I got an IOMMU IO page fault. What to do now?

[Paul Menzel]

Dear Linux folks,


On a Dell OptiPlex 5055, Linux 5.10.24 logged the IOMMU messages below. 
(GPU hang in amdgpu issue #1762 [1] might be related.)

     $ lspci -nn -s 05:00.0
     05:00.0 VGA compatible controller [0300]: Advanced Micro Devices, 
Inc. [AMD/ATI] Oland [Radeon HD 8570 / R7 240/340 OEM] [1002:6611] (rev 87)
     $ dmesg
     […]
     [6318399.745242] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xfffffff0c0 flags=0x0020]
     [6318399.757283] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xfffffff7c0 flags=0x0020]
     [6318399.769154] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xffffffe0c0 flags=0x0020]
     [6318399.780913] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xfffffffec0 flags=0x0020]
     [6318399.792734] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xffffffe5c0 flags=0x0020]
     [6318399.804309] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xffffffd0c0 flags=0x0020]
     [6318399.816091] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xffffffecc0 flags=0x0020]
     [6318399.827407] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xffffffd3c0 flags=0x0020]
     [6318399.838708] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xffffffc0c0 flags=0x0020]
     [6318399.850029] amdgpu 0000:05:00.0: AMD-Vi: Event logged 
[IO_PAGE_FAULT domain=0x000c address=0xffffffdac0 flags=0x0020]
     [6318399.861311] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffc1c0 flags=0x0020]
     [6318399.872044] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffc8c0 flags=0x0020]
     [6318399.882797] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffb0c0 flags=0x0020]
     [6318399.893655] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffcfc0 flags=0x0020]
     [6318399.904445] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffb6c0 flags=0x0020]
     [6318399.915222] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffa0c0 flags=0x0020]
     [6318399.925931] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffbdc0 flags=0x0020]
     [6318399.936691] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffa4c0 flags=0x0020]
     [6318399.947479] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffff90c0 flags=0x0020]
     [6318399.958270] AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 
domain=0x000c address=0xffffffabc0 flags=0x0020]

As this is not reproducible, how would debugging go? (The system was 
rebooted in the meantime.) What options should be enabled, that next 
time the required information is logged, or what commands should I 
execute when the system is still in that state, so the bug (driver, 
userspace, …) can be pinpointed and fixed?


Kind regards,

Paul


[1]: https://gitlab.freedesktop.org/drm/amd/-/issues/1762
      "Oland [Radeon HD 8570 / R7 240/340 OEM]: GPU hang"