PCI passthrough to VM get IMMOU error

Mattias Hedman

Well-Known Member
Jan 19, 2019
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I have followed TechnoTims guide to add an Nvidia card to a VM, I have done all the steps but when I add the PCIE card to teh VM and try to start it I get:
Skärmavbild 2022-03-19 kl. 14.24.16.png
When I check for IMMOU:
dmesg | grep -e DMAR -e IOMMU -e AMD-Vi [ 0.015676] ACPI: DMAR 0x000000007D3346F4 000160 (v01 DELL PE_SC3 00000001 DELL 00000001) [ 0.015742] ACPI: Reserving DMAR table memory at [mem 0x7d3346f4-0x7d334853] [ 1.455293] DMAR: Host address width 46 [ 1.455295] DMAR: DRHD base: 0x000000d6000000 flags: 0x0 [ 1.455303] DMAR: dmar0: reg_base_addr d6000000 ver 1:0 cap d2078c106f0462 ecap f020fe [ 1.455308] DMAR: DRHD base: 0x000000df900000 flags: 0x1 [ 1.455314] DMAR: dmar1: reg_base_addr df900000 ver 1:0 cap d2078c106f0462 ecap f020fe [ 1.455318] DMAR: RMRR base: 0x0000007f458000 end: 0x0000007f46ffff [ 1.455322] DMAR: RMRR base: 0x0000007f450000 end: 0x0000007f450fff [ 1.455325] DMAR: RMRR base: 0x0000007f452000 end: 0x0000007f452fff [ 1.455328] DMAR: ATSR flags: 0x0 [ 1.455332] DMAR-IR: IOAPIC id 2 under DRHD base 0xd6000000 IOMMU 0 [ 1.455336] DMAR-IR: IOAPIC id 0 under DRHD base 0xdf900000 IOMMU 1 [ 1.455339] DMAR-IR: IOAPIC id 1 under DRHD base 0xdf900000 IOMMU 1 [ 1.455342] DMAR-IR: HPET id 0 under DRHD base 0xdf900000 [ 1.455344] DMAR-IR: x2apic is disabled because BIOS sets x2apic opt out bit. [ 1.455345] DMAR-IR: Use 'intremap=no_x2apic_optout' to override the BIOS setting. [ 1.455886] DMAR-IR: Enabled IRQ remapping in xapic mode

I cant see IMMOU.

This is my grub file:
GRUB_DEFAULT=0 GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_iommu=on pcie_acs_override=downstream,multifunction video=efifb:eek:ff i915.enable_gvt=1" GRUB_CMDLINE_LINUX="biosdevname=0"

How do I solve this?
 
@chchia Yes and no... in the grub file I had something that I did not recognize, I removed that and rebuilt the grub.
I also fixed my /etc/kernel/cmdline file, in the Proxmox documentation it was stated it was to be one line, that I did not have before.
So after these fixes the VM started. :)
 

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