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

Message ID 20240216184153.2714504-8-oliver.upton@linux.dev
State New
Headers
Series KVM: arm64: Avoid serializing LPI get() / put() |

Commit Message

Oliver Upton Feb. 16, 2024, 6:41 p.m. UTC
  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(-)
  

Patch

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