Re: [PATCH 4/4] vl: Prioritize realizations of devices

[Peter Xu]

Hi, Dan,

On Thu, Sep 02, 2021 at 02:53:00PM +0100, Daniel P. Berrangé wrote:
> The correct ordering of devices/backends is generally pretty obvious
> for libvirt to determine. Most of the problems we've had related to
> ordering are on the QEMU side, because the ARGV given to QEMU made
> correct sense if parsed left-to-right, but QEMU didn't actually process
> them in that order. We've patched QEMU to hack around its inability to
> honour the CLI order repeatedly.

Is there a pointer to the problem?

> 
> Being completely self-ordering on the QEMU side using a topological
> sort would be neat from a conceptual purity POV, but that is quite a
> challenge to implement and I'm not convinced it is worth it, compared
> to other problems we want to spend time on.

I just noticed there can also be dependency between the buses; that cannot be
fixed by ordering of classes indeed as either proposed in this series, or
introduce a new priority.

Thanks,

-- 
Peter Xu