Re: [PATCH 0/7] PCI support for UML

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2021-02-23 at 16:27 +0100, Johannes Berg wrote:
> In order to simulate some devices and write tests completely
> independent of real PCI devices, we continued the development
> of time-travel and related bits, and are adding PCI support
> here now.
> 
> The way it works is that it communicates with the outside (of
> UML) with virtio, which we previously added using vhost-user,
> and then offers a PCI bus to the inside system, where normal
> PCI probing etc. happens, but all config space & IO accesses
> are forwarded over virtio.

I hadn't sent it out until now, but the userspace bits for all the time-
travel and PCI-over-vhost-user are here:

https://github.com/linux-test-project/usfstl/

If anyone has any suggestions on a good example PCI device that already
has a driver upstream I'd be interested - I looked for something simple
like LED or GPIO but no such thing I could find (that wasn't platform
dependent in some way). So far I've only implemented a virtual Intel
WiFi NIC, but that depends on a large body of code I can't publish. As
an example, it would be nice to write (and publish there) a simple PCI
device implementation. :)

johannes