From bfd7cd31e32f4f2a66d23558fbab6aa11c149fcb Mon Sep 17 00:00:00 2001 From: Eric Farman Date: Thu, 7 Jul 2022 15:57:29 +0200 Subject: [PATCH] vfio/ccw: Do not change FSM state in subchannel event [ Upstream commit cffcc109fd682075dee79bade3d60a07152a8fd1 ] The routine vfio_ccw_sch_event() is tasked with handling subchannel events, specifically machine checks, on behalf of vfio-ccw. It correctly calls cio_update_schib(), and if that fails (meaning the subchannel is gone) it makes an FSM event call to mark the subchannel Not Operational. If that worked, however, then it decides that if the FSM state was already Not Operational (implying the subchannel just came back), then it should simply change the FSM to partially- or fully-open. Remove this trickery, since a subchannel returning will require more probing than simply "oh all is well again" to ensure it works correctly. Fixes: bbe37e4cb8970 ("vfio: ccw: introduce a finite state machine") Signed-off-by: Eric Farman Reviewed-by: Matthew Rosato Link: https://lore.kernel.org/r/20220707135737.720765-4-farman@linux.ibm.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/s390/cio/vfio_ccw_drv.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c index 7a06cdff6572d..862b0eb0fe6de 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -205,19 +205,11 @@ static int vfio_ccw_sch_event(struct subchannel *sch, int process) if (work_pending(&sch->todo_work)) goto out_unlock; - if (cio_update_schib(sch)) { - vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); - rc = 0; - goto out_unlock; - } - - private = dev_get_drvdata(&sch->dev); - if (private->state == VFIO_CCW_STATE_NOT_OPER) { - private->state = private->mdev ? VFIO_CCW_STATE_IDLE : - VFIO_CCW_STATE_STANDBY; - } rc = 0; + if (cio_update_schib(sch)) + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); + out_unlock: spin_unlock_irqrestore(sch->lock, flags); -- 2.47.3