Commit df9ba959 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source 



The doorbell interrupt is only useful if the vcpu is blocked on WFI.
In all other cases, recieving a doorbell interrupt is just a waste
of cycles.

So let's only enable the doorbell if a vcpu is getting blocked,
and disable it when it is unblocked. This is very similar to
what we're doing for the background timer.

Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent bdb2d2cc

include/kvm/arm_vgic.h

+3 −0
Original line number Diff line number Diff line
@@ -381,4 +381,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int irq, 
int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int irq,

				 struct kvm_kernel_irq_routing_entry *irq_entry);



void kvm_vgic_v4_enable_doorbell(struct kvm_vcpu *vcpu);

void kvm_vgic_v4_disable_doorbell(struct kvm_vcpu *vcpu);



#endif /* __KVM_ARM_VGIC_H */

virt/kvm/arm/arm.c

+2 −0
Original line number Diff line number Diff line
@@ -315,11 +315,13 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) 
void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)

{

	kvm_timer_schedule(vcpu);

	kvm_vgic_v4_enable_doorbell(vcpu);

}



void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)

{

	kvm_timer_unschedule(vcpu);

	kvm_vgic_v4_disable_doorbell(vcpu);

}



int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)

virt/kvm/arm/vgic/vgic-v4.c

+18 −0
Original line number Diff line number Diff line
@@ -233,3 +233,21 @@ out: 
	mutex_unlock(&its->its_lock);

	return ret;

}



void kvm_vgic_v4_enable_doorbell(struct kvm_vcpu *vcpu)

{

	if (vgic_supports_direct_msis(vcpu->kvm)) {

		int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;

		if (irq)

			enable_irq(irq);

	}

}



void kvm_vgic_v4_disable_doorbell(struct kvm_vcpu *vcpu)

{

	if (vgic_supports_direct_msis(vcpu->kvm)) {

		int irq = vcpu->arch.vgic_cpu.vgic_v3.its_vpe.irq;

		if (irq)

			disable_irq(irq);

	}

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE