Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752104AbaKWSOa (ORCPT ); Sun, 23 Nov 2014 13:14:30 -0500 Received: from mail-wi0-f175.google.com ([209.85.212.175]:44102 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751958AbaKWSOZ (ORCPT ); Sun, 23 Nov 2014 13:14:25 -0500 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, joel.schopp@amd.com, kim.phillips@freescale.com, paulus@samba.org, gleb@kernel.org, pbonzini@redhat.com Cc: linux-kernel@vger.kernel.org, patches@linaro.org, will.deacon@arm.com, a.motakis@virtualopensystems.com, a.rigo@virtualopensystems.com, john.liuli@huawei.com, ming.lei@canonical.com, feng.wu@intel.com Subject: [RFC 2/4] KVM: arm: vgic: add forwarded irq rbtree lock Date: Sun, 23 Nov 2014 19:12:51 +0100 Message-Id: <1416766373-13569-3-git-send-email-eric.auger@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1416766373-13569-1-git-send-email-eric.auger@linaro.org> References: <1416766373-13569-1-git-send-email-eric.auger@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a lock related to the rb tree manipulation. The rb tree can be searched in one thread (irqfd handler for instance) and map/unmap may happen in another. Signed-off-by: Eric Auger --- v2 -> v3: re-arrange lock sequence in vgic_map_phys_irq --- include/kvm/arm_vgic.h | 1 + virt/kvm/arm/vgic.c | 56 ++++++++++++++++++++++++++++++++++++-------------- 2 files changed, 42 insertions(+), 15 deletions(-) diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index ea31ac6..9b3290b 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -220,6 +220,7 @@ struct vgic_dist { unsigned long *irq_pending_on_cpu; struct rb_root irq_phys_map; + spinlock_t rb_tree_lock; #endif }; diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 5484e3d..f592219 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1750,9 +1750,22 @@ static struct rb_root *vgic_get_irq_phys_map(struct kvm_vcpu *vcpu, int vgic_map_phys_irq(struct kvm_vcpu *vcpu, int virt_irq, int phys_irq) { - struct rb_root *root = vgic_get_irq_phys_map(vcpu, virt_irq); - struct rb_node **new = &root->rb_node, *parent = NULL; + struct rb_root *root; + struct rb_node **new, *parent = NULL; struct irq_phys_map *new_map; + struct vgic_dist *dist = &vcpu->kvm->arch.vgic; + + root = vgic_get_irq_phys_map(vcpu, virt_irq); + new = &root->rb_node; + + new_map = kzalloc(sizeof(*new_map), GFP_KERNEL); + if (!new_map) + return -ENOMEM; + + new_map->virt_irq = virt_irq; + new_map->phys_irq = phys_irq; + + spin_lock(&dist->rb_tree_lock); /* Boilerplate rb_tree code */ while (*new) { @@ -1764,19 +1777,16 @@ int vgic_map_phys_irq(struct kvm_vcpu *vcpu, int virt_irq, int phys_irq) new = &(*new)->rb_left; else if (this->virt_irq > virt_irq) new = &(*new)->rb_right; - else + else { + kfree(new_map); + spin_unlock(&dist->rb_tree_lock); return -EEXIST; + } } - new_map = kzalloc(sizeof(*new_map), GFP_KERNEL); - if (!new_map) - return -ENOMEM; - - new_map->virt_irq = virt_irq; - new_map->phys_irq = phys_irq; - rb_link_node(&new_map->node, parent, new); rb_insert_color(&new_map->node, root); + spin_unlock(&dist->rb_tree_lock); return 0; } @@ -1805,24 +1815,39 @@ static struct irq_phys_map *vgic_irq_map_search(struct kvm_vcpu *vcpu, int vgic_get_phys_irq(struct kvm_vcpu *vcpu, int virt_irq) { - struct irq_phys_map *map = vgic_irq_map_search(vcpu, virt_irq); + struct irq_phys_map *map; + struct vgic_dist *dist = &vcpu->kvm->arch.vgic; + int ret; + + spin_lock(&dist->rb_tree_lock); + map = vgic_irq_map_search(vcpu, virt_irq); if (map) - return map->phys_irq; + ret = map->phys_irq; + else + ret = -ENOENT; + + spin_unlock(&dist->rb_tree_lock); + return ret; - return -ENOENT; } int vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, int virt_irq, int phys_irq) { - struct irq_phys_map *map = vgic_irq_map_search(vcpu, virt_irq); + struct irq_phys_map *map; + struct vgic_dist *dist = &vcpu->kvm->arch.vgic; + + spin_lock(&dist->rb_tree_lock); + + map = vgic_irq_map_search(vcpu, virt_irq); if (map && map->phys_irq == phys_irq) { rb_erase(&map->node, vgic_get_irq_phys_map(vcpu, virt_irq)); kfree(map); + spin_unlock(&dist->rb_tree_lock); return 0; } - + spin_unlock(&dist->rb_tree_lock); return -ENOENT; } @@ -2078,6 +2103,7 @@ int kvm_vgic_create(struct kvm *kvm) } spin_lock_init(&kvm->arch.vgic.lock); + spin_lock_init(&kvm->arch.vgic.rb_tree_lock); kvm->arch.vgic.in_kernel = true; kvm->arch.vgic.vctrl_base = vgic->vctrl_base; kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/