[PATCH 15/15] KVM: arm64: vgic-its: Rely on RCU to protect translation cache reads

Oliver Upton
2024-01-24T20:49:51Z

Stop taking the lpi_list_lock when reading the LPI translation cache.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/vgic/vgic-its.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 1670b452c682..46ff21fea785 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -590,15 +590,14 @@ static struct vgic_irq *vgic_its_check_cache(struct kvm *kvm, phys_addr_t db,
{
struct vgic_dist *dist = &kvm->arch.vgic;
struct vgic_irq *irq;
- unsigned long flags;

- raw_spin_lock_irqsave(&dist->lpi_list_lock, flags);
+ rcu_read_lock();

irq = __vgic_its_check_cache(dist, db, devid, eventid);
if (irq && !vgic_try_get_irq_kref(irq))
irq = NULL;

- raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
+ rcu_read_unlock();

return irq;
}
--
2.43.0.429.g432eaa2c6b-goog