Re: [PATCH RFC 00/16] Implement Microvm for aarch64 architecture

[Peter Maydell]

On Mon, 17 Feb 2020 at 07:42, Xu Yandong <address@hidden> wrote:
>
> Implement Microvm for aarch64 architecture
>
> This series attempts to implement microvm for aarch64
> architecture.
>
> Just like how Sergio Lopez does for implementing microvm
> for x86 architecture. We remove parts of emulate devices which
> are not needed in microvm, compared with normal VM,
> We only keep PL011 (UART), PL031 (RTC) and virtio-mmio
> devices for microvm of aarch64.

For x86, 'microvm' makes sense, because the standard
PC models are models of real hardware with a lot of
legacy baggage. The situation is different for aarch64.
The 'virt' board is already intended as a "minimal
machine for booting a VM that knows it's a VM".
Why do we need another model that's intended for the
same purpose?

It would be more interesting to look at whether there
are reasonable places where we could allow command
line options to have the 'virt' board not provide
some devices where that makes a significant speed
improvement. Analysis of where the extra time is
actually going would also be helpful.

NB: I'm pretty firmly against dropping PCI. This is
a pluggable discoverable bus, and it's a much better
way to provide virtio than virtio-mmio.

thanks
-- PMM