[mythtv-users] DVB tuner not working in Xen PV guest

Simon Hobson linux at thehobsons.co.uk
Fri Jul 29 19:56:49 UTC 2011

Christian wrote:

>The PCI Passthrough guide 
>at <http://wiki.xensource.com/xenwiki/XenPCIpassthrough>http://wiki.xensource.com/xenwiki/XenPCIpassthrough states 
>that swiotlb=force and iommu=soft must be set as kernel boot options 
>in the domU.  Have you already tried hat?

Success, yay !

I find that page a tad less clear than it could be - at least for 
someone who hasn't been following the ins and outs of xen patches vs 
pvops kernels and so on. It's all the "you need this ...", "but if 
you have <something> then you need this other thing" stuff that had 
me caught up.

I think I had two things wrong.

Firstly, I had pciback.hide... in my Dom0 boot config, but it's now 
xen-pciback.hide ...

In my DomU I needed iommu=soft but not swiotlb=force - in fact it 
didn't work with swiotlb=force and iommu=soft both present. Get those 
right and suddenly dvbtune gets results, and now MythTV setup has 
found channels :)

Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.

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