From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: [PATCH v4 20/26] KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source Date: Fri, 6 Oct 2017 16:33:55 +0100 Message-ID: <20171006153401.5481-21-marc.zyngier@arm.com> References: <20171006153401.5481-1-marc.zyngier@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4E28549C23 for ; Fri, 6 Oct 2017 11:34:19 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id i9xwFl0O2KSQ for ; Fri, 6 Oct 2017 11:34:18 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4014D49C3C for ; Fri, 6 Oct 2017 11:34:18 -0400 (EDT) In-Reply-To: <20171006153401.5481-1-marc.zyngier@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Andre Przywara List-Id: kvmarm@lists.cs.columbia.edu 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 Signed-off-by: Marc Zyngier --- 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 2c250ee37878..5ee69aec990a 100644 --- a/virt/kvm/arm/vgic/vgic-v4.c +++ b/virt/kvm/arm/vgic/vgic-v4.c @@ -235,3 +235,21 @@ 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); + } +} -- 2.14.1