[PATCH 0/3] RFC: few random hacks to improve eventfd fallback path

[Maxim Levitsky]

These few patches are the result of a random hacking I did to make the qemu
cope with eventfd allocation failure, when using an iothread,
as it happened in bz #1897550.

I am not 100% sure which patches in this series are worth to merge, or if
this can be fixed in a better way.

After this patch series applied, qemu still hangs while running reproducer for
this BZ due to ABBA lock inversion which needs some heavy rework to get rid of.
I explained all the (gory) details in the bugzilla.

This patch series was (lightly) tested with make check, iotests and with
the reproducer.

Best regards,
        Maxim Levitsky

Maxim Levitsky (3):
  scsi: virtio-scsi: don't process IO on fenced dataplane
  virtio-scsi: don't uninitialize queues that we didn't initialize
  event_notifier: handle initialization failure better

 hw/scsi/virtio-scsi-dataplane.c | 26 +++++++++++++++++++-------
 include/qemu/event_notifier.h   |  1 +
 util/event_notifier-posix.c     | 16 ++++++++++++++++
 3 files changed, 36 insertions(+), 7 deletions(-)

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2.26.2