Commit d0823cb3 authored by Jia He's avatar Jia He Committed by Marc Zyngier
Browse files

KVM: arm/arm64: vgic: Do not use spin_lock_irqsave/restore with irq disabled 



kvm_vgic_sync_hwstate is only called with IRQ being disabled.
There is thus no need to call spin_lock_irqsave/restore in
vgic_fold_lr_state and vgic_prune_ap_list.

This patch replace them with the non irq-safe version.

Signed-off-by: default avatarJia He <jia.he@hxt-semitech.com>
Acked-by: default avatarChristoffer Dall <christoffer.dall@arm.com>
[maz: commit message tidy-up]
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent dc961e53

virt/kvm/arm/vgic/vgic-v2.c

+4 −3
Original line number Diff line number Diff line
@@ -62,7 +62,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) 
	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;

	struct vgic_v2_cpu_if *cpuif = &vgic_cpu->vgic_v2;

	int lr;

	unsigned long flags;



	DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());



	cpuif->vgic_hcr &= ~GICH_HCR_UIE;
@@ -83,7 +84,7 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) 


		irq = vgic_get_irq(vcpu->kvm, vcpu, intid);



		spin_lock_irqsave(&irq->irq_lock, flags);

		spin_lock(&irq->irq_lock);



		/* Always preserve the active bit */

		irq->active = !!(val & GICH_LR_ACTIVE_BIT);
@@ -126,7 +127,7 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) 
				vgic_irq_set_phys_active(irq, false);

		}



		spin_unlock_irqrestore(&irq->irq_lock, flags);

		spin_unlock(&irq->irq_lock);

		vgic_put_irq(vcpu->kvm, irq);

	}

virt/kvm/arm/vgic/vgic-v3.c

+4 −3
Original line number Diff line number Diff line
@@ -46,7 +46,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) 
	struct vgic_v3_cpu_if *cpuif = &vgic_cpu->vgic_v3;

	u32 model = vcpu->kvm->arch.vgic.vgic_model;

	int lr;

	unsigned long flags;



	DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());



	cpuif->vgic_hcr &= ~ICH_HCR_UIE;
@@ -75,7 +76,7 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) 
		if (!irq)	/* An LPI could have been unmapped. */

			continue;



		spin_lock_irqsave(&irq->irq_lock, flags);

		spin_lock(&irq->irq_lock);



		/* Always preserve the active bit */

		irq->active = !!(val & ICH_LR_ACTIVE_BIT);
@@ -118,7 +119,7 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) 
				vgic_irq_set_phys_active(irq, false);

		}



		spin_unlock_irqrestore(&irq->irq_lock, flags);

		spin_unlock(&irq->irq_lock);

		vgic_put_irq(vcpu->kvm, irq);

	}

virt/kvm/arm/vgic/vgic.c

+7 −6
Original line number Diff line number Diff line
@@ -593,10 +593,11 @@ static void vgic_prune_ap_list(struct kvm_vcpu *vcpu) 
{

	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;

	struct vgic_irq *irq, *tmp;

	unsigned long flags;



	DEBUG_SPINLOCK_BUG_ON(!irqs_disabled());



retry:

	spin_lock_irqsave(&vgic_cpu->ap_list_lock, flags);

	spin_lock(&vgic_cpu->ap_list_lock);



	list_for_each_entry_safe(irq, tmp, &vgic_cpu->ap_list_head, ap_list) {

		struct kvm_vcpu *target_vcpu, *vcpuA, *vcpuB;
@@ -637,7 +638,7 @@ retry: 
		/* This interrupt looks like it has to be migrated. */



		spin_unlock(&irq->irq_lock);

		spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags);

		spin_unlock(&vgic_cpu->ap_list_lock);



		/*

		 * Ensure locking order by always locking the smallest
@@ -651,7 +652,7 @@ retry: 
			vcpuB = vcpu;

		}



		spin_lock_irqsave(&vcpuA->arch.vgic_cpu.ap_list_lock, flags);

		spin_lock(&vcpuA->arch.vgic_cpu.ap_list_lock);

		spin_lock_nested(&vcpuB->arch.vgic_cpu.ap_list_lock,

				 SINGLE_DEPTH_NESTING);

		spin_lock(&irq->irq_lock);
@@ -676,7 +677,7 @@ retry: 


		spin_unlock(&irq->irq_lock);

		spin_unlock(&vcpuB->arch.vgic_cpu.ap_list_lock);

		spin_unlock_irqrestore(&vcpuA->arch.vgic_cpu.ap_list_lock, flags);

		spin_unlock(&vcpuA->arch.vgic_cpu.ap_list_lock);



		if (target_vcpu_needs_kick) {

			kvm_make_request(KVM_REQ_IRQ_PENDING, target_vcpu);
@@ -686,7 +687,7 @@ retry: 
		goto retry;

	}



	spin_unlock_irqrestore(&vgic_cpu->ap_list_lock, flags);

	spin_unlock(&vgic_cpu->ap_list_lock);

}



static inline void vgic_fold_lr_state(struct kvm_vcpu *vcpu)

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