From: Marc Zyngier <marc.zyngier@xxxxxxx> 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: Christoffer Dall <cdall@xxxxxxxxxx> Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> --- include/kvm/arm_vgic.h | 3 +++ virt/kvm/arm/arm.c | 2 ++ virt/kvm/arm/vgic/vgic-v4.c | 18 ++++++++++++++++++ 3 files changed, 23 insertions(+) diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 2f750c770bf2..8c896540a72c 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -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 */ diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 34a15c0c65ab..01e575b9f78b 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -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) diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c index 796e00c77903..1375a53054b9 100644 --- a/virt/kvm/arm/vgic/vgic-v4.c +++ b/virt/kvm/arm/vgic/vgic-v4.c @@ -233,3 +233,21 @@ int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int virq, 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); + } +} -- 2.14.2