Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ffeca0ae authored by Jens Freimann's avatar Jens Freimann Committed by Christian Borntraeger
Browse files

KVM: s390: optimize interrupt handling round trip time 



We can avoid checking guest control registers and guest PSW as well
as all the masking and calculations on the interrupt masks when
no interrupts are pending.

Also, the check for IRQ_PEND_COUNT can be removed, because we won't
enter the while loop if no interrupts are pending and invalid interrupt
types can't be injected.

Signed-off-by: default avatarJens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: default avatarDominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 27406cd5

arch/s390/kvm/interrupt.c

+4 −7
Original line number Diff line number Diff line
@@ -134,6 +134,8 @@ static unsigned long deliverable_irqs(struct kvm_vcpu *vcpu) 


	active_mask = pending_local_irqs(vcpu);

	active_mask |= pending_floating_irqs(vcpu);

	if (!active_mask)

		return 0;



	if (psw_extint_disabled(vcpu))

		active_mask &= ~IRQ_PEND_EXT_MASK;
@@ -941,12 +943,9 @@ int __must_check kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu) 
	if (cpu_timer_irq_pending(vcpu))

		set_bit(IRQ_PEND_EXT_CPU_TIMER, &li->pending_irqs);



	do {

		irqs = deliverable_irqs(vcpu);

	while ((irqs = deliverable_irqs(vcpu)) && !rc) {

		/* bits are in the order of interrupt priority */

		irq_type = find_first_bit(&irqs, IRQ_PEND_COUNT);

		if (irq_type == IRQ_PEND_COUNT)

			break;

		if (is_ioirq(irq_type)) {

			rc = __deliver_io(vcpu, irq_type);

		} else {
@@ -958,9 +957,7 @@ int __must_check kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu) 
			}

			rc = func(vcpu);

		}

		if (rc)

			break;

	} while (!rc);

	}



	set_intercept_indicators(vcpu);