[PATCH v3 07/10] KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe manner

Oliver Upton
2024-02-16T18:42:20Z

Free the vgic_irq structs in an RCU-safe manner to allow reads of the
LPI configuration data to happen in parallel with the release of LPIs.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/vgic/vgic.c | 2 +-
include/kvm/arm_vgic.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index 5988d162b765..be3ed4c5e1fa 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -124,7 +124,7 @@ void __vgic_put_lpi_locked(struct kvm *kvm, struct vgic_irq *irq)
xa_erase(&dist->lpi_xa, irq->intid);
atomic_dec(&dist->lpi_count);

- kfree(irq);
+ kfree_rcu(irq, rcu);
}

void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 71e9d719533b..47035946648e 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -117,6 +117,7 @@ struct irq_ops {

struct vgic_irq {
raw_spinlock_t irq_lock; /* Protects the content of the struct */
+ struct rcu_head rcu;
struct list_head ap_list;

struct kvm_vcpu *vcpu; /* SGIs and PPIs: The VCPU
--
2.44.0.rc0.258.g7320e95886-goog