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// Copyright 2020 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#[cfg(any(target_arch = "arm", target_arch = "aarch64"))]
mod aarch64;
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
mod x86_64;
use kvm_sys::*;
use libc::{open, O_CLOEXEC, O_RDWR};
use std::convert::TryFrom;
use std::ops::{Deref, DerefMut};
use std::os::raw::{c_char, c_ulong};
use std::os::unix::io::{AsRawFd, RawFd};
use sys_util::{
errno_result, ioctl_with_val, AsRawDescriptor, Error, FromRawDescriptor, GuestMemory,
RawDescriptor, Result, SafeDescriptor,
};
use crate::{Hypervisor, HypervisorCap, RunnableVcpu, Vcpu, VcpuExit, Vm};
pub struct Kvm {
kvm: SafeDescriptor,
}
type KvmCap = kvm::Cap;
impl Kvm {
/// Opens `/dev/kvm/` and returns a Kvm object on success.
pub fn new() -> Result<Kvm> {
// Open calls are safe because we give a constant nul-terminated string and verify the
// result.
let ret = unsafe { open("/dev/kvm\0".as_ptr() as *const c_char, O_RDWR | O_CLOEXEC) };
if ret < 0 {
return errno_result();
}
// Safe because we verify that ret is valid and we own the fd.
Ok(Kvm {
kvm: unsafe { SafeDescriptor::from_raw_descriptor(ret) },
})
}
}
impl AsRawDescriptor for Kvm {
fn as_raw_descriptor(&self) -> RawDescriptor {
self.kvm.as_raw_descriptor()
}
}
impl AsRawFd for Kvm {
fn as_raw_fd(&self) -> RawFd {
self.kvm.as_raw_descriptor()
}
}
impl Hypervisor for Kvm {
fn check_capability(&self, cap: &HypervisorCap) -> bool {
if let Ok(kvm_cap) = KvmCap::try_from(cap) {
// this ioctl is safe because we know this kvm descriptor is valid,
// and we are copying over the kvm capability (u32) as a c_ulong value.
unsafe { ioctl_with_val(self, KVM_CHECK_EXTENSION(), kvm_cap as c_ulong) == 1 }
} else {
// this capability cannot be converted on this platform, so return false
false
}
}
}
/// A wrapper around creating and using a KVM VM.
pub struct KvmVm {
guest_mem: GuestMemory,
}
impl KvmVm {
/// Constructs a new `KvmVm` using the given `Kvm` instance.
pub fn new(_kvm: &Kvm, guest_mem: GuestMemory) -> Result<KvmVm> {
Ok(KvmVm { guest_mem })
}
fn create_kvm_vcpu(&self, _id: usize) -> Result<KvmVcpu> {
Ok(KvmVcpu {})
}
}
impl Vm for KvmVm {
fn get_guest_mem(&self) -> &GuestMemory {
&self.guest_mem
}
}
/// A wrapper around creating and using a KVM Vcpu.
pub struct KvmVcpu {}
impl Vcpu for KvmVcpu {
type Runnable = RunnableKvmVcpu;
fn to_runnable(self) -> Result<Self::Runnable> {
Ok(RunnableKvmVcpu {
vcpu: self,
phantom: Default::default(),
})
}
fn request_interrupt_window(&self) -> Result<()> {
Ok(())
}
}
/// A KvmVcpu that has a thread and can be run.
pub struct RunnableKvmVcpu {
vcpu: KvmVcpu,
// vcpus must stay on the same thread once they start.
// Add the PhantomData pointer to ensure RunnableKvmVcpu is not `Send`.
phantom: std::marker::PhantomData<*mut u8>,
}
impl RunnableVcpu for RunnableKvmVcpu {
type Vcpu = KvmVcpu;
fn run(&self) -> Result<VcpuExit> {
Ok(VcpuExit::Unknown)
}
}
impl Deref for RunnableKvmVcpu {
type Target = <Self as RunnableVcpu>::Vcpu;
fn deref(&self) -> &Self::Target {
&self.vcpu
}
}
impl DerefMut for RunnableKvmVcpu {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.vcpu
}
}
impl<'a> TryFrom<&'a HypervisorCap> for KvmCap {
type Error = Error;
fn try_from(cap: &'a HypervisorCap) -> Result<KvmCap> {
match cap {
HypervisorCap::ArmPmuV3 => Ok(KvmCap::ArmPmuV3),
HypervisorCap::ImmediateExit => Ok(KvmCap::ImmediateExit),
HypervisorCap::S390UserSigp => Ok(KvmCap::S390UserSigp),
HypervisorCap::TscDeadlineTimer => Ok(KvmCap::TscDeadlineTimer),
HypervisorCap::UserMemory => Ok(KvmCap::UserMemory),
}
}
}
#[cfg(test)]
mod tests {
use super::{Hypervisor, HypervisorCap, Kvm};
#[test]
fn new() {
Kvm::new().unwrap();
}
#[test]
fn check_capability() {
let kvm = Kvm::new().unwrap();
assert!(kvm.check_capability(&HypervisorCap::UserMemory));
assert!(!kvm.check_capability(&HypervisorCap::S390UserSigp));
}
}
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