Thanks for quick reply.
i didn’t solve the issue yet, but your hint about BIOS settings made me realize that the IOMMU option was on Auto instead of Enabled. SVM was already enabled, CSM already disabled.
My BIOS has no option of setting a “boot GPU”, but i keep my “host” card (6800 XT) in the 1st PCIe slot, the card I want to passthrough (6900 XT) in the 2nd slot.
However, that didn’t fix the problem (even when I enabled IOMMU after restoring default settings), but I will check if there are more related options which could help.
I’ve seen a lot of AMD CBS options being on Auto and the IOMMU setting was in that section. I’ll try enabling them.
This is the fragment of my lspci -nnv output, with the devices I want to passthrough:
0e:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 [Radeon RX 6800/6800 XT / 6900 XT] [1002:73bf] (rev c0) (prog-if 00 [VGA controller])
Subsystem: XFX Limited Device [1eae:6901]
Flags: bus master, fast devsel, latency 0, IRQ 150, IOMMU group 30
Memory at 7000000000 (64-bit, prefetchable) [size=16G]
Memory at 7400000000 (64-bit, prefetchable) [size=256M]
I/O ports at d000 [size=256]
Memory at fc600000 (32-bit, non-prefetchable) [size=1M]
Expansion ROM at fc700000 [disabled] [size=128K]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [64] Express Legacy Endpoint, MSI 00
Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Capabilities: [150] Advanced Error Reporting
Capabilities: [200] Physical Resizable BAR
Capabilities: [240] Power Budgeting <?>
Capabilities: [270] Secondary PCI Express
Capabilities: [2a0] Access Control Services
Capabilities: [2d0] Process Address Space ID (PASID)
Capabilities: [320] Latency Tolerance Reporting
Capabilities: [410] Physical Layer 16.0 GT/s <?>
Capabilities: [440] Lane Margining at the Receiver <?>
Kernel driver in use: vfio-pci
Kernel modules: amdgpu
0e:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:ab28]
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:ab28]
Flags: bus master, fast devsel, latency 0, IRQ 147, IOMMU group 31
Memory at fc724000 (32-bit, non-prefetchable) [size=16K]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [64] Express Legacy Endpoint, MSI 00
Capabilities: [a0] MSI: Enable- Count=1/1 Maskable- 64bit+
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Capabilities: [150] Advanced Error Reporting
Capabilities: [2a0] Access Control Services
Kernel driver in use: vfio-pci
Kernel modules: snd_hda_intel
0e:00.2 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:73a6] (prog-if 30 [XHCI])
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:73a6]
Flags: bus master, fast devsel, latency 0, IRQ 148, IOMMU group 32
Memory at fc500000 (64-bit, non-prefetchable) [size=1M]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [64] Express Endpoint, MSI 00
Capabilities: [a0] MSI: Enable- Count=1/8 Maskable- 64bit+
Capabilities: [c0] MSI-X: Enable+ Count=8 Masked-
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Capabilities: [150] Advanced Error Reporting
Capabilities: [2a0] Access Control Services
Kernel driver in use: vfio-pci
Kernel modules: xhci_pci
0e:00.3 Serial bus controller [0c80]: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:73a4]
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:0408]
Flags: bus master, fast devsel, latency 0, IRQ 151, IOMMU group 33
Memory at fc720000 (64-bit, non-prefetchable) [size=16K]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [64] Express Endpoint, MSI 00
Capabilities: [a0] MSI: Enable+ Count=1/2 Maskable- 64bit+
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Capabilities: [150] Advanced Error Reporting
Capabilities: [2a0] Access Control Services
Kernel driver in use: vfio-pci
Looks fine, vfio-pci is a driver in use.
For comparison, there is the “host” card:
0b:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 21 [Radeon RX 6800/6800 XT / 6900 XT] [1002:73bf] (rev c1) (prog-if 00 [VGA controller])
Subsystem: XFX Limited Device [1eae:6701]
Flags: bus master, fast devsel, latency 0, IRQ 137, IOMMU group 26
Memory at 7800000000 (64-bit, prefetchable) [size=16G]
Memory at 7c00000000 (64-bit, prefetchable) [size=256M]
I/O ports at e000 [size=256]
Memory at fcc00000 (32-bit, non-prefetchable) [size=1M]
Expansion ROM at fcd00000 [disabled] [size=128K]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [64] Express Legacy Endpoint, MSI 00
Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Capabilities: [150] Advanced Error Reporting
Capabilities: [200] Physical Resizable BAR
Capabilities: [240] Power Budgeting <?>
Capabilities: [270] Secondary PCI Express
Capabilities: [2a0] Access Control Services
Capabilities: [2d0] Process Address Space ID (PASID)
Capabilities: [320] Latency Tolerance Reporting
Capabilities: [410] Physical Layer 16.0 GT/s <?>
Capabilities: [440] Lane Margining at the Receiver <?>
Kernel driver in use: amdgpu
Kernel modules: amdgpu
0b:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:ab28]
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:ab28]
Flags: bus master, fast devsel, latency 0, IRQ 144, IOMMU group 27
Memory at fcd20000 (32-bit, non-prefetchable) [size=16K]
Capabilities: [48] Vendor Specific Information: Len=08 <?>
Capabilities: [50] Power Management version 3
Capabilities: [64] Express Legacy Endpoint, MSI 00
Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Capabilities: [150] Advanced Error Reporting
Capabilities: [2a0] Access Control Services
Kernel driver in use: snd_hda_intel
Kernel modules: snd_hda_intel
The “host” card (6800 XT) doesn’t have the “USB controller” and the “bus controller”, because it has no USB-C port, and the 6900 XT card has it.