KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlock

Julien Thierry · christofferdall-arm · commit fc3bc475231e · 2019-01-24T15:09:01.000+01:00
vgic_dist-&gt;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 &lt;julien.thierry@arm.com&gt;
Acked-by: Christoffer Dall &lt;christoffer.dall@arm.com&gt;
Acked-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Christoffer Dall &lt;christoffer.dall@arm.com&gt;
diff --git 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
@@ -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
@@ -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
@@ -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);
 }

Original file line number	Diff line number	Diff line change
`@@ -64,7 +64,7 @@ void kvm_vgic_early_init(struct kvm *kvm)`
`64`	`64`	`struct vgic_dist *dist = &kvm->arch.vgic;`
`65`	`65`
`66`	`66`	`INIT_LIST_HEAD(&dist->lpi_list_head);`
`67`		`- spin_lock_init(&dist->lpi_list_lock);`
	`67`	`+ raw_spin_lock_init(&dist->lpi_list_lock);`
`68`	`68`	`}`
`69`	`69`
`70`	`70`	`/* CREATION */`