From: Eric Farman farman@linux.ibm.com
[ 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@linux.ibm.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Reviewed-by: Matthew Rosato mjrosato@linux.ibm.com Link: https://lore.kernel.org/r/20220707135737.720765-3-farman@linux.ibm.com Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/s390/cio/vfio_ccw_drv.c | 5 +++-- drivers/s390/cio/vfio_ccw_ops.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 35055eb94115..179eb614fa5b 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -106,9 +106,10 @@ 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 0e05bff78b8e..9a05dadcbb75 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; }