KVM: arm64: Move GICv3 trap configuration to kvm_calculate_traps()

Follow the pattern introduced with vcpu_set_hcr(), and introduce
vcpu_set_ich_hcr(), which configures the GICv3 traps at the same
point.

This will allow future changes to introduce trap configuration on
a per-VM basis.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240827152517.3909653-2-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>

Author: Marc Zyngier

arch/arm64/kvm/sys_regs.c

@@ -4551,6 +4551,7 @@ void kvm_calculate_traps(struct kvm_vcpu *vcpu)
 
 	mutex_lock(&kvm->arch.config_lock);
 	vcpu_set_hcr(vcpu);
+	vcpu_set_ich_hcr(vcpu);
 
 	if (cpus_have_final_cap(ARM64_HAS_HCX)) {
 		/*

arch/arm64/kvm/vgic/vgic-v3.c

@@ -292,6 +292,15 @@ void vgic_v3_enable(struct kvm_vcpu *vcpu)
 
 	/* Get the show on the road... */
 	vgic_v3->vgic_hcr = ICH_HCR_EN;
+}
+
+void vcpu_set_ich_hcr(struct kvm_vcpu *vcpu)
+{
+	struct vgic_v3_cpu_if *vgic_v3 = &vcpu->arch.vgic_cpu.vgic_v3;
+
+	if (!kvm_has_gicv3(vcpu->kvm))
+		return;
+
 	if (group0_trap)
 		vgic_v3->vgic_hcr |= ICH_HCR_TALL0;
 	if (group1_trap)

arch/arm64/kvm/vgic/vgic.h

@@ -346,6 +346,8 @@ void vgic_v4_configure_vsgis(struct kvm *kvm);
 void vgic_v4_get_vlpi_state(struct vgic_irq *irq, bool *val);
 int vgic_v4_request_vpe_irq(struct kvm_vcpu *vcpu, int irq);
 
+void vcpu_set_ich_hcr(struct kvm_vcpu *vcpu);
+
 static inline bool kvm_has_gicv3(struct kvm *kvm)
 {
 	return (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif) &&