From patchwork Thu Aug 14 12:18:44 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 4723951 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 67E38C0338 for ; Thu, 14 Aug 2014 12:21:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 238B9201E4 for ; Thu, 14 Aug 2014 12:21:29 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AB1EE2015A for ; Thu, 14 Aug 2014 12:21:27 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XHtzy-0004XR-63; Thu, 14 Aug 2014 12:19:18 +0000 Received: from fw-tnat.austin.arm.com ([217.140.110.23] helo=collaborate-mta1.arm.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XHtzv-0004Q1-HV for linux-arm-kernel@lists.infradead.org; Thu, 14 Aug 2014 12:19:16 +0000 Received: from approximate.cambridge.arm.com (approximate.cambridge.arm.com [10.1.209.43]) by collaborate-mta1.arm.com (Postfix) with ESMTPS id 507D513F61F; Thu, 14 Aug 2014 07:18:45 -0500 (CDT) From: Marc Zyngier To: Christoffer Dall Subject: Re: [PATCH 2/6] arm/arm64: KVM: Rename irq_active to irq_queued In-Reply-To: <1405003196-12403-3-git-send-email-christoffer.dall@linaro.org> (Christoffer Dall's message of "Thu, 10 Jul 2014 15:39:52 +0100") Organization: ARM Ltd References: <1405003196-12403-1-git-send-email-christoffer.dall@linaro.org> <1405003196-12403-3-git-send-email-christoffer.dall@linaro.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) Date: Thu, 14 Aug 2014 13:18:44 +0100 Message-ID: <87mwb7s1qz.fsf@approximate.cambridge.arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140814_051915_674937_F5A5F5E4 X-CRM114-Status: GOOD ( 24.22 ) X-Spam-Score: -0.7 (/) Cc: "kvmarm@lists.cs.columbia.edu" , "linux-arm-kernel@lists.infradead.org" , "eric.auger@linaro.org" X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi Christoffer, On Thu, Jul 10 2014 at 3:39:52 pm BST, Christoffer Dall wrote: > We have a special bitmap on the distributor struct to keep track of when > level-triggered interrupts are queued on the list registers. This was > named irq_active, which is confusing, because the active state of an > interrupt as per the GIC spec is a different thing, not specifically > related to edge-triggered/level-triggered configurations but rather > indicates an interrupt which has been ack'ed but not yet eoi'ed. > > Rename the bitmap and the corresponding accessor functions to irq_queued > to clarify what this is actually used for. > > Signed-off-by: Christoffer Dall So to illustrate what I was going on about the first time you summitted this patch, have a look at my below take on this. It is basically yours, but just with the bitmap named "irq_can_sample", which is exactly what this bitmap is about. What do you think? Thanks, M. From b6f864841878a5509e7d03581a224e270b25dd02 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 14 Aug 2014 13:14:34 +0100 Subject: [PATCH] KVM: arm: vgic: rename irq_active to irq_can sample Signed-off-by: Marc Zyngier --- include/kvm/arm_vgic.h | 4 ++-- virt/kvm/arm/vgic.c | 35 +++++++++++++++++++---------------- 2 files changed, 21 insertions(+), 18 deletions(-) diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 35b0c12..385d771 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -143,8 +143,8 @@ struct vgic_dist { /* Interrupt 'pin' level */ struct vgic_bitmap irq_state; - /* Level-triggered interrupt in progress */ - struct vgic_bitmap irq_active; + /* Can we sample the pending bit to inject an interrupt? */ + struct vgic_bitmap irq_can_sample; /* Interrupt priority. Not used yet. */ struct vgic_bytemap irq_priority; diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 73eba79..1dedf03 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -60,12 +60,12 @@ * the 'line' again. This is achieved as such: * * - When a level interrupt is moved onto a vcpu, the corresponding - * bit in irq_active is set. As long as this bit is set, the line + * bit in irq_can_sample is cleared. As long as this bit is 0, the line * will be ignored for further interrupts. The interrupt is injected * into the vcpu with the GICH_LR_EOI bit set (generate a * maintenance interrupt on EOI). * - When the interrupt is EOIed, the maintenance interrupt fires, - * and clears the corresponding bit in irq_active. This allow the + * and sets the corresponding bit in irq_can_sample. This allow the * interrupt line to be sampled again. */ @@ -196,25 +196,25 @@ static int vgic_irq_is_enabled(struct kvm_vcpu *vcpu, int irq) return vgic_bitmap_get_irq_val(&dist->irq_enabled, vcpu->vcpu_id, irq); } -static int vgic_irq_is_active(struct kvm_vcpu *vcpu, int irq) +static int vgic_irq_can_sample(struct kvm_vcpu *vcpu, int irq) { struct vgic_dist *dist = &vcpu->kvm->arch.vgic; - return vgic_bitmap_get_irq_val(&dist->irq_active, vcpu->vcpu_id, irq); + return vgic_bitmap_get_irq_val(&dist->irq_can_sample, vcpu->vcpu_id, irq); } -static void vgic_irq_set_active(struct kvm_vcpu *vcpu, int irq) +static void vgic_irq_allow_sample(struct kvm_vcpu *vcpu, int irq) { struct vgic_dist *dist = &vcpu->kvm->arch.vgic; - vgic_bitmap_set_irq_val(&dist->irq_active, vcpu->vcpu_id, irq, 1); + vgic_bitmap_set_irq_val(&dist->irq_can_sample, vcpu->vcpu_id, irq, 1); } -static void vgic_irq_clear_active(struct kvm_vcpu *vcpu, int irq) +static void vgic_irq_forbid_sample(struct kvm_vcpu *vcpu, int irq) { struct vgic_dist *dist = &vcpu->kvm->arch.vgic; - vgic_bitmap_set_irq_val(&dist->irq_active, vcpu->vcpu_id, irq, 0); + vgic_bitmap_set_irq_val(&dist->irq_can_sample, vcpu->vcpu_id, irq, 0); } static int vgic_dist_irq_is_pending(struct kvm_vcpu *vcpu, int irq) @@ -1079,8 +1079,8 @@ static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu) if (!vgic_irq_is_enabled(vcpu, vlr.irq)) { vgic_retire_lr(lr, vlr.irq, vcpu); - if (vgic_irq_is_active(vcpu, vlr.irq)) - vgic_irq_clear_active(vcpu, vlr.irq); + if (!vgic_irq_can_sample(vcpu, vlr.irq)) + vgic_irq_allow_sample(vcpu, vlr.irq); } } } @@ -1170,7 +1170,7 @@ static bool vgic_queue_sgi(struct kvm_vcpu *vcpu, int irq) static bool vgic_queue_hwirq(struct kvm_vcpu *vcpu, int irq) { - if (vgic_irq_is_active(vcpu, irq)) + if (!vgic_irq_can_sample(vcpu, irq)) return true; /* level interrupt, already queued */ if (vgic_queue_irq(vcpu, 0, irq)) { @@ -1178,7 +1178,7 @@ static bool vgic_queue_hwirq(struct kvm_vcpu *vcpu, int irq) vgic_dist_irq_clear(vcpu, irq); vgic_cpu_irq_clear(vcpu, irq); } else { - vgic_irq_set_active(vcpu, irq); + vgic_irq_forbid_sample(vcpu, irq); } return true; @@ -1252,8 +1252,8 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu) if (status & INT_STATUS_EOI) { /* - * Some level interrupts have been EOIed. Clear their - * active bit. + * Some level interrupts have been EOIed. Allow them + * to be resampled. */ u64 eisr = vgic_get_eisr(vcpu); unsigned long *eisr_ptr = (unsigned long *)&eisr; @@ -1262,7 +1262,7 @@ static bool vgic_process_maintenance(struct kvm_vcpu *vcpu) for_each_set_bit(lr, eisr_ptr, vgic->nr_lr) { struct vgic_lr vlr = vgic_get_lr(vcpu, lr); - vgic_irq_clear_active(vcpu, vlr.irq); + vgic_irq_allow_sample(vcpu, vlr.irq); WARN_ON(vlr.state & LR_STATE_MASK); vlr.state = 0; vgic_set_lr(vcpu, lr, vlr); @@ -1429,7 +1429,7 @@ static bool vgic_update_irq_state(struct kvm *kvm, int cpuid, goto out; } - if (is_level && vgic_irq_is_active(vcpu, irq_num)) { + if (is_level && !vgic_irq_can_sample(vcpu, irq_num)) { /* * Level interrupt in progress, will be picked up * when EOId. @@ -1506,6 +1506,9 @@ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu) if (i < VGIC_NR_PRIVATE_IRQS) vgic_bitmap_set_irq_val(&dist->irq_cfg, vcpu->vcpu_id, i, VGIC_CFG_EDGE); + /* Let vcpu0 also allow sampling of SPIs */ + if (i < VGIC_NR_PRIVATE_IRQS || vcpu->vcpu_id == 0) + vgic_irq_allow_sample(vcpu, i); vgic_cpu->vgic_irq_lr_map[i] = LR_EMPTY; }