kvm_rs/
vm.rs

1// SPDX-License-Identifier: MIT
2//
3// Copyright (c) 2021, Johannes Stoelp <dev@memzero.de>
4
5//! VM system ioctls.
6
7use std::fs;
8use std::io;
9use std::os::unix::io::FromRawFd;
10
11use crate::vcpu::Vcpu;
12use crate::{ioctl, kvm_sys, KvmRun, PhysAddr, UserMem};
13
14/// Wrapper for VM ioctls.
15///
16/// Representation of the file descriptor obtained by the [`KVM_CREATE_VM`][kvm-create-vm] ioctl.
17/// This wrapper provides access to the `VM ioctls` as described in [KVM API][kvm].
18///
19/// [kvm]: https://www.kernel.org/doc/html/latest/virt/kvm/api.html#general-description
20/// [kvm-create-vm]: https://www.kernel.org/doc/html/latest/virt/kvm/api.html#kvm-create-vm
21pub struct Vm {
22    vm: fs::File,
23    vcpu_mmap_size: usize,
24}
25
26impl Vm {
27    pub(crate) fn new(vm: fs::File, vcpu_mmap_size: usize) -> Vm {
28        Vm { vm, vcpu_mmap_size }
29    }
30
31    /// Map memory from userspace into the VM as `guest physical` memory starting at address
32    /// `phys_addr`.
33    /// The underlying operation is the [`KVM_SET_USER_MEMORY_REGION`][kvm-set-user-memory-region]
34    /// ioctl.
35    ///
36    /// # Safety
37    ///
38    /// The `mem: &UserMem` argument passed to this function must at least live as long the `Vcpu`
39    /// instance.
40    ///
41    /// [kvm-set-user-memory-region]: https://www.kernel.org/doc/html/latest/virt/kvm/api.html#kvm-set-user-memory-region
42    pub unsafe fn set_user_memory_region(
43        &self,
44        phys_addr: PhysAddr,
45        mem: &UserMem,
46    ) -> io::Result<()> {
47        // Create guest physical memory mapping for `slot : 0` at guest `phys_addr`.
48        let mut kvm_mem = kvm_sys::kvm_userspace_memory_region::default();
49        kvm_mem.userspace_addr = mem.ptr as u64;
50        kvm_mem.memory_size = mem.len as u64;
51        kvm_mem.guest_phys_addr = phys_addr.0;
52
53        ioctl(
54            &self.vm,
55            kvm_sys::KVM_SET_USER_MEMORY_REGION,
56            &kvm_mem as *const _ as u64,
57        )
58        .map(|_| ())
59    }
60
61    /// Create a new virtual cpu with the [`KVM_CREATE_VCPU`][kvm-create-vcpu] ioctl.
62    /// Returns a wrapper [`vcpu::Vcpu`][crate::vcpu::Vcpu] representing the VCPU.
63    ///
64    /// [kvm-create-vcpu]: https://www.kernel.org/doc/html/latest/virt/kvm/api.html#kvm-create-vcpu
65    pub fn create_vpcu(&self, id: u64) -> io::Result<Vcpu> {
66        let vcpu = ioctl(&self.vm, kvm_sys::KVM_CREATE_VCPU, id)
67            .map(|fd| unsafe { fs::File::from_raw_fd(fd) })?;
68
69        let kvm_run = KvmRun::new(&vcpu, self.vcpu_mmap_size)?;
70
71        Ok(Vcpu::new(vcpu, kvm_run))
72    }
73}
kvm_rs/vm.rs

kvm_rs/
vm.rs
