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