On Thu, 7 Mar 2024 08:37:53 +0000 "Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote: > > From: Alex Williamson <alex.williamson@xxxxxxxxxx> > > Sent: Thursday, March 7, 2024 5:15 AM > > > > Mask operations through config space changes to DisINTx may race INTx > > configuration changes via ioctl. Create wrappers that add locking for > > paths outside of the core interrupt code. > > > > In particular, irq_type is updated holding igate, therefore testing > > is_intx() requires holding igate. For example clearing DisINTx from > > config space can otherwise race changes of the interrupt configuration. > > > > Looks the suspend path still checks irq_type w/o holding igate: > > vdev->pm_intx_masked = ((vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX) && > vfio_pci_intx_mask(vdev)); > > Is it with assumption that no change of configuration is possible at > that point? Yes, I believe this is relatively safe because userspace is frozen at this point. That's not however to claim that irq_type is absolutely used consistently after this series. I just didn't see the other violations rise to the same level as the fixes in this series and wanted to avoid the distraction. I've stashed a number of patches that I'd eventually like to post as follow-ups to this series. Thanks, Alex
