On Fri, May 22, 2020 at 01:17:09PM -0600, Alex Williamson wrote: > v3: > > The memory_lock semaphore is only held in the MSI-X path for callouts > to functions that may access MSI-X MMIO space of the device, this > should resolve the circular locking dependency reported by Qian > (re-testing very much appreciated). I've also incorporated the > pci_map_rom() and pci_unmap_rom() calls under the memory_lock. Commit > 0cfd027be1d6 ("vfio_pci: Enable memory accesses before calling > pci_map_rom") made sure memory was enabled on the info path, but did > not provide locking to protect that state. The r/w path of the BAR > access is expanded to include ROM mapping/unmapping. Unless there > are objections, I'll plan to drop v2 from my next branch and replace > it with this. Thanks, FYI, the lockdep warning is gone.