Re: X58 Virtualization w/ Linux

Steve Novakov
2016-06-15T05:04:41Z

So I swapped over to ubuntu 16.04 server and I just saw this line in dmesg:

[0.100541] DMAR-IR: This system BIOS has enabled interrupt remapping on
a chipset that contains an erratum making that feature unstable. To
maintain system stability interrupt remapping is being disabled.please
contact your BIOS vendor for an update.

This line was actually present while using arch as well I just never
took the time to read past the first line (which just says enabled
interrupt remapping). This seems to be an issue with northbridge
stepping B3, and was apparently fixed in stepping C2 ( I have B3 : ( ).

I wonder if it's even possible to get this to work with my motherboard
now....**though ESXi can manage just fine...**

Maybe there's some way to trick linux into just trying to do it. I mean,
it seems to pass devices to pci-stub just fine.

Steve Novakov
B.A.Sc Engineering Physics
PhD Student - Physics
University of Michigan - Ann Arbor
On 6/14/2016 6:00 PM, Steve Novakov wrote:
> Some more info here from someone having exactly the same problem I am
> and at exactly the same stage
>
> http://www.tomshardware.com/answers/id-3049002/socket-1366-iomuu-compatibility-decent.html#18122605
>
>
> Steve Novakov
> B.A.Sc Engineering Physics
> PhD Student - Physics
> University of Michigan - Ann Arbor
> On 6/13/2016 4:11 PM, Steve Novakov wrote:
>> Interestingly, when I disable VT-D in the motherboard BIOS. I can
>> boot with "intel_iommu=on pci-stub.ids=DEVICEID"
>>
>> and the DEVICE is successfully loaded by the pci-stub driver,
>> according to $lspci -nnk readout
>>
>> additionally, I see:
>>
>> $dmesg | grep -e IOMMU
>>
>> [0.000000] DMAR: IOMMU enabled
>>
>> even though I actually DISABLED VT-D in the motherboard BIOS. Going
>> back now and enabling it in the BIOS causes freezing during boot again.
>>
>> I'm also having trouble assigning this device to the vfio-pci driver,
>> but that might be a separate issue.
>>
>> Steve Novakov
>> B.A.Sc Engineering Physics
>> PhD Student - Physics
>> University of Michigan - Ann Arbor
>> On 6/12/2016 11:32 PM, Steve Novakov wrote:
>>> > Usually, i am using intel_iommu=on and everything works well. But
>>> in your case, i guess you may also need intremap=off.
>>>
>>> Passing EITHER "intel_iommu=on intremap=off" OR " "intel_iommu=on
>>> vfio_iommu_type1.allow_unsafe_interrupts=1" during boot results in a
>>> freeze at boot. This happens at the loading initramfs step ("initrd
>>> /boot/initramfs-linux.img").
>>>
>>> Any further suggestions? Thanks,
>>>
>>> Steve Novakov
>>> B.A.Sc Engineering Physics
>>> PhD Student - Physics
>>> University of Michigan - Ann Arbor
>>>
>>>
>>>
>>
>