Re: panic: _bus_virt_to_bus for vioif on GCE with GENERIC kernel

[Reinoud Zandijk <reinoud%NetBSD.org@localhost>]

Hi Paul,

On Mon, Feb 01, 2021 at 06:46:17PM +1100, Paul Ripke wrote:
> On Mon, Feb 01, 2021 at 04:18:17PM +1100, Paul Ripke wrote:
> > However, forcing the full size virtio_net_hdr results in a working kernel!
...
> > Does that give any hints?

I'll double check all header size dependent code again. This is very odd but
good to know it makes a difference.

> Major correction: that patch results in a *booting* kernel, but without a
> working NIC. I forgot I was logged on via the serial console...

thats not surprising since the header lengths are wrong :)

> > > Legacy support has to be disabled in the hypervisor (like GCE) as it needs to
> > > pass a different PCI product number. In Qemu its a property of each virtio PCI
> > > device but in GCE it might be global.
> > 
> > Ah, I had wondered if that was the case. I haven't seen anything in the GCE
> > configs to control this; Googling for answers is also made awkward given
> > the ambiguous "PCI" acronym.

Its a wonder you got that far :) From what i read on the google compute engine
docs its far from trivial to set one up. It looks like they wanted to create a
swiss-knife that can do everything in one tool.

Reinoud