[PATCH v3 2/3] KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlock

From: Julien Thierry
Date: Mon Jan 07 2019 - 10:06:42 EST


vgic_dist->lpi_list_lock must always be taken with interrupts disabled as
it is used in interrupt context.

For configurations such as PREEMPT_RT_FULL, this means that it should
be a raw_spinlock since RT spinlocks are interruptible.

Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
Acked-by: Christoffer Dall <christoffer.dall@xxxxxxx>
Cc: Christoffer Dall <christoffer.dall@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
---
include/kvm/arm_vgic.h | 2 +-
virt/kvm/arm/vgic/vgic-init.c | 2 +-
virt/kvm/arm/vgic/vgic-its.c | 8 ++++----
virt/kvm/arm/vgic/vgic.c | 10 +++++-----
4 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index b542605..32954e1 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -256,7 +256,7 @@ struct vgic_dist {
u64 propbaser;

/* Protects the lpi_list and the count value below. */
- spinlock_t lpi_list_lock;
+ raw_spinlock_t lpi_list_lock;
struct list_head lpi_list_head;
int lpi_list_count;

diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 1128e97..330c1ad 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -64,7 +64,7 @@ void kvm_vgic_early_init(struct kvm *kvm)
struct vgic_dist *dist = &kvm->arch.vgic;

INIT_LIST_HEAD(&dist->lpi_list_head);
- spin_lock_init(&dist->lpi_list_lock);
+ raw_spin_lock_init(&dist->lpi_list_lock);
}

/* CREATION */
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 911ba61..ab3f477 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -73,7 +73,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,
irq->target_vcpu = vcpu;
irq->group = 1;

- spin_lock_irqsave(&dist->lpi_list_lock, flags);
+ raw_spin_lock_irqsave(&dist->lpi_list_lock, flags);

/*
* There could be a race with another vgic_add_lpi(), so we need to
@@ -101,7 +101,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,
dist->lpi_list_count++;

out_unlock:
- spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
+ raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);

/*
* We "cache" the configuration table entries in our struct vgic_irq's.
@@ -332,7 +332,7 @@ int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr)
if (!intids)
return -ENOMEM;

- spin_lock_irqsave(&dist->lpi_list_lock, flags);
+ raw_spin_lock_irqsave(&dist->lpi_list_lock, flags);
list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
if (i == irq_count)
break;
@@ -341,7 +341,7 @@ int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr)
continue;
intids[i++] = irq->intid;
}
- spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
+ raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);

*intid_ptr = intids;
return i;
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index bc36f2e..ea54a19 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -72,7 +72,7 @@ static struct vgic_irq *vgic_get_lpi(struct kvm *kvm, u32 intid)
struct vgic_irq *irq = NULL;
unsigned long flags;

- spin_lock_irqsave(&dist->lpi_list_lock, flags);
+ raw_spin_lock_irqsave(&dist->lpi_list_lock, flags);

list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) {
if (irq->intid != intid)
@@ -88,7 +88,7 @@ static struct vgic_irq *vgic_get_lpi(struct kvm *kvm, u32 intid)
irq = NULL;

out_unlock:
- spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
+ raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);

return irq;
}
@@ -138,15 +138,15 @@ void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
if (irq->intid < VGIC_MIN_LPI)
return;

- spin_lock_irqsave(&dist->lpi_list_lock, flags);
+ raw_spin_lock_irqsave(&dist->lpi_list_lock, flags);
if (!kref_put(&irq->refcount, vgic_irq_release)) {
- spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
+ raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
return;
};

list_del(&irq->lpi_list);
dist->lpi_list_count--;
- spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
+ raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);

kfree(irq);
}
--
1.9.1