KVM: arm64: Use lock guard in vgic_v4_set_forwarding()

The locking dance is about to get more interesting, switch the its_lock
over to a lock guard to make it a bit easier to handle.

Tested-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250523194722.4066715-2-oliver.upton@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c
index c7de6154627c494066a9cb84393bc07a2e5ff008..8b25e7650998169a285d6f28d5b12e6f5ec6390f 100644 (file)
--- a/arch/arm64/kvm/vgic/vgic-v4.c
+++ b/arch/arm64/kvm/vgic/vgic-v4.c
@@ -444,7 +444,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
        if (IS_ERR(its))
                return 0;
 
-       mutex_lock(&its->its_lock);
+       guard(mutex)(&its->its_lock);
 
        /*
         * Perform the actual DevID/EventID -> LPI translation.
@@ -455,11 +455,11 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
         */
        if (vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid,
                                 irq_entry->msi.data, &irq))
-               goto out;
+               return 0;
 
        /* Silently exit if the vLPI is already mapped */
        if (irq->hw)
-               goto out;
+               return 0;
 
        /*
         * Emit the mapping request. If it fails, the ITS probably
@@ -479,7 +479,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 
        ret = its_map_vlpi(virq, &map);
        if (ret)
-               goto out;
+               return ret;
 
        irq->hw         = true;
        irq->host_irq   = virq;
@@ -503,8 +503,6 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
                raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
        }
 
-out:
-       mutex_unlock(&its->its_lock);
        return ret;
 }