KVM: arm64: Force GICv3 trap activation when no irqchip is configured on VHE

On a VHE system, no GICv3 traps get configured when no irqchip is
present. This is not quite matching the "no GICv3" semantics that
we want to present.

Force such traps to be configured in this case.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240827152517.3909653-4-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Marc Zyngier

arch/arm64/kvm/vgic/vgic.c

@@ -922,21 +922,27 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 
 void kvm_vgic_load(struct kvm_vcpu *vcpu)
 {
-	if (unlikely(!vgic_initialized(vcpu->kvm)))
+	if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
+		if (has_vhe() && static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+			__vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
 		return;
+	}
 
-	if (kvm_vgic_global_state.type == VGIC_V2)
+	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
 		vgic_v2_load(vcpu);
 	else
 		vgic_v3_load(vcpu);
 }
 
 void kvm_vgic_put(struct kvm_vcpu *vcpu)
 {
-	if (unlikely(!vgic_initialized(vcpu->kvm)))
+	if (unlikely(!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))) {
+		if (has_vhe() && static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
+			__vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3);
 		return;
+	}
 
-	if (kvm_vgic_global_state.type == VGIC_V2)
+	if (!static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
 		vgic_v2_put(vcpu);
 	else
 		vgic_v3_put(vcpu);