[RFC PATCH v4 3/4] vfio-ccw: Reset FSM state to IDLE inside FSM

Eric Farman
2021-04-13T18:24:21Z

When an I/O request is made, the fsm_io_request() routine
moves the FSM state from IDLE to CP_PROCESSING, and then
fsm_io_helper() moves it to CP_PENDING if the START SUBCHANNEL
received a cc0. Yet, the error case to go from CP_PROCESSING
back to IDLE is done after the FSM call returns.

Let's move this up into the FSM proper, to provide some
better symmetry when unwinding in this case.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
drivers/s390/cio/vfio_ccw_fsm.c | 1 +
drivers/s390/cio/vfio_ccw_ops.c | 2 --
2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/s390/cio/vfio_ccw_fsm.c b/drivers/s390/cio/vfio_ccw_fsm.c
index 92d638f10b27..38b4a8256665 100644
--- a/drivers/s390/cio/vfio_ccw_fsm.c
+++ b/drivers/s390/cio/vfio_ccw_fsm.c
@@ -323,6 +323,7 @@ static void fsm_io_request(struct vfio_ccw_private *private,
}

err_out:
+ private->state = VFIO_CCW_STATE_IDLE;
trace_vfio_ccw_fsm_io_request(scsw->cmd.fctl, schid,
io_region->ret_code, errstr);
}
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 767ac41686fe..5971641964c6 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -276,8 +276,6 @@ static ssize_t vfio_ccw_mdev_write_io_region(struct vfio_ccw_private *private,
}

vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
- if (region->ret_code != 0)
- private->state = VFIO_CCW_STATE_IDLE;
ret = (region->ret_code != 0) ? region->ret_code : count;

out_unlock:
--
2.25.1