Re: [Xen-devel] Re: PCI passthrough stopped working, brainache!

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Mon, 2011-10-10 at 23:02 +0100, Andy Burns wrote:
> [Resent from subscribed address]
> 
> Recently had passthrough of 2xPCI DVB-T cards and 1xPCIe DVB-S2 card working,
> the last know config that was *certainly* working was
> 
> dom0
> xen-4.1.1-3.fc16.x86_64
> kernel-3.1.0-0.rc7.git0.0.fc16.x86_64
> 
> domU
> kernel-3.1.0-0.rc8.git0.0.fc16.x86_64
> 
> Since then I've updated
> 
> xen-4.1.1-6.fc16.x86_64 on dom0
> 
> kernel-3.1.0-0.rc9.git0.0.fc16.x86_64 on dom0 and domU
> 
> and updated all other packages to current F16 updates-testing,
> also lots of fiddling with grub2 and systemd on the domU
> 
> Only today did I realise that only the PCIe card is now working, not
> the PCI ones, and have since spent several hours trying to get back to
> a working configuration :-(
> 
> I've rolled my xen packages back from 4.1.1-6 to 4.1.1-3
> tried booting various combinations of 3.1.0-rc7/rc8/rc9 as dom0 and domU
> 
> made sure I still have "pci=resource_alignment" for all the relevant
> PCI devices on the dom0
> made sure I still have "iommu=soft" on the domU
> made sure pci-back is happy with "xm pci-list-assignable-devices"
> made sure devices really have been assigned with "xm pci-list mythf16"
> made sure the devices and drivers show in the domU with "lspci",
> "lsusb" and "lsmod"
> checked "xm dmesg" on dom0 and "dmesg" on dom0 and domU that drivers
> see the hardware and load firmware OK
> scandvb goes through the motions of tuning, but finds no stations,
> this  *feels* as though the issue is lack of DMA transfers.
> 
> How can I tell if the iommu=soft is taking effect?
> Anything stupid I sound like I've forgotten?

It looks as if you have been pretty thorough. 

One thing which is not clear is if you also downgraded all the Xen
utilities/tools packages when you say "Xen packages" or just the
hypervisor itself. (You probably downgraded everything, but I have to
ask).

Does Fedora (yum?) log which packages which it is upgrading? Is it
possible that e.g. scandvb or the firmware package has also been
upgraded (I admit this is slightly straw-clutching).

If you don't passthrough a device are you able to drive it from dom0?

It would probably be useful to post full dmesg output for hypervisor and
both kernels.

Ian.



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel