iommu issue

[FRancuz]

the iommu is stuck on disabled even when i made sure that vt-d is turned on in the bios.

from what i understand i need the iommu to be enabled to passthrough a gpu to a VM

i have no idea what else to do. 

[FRancuz]

i'm adding the diagnostic file if that will help

serwer-diagnostics-20240329-2136.zip

[bmartino1]

in bios. intel(R) Virtualization Technology optioin needs to be enabled asx well

 

vt-d is the "secure vm" option that enables sriov

You need iommu enabled at bios settign first.

  

On 4/4/2024 at 11:16 AM, bmartino1 said:

Verifying IOMMU parameters

 

dmesg | grep -e DMAR -e IOMMU

Intel will show something similar:

 

There should be a line that looks like "DMAR: IOMMU enabled".

If there is no output, something is wrong.

 

Verify IOMMU interrupt remapping is enabled

 

It is not possible to use PCI passthrough without interrupt remapping. Device assignment will fail with 'Failed to assign device "[device name]": Operation not permitted' or 'Interrupt Remapping hardware not found, passing devices to unprivileged domains is insecure.'.

All systems using an Intel processor and chipset that have support for Intel Virtualization Technology for Directed I/O (VT-d), but do not have support for interrupt remapping will see such an error. Interrupt remapping support is provided in newer processors and chipsets (both AMD and Intel).

To identify if your system has support for interrupt remapping:

 

dmesg | grep 'remapping'

 

If you see one of the following lines:

AMD-Vi: Interrupt remapping enabled

DMAR-IR: Enabled IRQ remapping in x2apic mode ('x2apic' can be different on old CPUs, but should still work)

then remapping is supported.

If your system doesn't support interrupt remapping, you can allow unsafe interrupts
^enabled under unraid VM settings...

 

[FRancuz]

i;ve enabled eveything in bios that i can and still:

 

does that mean that my system is just jnot compatible?

 

[bmartino1]

iommu is enabled. but eh device will not allow pci device pass through.

per notes from proxmonx stuff: https://pve.proxmox.com/wiki/PCI_Passthrough#Verify_IOMMU_interrupt_remapping_is_enabled:~:text=something is wrong.-,Verify IOMMU interrupt remapping is enabled,-It is not

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It is not possible to use PCI passthrough without interrupt remapping. Device assignment will fail with 'Failed to assign device "[device name]": Operation not permitted' or 'Interrupt Remapping hardware not found, passing devices to unprivileged domains is insecure.'.

 

All systems using an Intel processor and chipset that have support for Intel Virtualization Technology for Directed I/O (VT-d), but do not have support for interrupt remapping will see such an error. Interrupt remapping support is provided in newer processors and chipsets (both AMD and Intel).

 

To identify if your system has support for interrupt remapping:

dmesg | grep 'remapping'

 

If you see one of the following lines:

AMD-Vi: Interrupt remapping enabled

DMAR-IR: Enabled IRQ remapping in x2apic mode ('x2apic' can be different on old CPUs, but should still work)

then remapping is supported.

 

If your system doesn't support interrupt remapping, you can allow unsafe interrupts with:

echo "options vfio_iommu_type1 allow_unsafe_interrupts=1" > /etc/modprobe.d/iommu_unsafe_interrupts.conf
*but this is not a guarantee.

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However it may still work in unraid if you enable unsafe interrupts under vm settings:

 

setttings > VM Manger > advance toggle

 

allow unsafe interrupts

 

[bmartino1]

you need to find your amd advance cbs option and force set iommu to enabled.

 

not sure if that bios is up to date. what HP server, what processor?