From patchwork Wed Feb 11 08:32:23 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 5811171 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 [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C126CBF440 for ; Wed, 11 Feb 2015 08:47:39 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id BC66B20218 for ; Wed, 11 Feb 2015 08:47:38 +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 ABC7E20211 for ; Wed, 11 Feb 2015 08:47:36 +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 1YLSud-0003DP-Sb; Wed, 11 Feb 2015 08:44:47 +0000 Received: from mail-ie0-f171.google.com ([209.85.223.171]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YLSmM-0002Yd-SG for linux-arm-kernel@lists.infradead.org; Wed, 11 Feb 2015 08:36:16 +0000 Received: by iery20 with SMTP id y20so2324406ier.9 for ; Wed, 11 Feb 2015 00:35:54 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=RdbqbSGba2o1hXOYtygMToOltlVPilN6ZeW/zn1xdLk=; b=SDGLpDhw4wXkE3CbF76zPNXJMrpBvsQEQmbYWmmEo3JfNqHfT3YBnZMiAv8Y9KnFfZ ALbVyfb0GqsI6toogrH8f3XBeRxL7n5hKKVB7s8xMGT0bBGRH/Im3xBbCCsfgx9eLcjR CBldzTk7mCGsq1q24gP9zsaZwHRMpvCFK0u6QbUTnYHNKPlA2DQKc47yQ+ri3OjRYgNk 2WJgxCYC2OucFLVjdNf/T15R1fNfQbn2oQbIH8GPVZIYdQhmGzbRussyWGnAdE5HCymD 6cH4hB0gPjKO8swnqKuOVb9/ISvKXzT1Ucy8cJllVSinzIYC2PdxFTootppi+gVJnFxK c4nQ== X-Gm-Message-State: ALoCoQn+vORlk/3HqJ04GYZNExHGmg67C77eLa0XOz0oh/KkS3j0NbHucfA+me4Yi/78jrKv2juz X-Received: by 10.50.82.68 with SMTP id g4mr28401876igy.26.1423643753946; Wed, 11 Feb 2015 00:35:53 -0800 (PST) Received: from gnx2579.solutionip.com ([113.28.134.59]) by mx.google.com with ESMTPSA id m38sm62189ioi.39.2015.02.11.00.35.49 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 11 Feb 2015 00:35:53 -0800 (PST) From: Eric Auger To: eric.auger@st.com, eric.auger@linaro.org, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, alex.williamson@redhat.com, feng.wu@intel.com Subject: [RFC v4 13/13] KVM: arm: vgic: forwarding control Date: Wed, 11 Feb 2015 09:32:23 +0100 Message-Id: <1423643543-24409-14-git-send-email-eric.auger@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1423643543-24409-1-git-send-email-eric.auger@linaro.org> References: <1423643543-24409-1-git-send-email-eric.auger@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150211_003615_034147_540476FA X-CRM114-Status: GOOD ( 23.09 ) X-Spam-Score: -0.7 (/) Cc: b.reynal@virtualopensystems.com, patches@linaro.org, gleb@kernel.org, andre.przywara@arm.com, a.rigo@virtualopensystems.com, pbonzini@redhat.com, a.motakis@virtualopensystems.com 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_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 This patch sets __KVM_HAVE_ARCH_KVM_VFIO_FORWARD and implements kvm_arch_set_forward for ARM. As a result the KVM-VFIO device now allows to forward/unforward a VFIO device IRQ on ARM. kvm_arch_set_forward and kvm_arch_unset_forward mostly take care of VGIC programming: physical IRQ/guest IRQ mapping, list register cleanup, VGIC state machine. Signed-off-by: Eric Auger --- v3 -> v4: - code originally located in kvm_vfio_arm.c - kvm_arch_vfio_{set|unset}_forward renamed into kvm_arch_{set|unset}_forward - split into 2 functions (set/unset) since unset does not fail anymore - unset can be invoked at whatever time. Extra care is taken to handle transition in VGIC state machine, LR cleanup, ... v2 -> v3: - renaming of kvm_arch_set_fwd_state into kvm_arch_vfio_set_forward - takes a bool arg instead of kvm_fwd_irq_action enum - removal of KVM_VFIO_IRQ_CLEANUP - platform device check now happens here - more precise errors returned - irq_eoi handled externally to this patch (VGIC) - correct enable_irq bug done twice - reword the commit message - correct check of platform_bus_type - use raw_spin_lock_irqsave and check the validity of the handler --- arch/arm/include/asm/kvm_host.h | 1 + virt/kvm/arm/vgic.c | 190 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 191 insertions(+) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index a9f2c31..6e8be2b 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -29,6 +29,7 @@ #define __KVM_HAVE_ARCH_INTC_INITIALIZED #define __KVM_HAVE_ARCH_HALT_GUEST +#define __KVM_HAVE_ARCH_KVM_VFIO_FORWARD #if defined(CONFIG_KVM_ARM_MAX_VCPUS) #define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index ace8e46..81bb2f2 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -2691,3 +2691,193 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, { return 0; } + +/** + * kvm_arch_set_forward - Set forwarding for a given IRQ + * + * @kvm: handle to the VM + * @host_irq: physical IRQ number + * @guest_irq: virtual IRQ number + * + * This function is supposed to be called only if the IRQ + * is not in progress: ie. not active at VGIC level and not + * currently under injection in the KVM. + */ +int kvm_arch_set_forward(struct kvm *kvm, unsigned int host_irq, + unsigned int guest_irq) +{ + irq_hw_number_t gic_irq; + struct irq_desc *desc = irq_to_desc(host_irq); + struct irq_data *d; + unsigned long flags; + struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, 0); + int ret = 0; + int spi_id = guest_irq + VGIC_NR_PRIVATE_IRQS; + struct vgic_dist *dist = &kvm->arch.vgic; + + if (!vcpu) + return 0; + + spin_lock(&dist->lock); + + raw_spin_lock_irqsave(&desc->lock, flags); + d = &desc->irq_data; + gic_irq = irqd_to_hwirq(d); + irqd_set_irq_forwarded(d); + /* + * next physical IRQ will be be handled as forwarded + * by the host (priority drop only) + */ + + raw_spin_unlock_irqrestore(&desc->lock, flags); + + /* + * need to release the dist spin_lock here since + * vgic_map_phys_irq can sleep + */ + spin_unlock(&dist->lock); + ret = vgic_map_phys_irq(vcpu, spi_id, (int)gic_irq); + /* + * next guest_irq injection will be considered as + * forwarded and next flush will program LR + * without maintenance IRQ but with HW bit set + */ + return ret; +} + +/** + * kvm_arch_unset_forward - Unset forwarding for a given IRQ + * + * @kvm: handle to the VM + * @host_irq: physical IRQ number + * @guest_irq: virtual IRQ number + * @active: returns whether the physical IRQ is active + * + * This function must be called when the host_irq is disabled + * and guest has been exited and prevented from being re-entered. + * + */ +void kvm_arch_unset_forward(struct kvm *kvm, + unsigned int host_irq, + unsigned int guest_irq, + bool *active) +{ + struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, 0); + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + struct vgic_dist *dist = &kvm->arch.vgic; + int ret, lr; + struct vgic_lr vlr; + struct irq_desc *desc = irq_to_desc(host_irq); + struct irq_data *d; + unsigned long flags; + irq_hw_number_t gic_irq; + int spi_id = guest_irq + VGIC_NR_PRIVATE_IRQS; + struct irq_chip *chip; + bool queued, needs_deactivate = true; + + spin_lock(&dist->lock); + + irq_get_irqchip_state(host_irq, IRQCHIP_STATE_ACTIVE, active); + + if (!vcpu) + goto out; + + raw_spin_lock_irqsave(&desc->lock, flags); + d = irq_desc_get_irq_data(desc); + gic_irq = irqd_to_hwirq(d); + raw_spin_unlock_irqrestore(&desc->lock, flags); + + ret = vgic_unmap_phys_irq(vcpu, spi_id, gic_irq); + /* + * subsequent update_irq_pending or flush will handle this + * irq as forwarded + */ + + if (likely(!(*active))) { + /* + * the IRQ was not active. It may happen the handle_fasteoi_irq + * is entered afterwards due to lazy disable_irq. If this + * happens the IRQ will be deactivated and never be injected. + * let's simply prepare the states for subsequent non forwarded + * injection + */ + vgic_dist_irq_clear_level(vcpu, spi_id); + vgic_dist_irq_clear_pending(vcpu, spi_id); + vgic_irq_clear_queued(vcpu, spi_id); + needs_deactivate = false; + goto out; + } + + /* is there any list register with valid state? */ + lr = vgic_cpu->vgic_irq_lr_map[spi_id]; + queued = false; + if (lr != LR_EMPTY) { + vlr = vgic_get_lr(vcpu, lr); + if (vlr.state & LR_STATE_MASK) + queued = true; + } + + if (!queued) { + vgic_irq_clear_queued(vcpu, spi_id); + if (vgic_dist_irq_is_pending(vcpu, spi_id)) { + /* + * IRQ is injected but not yet queued. LR will be + * written with EOI_INT and process_maintenance will + * reset the states: queued, level(resampler). Pending + * will be reset on flush. + */ + vgic_dist_irq_set_level(vcpu, spi_id); + } else { + /* + * We are before the injection (update_irq_pending). + * This is the most tricky window. Due to the usage of + * disable_irq in generic unforward part (mandated by + * resamplefd unmask VFIO integration), there is a risk + * the fasteoi handler returns without calling the VFIO + * handler and deactivates the physical IRQ (lazy + * disable). Hence we cannot know whether the IRQ will + * ever be injected. The only solution found is to do as + * if the IRQ were not active. The active parameter + * typically is used by the caller to know whether + * it needs to mask * the IRQ. If not duly masked, + * another physical IRQ may hit again while the previous + * virtual IRQ is in progress. Update_irq_pending + * validate_injection will prevent this injection. + */ + vgic_dist_irq_clear_level(vcpu, spi_id); + *active = false; + } + goto out; + } + + /* + * the virtual IRQ is queued and a valid LR exists, let's patch it for + * EOI maintenance + */ + vlr.state |= LR_EOI_INT; + vgic_set_lr(vcpu, lr, vlr); + /* + * we expect a maintenance IRQ which will reset the + * queued, pending and level states + */ + vgic_dist_irq_set_level(vcpu, spi_id); + vgic_dist_irq_set_pending(vcpu, spi_id); + vgic_irq_set_queued(vcpu, spi_id); + +out: + + raw_spin_lock_irqsave(&desc->lock, flags); + d = irq_desc_get_irq_data(desc); + if (needs_deactivate) { + chip = irq_data_get_irq_chip(d); + chip->irq_eoi(d); + } + irqd_clr_irq_forwarded(d); + /* next occurrence will be deactivated by the host */ + raw_spin_unlock_irqrestore(&desc->lock, flags); + + *active = *active && vcpu; + + spin_unlock(&dist->lock); +} +