vm-memory

A library to access the physical memory of a virtual machine.

In a typical Virtual Machine Monitor (VMM) there are several components, such as boot loader, virtual device drivers, virtio backend drivers and vhost drivers, that need to access the VM physical memory. The vm-memory crate provides a set of traits to decouple VM memory consumers from VM memory providers. Based on these traits, VM memory consumers can access the physical memory of the VM without knowing the implementation details of the VM memory provider. Thus VMM components based on these traits can be shared and reused by multiple virtualization solutions.

Platform Support

• Arch: x86, AMD64, ARM64
• OS: Linux/Unix/Windows

Example

• Create a VM physical memory objects in hypervisor specific ways using the GuestMemoryMmap implementation of the GuestMemory trait:

fn provide_mem_to_virt_dev() {
    let gm = GuestMemoryMmap::new(&[
        (GuestAddress(0), 0x1000),
        (GuestAddress(0x1000), 0x1000)
    ]).unwrap();
    virt_device_io(&gm);
}

• Consumers access VM's physical memory

fn virt_device_io<T: GuestMemory>(mem: &T) {
    let sample_buf = &[1, 2, 3, 4, 5];
    assert_eq!(mem.write(sample_buf, GuestAddress(0xffc)).unwrap(), 5);
    let buf = &mut [0u8; 5];
    assert_eq!(mem.read(buf, GuestAddress(0xffc)).unwrap(), 5);
    assert_eq!(buf, sample_buf);
}

Documentations & References

• Design of The vm-memory Crate
• TODO List
• The rust-vmm Project

License

This project is licensed under

• Apache License, Version 2.0