Re: PCI passthru with Xen 3.0, NetBSD 5.1 dom0, Linux domU

[Konrad Rzeszutek Wilk <konrad.wilk%oracle.com@localhost>]

On Mon, Jun 06, 2011 at 05:03:08PM +0200, Julien Oster wrote:
> Hello Konrad,
> 
> On Mon, Jun 6, 2011 at 16:46, Konrad Rzeszutek Wilk
> <konrad.wilk%oracle.com@localhost> wrote:
> 
> > Did you set 'iommu=soft' in the Linux kernel?
> 
> Ah. iommu=soft seems to have done the trick! I can scan now, and I can
> see beacons with tcpdump.

<nods>
> 
> However, before every scan I get the following two messages, this
> seems to be reproducible every time:
> 
> [  206.084438] ath: Failed to stop TX DMA in 100 msec after killing last frame
> [  206.084534] ath: Failed to stop TX DMA!
> 
> Harmless? Will have to do further testing to see if everything works
> nonetheless.

Are the IRQs being delievered to DomU? You can check the /proc/interrupts.
Is it using MSI? I am not sure if NetBSD pciback supports MSI and if that
is what it tries it might have choked on something (and I remember
writting some patches for xen-pcifront to fix misbehaving backends).
I think they went in 2.6.39

> 
> > And are you using a kernel older than 2.6.37 for this?
> 
> No, should I?

No, just wanted to make sure you are using something more modern than 2.6.37.
You might want to backport 1d4610527bc71d3f9eea520fc51a02d54f79dcd0 or
just use 2.6.39.