----- Forwarded message from bugzilla-daemon@xxxxxxxxxx ----- https://bugzilla.kernel.org/show_bug.cgi?id=216449 I'm using vfio-pci to map an FPGA. I have an utility program that gets a file descriptor for the device and does an mmap to read and write registers. When I close the utility the FPGA is reset and all registers are gone. I wonder if this is the correct behaviour, I understand that the vfio_pci_try_bus_reset is performed only when refcnt reaches zero but, in case of other drivers, like UIO the behaviour is different. I expected to be able to close my utility and restart it and find the FPGA registers at the last configured value. The vfio_pci_try_bus_reset is in vfio_pci_disable that is called by pci_release. Probably even a module parameter to prevent calling vfio_pci_try_bus_reset could be useful.