Commits
Alex Williamson committed b68e7fa879c
vfio: Fix virqfd release race vfoi-pci supports a mechanism like KVM's irqfd for unmasking an interrupt through an eventfd. There are two ways to shutdown this interface: 1) close the eventfd, 2) ioctl (such as disabling the interrupt). Both of these do the release through a workqueue, which can result in a segfault if two jobs get queued for the same virqfd. Fix this by protecting the pointer to these virqfds by a spinlock. The vfio pci device will therefore no longer have a reference to it once the release job is queued under lock. On the ioctl side, we still flush the workqueue to ensure that any outstanding releases are completed. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>