PCI Passthrough works but GPU Passthrough won't

shawly

Member
Nov 8, 2015
25
2
23
Hello,

I've switched from ESXi to Proxmox VE 4 (latest packages and kernel installed ofc) yesterday and everything works fine, the TV card (Tevii S471) I couldn't pass through in ESXi works flawless under KVM aswell as my onboard SAS controller also passes through nicely.
Now I also wanted to pass through my AMD HD5450 and try how well this would work as virtual HTPC, problem is, the VM won't start and I can't figure out why...

dmesg stays normal after starting the VM, no warnings or errors, when look into the syslog it just wants to start the guest but then it said "failed: exit code 1"
I would love to send you the output of the log, but when I try to past the output it says I'm not allowed to post any kinds of links, images or videos, even if there isn't a single link in the damn log.. :mad:
But the log is not saying anything anyway..

Like I said, PCI passthrough on other VMs works nice. The config is exactly the same as on the other guests, except for the "x-vga=on" parameter, which is needed for GPU passthrough.

After it didn't work out I added "pcie_acs_override=downstream" to the grub options and also added the option "vfio_iommu_type1 allow_unsafe_interrupts=1" to modprobe, also didn't work.
I also added pci_stub with my GPUs pid and vid to the initramfs modules and blacklisted radeon, nothing worked yet.

I'm out of ideas, can someone tell me how you got an AMD card working with GPU passthrough? I thought they would normally work.

My hardware is a Supermicro X10-SL7-F and a Xeon E3-1245v3 if that is of any importance for you.

Update: The problem lies within the iommu grouping, I guess I have to wait for a new kernel...
 
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