arch/arm64/kvm/vgic/vgic-v5.c

// SPDX-License-Identifier: GPL-2.0-only

#include <kvm/arm_vgic.h>
#include <linux/irqchip/arm-vgic-info.h>

#include "vgic.h"

/*
 * Probe for a vGICv5 compatible interrupt controller, returning 0 on success.
 * Currently only supports GICv3-based VMs on a GICv5 host, and hence only
 * registers a VGIC_V3 device.
 */
int vgic_v5_probe(const struct gic_kvm_info *info)
{
	u64 ich_vtr_el2;
	int ret;

	if (!cpus_have_final_cap(ARM64_HAS_GICV5_LEGACY))
		return -ENODEV;

	kvm_vgic_global_state.type = VGIC_V5;
	kvm_vgic_global_state.has_gcie_v3_compat = true;

	/* We only support v3 compat mode - use vGICv3 limits */
	kvm_vgic_global_state.max_gic_vcpus = VGIC_V3_MAX_CPUS;

	kvm_vgic_global_state.vcpu_base = 0;
	kvm_vgic_global_state.vctrl_base = NULL;
	kvm_vgic_global_state.can_emulate_gicv2 = false;
	kvm_vgic_global_state.has_gicv4 = false;
	kvm_vgic_global_state.has_gicv4_1 = false;

	ich_vtr_el2 =  kvm_call_hyp_ret(__vgic_v3_get_gic_config);
	kvm_vgic_global_state.ich_vtr_el2 = (u32)ich_vtr_el2;

	/*
	 * The ListRegs field is 5 bits, but there is an architectural
	 * maximum of 16 list registers. Just ignore bit 4...
	 */
	kvm_vgic_global_state.nr_lr = (ich_vtr_el2 & 0xf) + 1;

	ret = kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V3);
	if (ret) {
		kvm_err("Cannot register GICv3-legacy KVM device.\n");
		return ret;
	}

	static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
	kvm_info("GCIE legacy system register CPU interface\n");

	vgic_v3_enable_cpuif_traps();

	return 0;
}