This is a note to let you know that I've just added the patch titled vfio/ccw: Fix FSM state if mdev probe fails to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: vfio-ccw-fix-fsm-state-if-mdev-probe-fails.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit aefc2d76f1fe0092329dbf7f10e24e4868092a0f Author: Eric Farman <farman@xxxxxxxxxxxxx> Date: Thu Jul 7 15:57:28 2022 +0200 vfio/ccw: Fix FSM state if mdev probe fails [ Upstream commit f6c876d67e956de8d69349b0ee43bc7277c09e5c ] The FSM is in STANDBY state when arriving in vfio_ccw_mdev_probe(), and this routine converts it to IDLE as part of its processing. The error exit sets it to IDLE (again) but clears the private->mdev pointer. The FSM should of course be managing the state itself, but the correct thing for vfio_ccw_mdev_probe() to do would be to put the state back the way it found it. The corresponding check of private->mdev in vfio_ccw_sch_io_todo() can be removed, since the distinction is unnecessary at this point. Fixes: 3bf1311f351ef ("vfio/ccw: Convert to use vfio_register_emulated_iommu_dev()") Signed-off-by: Eric Farman <farman@xxxxxxxxxxxxx> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Reviewed-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220707135737.720765-3-farman@xxxxxxxxxxxxx Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index ee182cfb467d..789175221e9a 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -107,9 +107,10 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work) /* * Reset to IDLE only if processing of a channel program * has finished. Do not overwrite a possible processing - * state if the final interrupt was for HSCH or CSCH. + * state if the interrupt was unsolicited, or if the final + * interrupt was for HSCH or CSCH. */ - if (private->mdev && cp_is_finished) + if (cp_is_finished) private->state = VFIO_CCW_STATE_IDLE; if (private->io_trigger) diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index d8589afac272..8d76f5b26e2b 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -146,7 +146,7 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev) vfio_uninit_group_dev(&private->vdev); atomic_inc(&private->avail); private->mdev = NULL; - private->state = VFIO_CCW_STATE_IDLE; + private->state = VFIO_CCW_STATE_STANDBY; return ret; }