Note: This bug report was written with the assistance of Claude (Anthropic AI) based on debugging sessions and system logs. The hardware, logs and testing were performed by the system owner. Also i am fairly new to CachyOS and Linux in general. I love this system and i try to learn new stuff everyday. Since i am not very knowlegable about passthrough i tried to get this running with Claude AI. I am not at all knowledgable if the suspicion of claude is correct. i am happy to supply more info if someone needs it. Summary When attempting GPU passthrough of an AMD Radeon RX 9070 (Navi 48, Device ID 1002:7550) via VFIO-PCI on Linux kernel 7.0.1, the kernel crashes with a NULL pointer dereference in vfio_pci_core_sriov_configure every time vfio-pci attempts to bind the device. The crash is reproducible 100% of the time regardless of binding method (libvirt managed, manual bind, virsh nodedev-detach). System Component Value CPU AMD Ryzen 7 7700X Motherboard Gigabyte B650 Gaming X AX GPU (passthrough) AMD Radeon RX 9070 (Navi 48, 1002:7550, rev c3) GPU (host) AMD Raphael iGPU (1002:164e) RAM 32 GB DDR5 OS CachyOS x86_64 Kernel 7.0.1-1-cachyos vendor-reset installed (lowell80 fork) Kernel parameters amd_iommu=on iommu=pt IOMMU Group The RX 9070 is alone in IOMMU group 15 – no ACS or group isolation issues: 03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 48 [Radeon RX 9070/9070 XT/9070 GRE] [1002:7550] (rev c3) 03:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 48 HDMI/DP Audio Controller [1002:ab40] Reset method cat /sys/bus/pci/devices/0000:03:00.0/reset_method bus No FLR (Function Level Reset) available. vendor-reset module is loaded but does not prevent the crash. Reproduction steps Boot with amd_iommu=on iommu=pt Confirm GPU is on amdgpu driver (host desktop running on iGPU) Attempt any of the following: virsh nodedev-detach pci_0000_03_00_0 echo "0000:03:00.0" > /sys/bus/pci/drivers/vfio-pci/bind virsh start <vm> with managed='yes' and GPU as hostdev Process hangs indefinitely or kernel crashes Kernel crash (dmesg) [ 467.617075] #PF: error_code(0x0000) - not-present page [ 467.617089] RIP: 0010:vfio_pci_core_sriov_configure+0x13/0x200 [vfio_pci_core] [ 467.617122] vfio_pci_core_unregister_device+0x16/0xc0 [vfio_pci_core] [ 467.617126] vfio_pci_remove+0x19/0x30 [vfio_pci] [ 467.617309] CR2: 0000000000000450 [ 467.617326] note: rpc-libvirtd exited with irqs disabled Full crash trace repeats identically across multiple reproduction attempts. Additional observations virsh nodedev-detach hangs indefinitely before the crash echo "1002 7550" > /sys/bus/pci/drivers/vfio-pci/new_id succeeds but subsequent bind crashes Setting iommu_group/type to identity does not help vendor-reset module is loaded and its hook is installed per dmesg, but has no effect The crash occurs both with libvirt managed='yes' and manual binding The iGPU (host display) is completely unaffected What works GPU runs normally on amdgpu on the host IOMMU is active and groups are correctly isolated All VFIO infrastructure (vfio, vfio_pci, vfio_iommu_type1) loads correctly What does not work Any attempt to transfer the device to vfio-pci triggers the crash Suspected cause The crash in vfio_pci_core_sriov_configure at offset +0x13 with CR2: 0000000000000450 suggests a NULL pointer dereference when vfio-pci attempts to configure SR-IOV on the device during binding. Navi 48 may expose SR-IOV capability bits that vfio-pci tries to dereference before the device is fully initialized under vfio control.