[mythtv-users] Xen DomU Backend & Nova-T

[Dirk]

On Jan 2, 2009, at 8:04 PM, Simon Hobson wrote:

> Dirk wrote:
>> I am trying to get a backend running in a domU. So far I have only
>> have the pci passthrough working. But if I try to record something
>> with cat /dev/video0 > test.mpg the file stays empty. This is with
>> pciback.hide only.
>>
>> So, I tried the options from this thread: pciback.permissive,
>> swiotlb=force and later swiotlb=256,force.  But nothing really works,
>> I get a kernel panic when I try to boot the domU.
>>
>> I am using debian etch with 2.6.18-6-xen-amd64, xen 3.0.3, I have a
>> pvr-250 and a pvr-350.
>
> I don't know if the issue is the same, I've just installed an
> HVR-1110 in a similar setup. It wasn't fully recognised in the 2.6.18
> kernel so I had to upgrade my DomU to 2.6.26 (Debian Lenny) which
> also required upgraded Xen to 3.2 using etch-backports (the Dom0 is
> Etch).
>
I have read several times that debian etch just works with xen. So,  
this seemed to be the easiest way. Of course I hoped that lenny would  
have been released around christmas. I expect to put a lot of time and  
effort in getting mythtv and xen working. I don't want to go through a  
dist-upgrade and resolve all the small problems that come with it.  
I'll upgrade when lenny is ready and not earlier.

> It now seems to work fine without anything other than the basic  
> pciback.hide.

That sounds promising.

For some unknown reason I got it working. I ended it up with this in  
the dom0:
module          /boot/vmlinuz-2.6.18-6-xen-amd64 root=/dev/md0 ro  
console=tty0 pciback.permissive pciback.hide=(03:05.0)(03:06.0)  
dom0_mem=-256M
and this for the domU:
vif  = [ 'mac=00:16:3e:18:56:bb, ip=192.168.1.22' ]

pci = [ '03:05.0','03:06.0' ]
extra = 'swiotlb=32,force'

After the cards started working the network stopped. For some reason  
udev adds a new ethX interface everytime you boot. I  didn't have this  
adding up before the tv cards worked, but I really don't know if the  
problem is related. Anyway, with a fixed mac address in the vif line  
and removing all the new interfaces from /etc/udev/rules.d/ 
z25_persistent-net.rules this problem was solved.

Dirk