| Message ID | 20171027142855.21584-21-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 27/10/2017 16:28, Marc Zyngier wrote: > 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@linaro.org> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Eric > --- > 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 8388c1cc23f6..092a4ec03e57 100644 > --- a/virt/kvm/arm/arm.c > +++ b/virt/kvm/arm/arm.c > @@ -316,11 +316,13 @@ 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 ea898af1a7a9..1a2f2fcdfa67 100644 > --- a/virt/kvm/arm/vgic/vgic-v4.c > +++ b/virt/kvm/arm/vgic/vgic-v4.c > @@ -237,3 +237,21 @@ 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); > + } > +} >
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 8388c1cc23f6..092a4ec03e57 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -316,11 +316,13 @@ 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 ea898af1a7a9..1a2f2fcdfa67 100644 --- a/virt/kvm/arm/vgic/vgic-v4.c +++ b/virt/kvm/arm/vgic/vgic-v4.c @@ -237,3 +237,21 @@ 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); + } +}