From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH v3 51/59] KVM: arm/arm64: GICv4: Add doorbell interrupt handling Date: Mon, 28 Aug 2017 20:18:55 +0200 Message-ID: <20170828181855.GM24649@cbox> References: <20170731172637.29355-1-marc.zyngier@arm.com> <20170731172637.29355-52-marc.zyngier@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Jason Cooper , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Thomas Gleixner , kvmarm@lists.cs.columbia.edu To: Marc Zyngier Return-path: Content-Disposition: inline In-Reply-To: <20170731172637.29355-52-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 List-Id: kvm.vger.kernel.org On Mon, Jul 31, 2017 at 06:26:29PM +0100, Marc Zyngier wrote: > When a vPE is not running, a VLPI being made pending results in a > doorbell interrupt being delivered. Let's handle this interrupt > and update the pending_last flag that indicates that VLPIs are > pending. The corresponding vcpu is also kicked into action. > > Signed-off-by: Marc Zyngier > --- > virt/kvm/arm/vgic/vgic-v4.c | 34 ++++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c > index 534d3051a078..6af3cde6d7d4 100644 > --- a/virt/kvm/arm/vgic/vgic-v4.c > +++ b/virt/kvm/arm/vgic/vgic-v4.c > @@ -21,6 +21,19 @@ > > #include "vgic.h" > > +static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info) > +{ > + struct kvm_vcpu *vcpu = info; > + > + if (!kvm_vgic_vcpu_pending_irq(vcpu)) { > + vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true; > + kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); > + kvm_vcpu_kick(vcpu); > + } Can this ever fire while vgic_v4_init() is running and before te rest of the system has been properly initialized with some entertaining results to follow? (I'm not sure if spurious doorbell non-resident vPE interrupts is a thing or not). > + > + return IRQ_HANDLED; > +} > + > int vgic_v4_init(struct kvm *kvm) > { > struct vgic_dist *dist = &kvm->arch.vgic; > @@ -57,16 +70,37 @@ int vgic_v4_init(struct kvm *kvm) > return ret; > } > > + kvm_for_each_vcpu(i, vcpu, kvm) { > + int irq = dist->its_vm.vpes[i]->irq; > + > + ret = request_irq(irq, vgic_v4_doorbell_handler, > + 0, "vcpu", vcpu); > + if (ret) { > + kvm_err("failed to allocate vcpu IRQ%d\n", irq); > + dist->its_vm.nr_vpes = i; That's a neat trick for the error handling. Might deserve a tiny comment. > + break; > + } > + } > + > + if (ret) > + vgic_v4_teardown(kvm); > + > return ret; > } > > void vgic_v4_teardown(struct kvm *kvm) > { > struct its_vm *its_vm = &kvm->arch.vgic.its_vm; > + int i; > > if (!its_vm->vpes) > return; > > + for (i = 0; i < its_vm->nr_vpes; i++) { > + struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, i); > + free_irq(its_vm->vpes[i]->irq, vcpu); > + } > + > its_free_vcpu_irqs(its_vm); > kfree(its_vm->vpes); > its_vm->nr_vpes = 0; > -- > 2.11.0 > Thanks, -Christoffer