Re: X58 Virtualization w/ Linux

Paolo Bonzini
2016-06-15T06:59:11Z

On 15/06/2016 07:04, Steve Novakov wrote:
> 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.

Passing devices to pci-stub doesn't require the IOMMU, it's just
swapping the driver that binds to the device. I think this is why with
VT-d disabled you cannot assign the device to vfio-pci.

Does it still freeze with Ubuntu 16.04 (VT-d enabled,
vfio_iommu_type1.allow_unsafe_interrupts=1)?

Thanks,

Paolo