Fixing DDA device out of resource (Error 12) in Hyper-V VM

The “DDA device out of resources (Error 12)” in a Hyper-V VM typically occurs when using Discrete Device Assignment (DDA) to pass through a physical GPU to a virtual machine, but there are insufficient resources (such as memory, I/O space, or interrupts) to assign the device. Here’s how to Fixing DDA device issue:

Steps to Resolve Error 12 (DDA Resource Issue) in Hyper-V:

1. Check if DDA is Enabled and Configured Correctly

• Ensure Discrete Device Assignment (DDA) is enabled and that the GPU has been properly detached from the host and assigned to the VM.
• The GPU should be correctly reserved for the VM using PowerShell commands. Example PowerShell commands to detach the GPU from the host and assign it to the VM:

   # Disable the device on the host (run this on the Hyper-V host)
   Disable-PnpDevice -InstanceId "PCI\VEN_xxxx&DEV_xxxx&SUBSYS_xxxxxxxx"

   # Assign the device to the VM (run on the host)
   Add-VMAssignableDevice -VMName "YourVMName" -LocationPath "PCIROOT(0)#PCI(1A03)#PCI(0000)"

2. Allocate More Memory to the VM

• Error 12 often arises when the VM doesn’t have enough memory to allocate to the GPU.
• Increase the VM’s memory allocation in Hyper-V Manager:
  1. Go to Hyper-V Manager → Select your VM → Settings.
  2. Under Memory, increase the assigned memory and ensure it’s enough to accommodate the GPU’s memory requirements.
  3. You may need to use Static Memory Allocation instead of dynamic memory, as DDA does not work well with dynamic memory.

3. Configure PCI Express Settings

• GPUs require adequate PCIe resources, and Error 12 can result from the VM being unable to map the PCIe resources needed by the GPU.
• Adjust the PCI Express settings for the VM. You might need to reserve specific resources for the PCIe device in the BIOS/UEFI or use virtualization options that allocate more PCIe I/O space to the VM.

4. Limit the Number of Devices Passed to the VM

• Reduce the number of devices passed through to the VM to free up system resources.
• Ensure only the GPU and essential devices are being assigned through DDA.

5. Update GPU Drivers on Host and VM

• Make sure the GPU drivers on both the Hyper-V host and the VM are up-to-date. Outdated drivers may not properly handle resource allocation, leading to Error 12.
• Check the vendor (e.g., NVIDIA or AMD) for updated drivers that support GPU passthrough in virtual environments.

6. Modify VM’s Firmware Settings

• Ensure that the VM is using Generation 2 firmware (if supported). Generation 2 VMs provide better hardware compatibility for DDA and PCIe devices.
  • Go to Hyper-V Manager → Right-click on the VM → Settings → Firmware → Ensure it’s set to Generation 2 (if applicable).

7. Check for BIOS/UEFI Updates

• Ensure that the Hyper-V host’s BIOS/UEFI firmware is up-to-date. Some systems require firmware updates to support GPU passthrough and proper PCIe resource management.

8. Check for Conflicting Devices

• Verify if there are any other conflicting devices (such as additional GPUs, NICs, etc.) consuming resources. Disable unnecessary devices or reassign them to other VMs or back to the host.

9. Reserve Memory in the Hyper-V Host

• You can use PowerShell to reserve more memory for the GPU on the Hyper-V host:
  powershell Set-VM "YourVMName" -LowMemoryMappedIoSpace 3Gb Set-VM "YourVMName" -HighMemoryMappedIoSpace 32Gb
• This reserves more memory-mapped I/O space, which might resolve the Error 12 if the issue is related to insufficient addressable memory.

10. Reboot the Host and VM

• After making the necessary changes, reboot both the Hyper-V host and the VM to apply the new settings and see if the issue is resolved.

Conclusion

The “DDA device out of resources (Error 12)” in the case of Hyper-V VM usually occurs at the time of utilizing Discrete Device Assignment (DDA) to simply pass through any physical and the best GPU dedicated server to a VM, but there are inadequate assets (like I/O space, interrupts, or memory) to allot the device.