[SOLVED] IOMMU enabling issues

ezelbanaan

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Mar 5, 2021
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So I'm trying to enable IOMMU so I can pas trough a PCIe device. I've follow the guide from the documentation but in the GUI it still says: "No IOMMU detected, please activate it.See Documentation for further information.".

When verifying if IOMMU is enabled using
Code:
dmesg | grep -e DMAR -e IOMMU
I get the following output:
Code:
[    0.000000] Warning: PCIe ACS overrides enabled; This may allow non-IOMMU protected peer-to-peer DMA
[    0.063842] DMAR: IOMMU enabled
So that means it is enabled.
The first line of the output is because remapping wasn't supported in x2apic mode, so I had to enter the following line according to the guide
Code:
echo "options vfio_iommu_type1 allow_unsafe_interrupts=1" > /etc/modprobe.d/iommu_unsafe_interrupts.conf

One Thing I did notice however was that I had no iommu_groups even though I have 2 PCIe devices installed.

Any help would be appreciated since I'd really like to solve the issue.
 
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Not every mainboard/CPU supports IOMMU groups. For example VT-d doesn't support it but VT-x does. So without IOMMU goups you can only passthrough the complete device but not individual IOMMU functions.
 
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Not every mainboard/CPU supports IOMMU groups. For example VT-d doesn't support it but VT-x does. So without IOMMU goups you can only passthrough the complete device but not individual IOMMU functions.
My CPU support VT-x, and with my MB I couldn't find any information about it. But I don't really need groups, I just want to past through the complete PCIe device. But when I try I get the error that IOMMU isnt activated.

What I'd like to do is instead of passing through 6 individual Hard Drive's I'd like to pass through the HBA I'm using.
 
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For PCI(e) passthrough you do need VT-d, VT-x is just for running the VMs. If you want to do passthrough you need IOMMU groups. Sometimes the error about No IOMMU detected is not correct. Which device (number) do you want to passthrough?
Can you show us the output of this command: for d in /sys/kernel/iommu_groups/*/devices/*; do n=${d#*/iommu_groups/*}; n=${n%%/*}; printf 'IOMMU group %s ' "$n"; lspci -nns "${d##*/}"; done? Then we will know if it is working for sure.
 
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For PCI(e) passthrough you do need VT-d, VT-x is just for running the VMs. If you want to do passthrough you need IOMMU groups. Sometimes the error about No IOMMU detected is not correct. Which device (number) do you want to passthrough?
Can you show us the output of this command: for d in /sys/kernel/iommu_groups/*/devices/*; do n=${d#*/iommu_groups/*}; n=${n%%/*}; printf 'IOMMU group %s ' "$n"; lspci -nns "${d##*/}"; done? Then we will know if it is working for sure.
Ok, my CPU supports VT-d for sure, my motherboard I'm not sure about. I already have VM's working so they both must at least support VT-x :).

After I run:
Code:
for d in /sys/kernel/iommu_groups/*/devices/*; do n=${d#*/iommu_groups/*}; n=${n%%/*}; printf 'IOMMU group %s ' "$n"; lspci -nns "${d##*/}"; done
I get the following output:
Code:
00:01.0 PCI bridge [0604]: Intel Corporation Xeon E5/Core i7 IIO PCI Express Root Port 1a [8086:3c02] (rev 07)
00:01.1 PCI bridge [0604]: Intel Corporation Xeon E5/Core i7 IIO PCI Express Root Port 1b [8086:3c03] (rev 07)
00:02.0 PCI bridge [0604]: Intel Corporation Xeon E5/Core i7 IIO PCI Express Root Port 2a [8086:3c04] (rev 07)
00:03.0 PCI bridge [0604]: Intel Corporation Xeon E5/Core i7 IIO PCI Express Root Port 3a in PCI Express Mode [8086:3c08] (rev 07)
00:05.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Address Map, VTd_Misc, System Management [8086:3c28] (rev 07)
00:05.2 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Control Status and Global Errors [8086:3c2a] (rev 07)
00:05.4 PIC [0800]: Intel Corporation Xeon E5/Core i7 I/O APIC [8086:3c2c] (rev 07)
00:11.0 PCI bridge [0604]: Intel Corporation C600/X79 series chipset PCI Express Virtual Root Port [8086:1d3e] (rev 06)
00:1a.0 USB controller [0c03]: Intel Corporation C600/X79 series chipset USB2 Enhanced Host Controller #2 [8086:1d2d] (rev 06)
00:1b.0 Audio device [0403]: Intel Corporation C600/X79 series chipset High Definition Audio Controller [8086:1d20] (rev 06)
00:1c.0 PCI bridge [0604]: Intel Corporation C600/X79 series chipset PCI Express Root Port 1 [8086:1d10] (rev b6)
00:1c.1 PCI bridge [0604]: Intel Corporation C600/X79 series chipset PCI Express Root Port 2 [8086:1d12] (rev b6)
00:1c.2 PCI bridge [0604]: Intel Corporation C600/X79 series chipset PCI Express Root Port 3 [8086:1d14] (rev b6)
00:1c.3 PCI bridge [0604]: Intel Corporation C600/X79 series chipset PCI Express Root Port 4 [8086:1d16] (rev b6)
00:1c.5 PCI bridge [0604]: Intel Corporation C600/X79 series chipset PCI Express Root Port 6 [8086:1d1a] (rev b6)
00:1d.0 USB controller [0c03]: Intel Corporation C600/X79 series chipset USB2 Enhanced Host Controller #1 [8086:1d26] (rev 06)
00:1e.0 PCI bridge [0604]: Intel Corporation 82801 PCI Bridge [8086:244e] (rev a6)
00:1f.0 ISA bridge [0601]: Intel Corporation C600/X79 series chipset LPC Controller [8086:1d41] (rev 06)
00:1f.2 SATA controller [0106]: Intel Corporation C600/X79 series chipset 6-Port SATA AHCI Controller [8086:1d02] (rev 06)
00:1f.3 SMBus [0c05]: Intel Corporation C600/X79 series chipset SMBus Host Controller [8086:1d22] (rev 06)
07:00.0 SATA controller [0106]: Marvell Technology Group Ltd. Device [1b4b:9215] (rev 11)
08:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 0c)
09:00.0 USB controller [0c03]: VIA Technologies, Inc. VL805 USB 3.0 Host Controller [1106:3483] (rev 01)
0a:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 0c)
7f:08.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link 0 [8086:3c80] (rev 07)
7f:08.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link Reut 0 [8086:3c83] (rev 07)
7f:08.4 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link Reut 0 [8086:3c84] (rev 07)
7f:09.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link 1 [8086:3c90] (rev 07)
7f:09.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link Reut 1 [8086:3c93] (rev 07)
7f:09.4 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link Reut 1 [8086:3c94] (rev 07)
7f:0a.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Power Control Unit 0 [8086:3cc0] (rev 07)
7f:0a.1 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Power Control Unit 1 [8086:3cc1] (rev 07)
7f:0a.2 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Power Control Unit 2 [8086:3cc2] (rev 07)
7f:0a.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Power Control Unit 3 [8086:3cd0] (rev 07)
7f:0b.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Interrupt Control Registers [8086:3ce0] (rev 07)
7f:0b.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Semaphore and Scratchpad Configuration Registers [8086:3ce3] (rev 07)
7f:0c.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
7f:0c.1 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
7f:0c.2 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
7f:0c.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
7f:0c.6 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller System Address Decoder 0 [8086:3cf4] (rev 07)
7f:0c.7 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 System Address Decoder [8086:3cf6] (rev 07)
7f:0d.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
7f:0d.1 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
7f:0d.2 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
7f:0d.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
7f:0d.6 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller System Address Decoder 1 [8086:3cf5] (rev 07)
7f:0e.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Processor Home Agent [8086:3ca0] (rev 07)
7f:0e.1 Performance counters [1101]: Intel Corporation Xeon E5/Core i7 Processor Home Agent Performance Monitoring [8086:3c46] (rev 07)
7f:0f.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Registers [8086:3ca8] (rev 07)
7f:0f.1 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller RAS Registers [8086:3c71] (rev 07)
7f:0f.2 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Target Address Decoder 0 [8086:3caa] (rev 07)
7f:0f.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Target Address Decoder 1 [8086:3cab] (rev 07)
7f:0f.4 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Target Address Decoder 2 [8086:3cac] (rev 07)
7f:0f.5 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Target Address Decoder 3 [8086:3cad] (rev 07)
7f:0f.6 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Target Address Decoder 4 [8086:3cae] (rev 07)
7f:10.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Channel 0-3 Thermal Control 0 [8086:3cb0] (rev 07)
7f:10.1 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Channel 0-3 Thermal Control 1 [8086:3cb1] (rev 07)
7f:10.2 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller ERROR Registers 0 [8086:3cb2] (rev 07)
7f:10.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller ERROR Registers 1 [8086:3cb3] (rev 07)
7f:10.4 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Channel 0-3 Thermal Control 2 [8086:3cb4] (rev 07)
7f:10.5 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller Channel 0-3 Thermal Control 3 [8086:3cb5] (rev 07)
7f:10.6 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller ERROR Registers 2 [8086:3cb6] (rev 07)
7f:10.7 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Integrated Memory Controller ERROR Registers 3 [8086:3cb7] (rev 07)
7f:11.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 DDRIO [8086:3cb8] (rev 07)
7f:13.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 R2PCIe [8086:3ce4] (rev 07)
7f:13.1 Performance counters [1101]: Intel Corporation Xeon E5/Core i7 Ring to PCI Express Performance Monitor [8086:3c43] (rev 07)
7f:13.4 Performance counters [1101]: Intel Corporation Xeon E5/Core i7 QuickPath Interconnect Agent Ring Registers [8086:3ce6] (rev 07)
7f:13.5 Performance counters [1101]: Intel Corporation Xeon E5/Core i7 Ring to QuickPath Interconnect Link 0 Performance Monitor [8086:3c44] (rev 07)
7f:13.6 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Ring to QuickPath Interconnect Link 1 Performance Monitor [8086:3c45] (rev 07)
80:03.0 PCI bridge [0604]: Intel Corporation Xeon E5/Core i7 IIO PCI Express Root Port 3a in PCI Express Mode [8086:3c08] (rev 07)
80:05.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Address Map, VTd_Misc, System Management [8086:3c28] (rev 07)
80:05.2 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Control Status and Global Errors [8086:3c2a] (rev 07)
80:05.4 PIC [0800]: Intel Corporation Xeon E5/Core i7 I/O APIC [8086:3c2c] (rev 07)
81:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Turks PRO [Radeon HD 6570/7570/8550] [1002:6759]
81:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Turks HDMI Audio [Radeon HD 6500/6600 / 6700M Series] [1002:aa90]
ff:08.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link 0 [8086:3c80] (rev 07)
ff:08.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link Reut 0 [8086:3c83] (rev 07)
ff:08.4 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link Reut 0 [8086:3c84] (rev 07)
ff:09.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link 1 [8086:3c90] (rev 07)
ff:09.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link Reut 1 [8086:3c93] (rev 07)
ff:09.4 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 QPI Link Reut 1 [8086:3c94] (rev 07)
ff:0a.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Power Control Unit 0 [8086:3cc0] (rev 07)
ff:0a.1 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Power Control Unit 1 [8086:3cc1] (rev 07)
ff:0a.2 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Power Control Unit 2 [8086:3cc2] (rev 07)
ff:0a.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Power Control Unit 3 [8086:3cd0] (rev 07)
ff:0b.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Interrupt Control Registers [8086:3ce0] (rev 07)
ff:0b.3 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Semaphore and Scratchpad Configuration Registers [8086:3ce3] (rev 07)
ff:0c.0 System peripheral [0880]: Intel Corporation Xeon E5/Core i7 Unicast Register 0 [8086:3ce8] (rev 07)
And a lot more but I deleted them because of character limit, the full version is in the attached file

This is a longer version of the list I can see in the GUI, the device I'd like to pass through is:
Code:
07:00.0 SATA controller [0106]: Marvell Technology Group Ltd. Device [1b4b:9215] (rev 11)
 

Attachments

  • IOMMU.txt
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Your motherboard/chipset needs to support VT-d, which it does. The lines of the output you showed do not start with IOMMU group #, which means that IOMMU is not (fully) enabled and passthrough won't work (yet). Can you show cat /proc/cmdline and lsmod | grep 'vfio'?
 
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Your motherboard/chipset needs to support VT-d, which it does. The lines of the output you showed do not start with IOMMU group #, which means that IOMMU is not (fully) enabled and passthrough won't work (yet). Can you show cat /proc/cmdline and lsmod | grep 'vfio'?
Code:
root@server:~# cat /proc/cmdline
initrd=\EFI\proxmox\5.4.73-1-pve\initrd.img-5.4.73-1-pve root=ZFS=rpool/ROOT/pve-1 boot=zfs quiet intel_iommu=on pcie_acs_override=downstream
root@server:~# lsmod | grep 'vfio'
vfio_pci               53248  0
vfio_virqfd            16384  1 vfio_pci
irqbypass              16384  2 vfio_pci,kvm
vfio_iommu_type1       32768  0
vfio                   32768  2 vfio_iommu_type1,vfio_pci
Well thats at least some good news :).
 
pcie_acs_override=downstream will prevent us from seeing the actual groups, but should allow you to try the passthrough. It is not clear why it would not work or not detect the IOMMU. Sometimes this message is incorrect, but I can find the post here again. Your kernel version shows that you are not on the latest version. Maybe do a apt-get update && apt-get dist-upgrade?
 
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pcie_acs_override=downstream will prevent us from seeing the actual groups, but should allow you to try the passthrough. It is not clear why it would not work or not detect the IOMMU. Sometimes this message is incorrect, but I can find the post here again. Your kernel version shows that you are not on the latest version. Maybe do a apt-get update && apt-get dist-upgrade?
Yeah, I tried that before but I got an error, same now:

Code:
root@server:~# apt-get update && apt-get dist-upgrade
Hit:1 http://security.debian.org buster/updates InRelease
Hit:2 http://ftp.nl.debian.org/debian buster InRelease                         
Get:3 http://ftp.nl.debian.org/debian buster-updates InRelease [51.9 kB]       
Err:4 https://enterprise.proxmox.com/debian/pve buster InRelease
  401  Unauthorized [IP: 212.224.123.70 443]
Reading package lists... Done                             
E: Failed to fetch https://enterprise.proxmox.com/debian/pve/dists/buster/InRelease  401  Unauthorized [IP: 212.224.123.70 443]
E: The repository 'https://enterprise.proxmox.com/debian/pve buster InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
 
If you don't pay for the subscription you aren't allowed to use the enterprise repository (which is used by default).
Here you can see how to switch to the non-subscription repo.
 
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Wenn du für keine Subscription bezahlst darfst du das (standardmäßig voreingestellte) Enterprise Repository nicht nutzen.
Hier steht wie man auf das kostenlose Non-Subscription-Repository wechseln kann.
Thanks, however this didn't fix the issue :(. When trying to boot a VM with the HBA passed through I still get the following error
Code:
TASK ERROR: IOMMU not present
 
Last edited:
I fixed the issue by resetting my bios and then I turned VT-d support back on and now it works, thanks for all the help.
 
I fixed the issue by resetting my bios and then I turned VT-d support back on and now it works, thanks for all the help.
Well... computers are hard! lol!! I was having a hell of a time getting IOMMU enabled and after reading your post I thought, what the hell, let's load optimized defaults in my BIOS. After loading optimized defaults and rebooting, I went back into BIOS and all I changed was bifurcating my pci nvme card back to 4x4x4x4x and setting my boot order. Got back into Proxmox and ran "dmesg | grep -e DMAR -e IOMMU" and got output "dmesg | grep -e DMAR -e IOMMU". YAY!
 

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