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 <eric.au...@linaro.org>
---
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
--
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