// SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
//
// Copyright © 2020, Microsoft Corporation
//

#![allow(dead_code)]
#![allow(unused_imports)]
#![allow(unused_variables)]
#![allow(unused_macros)]
#![allow(non_upper_case_globals)]

use crate::arch::emulator::{EmulationError, PlatformEmulator, PlatformError};
#[cfg(target_arch = "x86_64")]
use crate::arch::x86::emulator::{Emulator, EmulatorCpuState};
use crate::cpu;
use crate::cpu::Vcpu;
use crate::hypervisor;
use crate::vm::{self, VmmOps};
pub use mshv_bindings::*;
use mshv_ioctls::{set_registers_64, Mshv, VcpuFd, VmFd};
use serde_derive::{Deserialize, Serialize};
use std::sync::Arc;
use vm::DataMatch;
// x86_64 dependencies
#[cfg(target_arch = "x86_64")]
pub mod x86_64;
use crate::device;
use std::convert::TryInto;
use vmm_sys_util::eventfd::EventFd;
#[cfg(target_arch = "x86_64")]
pub use x86_64::VcpuMshvState as CpuState;
#[cfg(target_arch = "x86_64")]
pub use x86_64::*;

// Wei: for emulating irqfd and ioeventfd
use std::collections::HashMap;
use std::fs::File;
use std::io;
use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
use std::sync::{Mutex, RwLock};
use std::thread;

pub const PAGE_SHIFT: usize = 12;

#[derive(Debug, Default, Copy, Clone, Serialize, Deserialize)]
pub struct HvState {
    hypercall_page: u64,
}

pub use HvState as VmState;

/// Wrapper over mshv system ioctls.
pub struct MshvHypervisor {
    mshv: Mshv,
}

impl MshvHypervisor {
    /// Create a hypervisor based on Mshv
    pub fn new() -> hypervisor::Result<MshvHypervisor> {
        let mshv_obj =
            Mshv::new().map_err(|e| hypervisor::HypervisorError::HypervisorCreate(e.into()))?;
        Ok(MshvHypervisor { mshv: mshv_obj })
    }
}
/// Implementation of Hypervisor trait for Mshv
/// Example:
/// #[cfg(feature = "mshv")]
/// extern crate hypervisor
/// let mshv = hypervisor::mshv::MshvHypervisor::new().unwrap();
/// let hypervisor: Arc<dyn hypervisor::Hypervisor> = Arc::new(mshv);
/// let vm = hypervisor.create_vm().expect("new VM fd creation failed");
///
impl hypervisor::Hypervisor for MshvHypervisor {
    /// Create a mshv vm object and return the object as Vm trait object
    /// Example
    /// # extern crate hypervisor;
    /// # use hypervisor::MshvHypervisor;
    /// use hypervisor::MshvVm;
    /// let hypervisor = MshvHypervisor::new().unwrap();
    /// let vm = hypervisor.create_vm().unwrap()
    ///
    fn create_vm(&self) -> hypervisor::Result<Arc<dyn vm::Vm>> {
        let fd: VmFd;
        loop {
            match self.mshv.create_vm() {
                Ok(res) => fd = res,
                Err(e) => {
                    if e.errno() == libc::EINTR {
                        // If the error returned is EINTR, which means the
                        // ioctl has been interrupted, we have to retry as
                        // this can't be considered as a regular error.
                        continue;
                    } else {
                        return Err(hypervisor::HypervisorError::VmCreate(e.into()));
                    }
                }
            }
            break;
        }

        let msr_list = self.get_msr_list()?;
        let num_msrs = msr_list.as_fam_struct_ref().nmsrs as usize;
        let mut msrs = MsrEntries::new(num_msrs);
        let indices = msr_list.as_slice();
        let msr_entries = msrs.as_mut_slice();
        for (pos, index) in indices.iter().enumerate() {
            msr_entries[pos].index = *index;
        }
        let vm_fd = Arc::new(fd);

        Ok(Arc::new(MshvVm { fd: vm_fd, msrs }))
    }
    ///
    /// Get the supported CpuID
    ///
    fn get_cpuid(&self) -> hypervisor::Result<CpuId> {
        Ok(CpuId::new(1 as usize))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Retrieve the list of MSRs supported by KVM.
    ///
    fn get_msr_list(&self) -> hypervisor::Result<MsrList> {
        self.mshv
            .get_msr_index_list()
            .map_err(|e| hypervisor::HypervisorError::GetMsrList(e.into()))
    }
}

/// Vcpu struct for Microsoft Hypervisor
pub struct MshvVcpu {
    fd: VcpuFd,
    vp_index: u8,
    cpuid: CpuId,
    msrs: MsrEntries,
}

/// Implementation of Vcpu trait for Microsoft Hypervisor
/// Example:
/// #[cfg(feature = "mshv")]
/// extern crate hypervisor
/// let mshv = hypervisor::mshv::MshvHypervisor::new().unwrap();
/// let hypervisor: Arc<dyn hypervisor::Hypervisor> = Arc::new(mshv);
/// let vm = hypervisor.create_vm().expect("new VM fd creation failed");
/// let vcpu = vm.create_vcpu(0).unwrap();
/// vcpu.get/set().unwrap()
///
impl cpu::Vcpu for MshvVcpu {
    #[cfg(target_arch = "x86_64")]
    ///
    /// Returns the vCPU general purpose registers.
    ///
    fn get_regs(&self) -> cpu::Result<StandardRegisters> {
        self.fd
            .get_regs()
            .map_err(|e| cpu::HypervisorCpuError::GetStandardRegs(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Sets the vCPU general purpose registers.
    ///
    fn set_regs(&self, regs: &StandardRegisters) -> cpu::Result<()> {
        self.fd
            .set_regs(regs)
            .map_err(|e| cpu::HypervisorCpuError::SetStandardRegs(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Returns the vCPU special registers.
    ///
    fn get_sregs(&self) -> cpu::Result<SpecialRegisters> {
        self.fd
            .get_sregs()
            .map_err(|e| cpu::HypervisorCpuError::GetSpecialRegs(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Sets the vCPU special registers.
    ///
    fn set_sregs(&self, sregs: &SpecialRegisters) -> cpu::Result<()> {
        self.fd
            .set_sregs(sregs)
            .map_err(|e| cpu::HypervisorCpuError::SetSpecialRegs(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Returns the floating point state (FPU) from the vCPU.
    ///
    fn get_fpu(&self) -> cpu::Result<FpuState> {
        self.fd
            .get_fpu()
            .map_err(|e| cpu::HypervisorCpuError::GetFloatingPointRegs(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Set the floating point state (FPU) of a vCPU.
    ///
    fn set_fpu(&self, fpu: &FpuState) -> cpu::Result<()> {
        self.fd
            .set_fpu(fpu)
            .map_err(|e| cpu::HypervisorCpuError::SetFloatingPointRegs(e.into()))
    }

    #[cfg(target_arch = "x86_64")]
    ///
    /// Returns the model-specific registers (MSR) for this vCPU.
    ///
    fn get_msrs(&self, msrs: &mut MsrEntries) -> cpu::Result<usize> {
        self.fd
            .get_msrs(msrs)
            .map_err(|e| cpu::HypervisorCpuError::GetMsrEntries(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Setup the model-specific registers (MSR) for this vCPU.
    /// Returns the number of MSR entries actually written.
    ///
    fn set_msrs(&self, msrs: &MsrEntries) -> cpu::Result<usize> {
        self.fd
            .set_msrs(msrs)
            .map_err(|e| cpu::HypervisorCpuError::SetMsrEntries(e.into()))
    }

    #[cfg(target_arch = "x86_64")]
    ///
    /// X86 specific call that returns the vcpu's current "xcrs".
    ///
    fn get_xcrs(&self) -> cpu::Result<ExtendedControlRegisters> {
        self.fd
            .get_xcrs()
            .map_err(|e| cpu::HypervisorCpuError::GetXcsr(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// X86 specific call that sets the vcpu's current "xcrs".
    ///
    fn set_xcrs(&self, xcrs: &ExtendedControlRegisters) -> cpu::Result<()> {
        self.fd
            .set_xcrs(&xcrs)
            .map_err(|e| cpu::HypervisorCpuError::SetXcsr(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Returns currently pending exceptions, interrupts, and NMIs as well as related
    /// states of the vcpu.
    ///
    fn get_vcpu_events(&self) -> cpu::Result<VcpuEvents> {
        self.fd
            .get_vcpu_events()
            .map_err(|e| cpu::HypervisorCpuError::GetVcpuEvents(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Sets pending exceptions, interrupts, and NMIs as well as related states
    /// of the vcpu.
    ///
    fn set_vcpu_events(&self, events: &VcpuEvents) -> cpu::Result<()> {
        self.fd
            .set_vcpu_events(events)
            .map_err(|e| cpu::HypervisorCpuError::SetVcpuEvents(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// X86 specific call to enable HyperV SynIC
    ///
    fn enable_hyperv_synic(&self) -> cpu::Result<()> {
        /* We always have SynIC enabled on MSHV */
        Ok(())
    }
    fn run(&self) -> std::result::Result<cpu::VmExit, cpu::HypervisorCpuError> {
        Ok(cpu::VmExit::Ignore)
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// X86 specific call to setup the CPUID registers.
    ///
    fn set_cpuid2(&self, cpuid: &CpuId) -> cpu::Result<()> {
        Ok(())
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// X86 specific call to retrieve the CPUID registers.
    ///
    fn get_cpuid2(&self, num_entries: usize) -> cpu::Result<CpuId> {
        Ok(self.cpuid.clone())
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Returns the state of the LAPIC (Local Advanced Programmable Interrupt Controller).
    ///
    fn get_lapic(&self) -> cpu::Result<LapicState> {
        self.fd
            .get_lapic()
            .map_err(|e| cpu::HypervisorCpuError::GetlapicState(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// Sets the state of the LAPIC (Local Advanced Programmable Interrupt Controller).
    ///
    fn set_lapic(&self, lapic: &LapicState) -> cpu::Result<()> {
        self.fd
            .set_lapic(lapic)
            .map_err(|e| cpu::HypervisorCpuError::SetLapicState(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// X86 specific call that returns the vcpu's current "xsave struct".
    ///
    fn get_xsave(&self) -> cpu::Result<Xsave> {
        self.fd
            .get_xsave()
            .map_err(|e| cpu::HypervisorCpuError::GetXsaveState(e.into()))
    }
    #[cfg(target_arch = "x86_64")]
    ///
    /// X86 specific call that sets the vcpu's current "xsave struct".
    ///
    fn set_xsave(&self, xsave: &Xsave) -> cpu::Result<()> {
        self.fd
            .set_xsave(*xsave)
            .map_err(|e| cpu::HypervisorCpuError::SetXsaveState(e.into()))
    }
    fn set_state(&self, state: &CpuState) -> cpu::Result<()> {
        Ok(())
    }
    fn state(&self) -> cpu::Result<CpuState> {
        unimplemented!();
    }
}
/// Wrapper over Mshv VM ioctls.
pub struct MshvVm {
    fd: Arc<VmFd>,
    msrs: MsrEntries,
}
///
/// Implementation of Vm trait for Mshv
/// Example:
/// #[cfg(feature = "mshv")]
/// # extern crate hypervisor;
/// # use hypervisor::MshvHypervisor;
/// let mshv = MshvHypervisor::new().unwrap();
/// let hypervisor: Arc<dyn hypervisor::Hypervisor> = Arc::new(mshv);
/// let vm = hypervisor.create_vm().expect("new VM fd creation failed");
/// vm.set/get().unwrap()
///
impl vm::Vm for MshvVm {
    #[cfg(target_arch = "x86_64")]
    ///
    /// Sets the address of the three-page region in the VM's address space.
    ///
    fn set_tss_address(&self, offset: usize) -> vm::Result<()> {
        Ok(())
    }
    ///
    /// Creates an in-kernel interrupt controller.
    ///
    fn create_irq_chip(&self) -> vm::Result<()> {
        Ok(())
    }
    ///
    /// Registers an event that will, when signaled, trigger the `gsi` IRQ.
    ///
    fn register_irqfd(&self, fd: &EventFd, gsi: u32) -> vm::Result<()> {
        Ok(())
    }
    ///
    /// Unregisters an event that will, when signaled, trigger the `gsi` IRQ.
    ///
    fn unregister_irqfd(&self, _fd: &EventFd, gsi: u32) -> vm::Result<()> {
        Ok(())
    }
    ///
    /// Creates a VcpuFd object from a vcpu RawFd.
    ///
    fn create_vcpu(
        &self,
        id: u8,
        vmmops: Option<Arc<Box<dyn VmmOps>>>,
    ) -> vm::Result<Arc<dyn cpu::Vcpu>> {
        let vcpu_fd = self
            .fd
            .create_vcpu(id)
            .map_err(|e| vm::HypervisorVmError::CreateVcpu(e.into()))?;
        let vcpu = MshvVcpu {
            fd: vcpu_fd,
            vp_index: id,
            cpuid: CpuId::new(1 as usize),
            msrs: self.msrs.clone(),
        };
        Ok(Arc::new(vcpu))
    }
    #[cfg(target_arch = "x86_64")]
    fn enable_split_irq(&self) -> vm::Result<()> {
        Ok(())
    }
    fn register_ioevent(
        &self,
        fd: &EventFd,
        addr: &IoEventAddress,
        datamatch: Option<DataMatch>,
    ) -> vm::Result<()> {
        Ok(())
    }
    /// Unregister an event from a certain address it has been previously registered to.
    fn unregister_ioevent(&self, fd: &EventFd, addr: &IoEventAddress) -> vm::Result<()> {
        Ok(())
    }

    /// Creates/modifies a guest physical memory slot.
    fn set_user_memory_region(&self, user_memory_region: MemoryRegion) -> vm::Result<()> {
        self.fd
            .map_user_memory(user_memory_region)
            .map_err(|e| vm::HypervisorVmError::SetUserMemory(e.into()))?;
        Ok(())
    }

    fn make_user_memory_region(
        &self,
        _slot: u32,
        guest_phys_addr: u64,
        memory_size: u64,
        userspace_addr: u64,
        readonly: bool,
        log_dirty_pages: bool,
    ) -> MemoryRegion {
        let mut flags = HV_MAP_GPA_READABLE | HV_MAP_GPA_EXECUTABLE;
        if !readonly {
            flags |= HV_MAP_GPA_WRITABLE;
        }

        mshv_user_mem_region {
            flags,
            guest_pfn: guest_phys_addr >> PAGE_SHIFT,
            size: memory_size,
            userspace_addr: userspace_addr as u64,
        }
    }

    fn create_passthrough_device(&self) -> vm::Result<Arc<dyn device::Device>> {
        Err(vm::HypervisorVmError::CreatePassthroughDevice(anyhow!(
            "No passthrough support"
        )))
    }

    fn set_gsi_routing(&self, irq_routing: &[IrqRoutingEntry]) -> vm::Result<()> {
        Ok(())
    }
    ///
    /// Get the Vm state. Return VM specific data
    ///
    fn state(&self) -> vm::Result<VmState> {
        unimplemented!();
    }
    ///
    /// Set the VM state
    ///
    fn set_state(&self, state: VmState) -> vm::Result<()> {
        Ok(())
    }
    ///
    /// Get dirty pages bitmap (one bit per page)
    ///
    fn get_dirty_log(&self, slot: u32, memory_size: u64) -> vm::Result<Vec<u64>> {
        Err(vm::HypervisorVmError::GetDirtyLog(anyhow!(
            "get_dirty_log not implemented"
        )))
    }
}
pub use hv_cpuid_entry as CpuIdEntry;

#[derive(Copy, Clone, Debug)]
pub struct MshvIrqRoutingMsi {
    pub address_lo: u32,
    pub address_hi: u32,
    pub data: u32,
}

#[derive(Copy, Clone, Debug)]
pub enum MshvIrqRouting {
    Msi(MshvIrqRoutingMsi),
}

#[derive(Copy, Clone, Debug)]
pub struct MshvIrqRoutingEntry {
    pub gsi: u32,
    pub route: MshvIrqRouting,
}
pub type IrqRoutingEntry = MshvIrqRoutingEntry;

pub const CPUID_FLAG_VALID_INDEX: u32 = 0;