// Copyright 2020 ARM Limited
// SPDX-License-Identifier: Apache-2.0

pub mod kvm {
    use std::sync::Arc;
    use std::{boxed::Box, result};
    type Result<T> = result::Result<T, Error>;
    use crate::aarch64::gic::kvm::KvmGICDevice;
    use crate::aarch64::gic::{Error, GICDevice};
    use crate::aarch64::gicv3::kvm::KvmGICv3;
    use hypervisor::kvm::kvm_bindings;

    pub struct KvmGICv3ITS {
        /// The hypervisor agnostic device
        device: Arc<dyn hypervisor::Device>,

        /// GIC device properties, to be used for setting up the fdt entry
        gic_properties: [u64; 4],

        /// MSI device properties, to be used for setting up the fdt entry
        msi_properties: [u64; 2],

        /// Number of CPUs handled by the device
        vcpu_count: u64,
    }

    impl KvmGICv3ITS {
        const KVM_VGIC_V3_ITS_SIZE: u64 = (2 * KvmGICv3::SZ_64K);

        fn get_msi_size() -> u64 {
            KvmGICv3ITS::KVM_VGIC_V3_ITS_SIZE
        }

        fn get_msi_addr(vcpu_count: u64) -> u64 {
            KvmGICv3::get_redists_addr(vcpu_count) - KvmGICv3ITS::get_msi_size()
        }
    }

    impl GICDevice for KvmGICv3ITS {
        fn device(&self) -> &Arc<dyn hypervisor::Device> {
            &self.device
        }

        fn fdt_compatibility(&self) -> &str {
            "arm,gic-v3"
        }

        fn msi_compatible(&self) -> bool {
            true
        }

        fn msi_compatiblility(&self) -> &str {
            "arm,gic-v3-its"
        }

        fn fdt_maint_irq(&self) -> u32 {
            KvmGICv3::ARCH_GIC_V3_MAINT_IRQ
        }

        fn msi_properties(&self) -> &[u64] {
            &self.msi_properties
        }

        fn device_properties(&self) -> &[u64] {
            &self.gic_properties
        }

        fn vcpu_count(&self) -> u64 {
            self.vcpu_count
        }
    }

    impl KvmGICDevice for KvmGICv3ITS {
        fn version() -> u32 {
            KvmGICv3::version()
        }

        fn create_device(
            device: Arc<dyn hypervisor::Device>,
            vcpu_count: u64,
        ) -> Box<dyn GICDevice> {
            Box::new(KvmGICv3ITS {
                device: device,
                gic_properties: [
                    KvmGICv3::get_dist_addr(),
                    KvmGICv3::get_dist_size(),
                    KvmGICv3::get_redists_addr(vcpu_count),
                    KvmGICv3::get_redists_size(vcpu_count),
                ],
                msi_properties: [
                    KvmGICv3ITS::get_msi_addr(vcpu_count),
                    KvmGICv3ITS::get_msi_size(),
                ],
                vcpu_count: vcpu_count,
            })
        }

        fn init_device_attributes(
            vm: &Arc<dyn hypervisor::Vm>,
            gic_device: &Box<dyn GICDevice>,
        ) -> Result<()> {
            KvmGICv3::init_device_attributes(vm, gic_device)?;

            let mut its_device = kvm_bindings::kvm_create_device {
                type_: kvm_bindings::kvm_device_type_KVM_DEV_TYPE_ARM_VGIC_ITS,
                fd: 0,
                flags: 0,
            };

            let its_fd = vm
                .create_device(&mut its_device)
                .map_err(Error::CreateGIC)?;

            Self::set_device_attribute(
                &its_fd,
                kvm_bindings::KVM_DEV_ARM_VGIC_GRP_ADDR,
                u64::from(kvm_bindings::KVM_VGIC_ITS_ADDR_TYPE),
                &KvmGICv3ITS::get_msi_addr(u64::from(gic_device.vcpu_count())) as *const u64 as u64,
                0,
            )?;

            Self::set_device_attribute(
                &its_fd,
                kvm_bindings::KVM_DEV_ARM_VGIC_GRP_CTRL,
                u64::from(kvm_bindings::KVM_DEV_ARM_VGIC_CTRL_INIT),
                0,
                0,
            )?;

            Ok(())
        }
    }
}