Re: Struggling with PCI-Passthrough

[Alexander Brychcy <bober@brychcy.net>]

Am 10.03.2014 12:09, schrieb Andrew Cooper:
> On 10/03/14 09:59, Alexander Brychcy wrote:
>> Hi,
>>
>> I'm currently trying to create a Windows 7 HVM with GPU Passthrough.
>>
>> My setup is the following:
>> CPU:	Xeon E3-1230v3
>> Board:	Asus P9D-E/4L
>> RAM:	16GB Kingston from Board QVL
>> GPU:	Sapphire R9 270X 4GB
>>
>> The passthrough itself is working (Tested with Debian Wheezy dom0 on Xen
>> 4.1, then XenServer 6.2 and now Debian Jessie dom0 on Xen 4.3)
>>
>> Under Debian Jessie i was not able to passthrough the USB Controller,
>> although it appeard at xl pci-assignable-list and i cannot assign more
>> than 2GB of memory to the HVM.
>>
>> The overall problem is, that the HVM starts up and is running fine. But
>> after a unspecific amount of time the hole system freezes. The cursor in
>> dom0 still blinking, but no input possible - not even in xen serial
>> console. I had one run, without a freeze, but the GPU performance was
>> very poor, so i tried a manual reset. After the HVM reboot the
>> performance was as expected, but soon the system froze again.
>>
>> I'm not sure, if this problem is related to Xen, because i tried to
>> create the virtual machine with KVM and had the same issue. But i
>> switched to Xen to get the best performace.
>>
>> I will add my config and log files and hope you can help me to get this
>> setup fully working.
>>
>> Kind regards,
>> Alexander
> 
> Looking at the serial log, it would appear that Xen has decided to
> schedule no vcpus whatsoever, and is completely idle.
> 
> Looking at the 'Q' output, only two vcpus (one from each domain) are not
> in a blocked state, but no obvious reason for them to be blocked; they
> are not blocked waiting for events.
> 
> Are you able to try this with a debug version of Xen?  Perhaps an
> assertion will be tripped which might give more of a clue.
> 
> It is certainly interesting that the same behaviour exists with KVM,
> suggesting it is something to do with hardware interaction, but I can
> see no obvious reason why Xen is as idle as it is.
> 
> ~Andrew
> 

I will try everything to get this machine running, but i won't be able
test again before the weekend. The nullmodem cable was only borrowed and
it takes some time for my own to arrive.

Which switches do I have to set during configure to get a debug version?

I will start a new thread on xen-users when everything is set up. Just
clicked on the wrong mailto when starting this conversation.