http://amfeltec.com/products/flexible-x4-pci-express-4-way-splitter-gpu-oriented/

 

I inserted this device in my Unraid box and am getting this displayed at the console. It hangs there, so I have no network.

 

I see similar to this:

 

0.597489] Ignoring identity map for HW passthrough device 0000:00:14.0 [0x8c032000 - 0x8c03efff]

[    0.597492] Ignoring identity map for HW passthrough device 0000:00:1a.0 [0x8c032000 - 0x8c03efff]

[    0.597495] Ignoring identity map for HW passthrough device 0000:00:1d.0 [0x8c032000 - 0x8c03efff]

[    0.597498] IOMMU: Prepare 0-16MiB unity mapping for LPC

[    0.597499] Ignoring identity map for HW passthrough device 0000:00:1f.0 [0x0 - 0xffffff] <-----This is where mine hangs.

 

Or sometimes I just get IOMMU disabled, depending on what cards are in it or what slot it's in.

When I get that, dmesg shows my BIOS is broken.

 

The same box, booted to ESXi 6.0 U1, and I am able to pass 4 GPU's connected to this switch.

 

Googling the issue does not return very much, does KVM support this?

 

 

Thanks!

Eric

 

Put iommu=pt in your syslinux config.

I'll try that, I read that somewhere and didn't know if it was appropriate.

 

Thanks!

It's in there already.

 

I had to turn off all c-state stuff in the bios, and now it's working.

 

I am now able to have the switch in the first PCIe slot, set primary GPU as PCIe, boot from the card in the switch and steal it for a vm.

 

This is COOL!

Thanks!