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

Simon Hobson linux at thehobsons.co.uk
Mon Jul 25 19:06:18 UTC 2011

Christian wrote:
>The PCI Passthrough guide at 
>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?
>Let me know if it works, I'm also interested in virtualizing my backend.

No it didn't - and I'm a bit embarrassed that I missed that setting.

As I mentioned, I have Myth 0.21 running under Xen - that's with a 
2.6.18-xen-686 kernel on Xen 3.2.1 IIRC. It can cope with 3 
recordings off one tuner (DVB Multirec), but I think it's struggling 
to get recordings onto disk while there's a commflag job running (so 
I've mostly disabled comm flagging).

An obvious answer is to abandon trying to run Myth under Xen and just 
use my old box as a dedicated backend - but that means having two 
boxes on all the time and I get enough hassle over the "roomful of 
blinking lights" as it is !

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.

More information about the mythtv-users mailing list