Re: What is the purpose for "none" machine?

[Peter Maydell]

On Mon, 23 Jan 2023 at 17:36, Matwey V. Kornilov
<matwey.kornilov@gmail.com> wrote:
> I am playing with qemu-system-avr currently.
> I see that there is an "empty machine" called "none" in
>
>      qemu-system-avr -M help
>
> list.
>
> Is it a real thing? I am failed to run any code with "none" machine.

It is mostly for the benefit of management layer code (eg libvirt)
that wants to probe capabilities of QEMU[*], and secondarily used
in some of QEMU's own test suite.  The 'none' machine has no CPU,
no devices and no RAM, which is why you can't run any code on it.

[*] Management code can execute QEMU with the 'none' machine type,
telling QEMU not to actually run the guest on startup, and query
things via the QMP monitor protocol interface, for instance.

thanks
-- PMM