There is no such thing as
intel_iommu=pt and yes intel_iommu=on is needed: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#qm_pci_passthroughEDIT: And there are threads here about this twice a week, if you need more detailed information.
I believe IOMMU is enabled by default on my Proxmox VE 8 system. I observed that the outputs of dmesg | grep -i iommu were identical before and after adding intel_iommu=on to the kernel parameters, indicating no change in the IOMMU settings.
That is only when you use an AMD CPU. What CPU and motherboard are you using?
It is quite possible you added it in the wrong place (or VT-d is not enabled or not supported) and it did not make a change (or you are using an AMD CPU).
What is the output of
cat /proc/cmdline and for d in /sys/kernel/iommu_groups/*/devices/*; do n=${d#*/iommu_groups/*}; n=${n%%/*}; printf 'IOMMU group %s ' "$n"; lspci -nns "${d##*/}"; done?EDIT: Intel IOMMU was enabled by default on PVE 7 for a little while but it broke too many Intel systems and they reverted it back (and updated the manual years later).
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I'm glad that IOMMU worked by default on your system but many people did need to select a motherboard and Intel CPU that supports VT-d, enable it in BIOS and add
intel_iommu=on to the PVE8 kernel parameters before IOMMU works (as a search on this forum will show).root@pve:~# cat /proc/cmdline
for d in /sys/kernel/iommu_groups/*/devices/*; do
n=${d#*/iommu_groups/*}; n=${n%%/*};
printf 'IOMMU group %s ' "$n";
lspci -nns "${d##*/}";
done
initrd=\EFI\proxmox\6.5.13-5-pve\initrd.img-6.5.13-5-pve root=ZFS=rpool/ROOT/pve-1 boot=zfs
IOMMU group 0 0000:00:02.0 VGA compatible controller [0300]: Intel Corporation Raptor Lake-P [Iris Xe Graphics] [8086:a7a0] (rev 04)
IOMMU group 10 0000:00:16.0 Communication controller [0780]: Intel Corporation Alder Lake PCH HECI Controller [8086:51e0] (rev 01)
IOMMU group 10 0000:00:16.3 Serial controller [0700]: Intel Corporation Alder Lake AMT SOL Redirection [8086:51e3] (rev 01)
IOMMU group 11 0000:00:1c.0 PCI bridge [0604]: Intel Corporation Alder Lake-P PCH PCIe Root Port [8086:51bb] (rev 01)
IOMMU group 12 0000:00:1d.0 System peripheral [0880]: Intel Corporation RST VMD Managed Controller [8086:09ab]
IOMMU group 13 0000:00:1d.2 PCI bridge [0604]: Intel Corporation Device [8086:51b2] (rev 01)
IOMMU group 14 0000:00:1d.3 PCI bridge [0604]: Intel Corporation Device [8086:51b3] (rev 01)
IOMMU group 15 0000:00:1f.0 ISA bridge [0601]: Intel Corporation Raptor Lake LPC/eSPI Controller [8086:519d] (rev 01)
IOMMU group 15 0000:00:1f.3 Audio device [0403]: Intel Corporation Raptor Lake-P/U/H cAVS [8086:51ca] (rev 01)
IOMMU group 15 0000:00:1f.4 SMBus [0c05]: Intel Corporation Alder Lake PCH-P SMBus Host Controller [8086:51a3] (rev 01)
IOMMU group 15 0000:00:1f.5 Serial bus controller [0c80]: Intel Corporation Alder Lake-P PCH SPI Controller [8086:51a4] (rev 01)
IOMMU group 16 0000:01:00.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1812 6-Port PCIe x4 Gen2 Packet Switch [1b21:1812] (rev 01)
IOMMU group 17 0000:02:00.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1812 6-Port PCIe x4 Gen2 Packet Switch [1b21:1812] (rev 01)
IOMMU group 17 0000:03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller [10ec:8125] (rev 05)
IOMMU group 18 0000:02:08.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1812 6-Port PCIe x4 Gen2 Packet Switch [1b21:1812] (rev 01)
IOMMU group 18 0000:04:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller [10ec:8125] (rev 05)
IOMMU group 19 0000:02:0a.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1812 6-Port PCIe x4 Gen2 Packet Switch [1b21:1812] (rev 01)
IOMMU group 19 0000:05:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller [10ec:8125] (rev 05)
IOMMU group 1 0000:00:00.0 Host bridge [0600]: Intel Corporation Device [8086:a706]
IOMMU group 20 0000:02:0b.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1812 6-Port PCIe x4 Gen2 Packet Switch [1b21:1812] (rev 01)
IOMMU group 20 0000:06:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller [10ec:8125] (rev 05)
IOMMU group 21 0000:07:00.0 Ethernet controller [0200]: Intel Corporation Ethernet Controller X710 for 10GbE SFP+ [8086:1572] (rev 02)
IOMMU group 22 0000:07:00.1 Ethernet controller [0200]: Intel Corporation Ethernet Controller X710 for 10GbE SFP+ [8086:1572] (rev 02)
IOMMU group 23 0000:5c:00.0 Ethernet controller [0200]: Intel Corporation Ethernet Controller I226-V [8086:125c] (rev 04)
IOMMU group 24 0000:5d:00.0 Ethernet controller [0200]: Intel Corporation Ethernet Controller I226-LM [8086:125b] (rev 04)
IOMMU group 25 0000:5e:00.0 Network controller [0280]: MEDIATEK Corp. MT7922 802.11ax PCI Express Wireless Network Adapter [14c3:0616]
IOMMU group 2 0000:00:01.0 PCI bridge [0604]: Intel Corporation Device [8086:a70d]
IOMMU group 3 0000:00:06.0 System peripheral [0880]: Intel Corporation RST VMD Managed Controller [8086:09ab]
IOMMU group 4 0000:00:06.2 PCI bridge [0604]: Intel Corporation Device [8086:a73d]
IOMMU group 5 0000:00:07.0 PCI bridge [0604]: Intel Corporation Raptor Lake-P Thunderbolt 4 PCI Express Root Port [8086:a76e]
IOMMU group 6 0000:00:07.2 PCI bridge [0604]: Intel Corporation Raptor Lake-P Thunderbolt 4 PCI Express Root Port [8086:a72f]
IOMMU group 7 0000:00:0d.0 USB controller [0c03]: Intel Corporation Raptor Lake-P Thunderbolt 4 USB Controller [8086:a71e]
IOMMU group 7 0000:00:0d.2 USB controller [0c03]: Intel Corporation Raptor Lake-P Thunderbolt 4 NHI [8086:a73e]
IOMMU group 7 0000:00:0d.3 USB controller [0c03]: Intel Corporation Raptor Lake-P Thunderbolt 4 NHI [8086:a76d]
IOMMU group 8 0000:00:0e.0 RAID bus controller [0104]: Intel Corporation Volume Management Device NVMe RAID Controller Intel Corporation [8086:a77f]
IOMMU group 8 10000:e0:06.0 PCI bridge [0604]: Intel Corporation Raptor Lake PCIe 4.0 Graphics Port [8086:a74d]
IOMMU group 8 10000:e0:1c.0 System peripheral [0880]: Intel Corporation RST VMD Managed Controller [8086:09ab]
IOMMU group 8 10000:e0:1c.4 PCI bridge [0604]: Intel Corporation Device [8086:51bc] (rev 01)
IOMMU group 8 10000:e0:1d.0 PCI bridge [0604]: Intel Corporation Alder Lake PCI Express Root Port [8086:51b0] (rev 01)
IOMMU group 8 10000:e1:00.0 Non-Volatile memory controller [0108]: Phison Electronics Corporation PS5019-E19 PCIe4 NVMe Controller (DRAM-less) [1987:5019] (rev 01)
IOMMU group 8 10000:e2:00.0 Non-Volatile memory controller [0108]: Phison Electronics Corporation PS5019-E19 PCIe4 NVMe Controller (DRAM-less) [1987:5019] (rev 01)
IOMMU group 8 10000:e3:00.0 Non-Volatile memory controller [0108]: Phison Electronics Corporation PS5019-E19 PCIe4 NVMe Controller (DRAM-less) [1987:5019] (rev 01)
IOMMU group 9 0000:00:14.0 USB controller [0c03]: Intel Corporation Alder Lake PCH USB 3.2 xHCI Host Controller [8086:51ed] (rev 01)
IOMMU group 9 0000:00:14.2 RAM memory [0500]: Intel Corporation Alder Lake PCH Shared SRAM [8086:51ef] (rev 01)
Amazing! Did Proxmox enable intel_iommu by default again?!? And without updating the manual (again), after they recently changed it to:
EDIT: Just the other day people still needed to add intel_iommu to it to work: https://forum.proxmox.com/threads/iommu-groups-on-supermicro-x13sch-f.145392/post-655551
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