diff line number Diff line
@@ -204,11 +204,11 @@ static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem) 
	int cpus = 0;

	int n;



	spin_lock_bh(&fi->lock);

	spin_lock(&fi->lock);

	for (n = 0; n < KVM_MAX_VCPUS; n++)

		if (fi->local_int[n])

			cpus++;

	spin_unlock_bh(&fi->lock);

	spin_unlock(&fi->lock);



	/* deal with other level 3 hypervisors */

	if (stsi(mem, 3, 2, 2) == -ENOSYS)

arch/s390/kvm/sigp.c

+8 −8
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ static int __sigp_sense(struct kvm_vcpu *vcpu, u16 cpu_addr, 
	if (cpu_addr >= KVM_MAX_VCPUS)

		return 3; /* not operational */



	spin_lock_bh(&fi->lock);

	spin_lock(&fi->lock);

	if (fi->local_int[cpu_addr] == NULL)

		rc = 3; /* not operational */

	else if (atomic_read(fi->local_int[cpu_addr]->cpuflags)
@@ -64,7 +64,7 @@ static int __sigp_sense(struct kvm_vcpu *vcpu, u16 cpu_addr, 
		*reg |= SIGP_STAT_STOPPED;

		rc = 1; /* status stored */

	}

	spin_unlock_bh(&fi->lock);

	spin_unlock(&fi->lock);



	VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", cpu_addr, rc);

	return rc;
@@ -86,7 +86,7 @@ static int __sigp_emergency(struct kvm_vcpu *vcpu, u16 cpu_addr) 


	inti->type = KVM_S390_INT_EMERGENCY;



	spin_lock_bh(&fi->lock);

	spin_lock(&fi->lock);

	li = fi->local_int[cpu_addr];

	if (li == NULL) {

		rc = 3; /* not operational */
@@ -102,7 +102,7 @@ static int __sigp_emergency(struct kvm_vcpu *vcpu, u16 cpu_addr) 
	spin_unlock_bh(&li->lock);

	rc = 0; /* order accepted */

unlock:

	spin_unlock_bh(&fi->lock);

	spin_unlock(&fi->lock);

	VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", cpu_addr);

	return rc;

}
@@ -123,7 +123,7 @@ static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int store) 


	inti->type = KVM_S390_SIGP_STOP;



	spin_lock_bh(&fi->lock);

	spin_lock(&fi->lock);

	li = fi->local_int[cpu_addr];

	if (li == NULL) {

		rc = 3; /* not operational */
@@ -142,7 +142,7 @@ static int __sigp_stop(struct kvm_vcpu *vcpu, u16 cpu_addr, int store) 
	spin_unlock_bh(&li->lock);

	rc = 0; /* order accepted */

unlock:

	spin_unlock_bh(&fi->lock);

	spin_unlock(&fi->lock);

	VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", cpu_addr);

	return rc;

}
@@ -188,7 +188,7 @@ static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address, 
	if (!inti)

		return 2; /* busy */



	spin_lock_bh(&fi->lock);

	spin_lock(&fi->lock);

	li = fi->local_int[cpu_addr];



	if ((cpu_addr >= KVM_MAX_VCPUS) || (li == NULL)) {
@@ -220,7 +220,7 @@ static int __sigp_set_prefix(struct kvm_vcpu *vcpu, u16 cpu_addr, u32 address, 
out_li:

	spin_unlock_bh(&li->lock);

out_fi:

	spin_unlock_bh(&fi->lock);

	spin_unlock(&fi->lock);

	return rc;

}