Commit 30a0ce9c authored by Oliver Upton's avatar Oliver Upton Committed by Marc Zyngier
Browse files

KVM: arm64: vgic-its: Get rid of vgic_copy_lpi_list() 



The last user has been transitioned to walking the LPI xarray directly.
Cut the wart off, and get rid of the now unneeded lpi_count while doing
so.

Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240422200158.2606761-7-oliver.upton@linux.dev


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 85d3ccc8

arch/arm64/kvm/vgic/vgic-its.c

+0 −48
Original line number Diff line number Diff line
@@ -86,11 +86,8 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid, 
	if (ret) {

		xa_release(&dist->lpi_xa, intid);

		kfree(irq);

		goto out_unlock;

	}



	atomic_inc(&dist->lpi_count);



out_unlock:

	raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
@@ -316,51 +313,6 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq, 
	return 0;

}



/*

 * Create a snapshot of the current LPIs targeting @vcpu, so that we can

 * enumerate those LPIs without holding any lock.

 * Returns their number and puts the kmalloc'ed array into intid_ptr.

 */

int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr)

{

	struct vgic_dist *dist = &kvm->arch.vgic;

	XA_STATE(xas, &dist->lpi_xa, GIC_LPI_OFFSET);

	struct vgic_irq *irq;

	unsigned long flags;

	u32 *intids;

	int irq_count, i = 0;



	/*

	 * There is an obvious race between allocating the array and LPIs

	 * being mapped/unmapped. If we ended up here as a result of a

	 * command, we're safe (locks are held, preventing another

	 * command). If coming from another path (such as enabling LPIs),

	 * we must be careful not to overrun the array.

	 */

	irq_count = atomic_read(&dist->lpi_count);

	intids = kmalloc_array(irq_count, sizeof(intids[0]), GFP_KERNEL_ACCOUNT);

	if (!intids)

		return -ENOMEM;



	raw_spin_lock_irqsave(&dist->lpi_list_lock, flags);

	rcu_read_lock();



	xas_for_each(&xas, irq, VGIC_LPI_MAX_INTID) {

		if (i == irq_count)

			break;

		/* We don't need to "get" the IRQ, as we hold the list lock. */

		if (vcpu && irq->target_vcpu != vcpu)

			continue;

		intids[i++] = irq->intid;

	}



	rcu_read_unlock();

	raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);



	*intid_ptr = intids;

	return i;

}



static int update_affinity(struct vgic_irq *irq, struct kvm_vcpu *vcpu)

{

	int ret = 0;

arch/arm64/kvm/vgic/vgic.c

+0 −1
Original line number Diff line number Diff line
@@ -126,7 +126,6 @@ void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq) 
	__xa_erase(&dist->lpi_xa, irq->intid);

	xa_unlock_irqrestore(&dist->lpi_xa, flags);



	atomic_dec(&dist->lpi_count);

	kfree_rcu(irq, rcu);

}

arch/arm64/kvm/vgic/vgic.h

+0 −1
Original line number Diff line number Diff line
@@ -331,7 +331,6 @@ static inline bool vgic_dist_overlap(struct kvm *kvm, gpa_t base, size_t size) 
}



bool vgic_lpis_enabled(struct kvm_vcpu *vcpu);

int vgic_copy_lpi_list(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 **intid_ptr);

int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,

			 u32 devid, u32 eventid, struct vgic_irq **irq);

struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);

include/kvm/arm_vgic.h

+0 −1
Original line number Diff line number Diff line
@@ -279,7 +279,6 @@ struct vgic_dist { 


#define LPI_XA_MARK_DEBUG_ITER	XA_MARK_0

	struct xarray		lpi_xa;

	atomic_t		lpi_count;



	/* LPI translation cache */

	struct list_head	lpi_translation_cache;