Fix RMRR Error When Using PCI Passthrough for GPU

Permanent fix for this error on HP Servers

 

When i migrated my Unraid NAS into an HP DL380p i wanted to add a GPU for transcoding into my docker environment. Unknown to me however my logs quickly filled up with this error

Device is ineligible for IOMMU domain attach due to platform RMRR requirement. Contact your platform vendor.
Device is ineligible for IOMMU domain attach due to platform RMRR requirement. Contact your platform vendor.
Device is ineligible for IOMMU domain attach due to platform RMRR requirement. Contact your platform vendor.
Device is ineligible for IOMMU domain attach due to platform RMRR requirement. Contact your platform vendor.

This got pretty annoying, pretty fast. To fix this initially i found that some amazing folks over on the Unraid forum already had a way to stop it, unfortunately their method meant patching the unraid kernel and this had to be done manually during every unraid update.

Being me though i wanted my updates for unraid as fast as they were available. So after a lot more digging i found a way to disable the RMRR check in the server itself, no more errors in my log! This will require some familiarity with linux, though i hope to polish this guide in time and make it simpler to follow, but anyway time for the how;

  • Get a copy of Debian or Ubuntu flashed to a USB and run your server with it
  • Once booted into live mode you will need to download and install the below packages from HPEs website,
  • Download the conrep_rmrds.xml file which contains the data needed to manage pcie slots
  • Next you’ll need to create a file called exclude.dat and copy the below into it:
    • <Conrep> <Section name=”RMRDS_SlotX” helptext=”.”>Endpoints_Excluded</Section> </Conrep>
    • Where it says SlotX be sure to replace this with the the pci slot number that your gpu is plugged into, you can find this in your iLO web console under System Information/Device Inventory. If your using an unsupported gpu like me it will show up as Unknown, but if you remove all the other pcie devices it should be simple to spot.
  • Finally run the command conrep -l -x conrep_rmrds.xml -f exclude.dat This will enable support for PCI Device passthrough and disable that error once and for all.

 

 

 

 

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