Messages in this thread | | | Subject | Re: [PROBLEM] Frequently get "irq 31: nobody cared" when passing through 2x GPUs that share same pci switch via vfio | From | Matthew Ruffell <> | Date | Tue, 5 Oct 2021 18:02:24 +1300 |
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Hi Alex,
Have you had an opportunity to have a look at this a bit deeper?
On 16/09/21 4:32 am, Alex Williamson wrote: > > Adding debugging to the vfio-pci interrupt handler, it's correctly > deferring the interrupt as the GPU device is not identifying itself as > the source of the interrupt via the status register. In fact, setting > the disable INTx bit in the GPU command register while the interrupt > storm occurs does not stop the interrupts. > > The interrupt storm does seem to be related to the bus resets, but I > can't figure out yet how multiple devices per switch factors into the > issue. Serializing all bus resets via a mutex doesn't seem to change > the behavior. > > I'm still investigating, but if anyone knows how to get access to the > Broadcom datasheet or errata for this switch, please let me know.
We have managed to obtain a recent errata for this switch, and it doesn't mention any interrupt storms with nested switches. What would I be looking for in the errata? I cannot share our copy, sorry.
Is there anything that we can do to help?
Thanks,
Matthew
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